Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * CFQ, or complete fairness queueing, disk scheduler. |
| 3 | * |
| 4 | * Based on ideas from a previously unfinished io |
| 5 | * scheduler (round robin per-process disk scheduling) and Andrea Arcangeli. |
| 6 | * |
Jens Axboe | 0fe2347 | 2006-09-04 15:41:16 +0200 | [diff] [blame] | 7 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | #include <linux/module.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 10 | #include <linux/slab.h> |
Al Viro | 1cc9be6 | 2006-03-18 12:29:52 -0500 | [diff] [blame] | 11 | #include <linux/blkdev.h> |
| 12 | #include <linux/elevator.h> |
Randy Dunlap | ad5ebd2 | 2009-11-11 13:47:45 +0100 | [diff] [blame] | 13 | #include <linux/jiffies.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/rbtree.h> |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 15 | #include <linux/ioprio.h> |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 16 | #include <linux/blktrace_api.h> |
Tejun Heo | 6e736be | 2011-12-14 00:33:38 +0100 | [diff] [blame] | 17 | #include "blk.h" |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 18 | #include "cfq.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | |
| 20 | /* |
| 21 | * tunables |
| 22 | */ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 23 | /* max queue in one round of service */ |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 24 | static const int cfq_quantum = 8; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 25 | static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 26 | /* maximum backwards seek, in KiB */ |
| 27 | static const int cfq_back_max = 16 * 1024; |
| 28 | /* penalty of a backwards seek */ |
| 29 | static const int cfq_back_penalty = 2; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 30 | static const int cfq_slice_sync = HZ / 10; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 31 | static int cfq_slice_async = HZ / 25; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 32 | static const int cfq_slice_async_rq = 2; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 33 | static int cfq_slice_idle = HZ / 125; |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 34 | static int cfq_group_idle = HZ / 125; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 35 | static const int cfq_target_latency = HZ * 3/10; /* 300 ms */ |
| 36 | static const int cfq_hist_divisor = 4; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 37 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 38 | /* |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 39 | * offset from end of service tree |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 40 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 41 | #define CFQ_IDLE_DELAY (HZ / 5) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 42 | |
| 43 | /* |
| 44 | * below this threshold, we consider thinktime immediate |
| 45 | */ |
| 46 | #define CFQ_MIN_TT (2) |
| 47 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 48 | #define CFQ_SLICE_SCALE (5) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 49 | #define CFQ_HW_QUEUE_MIN (5) |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 50 | #define CFQ_SERVICE_SHIFT 12 |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 51 | |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 52 | #define CFQQ_SEEK_THR (sector_t)(8 * 100) |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 53 | #define CFQQ_CLOSE_THR (sector_t)(8 * 1024) |
Corrado Zoccolo | 41647e7 | 2010-02-27 19:45:40 +0100 | [diff] [blame] | 54 | #define CFQQ_SECT_THR_NONROT (sector_t)(2 * 32) |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 55 | #define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8) |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 56 | |
Tejun Heo | a612fdd | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 57 | #define RQ_CIC(rq) icq_to_cic((rq)->elv.icq) |
| 58 | #define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elv.priv[0]) |
| 59 | #define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elv.priv[1]) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 61 | static struct kmem_cache *cfq_pool; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 63 | #define CFQ_PRIO_LISTS IOPRIO_BE_NR |
| 64 | #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 65 | #define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT) |
| 66 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 67 | #define sample_valid(samples) ((samples) > 80) |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 68 | #define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node) |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 69 | |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 70 | struct cfq_ttime { |
| 71 | unsigned long last_end_request; |
| 72 | |
| 73 | unsigned long ttime_total; |
| 74 | unsigned long ttime_samples; |
| 75 | unsigned long ttime_mean; |
| 76 | }; |
| 77 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 78 | /* |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 79 | * Most of our rbtree usage is for sorting with min extraction, so |
| 80 | * if we cache the leftmost node we don't have to walk down the tree |
| 81 | * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should |
| 82 | * move this into the elevator for the rq sorting as well. |
| 83 | */ |
| 84 | struct cfq_rb_root { |
| 85 | struct rb_root rb; |
| 86 | struct rb_node *left; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 87 | unsigned count; |
Richard Kennedy | 73e9ffd | 2010-03-01 10:50:20 +0100 | [diff] [blame] | 88 | unsigned total_weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 89 | u64 min_vdisktime; |
Shaohua Li | f5f2b6c | 2011-07-12 14:24:55 +0200 | [diff] [blame] | 90 | struct cfq_ttime ttime; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 91 | }; |
Shaohua Li | f5f2b6c | 2011-07-12 14:24:55 +0200 | [diff] [blame] | 92 | #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, \ |
| 93 | .ttime = {.last_end_request = jiffies,},} |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 94 | |
| 95 | /* |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 96 | * Per process-grouping structure |
| 97 | */ |
| 98 | struct cfq_queue { |
| 99 | /* reference count */ |
Shaohua Li | 30d7b94 | 2011-01-07 08:46:59 +0100 | [diff] [blame] | 100 | int ref; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 101 | /* various state flags, see below */ |
| 102 | unsigned int flags; |
| 103 | /* parent cfq_data */ |
| 104 | struct cfq_data *cfqd; |
| 105 | /* service_tree member */ |
| 106 | struct rb_node rb_node; |
| 107 | /* service_tree key */ |
| 108 | unsigned long rb_key; |
| 109 | /* prio tree member */ |
| 110 | struct rb_node p_node; |
| 111 | /* prio tree root we belong to, if any */ |
| 112 | struct rb_root *p_root; |
| 113 | /* sorted list of pending requests */ |
| 114 | struct rb_root sort_list; |
| 115 | /* if fifo isn't expired, next request to serve */ |
| 116 | struct request *next_rq; |
| 117 | /* requests queued in sort_list */ |
| 118 | int queued[2]; |
| 119 | /* currently allocated requests */ |
| 120 | int allocated[2]; |
| 121 | /* fifo list of requests in sort_list */ |
| 122 | struct list_head fifo; |
| 123 | |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 124 | /* time when queue got scheduled in to dispatch first request. */ |
| 125 | unsigned long dispatch_start; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 126 | unsigned int allocated_slice; |
Richard Kennedy | c4081ba | 2010-02-22 13:49:24 +0100 | [diff] [blame] | 127 | unsigned int slice_dispatch; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 128 | /* time when first request from queue completed and slice started. */ |
| 129 | unsigned long slice_start; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 130 | unsigned long slice_end; |
| 131 | long slice_resid; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 132 | |
Christoph Hellwig | 65299a3 | 2011-08-23 14:50:29 +0200 | [diff] [blame] | 133 | /* pending priority requests */ |
| 134 | int prio_pending; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 135 | /* number of requests that are on the dispatch list or inside driver */ |
| 136 | int dispatched; |
| 137 | |
| 138 | /* io prio of this group */ |
| 139 | unsigned short ioprio, org_ioprio; |
Justin TerAvest | 4aede84 | 2011-07-12 08:31:45 +0200 | [diff] [blame] | 140 | unsigned short ioprio_class; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 141 | |
Richard Kennedy | c4081ba | 2010-02-22 13:49:24 +0100 | [diff] [blame] | 142 | pid_t pid; |
| 143 | |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 144 | u32 seek_history; |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 145 | sector_t last_request_pos; |
| 146 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 147 | struct cfq_rb_root *service_tree; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 148 | struct cfq_queue *new_cfqq; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 149 | struct cfq_group *cfqg; |
Vivek Goyal | c4e7893 | 2010-08-23 12:25:03 +0200 | [diff] [blame] | 150 | /* Number of sectors dispatched from queue in single dispatch round */ |
| 151 | unsigned long nr_sectors; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 152 | }; |
| 153 | |
| 154 | /* |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 155 | * First index in the service_trees. |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 156 | * IDLE is handled separately, so it has negative index |
| 157 | */ |
| 158 | enum wl_prio_t { |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 159 | BE_WORKLOAD = 0, |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 160 | RT_WORKLOAD = 1, |
| 161 | IDLE_WORKLOAD = 2, |
Vivek Goyal | b462732 | 2010-10-22 09:48:43 +0200 | [diff] [blame] | 162 | CFQ_PRIO_NR, |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 163 | }; |
| 164 | |
| 165 | /* |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 166 | * Second index in the service_trees. |
| 167 | */ |
| 168 | enum wl_type_t { |
| 169 | ASYNC_WORKLOAD = 0, |
| 170 | SYNC_NOIDLE_WORKLOAD = 1, |
| 171 | SYNC_WORKLOAD = 2 |
| 172 | }; |
| 173 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 174 | /* This is per cgroup per device grouping structure */ |
| 175 | struct cfq_group { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 176 | /* group service_tree member */ |
| 177 | struct rb_node rb_node; |
| 178 | |
| 179 | /* group service_tree key */ |
| 180 | u64 vdisktime; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 181 | unsigned int weight; |
Justin TerAvest | 8184f93 | 2011-03-17 16:12:36 +0100 | [diff] [blame] | 182 | unsigned int new_weight; |
| 183 | bool needs_update; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 184 | |
| 185 | /* number of cfqq currently on this group */ |
| 186 | int nr_cfqq; |
| 187 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 188 | /* |
Kyungmin Park | 4495a7d | 2011-05-31 10:04:09 +0200 | [diff] [blame] | 189 | * Per group busy queues average. Useful for workload slice calc. We |
Vivek Goyal | b462732 | 2010-10-22 09:48:43 +0200 | [diff] [blame] | 190 | * create the array for each prio class but at run time it is used |
| 191 | * only for RT and BE class and slot for IDLE class remains unused. |
| 192 | * This is primarily done to avoid confusion and a gcc warning. |
| 193 | */ |
| 194 | unsigned int busy_queues_avg[CFQ_PRIO_NR]; |
| 195 | /* |
| 196 | * rr lists of queues with requests. We maintain service trees for |
| 197 | * RT and BE classes. These trees are subdivided in subclasses |
| 198 | * of SYNC, SYNC_NOIDLE and ASYNC based on workload type. For IDLE |
| 199 | * class there is no subclassification and all the cfq queues go on |
| 200 | * a single tree service_tree_idle. |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 201 | * Counts are embedded in the cfq_rb_root |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 202 | */ |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 203 | struct cfq_rb_root service_trees[2][3]; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 204 | struct cfq_rb_root service_tree_idle; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 205 | |
| 206 | unsigned long saved_workload_slice; |
| 207 | enum wl_type_t saved_workload; |
| 208 | enum wl_prio_t saved_serving_prio; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 209 | struct blkio_group blkg; |
| 210 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 211 | struct hlist_node cfqd_node; |
Shaohua Li | 329a678 | 2011-01-07 08:48:28 +0100 | [diff] [blame] | 212 | int ref; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 213 | #endif |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 214 | /* number of requests that are on the dispatch list or inside driver */ |
| 215 | int dispatched; |
Shaohua Li | 7700fc4 | 2011-07-12 14:24:56 +0200 | [diff] [blame] | 216 | struct cfq_ttime ttime; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 217 | }; |
| 218 | |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 219 | struct cfq_io_cq { |
| 220 | struct io_cq icq; /* must be the first member */ |
| 221 | struct cfq_queue *cfqq[2]; |
| 222 | struct cfq_ttime ttime; |
| 223 | }; |
| 224 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 225 | /* |
| 226 | * Per block device queue structure |
| 227 | */ |
| 228 | struct cfq_data { |
| 229 | struct request_queue *queue; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 230 | /* Root service tree for cfq_groups */ |
| 231 | struct cfq_rb_root grp_service_tree; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 232 | struct cfq_group root_group; |
| 233 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 234 | /* |
| 235 | * The priority currently being served |
| 236 | */ |
| 237 | enum wl_prio_t serving_prio; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 238 | enum wl_type_t serving_type; |
| 239 | unsigned long workload_expires; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 240 | struct cfq_group *serving_group; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 241 | |
| 242 | /* |
| 243 | * Each priority tree is sorted by next_request position. These |
| 244 | * trees are used when determining if two or more queues are |
| 245 | * interleaving requests (see cfq_close_cooperator). |
| 246 | */ |
| 247 | struct rb_root prio_trees[CFQ_PRIO_LISTS]; |
| 248 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 249 | unsigned int busy_queues; |
Shaohua Li | ef8a41d | 2011-03-07 09:26:29 +0100 | [diff] [blame] | 250 | unsigned int busy_sync_queues; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 251 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 252 | int rq_in_driver; |
| 253 | int rq_in_flight[2]; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 254 | |
| 255 | /* |
| 256 | * queue-depth detection |
| 257 | */ |
| 258 | int rq_queued; |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 259 | int hw_tag; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 260 | /* |
| 261 | * hw_tag can be |
| 262 | * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection) |
| 263 | * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth) |
| 264 | * 0 => no NCQ |
| 265 | */ |
| 266 | int hw_tag_est_depth; |
| 267 | unsigned int hw_tag_samples; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 268 | |
| 269 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 270 | * idle window management |
| 271 | */ |
| 272 | struct timer_list idle_slice_timer; |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 273 | struct work_struct unplug_work; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 274 | |
| 275 | struct cfq_queue *active_queue; |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 276 | struct cfq_io_cq *active_cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 277 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 278 | /* |
| 279 | * async queue for each priority case |
| 280 | */ |
| 281 | struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; |
| 282 | struct cfq_queue *async_idle_cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 283 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 284 | sector_t last_position; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | /* |
| 287 | * tunables, see top of file |
| 288 | */ |
| 289 | unsigned int cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 290 | unsigned int cfq_fifo_expire[2]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | unsigned int cfq_back_penalty; |
| 292 | unsigned int cfq_back_max; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 293 | unsigned int cfq_slice[2]; |
| 294 | unsigned int cfq_slice_async_rq; |
| 295 | unsigned int cfq_slice_idle; |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 296 | unsigned int cfq_group_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 297 | unsigned int cfq_latency; |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 298 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 299 | /* |
| 300 | * Fallback dummy cfqq for extreme OOM conditions |
| 301 | */ |
| 302 | struct cfq_queue oom_cfqq; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 303 | |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 304 | unsigned long last_delayed_sync; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 305 | |
| 306 | /* List of cfq groups being managed on this device*/ |
| 307 | struct hlist_head cfqg_list; |
Vivek Goyal | 56edf7d | 2011-05-19 15:38:22 -0400 | [diff] [blame] | 308 | |
| 309 | /* Number of groups which are on blkcg->blkg_list */ |
| 310 | unsigned int nr_blkcg_linked_grps; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | }; |
| 312 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 313 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd); |
| 314 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 315 | static struct cfq_rb_root *service_tree_for(struct cfq_group *cfqg, |
| 316 | enum wl_prio_t prio, |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 317 | enum wl_type_t type) |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 318 | { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 319 | if (!cfqg) |
| 320 | return NULL; |
| 321 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 322 | if (prio == IDLE_WORKLOAD) |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 323 | return &cfqg->service_tree_idle; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 324 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 325 | return &cfqg->service_trees[prio][type]; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 326 | } |
| 327 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 328 | enum cfqq_state_flags { |
Jens Axboe | b0b8d74 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 329 | CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ |
| 330 | CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 331 | CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ |
Jens Axboe | b0b8d74 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 332 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ |
Jens Axboe | b0b8d74 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 333 | CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ |
| 334 | CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ |
| 335 | CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 336 | CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 337 | CFQ_CFQQ_FLAG_sync, /* synchronous queue */ |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 338 | CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 339 | CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */ |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 340 | CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 341 | CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 342 | }; |
| 343 | |
| 344 | #define CFQ_CFQQ_FNS(name) \ |
| 345 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ |
| 346 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 347 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 348 | } \ |
| 349 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ |
| 350 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 351 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 352 | } \ |
| 353 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ |
| 354 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 355 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 356 | } |
| 357 | |
| 358 | CFQ_CFQQ_FNS(on_rr); |
| 359 | CFQ_CFQQ_FNS(wait_request); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 360 | CFQ_CFQQ_FNS(must_dispatch); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 361 | CFQ_CFQQ_FNS(must_alloc_slice); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 362 | CFQ_CFQQ_FNS(fifo_expire); |
| 363 | CFQ_CFQQ_FNS(idle_window); |
| 364 | CFQ_CFQQ_FNS(prio_changed); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 365 | CFQ_CFQQ_FNS(slice_new); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 366 | CFQ_CFQQ_FNS(sync); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 367 | CFQ_CFQQ_FNS(coop); |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 368 | CFQ_CFQQ_FNS(split_coop); |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 369 | CFQ_CFQQ_FNS(deep); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 370 | CFQ_CFQQ_FNS(wait_busy); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 371 | #undef CFQ_CFQQ_FNS |
| 372 | |
Vivek Goyal | afc24d4 | 2010-04-26 19:27:56 +0200 | [diff] [blame] | 373 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 374 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 375 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \ |
| 376 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ |
Kyungmin Park | 4495a7d | 2011-05-31 10:04:09 +0200 | [diff] [blame] | 377 | blkg_path(&(cfqq)->cfqg->blkg), ##args) |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 378 | |
| 379 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) \ |
| 380 | blk_add_trace_msg((cfqd)->queue, "%s " fmt, \ |
Kyungmin Park | 4495a7d | 2011-05-31 10:04:09 +0200 | [diff] [blame] | 381 | blkg_path(&(cfqg)->blkg), ##args) \ |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 382 | |
| 383 | #else |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 384 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 385 | blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args) |
Kyungmin Park | 4495a7d | 2011-05-31 10:04:09 +0200 | [diff] [blame] | 386 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0) |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 387 | #endif |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 388 | #define cfq_log(cfqd, fmt, args...) \ |
| 389 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) |
| 390 | |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 391 | /* Traverses through cfq group service trees */ |
| 392 | #define for_each_cfqg_st(cfqg, i, j, st) \ |
| 393 | for (i = 0; i <= IDLE_WORKLOAD; i++) \ |
| 394 | for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\ |
| 395 | : &cfqg->service_tree_idle; \ |
| 396 | (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \ |
| 397 | (i == IDLE_WORKLOAD && j == 0); \ |
| 398 | j++, st = i < IDLE_WORKLOAD ? \ |
| 399 | &cfqg->service_trees[i][j]: NULL) \ |
| 400 | |
Shaohua Li | f5f2b6c | 2011-07-12 14:24:55 +0200 | [diff] [blame] | 401 | static inline bool cfq_io_thinktime_big(struct cfq_data *cfqd, |
| 402 | struct cfq_ttime *ttime, bool group_idle) |
| 403 | { |
| 404 | unsigned long slice; |
| 405 | if (!sample_valid(ttime->ttime_samples)) |
| 406 | return false; |
| 407 | if (group_idle) |
| 408 | slice = cfqd->cfq_group_idle; |
| 409 | else |
| 410 | slice = cfqd->cfq_slice_idle; |
| 411 | return ttime->ttime_mean > slice; |
| 412 | } |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 413 | |
Vivek Goyal | 02b3508 | 2010-08-23 12:23:53 +0200 | [diff] [blame] | 414 | static inline bool iops_mode(struct cfq_data *cfqd) |
| 415 | { |
| 416 | /* |
| 417 | * If we are not idling on queues and it is a NCQ drive, parallel |
| 418 | * execution of requests is on and measuring time is not possible |
| 419 | * in most of the cases until and unless we drive shallower queue |
| 420 | * depths and that becomes a performance bottleneck. In such cases |
| 421 | * switch to start providing fairness in terms of number of IOs. |
| 422 | */ |
| 423 | if (!cfqd->cfq_slice_idle && cfqd->hw_tag) |
| 424 | return true; |
| 425 | else |
| 426 | return false; |
| 427 | } |
| 428 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 429 | static inline enum wl_prio_t cfqq_prio(struct cfq_queue *cfqq) |
| 430 | { |
| 431 | if (cfq_class_idle(cfqq)) |
| 432 | return IDLE_WORKLOAD; |
| 433 | if (cfq_class_rt(cfqq)) |
| 434 | return RT_WORKLOAD; |
| 435 | return BE_WORKLOAD; |
| 436 | } |
| 437 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 438 | |
| 439 | static enum wl_type_t cfqq_type(struct cfq_queue *cfqq) |
| 440 | { |
| 441 | if (!cfq_cfqq_sync(cfqq)) |
| 442 | return ASYNC_WORKLOAD; |
| 443 | if (!cfq_cfqq_idle_window(cfqq)) |
| 444 | return SYNC_NOIDLE_WORKLOAD; |
| 445 | return SYNC_WORKLOAD; |
| 446 | } |
| 447 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 448 | static inline int cfq_group_busy_queues_wl(enum wl_prio_t wl, |
| 449 | struct cfq_data *cfqd, |
| 450 | struct cfq_group *cfqg) |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 451 | { |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 452 | if (wl == IDLE_WORKLOAD) |
| 453 | return cfqg->service_tree_idle.count; |
| 454 | |
| 455 | return cfqg->service_trees[wl][ASYNC_WORKLOAD].count |
| 456 | + cfqg->service_trees[wl][SYNC_NOIDLE_WORKLOAD].count |
| 457 | + cfqg->service_trees[wl][SYNC_WORKLOAD].count; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 458 | } |
| 459 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 460 | static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, |
| 461 | struct cfq_group *cfqg) |
| 462 | { |
| 463 | return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count |
| 464 | + cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count; |
| 465 | } |
| 466 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 467 | static void cfq_dispatch_insert(struct request_queue *, struct request *); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 468 | static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 469 | struct io_context *, gfp_t); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 470 | |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 471 | static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq) |
| 472 | { |
| 473 | /* cic->icq is the first member, %NULL will convert to %NULL */ |
| 474 | return container_of(icq, struct cfq_io_cq, icq); |
| 475 | } |
| 476 | |
Tejun Heo | 47fdd4c | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 477 | static inline struct cfq_io_cq *cfq_cic_lookup(struct cfq_data *cfqd, |
| 478 | struct io_context *ioc) |
| 479 | { |
| 480 | if (ioc) |
| 481 | return icq_to_cic(ioc_lookup_icq(ioc, cfqd->queue)); |
| 482 | return NULL; |
| 483 | } |
| 484 | |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 485 | static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_cq *cic, bool is_sync) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 486 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 487 | return cic->cfqq[is_sync]; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 488 | } |
| 489 | |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 490 | static inline void cic_set_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq, |
| 491 | bool is_sync) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 492 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 493 | cic->cfqq[is_sync] = cfqq; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 494 | } |
| 495 | |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 496 | static inline struct cfq_data *cic_to_cfqd(struct cfq_io_cq *cic) |
Konstantin Khlebnikov | bca4b91 | 2010-05-20 23:21:34 +0400 | [diff] [blame] | 497 | { |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 498 | return cic->icq.q->elevator->elevator_data; |
Konstantin Khlebnikov | bca4b91 | 2010-05-20 23:21:34 +0400 | [diff] [blame] | 499 | } |
| 500 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 501 | /* |
| 502 | * We regard a request as SYNC, if it's either a read or has the SYNC bit |
| 503 | * set (in which case it could also be direct WRITE). |
| 504 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 505 | static inline bool cfq_bio_sync(struct bio *bio) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 506 | { |
Christoph Hellwig | 7b6d91d | 2010-08-07 18:20:39 +0200 | [diff] [blame] | 507 | return bio_data_dir(bio) == READ || (bio->bi_rw & REQ_SYNC); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 508 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 510 | /* |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 511 | * scheduler run of queue, if there are requests pending and no one in the |
| 512 | * driver that will restart queueing |
| 513 | */ |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 514 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 515 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 516 | if (cfqd->busy_queues) { |
| 517 | cfq_log(cfqd, "schedule dispatch"); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 518 | kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 519 | } |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 520 | } |
| 521 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | /* |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 523 | * Scale schedule slice based on io priority. Use the sync time slice only |
| 524 | * if a queue is marked sync and has sync io queued. A sync queue with async |
| 525 | * io only, should not get full sync slice length. |
| 526 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 527 | static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync, |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 528 | unsigned short prio) |
| 529 | { |
| 530 | const int base_slice = cfqd->cfq_slice[sync]; |
| 531 | |
| 532 | WARN_ON(prio >= IOPRIO_BE_NR); |
| 533 | |
| 534 | return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); |
| 535 | } |
| 536 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 537 | static inline int |
| 538 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 539 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 540 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 541 | } |
| 542 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 543 | static inline u64 cfq_scale_slice(unsigned long delta, struct cfq_group *cfqg) |
| 544 | { |
| 545 | u64 d = delta << CFQ_SERVICE_SHIFT; |
| 546 | |
| 547 | d = d * BLKIO_WEIGHT_DEFAULT; |
| 548 | do_div(d, cfqg->weight); |
| 549 | return d; |
| 550 | } |
| 551 | |
| 552 | static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime) |
| 553 | { |
| 554 | s64 delta = (s64)(vdisktime - min_vdisktime); |
| 555 | if (delta > 0) |
| 556 | min_vdisktime = vdisktime; |
| 557 | |
| 558 | return min_vdisktime; |
| 559 | } |
| 560 | |
| 561 | static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime) |
| 562 | { |
| 563 | s64 delta = (s64)(vdisktime - min_vdisktime); |
| 564 | if (delta < 0) |
| 565 | min_vdisktime = vdisktime; |
| 566 | |
| 567 | return min_vdisktime; |
| 568 | } |
| 569 | |
| 570 | static void update_min_vdisktime(struct cfq_rb_root *st) |
| 571 | { |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 572 | struct cfq_group *cfqg; |
| 573 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 574 | if (st->left) { |
| 575 | cfqg = rb_entry_cfqg(st->left); |
Gui Jianfeng | a603271 | 2011-03-07 09:28:09 +0100 | [diff] [blame] | 576 | st->min_vdisktime = max_vdisktime(st->min_vdisktime, |
| 577 | cfqg->vdisktime); |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 578 | } |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 579 | } |
| 580 | |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 581 | /* |
| 582 | * get averaged number of queues of RT/BE priority. |
| 583 | * average is updated, with a formula that gives more weight to higher numbers, |
| 584 | * to quickly follows sudden increases and decrease slowly |
| 585 | */ |
| 586 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 587 | static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd, |
| 588 | struct cfq_group *cfqg, bool rt) |
Jens Axboe | 5869619 | 2009-10-28 09:27:07 +0100 | [diff] [blame] | 589 | { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 590 | unsigned min_q, max_q; |
| 591 | unsigned mult = cfq_hist_divisor - 1; |
| 592 | unsigned round = cfq_hist_divisor / 2; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 593 | unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg); |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 594 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 595 | min_q = min(cfqg->busy_queues_avg[rt], busy); |
| 596 | max_q = max(cfqg->busy_queues_avg[rt], busy); |
| 597 | cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) / |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 598 | cfq_hist_divisor; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 599 | return cfqg->busy_queues_avg[rt]; |
| 600 | } |
| 601 | |
| 602 | static inline unsigned |
| 603 | cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 604 | { |
| 605 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 606 | |
| 607 | return cfq_target_latency * cfqg->weight / st->total_weight; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 608 | } |
| 609 | |
Shaohua Li | c553f8e | 2011-01-14 08:41:03 +0100 | [diff] [blame] | 610 | static inline unsigned |
Vivek Goyal | ba5bd52 | 2011-01-19 08:25:02 -0700 | [diff] [blame] | 611 | cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 612 | { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 613 | unsigned slice = cfq_prio_to_slice(cfqd, cfqq); |
| 614 | if (cfqd->cfq_latency) { |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 615 | /* |
| 616 | * interested queues (we consider only the ones with the same |
| 617 | * priority class in the cfq group) |
| 618 | */ |
| 619 | unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg, |
| 620 | cfq_class_rt(cfqq)); |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 621 | unsigned sync_slice = cfqd->cfq_slice[1]; |
| 622 | unsigned expect_latency = sync_slice * iq; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 623 | unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg); |
| 624 | |
| 625 | if (expect_latency > group_slice) { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 626 | unsigned base_low_slice = 2 * cfqd->cfq_slice_idle; |
| 627 | /* scale low_slice according to IO priority |
| 628 | * and sync vs async */ |
| 629 | unsigned low_slice = |
| 630 | min(slice, base_low_slice * slice / sync_slice); |
| 631 | /* the adapted slice value is scaled to fit all iqs |
| 632 | * into the target latency */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 633 | slice = max(slice * group_slice / expect_latency, |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 634 | low_slice); |
| 635 | } |
| 636 | } |
Shaohua Li | c553f8e | 2011-01-14 08:41:03 +0100 | [diff] [blame] | 637 | return slice; |
| 638 | } |
| 639 | |
| 640 | static inline void |
| 641 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 642 | { |
Vivek Goyal | ba5bd52 | 2011-01-19 08:25:02 -0700 | [diff] [blame] | 643 | unsigned slice = cfq_scaled_cfqq_slice(cfqd, cfqq); |
Shaohua Li | c553f8e | 2011-01-14 08:41:03 +0100 | [diff] [blame] | 644 | |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 645 | cfqq->slice_start = jiffies; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 646 | cfqq->slice_end = jiffies + slice; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 647 | cfqq->allocated_slice = slice; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 648 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 649 | } |
| 650 | |
| 651 | /* |
| 652 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end |
| 653 | * isn't valid until the first request from the dispatch is activated |
| 654 | * and the slice time set. |
| 655 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 656 | static inline bool cfq_slice_used(struct cfq_queue *cfqq) |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 657 | { |
| 658 | if (cfq_cfqq_slice_new(cfqq)) |
Shaohua Li | c1e4475 | 2010-11-08 15:01:02 +0100 | [diff] [blame] | 659 | return false; |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 660 | if (time_before(jiffies, cfqq->slice_end)) |
Shaohua Li | c1e4475 | 2010-11-08 15:01:02 +0100 | [diff] [blame] | 661 | return false; |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 662 | |
Shaohua Li | c1e4475 | 2010-11-08 15:01:02 +0100 | [diff] [blame] | 663 | return true; |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 664 | } |
| 665 | |
| 666 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 667 | * Lifted from AS - choose which of rq1 and rq2 that is best served now. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 668 | * We choose the request that is closest to the head right now. Distance |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 669 | * behind the head is penalized and only allowed to a certain extent. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 671 | static struct request * |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 672 | cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, sector_t last) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | { |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 674 | sector_t s1, s2, d1 = 0, d2 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | unsigned long back_max; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 676 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ |
| 677 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ |
| 678 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 679 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 680 | if (rq1 == NULL || rq1 == rq2) |
| 681 | return rq2; |
| 682 | if (rq2 == NULL) |
| 683 | return rq1; |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 684 | |
Namhyung Kim | 229836b | 2011-05-24 10:23:21 +0200 | [diff] [blame] | 685 | if (rq_is_sync(rq1) != rq_is_sync(rq2)) |
| 686 | return rq_is_sync(rq1) ? rq1 : rq2; |
| 687 | |
Christoph Hellwig | 65299a3 | 2011-08-23 14:50:29 +0200 | [diff] [blame] | 688 | if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_PRIO) |
| 689 | return rq1->cmd_flags & REQ_PRIO ? rq1 : rq2; |
Jens Axboe | b53d1ed | 2011-08-19 08:34:48 +0200 | [diff] [blame] | 690 | |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 691 | s1 = blk_rq_pos(rq1); |
| 692 | s2 = blk_rq_pos(rq2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | /* |
| 695 | * by definition, 1KiB is 2 sectors |
| 696 | */ |
| 697 | back_max = cfqd->cfq_back_max * 2; |
| 698 | |
| 699 | /* |
| 700 | * Strict one way elevator _except_ in the case where we allow |
| 701 | * short backward seeks which are biased as twice the cost of a |
| 702 | * similar forward seek. |
| 703 | */ |
| 704 | if (s1 >= last) |
| 705 | d1 = s1 - last; |
| 706 | else if (s1 + back_max >= last) |
| 707 | d1 = (last - s1) * cfqd->cfq_back_penalty; |
| 708 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 709 | wrap |= CFQ_RQ1_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | |
| 711 | if (s2 >= last) |
| 712 | d2 = s2 - last; |
| 713 | else if (s2 + back_max >= last) |
| 714 | d2 = (last - s2) * cfqd->cfq_back_penalty; |
| 715 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 716 | wrap |= CFQ_RQ2_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | |
| 718 | /* Found required data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 719 | |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 720 | /* |
| 721 | * By doing switch() on the bit mask "wrap" we avoid having to |
| 722 | * check two variables for all permutations: --> faster! |
| 723 | */ |
| 724 | switch (wrap) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 725 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 726 | if (d1 < d2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 727 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 728 | else if (d2 < d1) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 729 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 730 | else { |
| 731 | if (s1 >= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 732 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 733 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 734 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 735 | } |
| 736 | |
| 737 | case CFQ_RQ2_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 738 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 739 | case CFQ_RQ1_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 740 | return rq2; |
| 741 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 742 | default: |
| 743 | /* |
| 744 | * Since both rqs are wrapped, |
| 745 | * start with the one that's further behind head |
| 746 | * (--> only *one* back seek required), |
| 747 | * since back seek takes more time than forward. |
| 748 | */ |
| 749 | if (s1 <= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 750 | return rq1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 752 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | } |
| 754 | } |
| 755 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 756 | /* |
| 757 | * The below is leftmost cache rbtree addon |
| 758 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 759 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 760 | { |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 761 | /* Service tree is empty */ |
| 762 | if (!root->count) |
| 763 | return NULL; |
| 764 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 765 | if (!root->left) |
| 766 | root->left = rb_first(&root->rb); |
| 767 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 768 | if (root->left) |
| 769 | return rb_entry(root->left, struct cfq_queue, rb_node); |
| 770 | |
| 771 | return NULL; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 772 | } |
| 773 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 774 | static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root) |
| 775 | { |
| 776 | if (!root->left) |
| 777 | root->left = rb_first(&root->rb); |
| 778 | |
| 779 | if (root->left) |
| 780 | return rb_entry_cfqg(root->left); |
| 781 | |
| 782 | return NULL; |
| 783 | } |
| 784 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 785 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
| 786 | { |
| 787 | rb_erase(n, root); |
| 788 | RB_CLEAR_NODE(n); |
| 789 | } |
| 790 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 791 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) |
| 792 | { |
| 793 | if (root->left == n) |
| 794 | root->left = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 795 | rb_erase_init(n, &root->rb); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 796 | --root->count; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 797 | } |
| 798 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | /* |
| 800 | * would be nice to take fifo expire time into account as well |
| 801 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 802 | static struct request * |
| 803 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 804 | struct request *last) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 806 | struct rb_node *rbnext = rb_next(&last->rb_node); |
| 807 | struct rb_node *rbprev = rb_prev(&last->rb_node); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 808 | struct request *next = NULL, *prev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 809 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 810 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 811 | |
| 812 | if (rbprev) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 813 | prev = rb_entry_rq(rbprev); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 814 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | if (rbnext) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 816 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 817 | else { |
| 818 | rbnext = rb_first(&cfqq->sort_list); |
| 819 | if (rbnext && rbnext != &last->rb_node) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 820 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 821 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 822 | |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 823 | return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 824 | } |
| 825 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 826 | static unsigned long cfq_slice_offset(struct cfq_data *cfqd, |
| 827 | struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 828 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 829 | /* |
| 830 | * just an approximation, should be ok. |
| 831 | */ |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 832 | return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - |
Jens Axboe | 464191c | 2009-11-30 09:38:13 +0100 | [diff] [blame] | 833 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 834 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 836 | static inline s64 |
| 837 | cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg) |
| 838 | { |
| 839 | return cfqg->vdisktime - st->min_vdisktime; |
| 840 | } |
| 841 | |
| 842 | static void |
| 843 | __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) |
| 844 | { |
| 845 | struct rb_node **node = &st->rb.rb_node; |
| 846 | struct rb_node *parent = NULL; |
| 847 | struct cfq_group *__cfqg; |
| 848 | s64 key = cfqg_key(st, cfqg); |
| 849 | int left = 1; |
| 850 | |
| 851 | while (*node != NULL) { |
| 852 | parent = *node; |
| 853 | __cfqg = rb_entry_cfqg(parent); |
| 854 | |
| 855 | if (key < cfqg_key(st, __cfqg)) |
| 856 | node = &parent->rb_left; |
| 857 | else { |
| 858 | node = &parent->rb_right; |
| 859 | left = 0; |
| 860 | } |
| 861 | } |
| 862 | |
| 863 | if (left) |
| 864 | st->left = &cfqg->rb_node; |
| 865 | |
| 866 | rb_link_node(&cfqg->rb_node, parent, node); |
| 867 | rb_insert_color(&cfqg->rb_node, &st->rb); |
| 868 | } |
| 869 | |
| 870 | static void |
Justin TerAvest | 8184f93 | 2011-03-17 16:12:36 +0100 | [diff] [blame] | 871 | cfq_update_group_weight(struct cfq_group *cfqg) |
| 872 | { |
| 873 | BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node)); |
| 874 | if (cfqg->needs_update) { |
| 875 | cfqg->weight = cfqg->new_weight; |
| 876 | cfqg->needs_update = false; |
| 877 | } |
| 878 | } |
| 879 | |
| 880 | static void |
| 881 | cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) |
| 882 | { |
| 883 | BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node)); |
| 884 | |
| 885 | cfq_update_group_weight(cfqg); |
| 886 | __cfq_group_service_tree_add(st, cfqg); |
| 887 | st->total_weight += cfqg->weight; |
| 888 | } |
| 889 | |
| 890 | static void |
| 891 | cfq_group_notify_queue_add(struct cfq_data *cfqd, struct cfq_group *cfqg) |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 892 | { |
| 893 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 894 | struct cfq_group *__cfqg; |
| 895 | struct rb_node *n; |
| 896 | |
| 897 | cfqg->nr_cfqq++; |
Gui Jianfeng | 760701b | 2010-11-30 20:52:47 +0100 | [diff] [blame] | 898 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 899 | return; |
| 900 | |
| 901 | /* |
| 902 | * Currently put the group at the end. Later implement something |
| 903 | * so that groups get lesser vtime based on their weights, so that |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 904 | * if group does not loose all if it was not continuously backlogged. |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 905 | */ |
| 906 | n = rb_last(&st->rb); |
| 907 | if (n) { |
| 908 | __cfqg = rb_entry_cfqg(n); |
| 909 | cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY; |
| 910 | } else |
| 911 | cfqg->vdisktime = st->min_vdisktime; |
Justin TerAvest | 8184f93 | 2011-03-17 16:12:36 +0100 | [diff] [blame] | 912 | cfq_group_service_tree_add(st, cfqg); |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 913 | } |
| 914 | |
| 915 | static void |
Justin TerAvest | 8184f93 | 2011-03-17 16:12:36 +0100 | [diff] [blame] | 916 | cfq_group_service_tree_del(struct cfq_rb_root *st, struct cfq_group *cfqg) |
| 917 | { |
| 918 | st->total_weight -= cfqg->weight; |
| 919 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
| 920 | cfq_rb_erase(&cfqg->rb_node, st); |
| 921 | } |
| 922 | |
| 923 | static void |
| 924 | cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg) |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 925 | { |
| 926 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 927 | |
| 928 | BUG_ON(cfqg->nr_cfqq < 1); |
| 929 | cfqg->nr_cfqq--; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 930 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 931 | /* If there are other cfq queues under this group, don't delete it */ |
| 932 | if (cfqg->nr_cfqq) |
| 933 | return; |
| 934 | |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 935 | cfq_log_cfqg(cfqd, cfqg, "del_from_rr group"); |
Justin TerAvest | 8184f93 | 2011-03-17 16:12:36 +0100 | [diff] [blame] | 936 | cfq_group_service_tree_del(st, cfqg); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 937 | cfqg->saved_workload_slice = 0; |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 938 | cfq_blkiocg_update_dequeue_stats(&cfqg->blkg, 1); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 939 | } |
| 940 | |
Justin TerAvest | 167400d | 2011-03-12 16:54:00 +0100 | [diff] [blame] | 941 | static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq, |
| 942 | unsigned int *unaccounted_time) |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 943 | { |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 944 | unsigned int slice_used; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 945 | |
| 946 | /* |
| 947 | * Queue got expired before even a single request completed or |
| 948 | * got expired immediately after first request completion. |
| 949 | */ |
| 950 | if (!cfqq->slice_start || cfqq->slice_start == jiffies) { |
| 951 | /* |
| 952 | * Also charge the seek time incurred to the group, otherwise |
| 953 | * if there are mutiple queues in the group, each can dispatch |
| 954 | * a single request on seeky media and cause lots of seek time |
| 955 | * and group will never know it. |
| 956 | */ |
| 957 | slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start), |
| 958 | 1); |
| 959 | } else { |
| 960 | slice_used = jiffies - cfqq->slice_start; |
Justin TerAvest | 167400d | 2011-03-12 16:54:00 +0100 | [diff] [blame] | 961 | if (slice_used > cfqq->allocated_slice) { |
| 962 | *unaccounted_time = slice_used - cfqq->allocated_slice; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 963 | slice_used = cfqq->allocated_slice; |
Justin TerAvest | 167400d | 2011-03-12 16:54:00 +0100 | [diff] [blame] | 964 | } |
| 965 | if (time_after(cfqq->slice_start, cfqq->dispatch_start)) |
| 966 | *unaccounted_time += cfqq->slice_start - |
| 967 | cfqq->dispatch_start; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 968 | } |
| 969 | |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 970 | return slice_used; |
| 971 | } |
| 972 | |
| 973 | static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 974 | struct cfq_queue *cfqq) |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 975 | { |
| 976 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
Justin TerAvest | 167400d | 2011-03-12 16:54:00 +0100 | [diff] [blame] | 977 | unsigned int used_sl, charge, unaccounted_sl = 0; |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 978 | int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) |
| 979 | - cfqg->service_tree_idle.count; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 980 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 981 | BUG_ON(nr_sync < 0); |
Justin TerAvest | 167400d | 2011-03-12 16:54:00 +0100 | [diff] [blame] | 982 | used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl); |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 983 | |
Vivek Goyal | 02b3508 | 2010-08-23 12:23:53 +0200 | [diff] [blame] | 984 | if (iops_mode(cfqd)) |
| 985 | charge = cfqq->slice_dispatch; |
| 986 | else if (!cfq_cfqq_sync(cfqq) && !nr_sync) |
| 987 | charge = cfqq->allocated_slice; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 988 | |
| 989 | /* Can't update vdisktime while group is on service tree */ |
Justin TerAvest | 8184f93 | 2011-03-17 16:12:36 +0100 | [diff] [blame] | 990 | cfq_group_service_tree_del(st, cfqg); |
Vivek Goyal | 02b3508 | 2010-08-23 12:23:53 +0200 | [diff] [blame] | 991 | cfqg->vdisktime += cfq_scale_slice(charge, cfqg); |
Justin TerAvest | 8184f93 | 2011-03-17 16:12:36 +0100 | [diff] [blame] | 992 | /* If a new weight was requested, update now, off tree */ |
| 993 | cfq_group_service_tree_add(st, cfqg); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 994 | |
| 995 | /* This group is being expired. Save the context */ |
| 996 | if (time_after(cfqd->workload_expires, jiffies)) { |
| 997 | cfqg->saved_workload_slice = cfqd->workload_expires |
| 998 | - jiffies; |
| 999 | cfqg->saved_workload = cfqd->serving_type; |
| 1000 | cfqg->saved_serving_prio = cfqd->serving_prio; |
| 1001 | } else |
| 1002 | cfqg->saved_workload_slice = 0; |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 1003 | |
| 1004 | cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime, |
| 1005 | st->min_vdisktime); |
Joe Perches | fd16d26 | 2011-06-13 10:42:49 +0200 | [diff] [blame] | 1006 | cfq_log_cfqq(cfqq->cfqd, cfqq, |
| 1007 | "sl_used=%u disp=%u charge=%u iops=%u sect=%lu", |
| 1008 | used_sl, cfqq->slice_dispatch, charge, |
| 1009 | iops_mode(cfqd), cfqq->nr_sectors); |
Justin TerAvest | 167400d | 2011-03-12 16:54:00 +0100 | [diff] [blame] | 1010 | cfq_blkiocg_update_timeslice_used(&cfqg->blkg, used_sl, |
| 1011 | unaccounted_sl); |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 1012 | cfq_blkiocg_set_start_empty_time(&cfqg->blkg); |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1013 | } |
| 1014 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1015 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 1016 | static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg) |
| 1017 | { |
| 1018 | if (blkg) |
| 1019 | return container_of(blkg, struct cfq_group, blkg); |
| 1020 | return NULL; |
| 1021 | } |
| 1022 | |
Paul Bolle | 8aea454 | 2011-06-06 05:07:54 +0200 | [diff] [blame] | 1023 | static void cfq_update_blkio_group_weight(void *key, struct blkio_group *blkg, |
| 1024 | unsigned int weight) |
Vivek Goyal | f8d461d | 2009-12-03 12:59:52 -0500 | [diff] [blame] | 1025 | { |
Justin TerAvest | 8184f93 | 2011-03-17 16:12:36 +0100 | [diff] [blame] | 1026 | struct cfq_group *cfqg = cfqg_of_blkg(blkg); |
| 1027 | cfqg->new_weight = weight; |
| 1028 | cfqg->needs_update = true; |
Vivek Goyal | f8d461d | 2009-12-03 12:59:52 -0500 | [diff] [blame] | 1029 | } |
| 1030 | |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1031 | static void cfq_init_add_cfqg_lists(struct cfq_data *cfqd, |
| 1032 | struct cfq_group *cfqg, struct blkio_cgroup *blkcg) |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1033 | { |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 1034 | struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info; |
| 1035 | unsigned int major, minor; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1036 | |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1037 | /* |
| 1038 | * Add group onto cgroup list. It might happen that bdi->dev is |
| 1039 | * not initialized yet. Initialize this new group without major |
| 1040 | * and minor info and this info will be filled in once a new thread |
| 1041 | * comes for IO. |
| 1042 | */ |
| 1043 | if (bdi->dev) { |
Ricky Benitez | a74b2ad | 2010-04-05 18:22:17 +0200 | [diff] [blame] | 1044 | sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1045 | cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, |
| 1046 | (void *)cfqd, MKDEV(major, minor)); |
| 1047 | } else |
| 1048 | cfq_blkiocg_add_blkio_group(blkcg, &cfqg->blkg, |
| 1049 | (void *)cfqd, 0); |
| 1050 | |
| 1051 | cfqd->nr_blkcg_linked_grps++; |
| 1052 | cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev); |
| 1053 | |
| 1054 | /* Add group on cfqd list */ |
| 1055 | hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list); |
| 1056 | } |
| 1057 | |
| 1058 | /* |
| 1059 | * Should be called from sleepable context. No request queue lock as per |
| 1060 | * cpu stats are allocated dynamically and alloc_percpu needs to be called |
| 1061 | * from sleepable context. |
| 1062 | */ |
| 1063 | static struct cfq_group * cfq_alloc_cfqg(struct cfq_data *cfqd) |
| 1064 | { |
| 1065 | struct cfq_group *cfqg = NULL; |
Vivek Goyal | 5624a4e | 2011-05-19 15:38:28 -0400 | [diff] [blame] | 1066 | int i, j, ret; |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1067 | struct cfq_rb_root *st; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1068 | |
| 1069 | cfqg = kzalloc_node(sizeof(*cfqg), GFP_ATOMIC, cfqd->queue->node); |
| 1070 | if (!cfqg) |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1071 | return NULL; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1072 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1073 | for_each_cfqg_st(cfqg, i, j, st) |
| 1074 | *st = CFQ_RB_ROOT; |
| 1075 | RB_CLEAR_NODE(&cfqg->rb_node); |
| 1076 | |
Shaohua Li | 7700fc4 | 2011-07-12 14:24:56 +0200 | [diff] [blame] | 1077 | cfqg->ttime.last_end_request = jiffies; |
| 1078 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1079 | /* |
| 1080 | * Take the initial reference that will be released on destroy |
| 1081 | * This can be thought of a joint reference by cgroup and |
| 1082 | * elevator which will be dropped by either elevator exit |
| 1083 | * or cgroup deletion path depending on who is exiting first. |
| 1084 | */ |
Shaohua Li | 329a678 | 2011-01-07 08:48:28 +0100 | [diff] [blame] | 1085 | cfqg->ref = 1; |
Vivek Goyal | 5624a4e | 2011-05-19 15:38:28 -0400 | [diff] [blame] | 1086 | |
| 1087 | ret = blkio_alloc_blkg_stats(&cfqg->blkg); |
| 1088 | if (ret) { |
| 1089 | kfree(cfqg); |
| 1090 | return NULL; |
| 1091 | } |
| 1092 | |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1093 | return cfqg; |
| 1094 | } |
| 1095 | |
| 1096 | static struct cfq_group * |
| 1097 | cfq_find_cfqg(struct cfq_data *cfqd, struct blkio_cgroup *blkcg) |
| 1098 | { |
| 1099 | struct cfq_group *cfqg = NULL; |
| 1100 | void *key = cfqd; |
| 1101 | struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info; |
| 1102 | unsigned int major, minor; |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1103 | |
Vivek Goyal | 180be2a | 2010-09-14 08:47:11 +0200 | [diff] [blame] | 1104 | /* |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1105 | * This is the common case when there are no blkio cgroups. |
| 1106 | * Avoid lookup in this case |
Vivek Goyal | 180be2a | 2010-09-14 08:47:11 +0200 | [diff] [blame] | 1107 | */ |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1108 | if (blkcg == &blkio_root_cgroup) |
| 1109 | cfqg = &cfqd->root_group; |
| 1110 | else |
| 1111 | cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key)); |
| 1112 | |
| 1113 | if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) { |
Vivek Goyal | 180be2a | 2010-09-14 08:47:11 +0200 | [diff] [blame] | 1114 | sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1115 | cfqg->blkg.dev = MKDEV(major, minor); |
| 1116 | } |
Vivek Goyal | 180be2a | 2010-09-14 08:47:11 +0200 | [diff] [blame] | 1117 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1118 | return cfqg; |
| 1119 | } |
| 1120 | |
| 1121 | /* |
Vivek Goyal | 3e59cf9 | 2011-05-19 15:38:21 -0400 | [diff] [blame] | 1122 | * Search for the cfq group current task belongs to. request_queue lock must |
| 1123 | * be held. |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1124 | */ |
Vivek Goyal | 3e59cf9 | 2011-05-19 15:38:21 -0400 | [diff] [blame] | 1125 | static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd) |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1126 | { |
Vivek Goyal | 70087dc | 2011-05-16 15:24:08 +0200 | [diff] [blame] | 1127 | struct blkio_cgroup *blkcg; |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1128 | struct cfq_group *cfqg = NULL, *__cfqg = NULL; |
| 1129 | struct request_queue *q = cfqd->queue; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1130 | |
| 1131 | rcu_read_lock(); |
Vivek Goyal | 70087dc | 2011-05-16 15:24:08 +0200 | [diff] [blame] | 1132 | blkcg = task_blkio_cgroup(current); |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1133 | cfqg = cfq_find_cfqg(cfqd, blkcg); |
| 1134 | if (cfqg) { |
| 1135 | rcu_read_unlock(); |
| 1136 | return cfqg; |
| 1137 | } |
| 1138 | |
| 1139 | /* |
| 1140 | * Need to allocate a group. Allocation of group also needs allocation |
| 1141 | * of per cpu stats which in-turn takes a mutex() and can block. Hence |
| 1142 | * we need to drop rcu lock and queue_lock before we call alloc. |
| 1143 | * |
| 1144 | * Not taking any queue reference here and assuming that queue is |
| 1145 | * around by the time we return. CFQ queue allocation code does |
| 1146 | * the same. It might be racy though. |
| 1147 | */ |
| 1148 | |
| 1149 | rcu_read_unlock(); |
| 1150 | spin_unlock_irq(q->queue_lock); |
| 1151 | |
| 1152 | cfqg = cfq_alloc_cfqg(cfqd); |
| 1153 | |
| 1154 | spin_lock_irq(q->queue_lock); |
| 1155 | |
| 1156 | rcu_read_lock(); |
| 1157 | blkcg = task_blkio_cgroup(current); |
| 1158 | |
| 1159 | /* |
| 1160 | * If some other thread already allocated the group while we were |
| 1161 | * not holding queue lock, free up the group |
| 1162 | */ |
| 1163 | __cfqg = cfq_find_cfqg(cfqd, blkcg); |
| 1164 | |
| 1165 | if (__cfqg) { |
| 1166 | kfree(cfqg); |
| 1167 | rcu_read_unlock(); |
| 1168 | return __cfqg; |
| 1169 | } |
| 1170 | |
Vivek Goyal | 3e59cf9 | 2011-05-19 15:38:21 -0400 | [diff] [blame] | 1171 | if (!cfqg) |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1172 | cfqg = &cfqd->root_group; |
Vivek Goyal | f469a7b | 2011-05-19 15:38:23 -0400 | [diff] [blame] | 1173 | |
| 1174 | cfq_init_add_cfqg_lists(cfqd, cfqg, blkcg); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1175 | rcu_read_unlock(); |
| 1176 | return cfqg; |
| 1177 | } |
| 1178 | |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1179 | static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg) |
| 1180 | { |
Shaohua Li | 329a678 | 2011-01-07 08:48:28 +0100 | [diff] [blame] | 1181 | cfqg->ref++; |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1182 | return cfqg; |
| 1183 | } |
| 1184 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1185 | static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) |
| 1186 | { |
| 1187 | /* Currently, all async queues are mapped to root group */ |
| 1188 | if (!cfq_cfqq_sync(cfqq)) |
| 1189 | cfqg = &cfqq->cfqd->root_group; |
| 1190 | |
| 1191 | cfqq->cfqg = cfqg; |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1192 | /* cfqq reference on cfqg */ |
Shaohua Li | 329a678 | 2011-01-07 08:48:28 +0100 | [diff] [blame] | 1193 | cfqq->cfqg->ref++; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1194 | } |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1195 | |
| 1196 | static void cfq_put_cfqg(struct cfq_group *cfqg) |
| 1197 | { |
| 1198 | struct cfq_rb_root *st; |
| 1199 | int i, j; |
| 1200 | |
Shaohua Li | 329a678 | 2011-01-07 08:48:28 +0100 | [diff] [blame] | 1201 | BUG_ON(cfqg->ref <= 0); |
| 1202 | cfqg->ref--; |
| 1203 | if (cfqg->ref) |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1204 | return; |
| 1205 | for_each_cfqg_st(cfqg, i, j, st) |
Gui Jianfeng | b54ce60 | 2010-11-30 20:52:46 +0100 | [diff] [blame] | 1206 | BUG_ON(!RB_EMPTY_ROOT(&st->rb)); |
Vivek Goyal | 5624a4e | 2011-05-19 15:38:28 -0400 | [diff] [blame] | 1207 | free_percpu(cfqg->blkg.stats_cpu); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1208 | kfree(cfqg); |
| 1209 | } |
| 1210 | |
| 1211 | static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 1212 | { |
| 1213 | /* Something wrong if we are trying to remove same group twice */ |
| 1214 | BUG_ON(hlist_unhashed(&cfqg->cfqd_node)); |
| 1215 | |
| 1216 | hlist_del_init(&cfqg->cfqd_node); |
| 1217 | |
Vivek Goyal | a5395b8 | 2011-08-02 09:24:09 +0200 | [diff] [blame] | 1218 | BUG_ON(cfqd->nr_blkcg_linked_grps <= 0); |
| 1219 | cfqd->nr_blkcg_linked_grps--; |
| 1220 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1221 | /* |
| 1222 | * Put the reference taken at the time of creation so that when all |
| 1223 | * queues are gone, group can be destroyed. |
| 1224 | */ |
| 1225 | cfq_put_cfqg(cfqg); |
| 1226 | } |
| 1227 | |
| 1228 | static void cfq_release_cfq_groups(struct cfq_data *cfqd) |
| 1229 | { |
| 1230 | struct hlist_node *pos, *n; |
| 1231 | struct cfq_group *cfqg; |
| 1232 | |
| 1233 | hlist_for_each_entry_safe(cfqg, pos, n, &cfqd->cfqg_list, cfqd_node) { |
| 1234 | /* |
| 1235 | * If cgroup removal path got to blk_group first and removed |
| 1236 | * it from cgroup list, then it will take care of destroying |
| 1237 | * cfqg also. |
| 1238 | */ |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 1239 | if (!cfq_blkiocg_del_blkio_group(&cfqg->blkg)) |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1240 | cfq_destroy_cfqg(cfqd, cfqg); |
| 1241 | } |
| 1242 | } |
| 1243 | |
| 1244 | /* |
| 1245 | * Blk cgroup controller notification saying that blkio_group object is being |
| 1246 | * delinked as associated cgroup object is going away. That also means that |
| 1247 | * no new IO will come in this group. So get rid of this group as soon as |
| 1248 | * any pending IO in the group is finished. |
| 1249 | * |
| 1250 | * This function is called under rcu_read_lock(). key is the rcu protected |
| 1251 | * pointer. That means "key" is a valid cfq_data pointer as long as we are rcu |
| 1252 | * read lock. |
| 1253 | * |
| 1254 | * "key" was fetched from blkio_group under blkio_cgroup->lock. That means |
| 1255 | * it should not be NULL as even if elevator was exiting, cgroup deltion |
| 1256 | * path got to it first. |
| 1257 | */ |
Paul Bolle | 8aea454 | 2011-06-06 05:07:54 +0200 | [diff] [blame] | 1258 | static void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg) |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1259 | { |
| 1260 | unsigned long flags; |
| 1261 | struct cfq_data *cfqd = key; |
| 1262 | |
| 1263 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 1264 | cfq_destroy_cfqg(cfqd, cfqg_of_blkg(blkg)); |
| 1265 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 1266 | } |
| 1267 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1268 | #else /* GROUP_IOSCHED */ |
Vivek Goyal | 3e59cf9 | 2011-05-19 15:38:21 -0400 | [diff] [blame] | 1269 | static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd) |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1270 | { |
| 1271 | return &cfqd->root_group; |
| 1272 | } |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1273 | |
| 1274 | static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg) |
| 1275 | { |
Dmitry Monakhov | 50eaeb3 | 2010-04-28 19:50:33 +0200 | [diff] [blame] | 1276 | return cfqg; |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1277 | } |
| 1278 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1279 | static inline void |
| 1280 | cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { |
| 1281 | cfqq->cfqg = cfqg; |
| 1282 | } |
| 1283 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1284 | static void cfq_release_cfq_groups(struct cfq_data *cfqd) {} |
| 1285 | static inline void cfq_put_cfqg(struct cfq_group *cfqg) {} |
| 1286 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1287 | #endif /* GROUP_IOSCHED */ |
| 1288 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1289 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1290 | * The cfqd->service_trees holds all pending cfq_queue's that have |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1291 | * requests waiting to be processed. It is sorted in the order that |
| 1292 | * we will service the queues. |
| 1293 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1294 | static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1295 | bool add_front) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1296 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1297 | struct rb_node **p, *parent; |
| 1298 | struct cfq_queue *__cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1299 | unsigned long rb_key; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1300 | struct cfq_rb_root *service_tree; |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1301 | int left; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1302 | int new_cfqq = 1; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 1303 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1304 | service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq), |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 1305 | cfqq_type(cfqq)); |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1306 | if (cfq_class_idle(cfqq)) { |
| 1307 | rb_key = CFQ_IDLE_DELAY; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1308 | parent = rb_last(&service_tree->rb); |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1309 | if (parent && parent != &cfqq->rb_node) { |
| 1310 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 1311 | rb_key += __cfqq->rb_key; |
| 1312 | } else |
| 1313 | rb_key += jiffies; |
| 1314 | } else if (!add_front) { |
Jens Axboe | b9c8946 | 2009-10-06 20:53:44 +0200 | [diff] [blame] | 1315 | /* |
| 1316 | * Get our rb key offset. Subtract any residual slice |
| 1317 | * value carried from last service. A negative resid |
| 1318 | * count indicates slice overrun, and this should position |
| 1319 | * the next service time further away in the tree. |
| 1320 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1321 | rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; |
Jens Axboe | b9c8946 | 2009-10-06 20:53:44 +0200 | [diff] [blame] | 1322 | rb_key -= cfqq->slice_resid; |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1323 | cfqq->slice_resid = 0; |
Corrado Zoccolo | 48e025e | 2009-10-05 08:49:23 +0200 | [diff] [blame] | 1324 | } else { |
| 1325 | rb_key = -HZ; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1326 | __cfqq = cfq_rb_first(service_tree); |
Corrado Zoccolo | 48e025e | 2009-10-05 08:49:23 +0200 | [diff] [blame] | 1327 | rb_key += __cfqq ? __cfqq->rb_key : jiffies; |
| 1328 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1329 | |
| 1330 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1331 | new_cfqq = 0; |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 1332 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1333 | * same position, nothing more to do |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 1334 | */ |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1335 | if (rb_key == cfqq->rb_key && |
| 1336 | cfqq->service_tree == service_tree) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1337 | return; |
Jens Axboe | 53b0374 | 2006-07-28 09:48:51 +0200 | [diff] [blame] | 1338 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1339 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
| 1340 | cfqq->service_tree = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1341 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1342 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1343 | left = 1; |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1344 | parent = NULL; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1345 | cfqq->service_tree = service_tree; |
| 1346 | p = &service_tree->rb.rb_node; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1347 | while (*p) { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1348 | struct rb_node **n; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1349 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1350 | parent = *p; |
| 1351 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 1352 | |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 1353 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1354 | * sort by key, that represents service time. |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 1355 | */ |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1356 | if (time_before(rb_key, __cfqq->rb_key)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1357 | n = &(*p)->rb_left; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1358 | else { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1359 | n = &(*p)->rb_right; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1360 | left = 0; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1361 | } |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1362 | |
| 1363 | p = n; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1364 | } |
| 1365 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1366 | if (left) |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1367 | service_tree->left = &cfqq->rb_node; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1368 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1369 | cfqq->rb_key = rb_key; |
| 1370 | rb_link_node(&cfqq->rb_node, parent, p); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1371 | rb_insert_color(&cfqq->rb_node, &service_tree->rb); |
| 1372 | service_tree->count++; |
Namhyung Kim | 20359f2 | 2011-05-24 10:23:22 +0200 | [diff] [blame] | 1373 | if (add_front || !new_cfqq) |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1374 | return; |
Justin TerAvest | 8184f93 | 2011-03-17 16:12:36 +0100 | [diff] [blame] | 1375 | cfq_group_notify_queue_add(cfqd, cfqq->cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1376 | } |
| 1377 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1378 | static struct cfq_queue * |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1379 | cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, |
| 1380 | sector_t sector, struct rb_node **ret_parent, |
| 1381 | struct rb_node ***rb_link) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1382 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1383 | struct rb_node **p, *parent; |
| 1384 | struct cfq_queue *cfqq = NULL; |
| 1385 | |
| 1386 | parent = NULL; |
| 1387 | p = &root->rb_node; |
| 1388 | while (*p) { |
| 1389 | struct rb_node **n; |
| 1390 | |
| 1391 | parent = *p; |
| 1392 | cfqq = rb_entry(parent, struct cfq_queue, p_node); |
| 1393 | |
| 1394 | /* |
| 1395 | * Sort strictly based on sector. Smallest to the left, |
| 1396 | * largest to the right. |
| 1397 | */ |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1398 | if (sector > blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1399 | n = &(*p)->rb_right; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1400 | else if (sector < blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1401 | n = &(*p)->rb_left; |
| 1402 | else |
| 1403 | break; |
| 1404 | p = n; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1405 | cfqq = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1406 | } |
| 1407 | |
| 1408 | *ret_parent = parent; |
| 1409 | if (rb_link) |
| 1410 | *rb_link = p; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1411 | return cfqq; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1412 | } |
| 1413 | |
| 1414 | static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1415 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1416 | struct rb_node **p, *parent; |
| 1417 | struct cfq_queue *__cfqq; |
| 1418 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1419 | if (cfqq->p_root) { |
| 1420 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1421 | cfqq->p_root = NULL; |
| 1422 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1423 | |
| 1424 | if (cfq_class_idle(cfqq)) |
| 1425 | return; |
| 1426 | if (!cfqq->next_rq) |
| 1427 | return; |
| 1428 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1429 | cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1430 | __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, |
| 1431 | blk_rq_pos(cfqq->next_rq), &parent, &p); |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1432 | if (!__cfqq) { |
| 1433 | rb_link_node(&cfqq->p_node, parent, p); |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1434 | rb_insert_color(&cfqq->p_node, cfqq->p_root); |
| 1435 | } else |
| 1436 | cfqq->p_root = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1437 | } |
| 1438 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1439 | /* |
| 1440 | * Update cfqq's position in the service tree. |
| 1441 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1442 | static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1443 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1444 | /* |
| 1445 | * Resorting requires the cfqq to be on the RR list already. |
| 1446 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1447 | if (cfq_cfqq_on_rr(cfqq)) { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1448 | cfq_service_tree_add(cfqd, cfqq, 0); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1449 | cfq_prio_tree_add(cfqd, cfqq); |
| 1450 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1451 | } |
| 1452 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1453 | /* |
| 1454 | * add to busy list of queues for service, trying to be fair in ordering |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1455 | * the pending list according to last request service |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1456 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1457 | static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1458 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1459 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1460 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
| 1461 | cfq_mark_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1462 | cfqd->busy_queues++; |
Shaohua Li | ef8a41d | 2011-03-07 09:26:29 +0100 | [diff] [blame] | 1463 | if (cfq_cfqq_sync(cfqq)) |
| 1464 | cfqd->busy_sync_queues++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1465 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1466 | cfq_resort_rr_list(cfqd, cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1467 | } |
| 1468 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1469 | /* |
| 1470 | * Called when the cfqq no longer has requests pending, remove it from |
| 1471 | * the service tree. |
| 1472 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1473 | static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1474 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1475 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1476 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
| 1477 | cfq_clear_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1478 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1479 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
| 1480 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
| 1481 | cfqq->service_tree = NULL; |
| 1482 | } |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1483 | if (cfqq->p_root) { |
| 1484 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1485 | cfqq->p_root = NULL; |
| 1486 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1487 | |
Justin TerAvest | 8184f93 | 2011-03-17 16:12:36 +0100 | [diff] [blame] | 1488 | cfq_group_notify_queue_del(cfqd, cfqq->cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1489 | BUG_ON(!cfqd->busy_queues); |
| 1490 | cfqd->busy_queues--; |
Shaohua Li | ef8a41d | 2011-03-07 09:26:29 +0100 | [diff] [blame] | 1491 | if (cfq_cfqq_sync(cfqq)) |
| 1492 | cfqd->busy_sync_queues--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1493 | } |
| 1494 | |
| 1495 | /* |
| 1496 | * rb tree support functions |
| 1497 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1498 | static void cfq_del_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1499 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1500 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1501 | const int sync = rq_is_sync(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1502 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1503 | BUG_ON(!cfqq->queued[sync]); |
| 1504 | cfqq->queued[sync]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1505 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1506 | elv_rb_del(&cfqq->sort_list, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1507 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1508 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) { |
| 1509 | /* |
| 1510 | * Queue will be deleted from service tree when we actually |
| 1511 | * expire it later. Right now just remove it from prio tree |
| 1512 | * as it is empty. |
| 1513 | */ |
| 1514 | if (cfqq->p_root) { |
| 1515 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1516 | cfqq->p_root = NULL; |
| 1517 | } |
| 1518 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1519 | } |
| 1520 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1521 | static void cfq_add_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1522 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1523 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1524 | struct cfq_data *cfqd = cfqq->cfqd; |
Jeff Moyer | 796d511 | 2011-06-02 21:19:05 +0200 | [diff] [blame] | 1525 | struct request *prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1526 | |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1527 | cfqq->queued[rq_is_sync(rq)]++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1528 | |
Jeff Moyer | 796d511 | 2011-06-02 21:19:05 +0200 | [diff] [blame] | 1529 | elv_rb_add(&cfqq->sort_list, rq); |
Jens Axboe | 5fccbf6 | 2006-10-31 14:21:55 +0100 | [diff] [blame] | 1530 | |
| 1531 | if (!cfq_cfqq_on_rr(cfqq)) |
| 1532 | cfq_add_cfqq_rr(cfqd, cfqq); |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 1533 | |
| 1534 | /* |
| 1535 | * check if this request is a better next-serve candidate |
| 1536 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1537 | prev = cfqq->next_rq; |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1538 | cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq, cfqd->last_position); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1539 | |
| 1540 | /* |
| 1541 | * adjust priority tree position, if ->next_rq changes |
| 1542 | */ |
| 1543 | if (prev != cfqq->next_rq) |
| 1544 | cfq_prio_tree_add(cfqd, cfqq); |
| 1545 | |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 1546 | BUG_ON(!cfqq->next_rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1547 | } |
| 1548 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1549 | static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1550 | { |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1551 | elv_rb_del(&cfqq->sort_list, rq); |
| 1552 | cfqq->queued[rq_is_sync(rq)]--; |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 1553 | cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, |
| 1554 | rq_data_dir(rq), rq_is_sync(rq)); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1555 | cfq_add_rq_rb(rq); |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 1556 | cfq_blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg, |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1557 | &cfqq->cfqd->serving_group->blkg, rq_data_dir(rq), |
| 1558 | rq_is_sync(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1559 | } |
| 1560 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1561 | static struct request * |
| 1562 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1563 | { |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1564 | struct task_struct *tsk = current; |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 1565 | struct cfq_io_cq *cic; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1566 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1567 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1568 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1569 | if (!cic) |
| 1570 | return NULL; |
| 1571 | |
| 1572 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1573 | if (cfqq) { |
| 1574 | sector_t sector = bio->bi_sector + bio_sectors(bio); |
| 1575 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1576 | return elv_rb_find(&cfqq->sort_list, sector); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1577 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1578 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1579 | return NULL; |
| 1580 | } |
| 1581 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1582 | static void cfq_activate_request(struct request_queue *q, struct request *rq) |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1583 | { |
| 1584 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1585 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1586 | cfqd->rq_in_driver++; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1587 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1588 | cfqd->rq_in_driver); |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 1589 | |
Tejun Heo | 5b93629 | 2009-05-07 22:24:38 +0900 | [diff] [blame] | 1590 | cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1591 | } |
| 1592 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1593 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1594 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1595 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1596 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1597 | WARN_ON(!cfqd->rq_in_driver); |
| 1598 | cfqd->rq_in_driver--; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1599 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1600 | cfqd->rq_in_driver); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1601 | } |
| 1602 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1603 | static void cfq_remove_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1604 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1605 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1606 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1607 | if (cfqq->next_rq == rq) |
| 1608 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1609 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1610 | list_del_init(&rq->queuelist); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1611 | cfq_del_rq_rb(rq); |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 1612 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 1613 | cfqq->cfqd->rq_queued--; |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 1614 | cfq_blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, |
| 1615 | rq_data_dir(rq), rq_is_sync(rq)); |
Christoph Hellwig | 65299a3 | 2011-08-23 14:50:29 +0200 | [diff] [blame] | 1616 | if (rq->cmd_flags & REQ_PRIO) { |
| 1617 | WARN_ON(!cfqq->prio_pending); |
| 1618 | cfqq->prio_pending--; |
Jens Axboe | b53d1ed | 2011-08-19 08:34:48 +0200 | [diff] [blame] | 1619 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1620 | } |
| 1621 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1622 | static int cfq_merge(struct request_queue *q, struct request **req, |
| 1623 | struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1624 | { |
| 1625 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1626 | struct request *__rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1627 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1628 | __rq = cfq_find_rq_fmerge(cfqd, bio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1629 | if (__rq && elv_rq_merge_ok(__rq, bio)) { |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 1630 | *req = __rq; |
| 1631 | return ELEVATOR_FRONT_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1632 | } |
| 1633 | |
| 1634 | return ELEVATOR_NO_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1635 | } |
| 1636 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1637 | static void cfq_merged_request(struct request_queue *q, struct request *req, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1638 | int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1639 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1640 | if (type == ELEVATOR_FRONT_MERGE) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1641 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1642 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1643 | cfq_reposition_rq_rb(cfqq, req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1644 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1645 | } |
| 1646 | |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 1647 | static void cfq_bio_merged(struct request_queue *q, struct request *req, |
| 1648 | struct bio *bio) |
| 1649 | { |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 1650 | cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(req))->blkg, |
| 1651 | bio_data_dir(bio), cfq_bio_sync(bio)); |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 1652 | } |
| 1653 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1654 | static void |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1655 | cfq_merged_requests(struct request_queue *q, struct request *rq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1656 | struct request *next) |
| 1657 | { |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1658 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Shaohua Li | 4a0b75c | 2011-12-16 14:00:22 +0100 | [diff] [blame] | 1659 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1660 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1661 | /* |
| 1662 | * reposition in fifo if next is older than rq |
| 1663 | */ |
| 1664 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1665 | time_before(rq_fifo_time(next), rq_fifo_time(rq))) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1666 | list_move(&rq->queuelist, &next->queuelist); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1667 | rq_set_fifo_time(rq, rq_fifo_time(next)); |
| 1668 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1669 | |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1670 | if (cfqq->next_rq == next) |
| 1671 | cfqq->next_rq = rq; |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1672 | cfq_remove_request(next); |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 1673 | cfq_blkiocg_update_io_merged_stats(&(RQ_CFQG(rq))->blkg, |
| 1674 | rq_data_dir(next), rq_is_sync(next)); |
Shaohua Li | 4a0b75c | 2011-12-16 14:00:22 +0100 | [diff] [blame] | 1675 | |
| 1676 | cfqq = RQ_CFQQ(next); |
| 1677 | /* |
| 1678 | * all requests of this queue are merged to other queues, delete it |
| 1679 | * from the service tree. If it's the active_queue, |
| 1680 | * cfq_dispatch_requests() will choose to expire it or do idle |
| 1681 | */ |
| 1682 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list) && |
| 1683 | cfqq != cfqd->active_queue) |
| 1684 | cfq_del_cfqq_rr(cfqd, cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1685 | } |
| 1686 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1687 | static int cfq_allow_merge(struct request_queue *q, struct request *rq, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1688 | struct bio *bio) |
| 1689 | { |
| 1690 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 1691 | struct cfq_io_cq *cic; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1692 | struct cfq_queue *cfqq; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1693 | |
| 1694 | /* |
Jens Axboe | ec8acb6 | 2007-01-02 18:32:11 +0100 | [diff] [blame] | 1695 | * Disallow merge of a sync bio into an async request. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1696 | */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1697 | if (cfq_bio_sync(bio) && !rq_is_sync(rq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1698 | return false; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1699 | |
| 1700 | /* |
Tejun Heo | f1a4f4d | 2011-12-14 00:33:39 +0100 | [diff] [blame] | 1701 | * Lookup the cfqq that this bio will be queued with and allow |
Tejun Heo | 07c2bd3 | 2012-02-08 09:19:42 +0100 | [diff] [blame] | 1702 | * merge only if rq is queued there. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1703 | */ |
Tejun Heo | 07c2bd3 | 2012-02-08 09:19:42 +0100 | [diff] [blame] | 1704 | cic = cfq_cic_lookup(cfqd, current->io_context); |
| 1705 | if (!cic) |
| 1706 | return false; |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 1707 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1708 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1709 | return cfqq == RQ_CFQQ(rq); |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1710 | } |
| 1711 | |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1712 | static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1713 | { |
| 1714 | del_timer(&cfqd->idle_slice_timer); |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 1715 | cfq_blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg); |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1716 | } |
| 1717 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1718 | static void __cfq_set_active_queue(struct cfq_data *cfqd, |
| 1719 | struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1720 | { |
| 1721 | if (cfqq) { |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 1722 | cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d", |
| 1723 | cfqd->serving_prio, cfqd->serving_type); |
Justin TerAvest | 62a37f6 | 2011-03-23 08:25:44 +0100 | [diff] [blame] | 1724 | cfq_blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg); |
| 1725 | cfqq->slice_start = 0; |
| 1726 | cfqq->dispatch_start = jiffies; |
| 1727 | cfqq->allocated_slice = 0; |
| 1728 | cfqq->slice_end = 0; |
| 1729 | cfqq->slice_dispatch = 0; |
| 1730 | cfqq->nr_sectors = 0; |
| 1731 | |
| 1732 | cfq_clear_cfqq_wait_request(cfqq); |
| 1733 | cfq_clear_cfqq_must_dispatch(cfqq); |
| 1734 | cfq_clear_cfqq_must_alloc_slice(cfqq); |
| 1735 | cfq_clear_cfqq_fifo_expire(cfqq); |
| 1736 | cfq_mark_cfqq_slice_new(cfqq); |
| 1737 | |
| 1738 | cfq_del_timer(cfqd, cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1739 | } |
| 1740 | |
| 1741 | cfqd->active_queue = cfqq; |
| 1742 | } |
| 1743 | |
| 1744 | /* |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1745 | * current cfqq expired its slice (or was too idle), select new one |
| 1746 | */ |
| 1747 | static void |
| 1748 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 1749 | bool timed_out) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1750 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1751 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); |
| 1752 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1753 | if (cfq_cfqq_wait_request(cfqq)) |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1754 | cfq_del_timer(cfqd, cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1755 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1756 | cfq_clear_cfqq_wait_request(cfqq); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 1757 | cfq_clear_cfqq_wait_busy(cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1758 | |
| 1759 | /* |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 1760 | * If this cfqq is shared between multiple processes, check to |
| 1761 | * make sure that those processes are still issuing I/Os within |
| 1762 | * the mean seek distance. If not, it may be time to break the |
| 1763 | * queues apart again. |
| 1764 | */ |
| 1765 | if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq)) |
| 1766 | cfq_mark_cfqq_split_coop(cfqq); |
| 1767 | |
| 1768 | /* |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1769 | * store what was left of this slice, if the queue idled/timed out |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1770 | */ |
Shaohua Li | c553f8e | 2011-01-14 08:41:03 +0100 | [diff] [blame] | 1771 | if (timed_out) { |
| 1772 | if (cfq_cfqq_slice_new(cfqq)) |
Vivek Goyal | ba5bd52 | 2011-01-19 08:25:02 -0700 | [diff] [blame] | 1773 | cfqq->slice_resid = cfq_scaled_cfqq_slice(cfqd, cfqq); |
Shaohua Li | c553f8e | 2011-01-14 08:41:03 +0100 | [diff] [blame] | 1774 | else |
| 1775 | cfqq->slice_resid = cfqq->slice_end - jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1776 | cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); |
| 1777 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1778 | |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 1779 | cfq_group_served(cfqd, cfqq->cfqg, cfqq); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1780 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1781 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 1782 | cfq_del_cfqq_rr(cfqd, cfqq); |
| 1783 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1784 | cfq_resort_rr_list(cfqd, cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1785 | |
| 1786 | if (cfqq == cfqd->active_queue) |
| 1787 | cfqd->active_queue = NULL; |
| 1788 | |
| 1789 | if (cfqd->active_cic) { |
Tejun Heo | 11a3122 | 2012-02-07 07:51:30 +0100 | [diff] [blame] | 1790 | put_io_context(cfqd->active_cic->icq.ioc); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1791 | cfqd->active_cic = NULL; |
| 1792 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1793 | } |
| 1794 | |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 1795 | static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1796 | { |
| 1797 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 1798 | |
| 1799 | if (cfqq) |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 1800 | __cfq_slice_expired(cfqd, cfqq, timed_out); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1801 | } |
| 1802 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1803 | /* |
| 1804 | * Get next queue for service. Unless we have a queue preemption, |
| 1805 | * we'll simply select the first cfqq in the service tree. |
| 1806 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1807 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1808 | { |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1809 | struct cfq_rb_root *service_tree = |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1810 | service_tree_for(cfqd->serving_group, cfqd->serving_prio, |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 1811 | cfqd->serving_type); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1812 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1813 | if (!cfqd->rq_queued) |
| 1814 | return NULL; |
| 1815 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1816 | /* There is nothing to dispatch */ |
| 1817 | if (!service_tree) |
| 1818 | return NULL; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1819 | if (RB_EMPTY_ROOT(&service_tree->rb)) |
| 1820 | return NULL; |
| 1821 | return cfq_rb_first(service_tree); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1822 | } |
| 1823 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1824 | static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd) |
| 1825 | { |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1826 | struct cfq_group *cfqg; |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1827 | struct cfq_queue *cfqq; |
| 1828 | int i, j; |
| 1829 | struct cfq_rb_root *st; |
| 1830 | |
| 1831 | if (!cfqd->rq_queued) |
| 1832 | return NULL; |
| 1833 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1834 | cfqg = cfq_get_next_cfqg(cfqd); |
| 1835 | if (!cfqg) |
| 1836 | return NULL; |
| 1837 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1838 | for_each_cfqg_st(cfqg, i, j, st) |
| 1839 | if ((cfqq = cfq_rb_first(st)) != NULL) |
| 1840 | return cfqq; |
| 1841 | return NULL; |
| 1842 | } |
| 1843 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1844 | /* |
| 1845 | * Get and set a new active queue for service. |
| 1846 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1847 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, |
| 1848 | struct cfq_queue *cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1849 | { |
Jens Axboe | e00ef79 | 2009-11-04 08:54:55 +0100 | [diff] [blame] | 1850 | if (!cfqq) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1851 | cfqq = cfq_get_next_queue(cfqd); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1852 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1853 | __cfq_set_active_queue(cfqd, cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1854 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1855 | } |
| 1856 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1857 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, |
| 1858 | struct request *rq) |
| 1859 | { |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1860 | if (blk_rq_pos(rq) >= cfqd->last_position) |
| 1861 | return blk_rq_pos(rq) - cfqd->last_position; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1862 | else |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1863 | return cfqd->last_position - blk_rq_pos(rq); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1864 | } |
| 1865 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 1866 | static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 1867 | struct request *rq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1868 | { |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 1869 | return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1870 | } |
| 1871 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1872 | static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, |
| 1873 | struct cfq_queue *cur_cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1874 | { |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1875 | struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1876 | struct rb_node *parent, *node; |
| 1877 | struct cfq_queue *__cfqq; |
| 1878 | sector_t sector = cfqd->last_position; |
| 1879 | |
| 1880 | if (RB_EMPTY_ROOT(root)) |
| 1881 | return NULL; |
| 1882 | |
| 1883 | /* |
| 1884 | * First, if we find a request starting at the end of the last |
| 1885 | * request, choose it. |
| 1886 | */ |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1887 | __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1888 | if (__cfqq) |
| 1889 | return __cfqq; |
| 1890 | |
| 1891 | /* |
| 1892 | * If the exact sector wasn't found, the parent of the NULL leaf |
| 1893 | * will contain the closest sector. |
| 1894 | */ |
| 1895 | __cfqq = rb_entry(parent, struct cfq_queue, p_node); |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 1896 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1897 | return __cfqq; |
| 1898 | |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1899 | if (blk_rq_pos(__cfqq->next_rq) < sector) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1900 | node = rb_next(&__cfqq->p_node); |
| 1901 | else |
| 1902 | node = rb_prev(&__cfqq->p_node); |
| 1903 | if (!node) |
| 1904 | return NULL; |
| 1905 | |
| 1906 | __cfqq = rb_entry(node, struct cfq_queue, p_node); |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 1907 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1908 | return __cfqq; |
| 1909 | |
| 1910 | return NULL; |
| 1911 | } |
| 1912 | |
| 1913 | /* |
| 1914 | * cfqd - obvious |
| 1915 | * cur_cfqq - passed in so that we don't decide that the current queue is |
| 1916 | * closely cooperating with itself. |
| 1917 | * |
| 1918 | * So, basically we're assuming that that cur_cfqq has dispatched at least |
| 1919 | * one request, and that cfqd->last_position reflects a position on the disk |
| 1920 | * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid |
| 1921 | * assumption. |
| 1922 | */ |
| 1923 | static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 1924 | struct cfq_queue *cur_cfqq) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1925 | { |
| 1926 | struct cfq_queue *cfqq; |
| 1927 | |
Divyesh Shah | 39c01b2 | 2010-03-25 15:45:57 +0100 | [diff] [blame] | 1928 | if (cfq_class_idle(cur_cfqq)) |
| 1929 | return NULL; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1930 | if (!cfq_cfqq_sync(cur_cfqq)) |
| 1931 | return NULL; |
| 1932 | if (CFQQ_SEEKY(cur_cfqq)) |
| 1933 | return NULL; |
| 1934 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1935 | /* |
Gui Jianfeng | b9d8f4c | 2009-12-08 08:54:17 +0100 | [diff] [blame] | 1936 | * Don't search priority tree if it's the only queue in the group. |
| 1937 | */ |
| 1938 | if (cur_cfqq->cfqg->nr_cfqq == 1) |
| 1939 | return NULL; |
| 1940 | |
| 1941 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1942 | * We should notice if some of the queues are cooperating, eg |
| 1943 | * working closely on the same area of the disk. In that case, |
| 1944 | * we can group them together and don't waste time idling. |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1945 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1946 | cfqq = cfqq_close(cfqd, cur_cfqq); |
| 1947 | if (!cfqq) |
| 1948 | return NULL; |
| 1949 | |
Vivek Goyal | 8682e1f | 2009-12-03 12:59:50 -0500 | [diff] [blame] | 1950 | /* If new queue belongs to different cfq_group, don't choose it */ |
| 1951 | if (cur_cfqq->cfqg != cfqq->cfqg) |
| 1952 | return NULL; |
| 1953 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1954 | /* |
| 1955 | * It only makes sense to merge sync queues. |
| 1956 | */ |
| 1957 | if (!cfq_cfqq_sync(cfqq)) |
| 1958 | return NULL; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1959 | if (CFQQ_SEEKY(cfqq)) |
| 1960 | return NULL; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1961 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1962 | /* |
| 1963 | * Do not merge queues of different priority classes |
| 1964 | */ |
| 1965 | if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq)) |
| 1966 | return NULL; |
| 1967 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1968 | return cfqq; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1969 | } |
| 1970 | |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1971 | /* |
| 1972 | * Determine whether we should enforce idle window for this queue. |
| 1973 | */ |
| 1974 | |
| 1975 | static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1976 | { |
| 1977 | enum wl_prio_t prio = cfqq_prio(cfqq); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1978 | struct cfq_rb_root *service_tree = cfqq->service_tree; |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1979 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1980 | BUG_ON(!service_tree); |
| 1981 | BUG_ON(!service_tree->count); |
| 1982 | |
Vivek Goyal | b6508c1 | 2010-08-23 12:23:33 +0200 | [diff] [blame] | 1983 | if (!cfqd->cfq_slice_idle) |
| 1984 | return false; |
| 1985 | |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1986 | /* We never do for idle class queues. */ |
| 1987 | if (prio == IDLE_WORKLOAD) |
| 1988 | return false; |
| 1989 | |
| 1990 | /* We do for queues that were marked with idle window flag. */ |
Shaohua Li | 3c764b7 | 2009-12-04 13:12:06 +0100 | [diff] [blame] | 1991 | if (cfq_cfqq_idle_window(cfqq) && |
| 1992 | !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)) |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1993 | return true; |
| 1994 | |
| 1995 | /* |
| 1996 | * Otherwise, we do only if they are the last ones |
| 1997 | * in their service tree. |
| 1998 | */ |
Shaohua Li | f5f2b6c | 2011-07-12 14:24:55 +0200 | [diff] [blame] | 1999 | if (service_tree->count == 1 && cfq_cfqq_sync(cfqq) && |
| 2000 | !cfq_io_thinktime_big(cfqd, &service_tree->ttime, false)) |
Shaohua Li | c1e4475 | 2010-11-08 15:01:02 +0100 | [diff] [blame] | 2001 | return true; |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 2002 | cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", |
| 2003 | service_tree->count); |
Shaohua Li | c1e4475 | 2010-11-08 15:01:02 +0100 | [diff] [blame] | 2004 | return false; |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 2005 | } |
| 2006 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2007 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2008 | { |
Jens Axboe | 1792669 | 2007-01-19 11:59:30 +1100 | [diff] [blame] | 2009 | struct cfq_queue *cfqq = cfqd->active_queue; |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2010 | struct cfq_io_cq *cic; |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 2011 | unsigned long sl, group_idle = 0; |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 2012 | |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 2013 | /* |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 2014 | * SSD device without seek penalty, disable idling. But only do so |
| 2015 | * for devices that support queuing, otherwise we still have a problem |
| 2016 | * with sync vs async workloads. |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 2017 | */ |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 2018 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 2019 | return; |
| 2020 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 2021 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2022 | WARN_ON(cfq_cfqq_slice_new(cfqq)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2023 | |
| 2024 | /* |
| 2025 | * idle is disabled, either manually or by past process history |
| 2026 | */ |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 2027 | if (!cfq_should_idle(cfqd, cfqq)) { |
| 2028 | /* no queue idling. Check for group idling */ |
| 2029 | if (cfqd->cfq_group_idle) |
| 2030 | group_idle = cfqd->cfq_group_idle; |
| 2031 | else |
| 2032 | return; |
| 2033 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2034 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2035 | /* |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 2036 | * still active requests from this queue, don't idle |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2037 | */ |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 2038 | if (cfqq->dispatched) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2039 | return; |
| 2040 | |
| 2041 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2042 | * task has exited, don't wait |
| 2043 | */ |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 2044 | cic = cfqd->active_cic; |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2045 | if (!cic || !atomic_read(&cic->icq.ioc->nr_tasks)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2046 | return; |
| 2047 | |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 2048 | /* |
| 2049 | * If our average think time is larger than the remaining time |
| 2050 | * slice, then don't idle. This avoids overrunning the allotted |
| 2051 | * time slice. |
| 2052 | */ |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 2053 | if (sample_valid(cic->ttime.ttime_samples) && |
| 2054 | (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) { |
Joe Perches | fd16d26 | 2011-06-13 10:42:49 +0200 | [diff] [blame] | 2055 | cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%lu", |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 2056 | cic->ttime.ttime_mean); |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 2057 | return; |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 2058 | } |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 2059 | |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 2060 | /* There are other queues in the group, don't do group idle */ |
| 2061 | if (group_idle && cfqq->cfqg->nr_cfqq > 1) |
| 2062 | return; |
| 2063 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2064 | cfq_mark_cfqq_wait_request(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2065 | |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 2066 | if (group_idle) |
| 2067 | sl = cfqd->cfq_group_idle; |
| 2068 | else |
| 2069 | sl = cfqd->cfq_slice_idle; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 2070 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 2071 | mod_timer(&cfqd->idle_slice_timer, jiffies + sl); |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 2072 | cfq_blkiocg_update_set_idle_time_stats(&cfqq->cfqg->blkg); |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 2073 | cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu group_idle: %d", sl, |
| 2074 | group_idle ? 1 : 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2075 | } |
| 2076 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2077 | /* |
| 2078 | * Move request from internal lists to the request queue dispatch list. |
| 2079 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2080 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2081 | { |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2082 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2083 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2084 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2085 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); |
| 2086 | |
Jeff Moyer | 06d2188 | 2009-09-11 17:08:59 +0200 | [diff] [blame] | 2087 | cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 2088 | cfq_remove_request(rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2089 | cfqq->dispatched++; |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 2090 | (RQ_CFQG(rq))->dispatched++; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 2091 | elv_dispatch_sort(q, rq); |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2092 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 2093 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++; |
Vivek Goyal | c4e7893 | 2010-08-23 12:25:03 +0200 | [diff] [blame] | 2094 | cfqq->nr_sectors += blk_rq_sectors(rq); |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 2095 | cfq_blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq), |
Divyesh Shah | 84c124d | 2010-04-09 08:31:19 +0200 | [diff] [blame] | 2096 | rq_data_dir(rq), rq_is_sync(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2097 | } |
| 2098 | |
| 2099 | /* |
| 2100 | * return expired entry, or NULL to just start from scratch in rbtree |
| 2101 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2102 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2103 | { |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 2104 | struct request *rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2105 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2106 | if (cfq_cfqq_fifo_expire(cfqq)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2107 | return NULL; |
Jens Axboe | cb88741 | 2007-01-19 12:01:16 +1100 | [diff] [blame] | 2108 | |
| 2109 | cfq_mark_cfqq_fifo_expire(cfqq); |
| 2110 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2111 | if (list_empty(&cfqq->fifo)) |
| 2112 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2113 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2114 | rq = rq_entry_fifo(cfqq->fifo.next); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 2115 | if (time_before(jiffies, rq_fifo_time(rq))) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2116 | rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2117 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 2118 | cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2119 | return rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2120 | } |
| 2121 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2122 | static inline int |
| 2123 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2124 | { |
| 2125 | const int base_rq = cfqd->cfq_slice_async_rq; |
| 2126 | |
| 2127 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); |
| 2128 | |
Namhyung Kim | b9f8ce0 | 2011-05-24 10:23:21 +0200 | [diff] [blame] | 2129 | return 2 * base_rq * (IOPRIO_BE_NR - cfqq->ioprio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2130 | } |
| 2131 | |
| 2132 | /* |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2133 | * Must be called with the queue_lock held. |
| 2134 | */ |
| 2135 | static int cfqq_process_refs(struct cfq_queue *cfqq) |
| 2136 | { |
| 2137 | int process_refs, io_refs; |
| 2138 | |
| 2139 | io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE]; |
Shaohua Li | 30d7b94 | 2011-01-07 08:46:59 +0100 | [diff] [blame] | 2140 | process_refs = cfqq->ref - io_refs; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2141 | BUG_ON(process_refs < 0); |
| 2142 | return process_refs; |
| 2143 | } |
| 2144 | |
| 2145 | static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) |
| 2146 | { |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 2147 | int process_refs, new_process_refs; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2148 | struct cfq_queue *__cfqq; |
| 2149 | |
Jeff Moyer | c10b61f | 2010-06-17 10:19:11 -0400 | [diff] [blame] | 2150 | /* |
| 2151 | * If there are no process references on the new_cfqq, then it is |
| 2152 | * unsafe to follow the ->new_cfqq chain as other cfqq's in the |
| 2153 | * chain may have dropped their last reference (not just their |
| 2154 | * last process reference). |
| 2155 | */ |
| 2156 | if (!cfqq_process_refs(new_cfqq)) |
| 2157 | return; |
| 2158 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2159 | /* Avoid a circular list and skip interim queue merges */ |
| 2160 | while ((__cfqq = new_cfqq->new_cfqq)) { |
| 2161 | if (__cfqq == cfqq) |
| 2162 | return; |
| 2163 | new_cfqq = __cfqq; |
| 2164 | } |
| 2165 | |
| 2166 | process_refs = cfqq_process_refs(cfqq); |
Jeff Moyer | c10b61f | 2010-06-17 10:19:11 -0400 | [diff] [blame] | 2167 | new_process_refs = cfqq_process_refs(new_cfqq); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2168 | /* |
| 2169 | * If the process for the cfqq has gone away, there is no |
| 2170 | * sense in merging the queues. |
| 2171 | */ |
Jeff Moyer | c10b61f | 2010-06-17 10:19:11 -0400 | [diff] [blame] | 2172 | if (process_refs == 0 || new_process_refs == 0) |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2173 | return; |
| 2174 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 2175 | /* |
| 2176 | * Merge in the direction of the lesser amount of work. |
| 2177 | */ |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 2178 | if (new_process_refs >= process_refs) { |
| 2179 | cfqq->new_cfqq = new_cfqq; |
Shaohua Li | 30d7b94 | 2011-01-07 08:46:59 +0100 | [diff] [blame] | 2180 | new_cfqq->ref += process_refs; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 2181 | } else { |
| 2182 | new_cfqq->new_cfqq = cfqq; |
Shaohua Li | 30d7b94 | 2011-01-07 08:46:59 +0100 | [diff] [blame] | 2183 | cfqq->ref += new_process_refs; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 2184 | } |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2185 | } |
| 2186 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2187 | static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2188 | struct cfq_group *cfqg, enum wl_prio_t prio) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2189 | { |
| 2190 | struct cfq_queue *queue; |
| 2191 | int i; |
| 2192 | bool key_valid = false; |
| 2193 | unsigned long lowest_key = 0; |
| 2194 | enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; |
| 2195 | |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2196 | for (i = 0; i <= SYNC_WORKLOAD; ++i) { |
| 2197 | /* select the one with lowest rb_key */ |
| 2198 | queue = cfq_rb_first(service_tree_for(cfqg, prio, i)); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2199 | if (queue && |
| 2200 | (!key_valid || time_before(queue->rb_key, lowest_key))) { |
| 2201 | lowest_key = queue->rb_key; |
| 2202 | cur_best = i; |
| 2203 | key_valid = true; |
| 2204 | } |
| 2205 | } |
| 2206 | |
| 2207 | return cur_best; |
| 2208 | } |
| 2209 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2210 | static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2211 | { |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2212 | unsigned slice; |
| 2213 | unsigned count; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2214 | struct cfq_rb_root *st; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2215 | unsigned group_slice; |
Shaohua Li writes | e4ea0c1 | 2010-12-13 14:32:22 +0100 | [diff] [blame] | 2216 | enum wl_prio_t original_prio = cfqd->serving_prio; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2217 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2218 | /* Choose next priority. RT > BE > IDLE */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2219 | if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2220 | cfqd->serving_prio = RT_WORKLOAD; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2221 | else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2222 | cfqd->serving_prio = BE_WORKLOAD; |
| 2223 | else { |
| 2224 | cfqd->serving_prio = IDLE_WORKLOAD; |
| 2225 | cfqd->workload_expires = jiffies + 1; |
| 2226 | return; |
| 2227 | } |
| 2228 | |
Shaohua Li writes | e4ea0c1 | 2010-12-13 14:32:22 +0100 | [diff] [blame] | 2229 | if (original_prio != cfqd->serving_prio) |
| 2230 | goto new_workload; |
| 2231 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2232 | /* |
| 2233 | * For RT and BE, we have to choose also the type |
| 2234 | * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload |
| 2235 | * expiration time |
| 2236 | */ |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2237 | st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2238 | count = st->count; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2239 | |
| 2240 | /* |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2241 | * check workload expiration, and that we still have other queues ready |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2242 | */ |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2243 | if (count && !time_after(jiffies, cfqd->workload_expires)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2244 | return; |
| 2245 | |
Shaohua Li writes | e4ea0c1 | 2010-12-13 14:32:22 +0100 | [diff] [blame] | 2246 | new_workload: |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2247 | /* otherwise select new workload type */ |
| 2248 | cfqd->serving_type = |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2249 | cfq_choose_wl(cfqd, cfqg, cfqd->serving_prio); |
| 2250 | st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2251 | count = st->count; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2252 | |
| 2253 | /* |
| 2254 | * the workload slice is computed as a fraction of target latency |
| 2255 | * proportional to the number of queues in that workload, over |
| 2256 | * all the queues in the same priority class |
| 2257 | */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2258 | group_slice = cfq_group_slice(cfqd, cfqg); |
| 2259 | |
| 2260 | slice = group_slice * count / |
| 2261 | max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_prio], |
| 2262 | cfq_group_busy_queues_wl(cfqd->serving_prio, cfqd, cfqg)); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2263 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 2264 | if (cfqd->serving_type == ASYNC_WORKLOAD) { |
| 2265 | unsigned int tmp; |
| 2266 | |
| 2267 | /* |
| 2268 | * Async queues are currently system wide. Just taking |
| 2269 | * proportion of queues with-in same group will lead to higher |
| 2270 | * async ratio system wide as generally root group is going |
| 2271 | * to have higher weight. A more accurate thing would be to |
| 2272 | * calculate system wide asnc/sync ratio. |
| 2273 | */ |
| 2274 | tmp = cfq_target_latency * cfqg_busy_async_queues(cfqd, cfqg); |
| 2275 | tmp = tmp/cfqd->busy_queues; |
| 2276 | slice = min_t(unsigned, slice, tmp); |
| 2277 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2278 | /* async workload slice is scaled down according to |
| 2279 | * the sync/async slice ratio. */ |
| 2280 | slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1]; |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 2281 | } else |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2282 | /* sync workload slice is at least 2 * cfq_slice_idle */ |
| 2283 | slice = max(slice, 2 * cfqd->cfq_slice_idle); |
| 2284 | |
| 2285 | slice = max_t(unsigned, slice, CFQ_MIN_TT); |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 2286 | cfq_log(cfqd, "workload slice:%d", slice); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2287 | cfqd->workload_expires = jiffies + slice; |
| 2288 | } |
| 2289 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2290 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) |
| 2291 | { |
| 2292 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 2293 | struct cfq_group *cfqg; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2294 | |
| 2295 | if (RB_EMPTY_ROOT(&st->rb)) |
| 2296 | return NULL; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 2297 | cfqg = cfq_rb_first_group(st); |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 2298 | update_min_vdisktime(st); |
| 2299 | return cfqg; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2300 | } |
| 2301 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2302 | static void cfq_choose_cfqg(struct cfq_data *cfqd) |
| 2303 | { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2304 | struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); |
| 2305 | |
| 2306 | cfqd->serving_group = cfqg; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 2307 | |
| 2308 | /* Restore the workload type data */ |
| 2309 | if (cfqg->saved_workload_slice) { |
| 2310 | cfqd->workload_expires = jiffies + cfqg->saved_workload_slice; |
| 2311 | cfqd->serving_type = cfqg->saved_workload; |
| 2312 | cfqd->serving_prio = cfqg->saved_serving_prio; |
Gui Jianfeng | 66ae291 | 2009-12-15 10:08:45 +0100 | [diff] [blame] | 2313 | } else |
| 2314 | cfqd->workload_expires = jiffies - 1; |
| 2315 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2316 | choose_service_tree(cfqd, cfqg); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2317 | } |
| 2318 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2319 | /* |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2320 | * Select a queue for service. If we have a current active queue, |
| 2321 | * check whether to continue servicing it, or retrieve and set a new one. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2322 | */ |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2323 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2324 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2325 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2326 | |
| 2327 | cfqq = cfqd->active_queue; |
| 2328 | if (!cfqq) |
| 2329 | goto new_queue; |
| 2330 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2331 | if (!cfqd->rq_queued) |
| 2332 | return NULL; |
Vivek Goyal | c244bb5 | 2009-12-08 17:52:57 -0500 | [diff] [blame] | 2333 | |
| 2334 | /* |
| 2335 | * We were waiting for group to get backlogged. Expire the queue |
| 2336 | */ |
| 2337 | if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 2338 | goto expire; |
| 2339 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2340 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2341 | * The active queue has run out of time, expire it and select new. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2342 | */ |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2343 | if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) { |
| 2344 | /* |
| 2345 | * If slice had not expired at the completion of last request |
| 2346 | * we might not have turned on wait_busy flag. Don't expire |
| 2347 | * the queue yet. Allow the group to get backlogged. |
| 2348 | * |
| 2349 | * The very fact that we have used the slice, that means we |
| 2350 | * have been idling all along on this queue and it should be |
| 2351 | * ok to wait for this request to complete. |
| 2352 | */ |
Vivek Goyal | 82bbbf2 | 2009-12-10 19:25:41 +0100 | [diff] [blame] | 2353 | if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list) |
| 2354 | && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { |
| 2355 | cfqq = NULL; |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2356 | goto keep_queue; |
Vivek Goyal | 82bbbf2 | 2009-12-10 19:25:41 +0100 | [diff] [blame] | 2357 | } else |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 2358 | goto check_group_idle; |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2359 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2360 | |
| 2361 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2362 | * The active queue has requests and isn't expired, allow it to |
| 2363 | * dispatch. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2364 | */ |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 2365 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2366 | goto keep_queue; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2367 | |
| 2368 | /* |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2369 | * If another queue has a request waiting within our mean seek |
| 2370 | * distance, let it run. The expire code will check for close |
| 2371 | * cooperators and put the close queue at the front of the service |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2372 | * tree. If possible, merge the expiring queue with the new cfqq. |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2373 | */ |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 2374 | new_cfqq = cfq_close_cooperator(cfqd, cfqq); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2375 | if (new_cfqq) { |
| 2376 | if (!cfqq->new_cfqq) |
| 2377 | cfq_setup_merge(cfqq, new_cfqq); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2378 | goto expire; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2379 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2380 | |
| 2381 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2382 | * No requests pending. If the active queue still has requests in |
| 2383 | * flight or is idling for a new request, allow either of these |
| 2384 | * conditions to happen (or time out) before selecting a new queue. |
| 2385 | */ |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 2386 | if (timer_pending(&cfqd->idle_slice_timer)) { |
| 2387 | cfqq = NULL; |
| 2388 | goto keep_queue; |
| 2389 | } |
| 2390 | |
Shaohua Li | 8e1ac66 | 2010-11-08 15:01:04 +0100 | [diff] [blame] | 2391 | /* |
| 2392 | * This is a deep seek queue, but the device is much faster than |
| 2393 | * the queue can deliver, don't idle |
| 2394 | **/ |
| 2395 | if (CFQQ_SEEKY(cfqq) && cfq_cfqq_idle_window(cfqq) && |
| 2396 | (cfq_cfqq_slice_new(cfqq) || |
| 2397 | (cfqq->slice_end - jiffies > jiffies - cfqq->slice_start))) { |
| 2398 | cfq_clear_cfqq_deep(cfqq); |
| 2399 | cfq_clear_cfqq_idle_window(cfqq); |
| 2400 | } |
| 2401 | |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 2402 | if (cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { |
| 2403 | cfqq = NULL; |
| 2404 | goto keep_queue; |
| 2405 | } |
| 2406 | |
| 2407 | /* |
| 2408 | * If group idle is enabled and there are requests dispatched from |
| 2409 | * this group, wait for requests to complete. |
| 2410 | */ |
| 2411 | check_group_idle: |
Shaohua Li | 7700fc4 | 2011-07-12 14:24:56 +0200 | [diff] [blame] | 2412 | if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1 && |
| 2413 | cfqq->cfqg->dispatched && |
| 2414 | !cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) { |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2415 | cfqq = NULL; |
| 2416 | goto keep_queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2417 | } |
| 2418 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2419 | expire: |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2420 | cfq_slice_expired(cfqd, 0); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2421 | new_queue: |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2422 | /* |
| 2423 | * Current queue expired. Check if we have to switch to a new |
| 2424 | * service tree |
| 2425 | */ |
| 2426 | if (!new_cfqq) |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2427 | cfq_choose_cfqg(cfqd); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2428 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2429 | cfqq = cfq_set_active_queue(cfqd, new_cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2430 | keep_queue: |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2431 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2432 | } |
| 2433 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2434 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2435 | { |
| 2436 | int dispatched = 0; |
| 2437 | |
| 2438 | while (cfqq->next_rq) { |
| 2439 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); |
| 2440 | dispatched++; |
| 2441 | } |
| 2442 | |
| 2443 | BUG_ON(!list_empty(&cfqq->fifo)); |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2444 | |
| 2445 | /* By default cfqq is not expired if it is empty. Do it explicitly */ |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2446 | __cfq_slice_expired(cfqq->cfqd, cfqq, 0); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2447 | return dispatched; |
| 2448 | } |
| 2449 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2450 | /* |
| 2451 | * Drain our current requests. Used for barriers and when switching |
| 2452 | * io schedulers on-the-fly. |
| 2453 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2454 | static int cfq_forced_dispatch(struct cfq_data *cfqd) |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2455 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 2456 | struct cfq_queue *cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2457 | int dispatched = 0; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2458 | |
Divyesh Shah | 3440c49 | 2010-04-09 09:29:57 +0200 | [diff] [blame] | 2459 | /* Expire the timeslice of the current active queue first */ |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2460 | cfq_slice_expired(cfqd, 0); |
Divyesh Shah | 3440c49 | 2010-04-09 09:29:57 +0200 | [diff] [blame] | 2461 | while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) { |
| 2462 | __cfq_set_active_queue(cfqd, cfqq); |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2463 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); |
Divyesh Shah | 3440c49 | 2010-04-09 09:29:57 +0200 | [diff] [blame] | 2464 | } |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2465 | |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2466 | BUG_ON(cfqd->busy_queues); |
| 2467 | |
Jeff Moyer | 6923715 | 2009-06-12 15:29:30 +0200 | [diff] [blame] | 2468 | cfq_log(cfqd, "forced_dispatch=%d", dispatched); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2469 | return dispatched; |
| 2470 | } |
| 2471 | |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2472 | static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, |
| 2473 | struct cfq_queue *cfqq) |
| 2474 | { |
| 2475 | /* the queue hasn't finished any request, can't estimate */ |
| 2476 | if (cfq_cfqq_slice_new(cfqq)) |
Shaohua Li | c1e4475 | 2010-11-08 15:01:02 +0100 | [diff] [blame] | 2477 | return true; |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2478 | if (time_after(jiffies + cfqd->cfq_slice_idle * cfqq->dispatched, |
| 2479 | cfqq->slice_end)) |
Shaohua Li | c1e4475 | 2010-11-08 15:01:02 +0100 | [diff] [blame] | 2480 | return true; |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2481 | |
Shaohua Li | c1e4475 | 2010-11-08 15:01:02 +0100 | [diff] [blame] | 2482 | return false; |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2483 | } |
| 2484 | |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2485 | static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2486 | { |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2487 | unsigned int max_dispatch; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2488 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2489 | /* |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2490 | * Drain async requests before we start sync IO |
| 2491 | */ |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 2492 | if (cfq_should_idle(cfqd, cfqq) && cfqd->rq_in_flight[BLK_RW_ASYNC]) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2493 | return false; |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2494 | |
| 2495 | /* |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2496 | * If this is an async queue and we have sync IO in flight, let it wait |
| 2497 | */ |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 2498 | if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2499 | return false; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2500 | |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2501 | max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2502 | if (cfq_class_idle(cfqq)) |
| 2503 | max_dispatch = 1; |
| 2504 | |
| 2505 | /* |
| 2506 | * Does this cfqq already have too much IO in flight? |
| 2507 | */ |
| 2508 | if (cfqq->dispatched >= max_dispatch) { |
Shaohua Li | ef8a41d | 2011-03-07 09:26:29 +0100 | [diff] [blame] | 2509 | bool promote_sync = false; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2510 | /* |
| 2511 | * idle queue must always only have a single IO in flight |
| 2512 | */ |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2513 | if (cfq_class_idle(cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2514 | return false; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2515 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2516 | /* |
Li, Shaohua | c4ade94 | 2011-03-23 08:30:34 +0100 | [diff] [blame] | 2517 | * If there is only one sync queue |
| 2518 | * we can ignore async queue here and give the sync |
Shaohua Li | ef8a41d | 2011-03-07 09:26:29 +0100 | [diff] [blame] | 2519 | * queue no dispatch limit. The reason is a sync queue can |
| 2520 | * preempt async queue, limiting the sync queue doesn't make |
| 2521 | * sense. This is useful for aiostress test. |
| 2522 | */ |
Li, Shaohua | c4ade94 | 2011-03-23 08:30:34 +0100 | [diff] [blame] | 2523 | if (cfq_cfqq_sync(cfqq) && cfqd->busy_sync_queues == 1) |
| 2524 | promote_sync = true; |
Shaohua Li | ef8a41d | 2011-03-07 09:26:29 +0100 | [diff] [blame] | 2525 | |
| 2526 | /* |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2527 | * We have other queues, don't allow more IO from this one |
| 2528 | */ |
Shaohua Li | ef8a41d | 2011-03-07 09:26:29 +0100 | [diff] [blame] | 2529 | if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq) && |
| 2530 | !promote_sync) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2531 | return false; |
Jens Axboe | 9ede209 | 2007-01-19 12:11:44 +1100 | [diff] [blame] | 2532 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2533 | /* |
Shaohua Li | 474b18c | 2009-12-03 12:58:05 +0100 | [diff] [blame] | 2534 | * Sole queue user, no limit |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2535 | */ |
Shaohua Li | ef8a41d | 2011-03-07 09:26:29 +0100 | [diff] [blame] | 2536 | if (cfqd->busy_queues == 1 || promote_sync) |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2537 | max_dispatch = -1; |
| 2538 | else |
| 2539 | /* |
| 2540 | * Normally we start throttling cfqq when cfq_quantum/2 |
| 2541 | * requests have been dispatched. But we can drive |
| 2542 | * deeper queue depths at the beginning of slice |
| 2543 | * subjected to upper limit of cfq_quantum. |
| 2544 | * */ |
| 2545 | max_dispatch = cfqd->cfq_quantum; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2546 | } |
| 2547 | |
| 2548 | /* |
| 2549 | * Async queues must wait a bit before being allowed dispatch. |
| 2550 | * We also ramp up the dispatch depth gradually for async IO, |
| 2551 | * based on the last sync IO we serviced |
| 2552 | */ |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2553 | if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 2554 | unsigned long last_sync = jiffies - cfqd->last_delayed_sync; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2555 | unsigned int depth; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2556 | |
Jens Axboe | 61f0c1d | 2009-10-03 19:46:03 +0200 | [diff] [blame] | 2557 | depth = last_sync / cfqd->cfq_slice[1]; |
Jens Axboe | e00c54c | 2009-10-04 20:36:19 +0200 | [diff] [blame] | 2558 | if (!depth && !cfqq->dispatched) |
| 2559 | depth = 1; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2560 | if (depth < max_dispatch) |
| 2561 | max_dispatch = depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2562 | } |
| 2563 | |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2564 | /* |
| 2565 | * If we're below the current max, allow a dispatch |
| 2566 | */ |
| 2567 | return cfqq->dispatched < max_dispatch; |
| 2568 | } |
| 2569 | |
| 2570 | /* |
| 2571 | * Dispatch a request from cfqq, moving them to the request queue |
| 2572 | * dispatch list. |
| 2573 | */ |
| 2574 | static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2575 | { |
| 2576 | struct request *rq; |
| 2577 | |
| 2578 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); |
| 2579 | |
| 2580 | if (!cfq_may_dispatch(cfqd, cfqq)) |
| 2581 | return false; |
| 2582 | |
| 2583 | /* |
| 2584 | * follow expired path, else get first next available |
| 2585 | */ |
| 2586 | rq = cfq_check_fifo(cfqq); |
| 2587 | if (!rq) |
| 2588 | rq = cfqq->next_rq; |
| 2589 | |
| 2590 | /* |
| 2591 | * insert request into driver dispatch list |
| 2592 | */ |
| 2593 | cfq_dispatch_insert(cfqd->queue, rq); |
| 2594 | |
| 2595 | if (!cfqd->active_cic) { |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2596 | struct cfq_io_cq *cic = RQ_CIC(rq); |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2597 | |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2598 | atomic_long_inc(&cic->icq.ioc->refcount); |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2599 | cfqd->active_cic = cic; |
| 2600 | } |
| 2601 | |
| 2602 | return true; |
| 2603 | } |
| 2604 | |
| 2605 | /* |
| 2606 | * Find the cfqq that we need to service and move a request from that to the |
| 2607 | * dispatch list |
| 2608 | */ |
| 2609 | static int cfq_dispatch_requests(struct request_queue *q, int force) |
| 2610 | { |
| 2611 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 2612 | struct cfq_queue *cfqq; |
| 2613 | |
| 2614 | if (!cfqd->busy_queues) |
| 2615 | return 0; |
| 2616 | |
| 2617 | if (unlikely(force)) |
| 2618 | return cfq_forced_dispatch(cfqd); |
| 2619 | |
| 2620 | cfqq = cfq_select_queue(cfqd); |
| 2621 | if (!cfqq) |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2622 | return 0; |
| 2623 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2624 | /* |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2625 | * Dispatch a request from this cfqq, if it is allowed |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2626 | */ |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2627 | if (!cfq_dispatch_request(cfqd, cfqq)) |
| 2628 | return 0; |
| 2629 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2630 | cfqq->slice_dispatch++; |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 2631 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2632 | |
| 2633 | /* |
| 2634 | * expire an async queue immediately if it has used up its slice. idle |
| 2635 | * queue always expire after 1 dispatch round. |
| 2636 | */ |
| 2637 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && |
| 2638 | cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || |
| 2639 | cfq_class_idle(cfqq))) { |
| 2640 | cfqq->slice_end = jiffies + 1; |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2641 | cfq_slice_expired(cfqd, 0); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2642 | } |
| 2643 | |
Shan Wei | b217a90 | 2009-09-01 10:06:42 +0200 | [diff] [blame] | 2644 | cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2645 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2646 | } |
| 2647 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2648 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2649 | * task holds one reference to the queue, dropped when task exits. each rq |
| 2650 | * in-flight on this queue also holds a reference, dropped when rq is freed. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2651 | * |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2652 | * Each cfq queue took a reference on the parent group. Drop it now. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2653 | * queue lock must be held here. |
| 2654 | */ |
| 2655 | static void cfq_put_queue(struct cfq_queue *cfqq) |
| 2656 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2657 | struct cfq_data *cfqd = cfqq->cfqd; |
Justin TerAvest | 0bbfeb8 | 2011-03-01 15:05:08 -0500 | [diff] [blame] | 2658 | struct cfq_group *cfqg; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2659 | |
Shaohua Li | 30d7b94 | 2011-01-07 08:46:59 +0100 | [diff] [blame] | 2660 | BUG_ON(cfqq->ref <= 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2661 | |
Shaohua Li | 30d7b94 | 2011-01-07 08:46:59 +0100 | [diff] [blame] | 2662 | cfqq->ref--; |
| 2663 | if (cfqq->ref) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2664 | return; |
| 2665 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2666 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2667 | BUG_ON(rb_first(&cfqq->sort_list)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2668 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2669 | cfqg = cfqq->cfqg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2670 | |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2671 | if (unlikely(cfqd->active_queue == cfqq)) { |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2672 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2673 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2674 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2675 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2676 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2677 | kmem_cache_free(cfq_pool, cfqq); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2678 | cfq_put_cfqg(cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2679 | } |
| 2680 | |
Shaohua Li | d02a2c0 | 2010-05-25 10:16:53 +0200 | [diff] [blame] | 2681 | static void cfq_put_cooperator(struct cfq_queue *cfqq) |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2682 | { |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2683 | struct cfq_queue *__cfqq, *next; |
| 2684 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2685 | /* |
| 2686 | * If this queue was scheduled to merge with another queue, be |
| 2687 | * sure to drop the reference taken on that queue (and others in |
| 2688 | * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. |
| 2689 | */ |
| 2690 | __cfqq = cfqq->new_cfqq; |
| 2691 | while (__cfqq) { |
| 2692 | if (__cfqq == cfqq) { |
| 2693 | WARN(1, "cfqq->new_cfqq loop detected\n"); |
| 2694 | break; |
| 2695 | } |
| 2696 | next = __cfqq->new_cfqq; |
| 2697 | cfq_put_queue(__cfqq); |
| 2698 | __cfqq = next; |
| 2699 | } |
Shaohua Li | d02a2c0 | 2010-05-25 10:16:53 +0200 | [diff] [blame] | 2700 | } |
| 2701 | |
| 2702 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2703 | { |
| 2704 | if (unlikely(cfqq == cfqd->active_queue)) { |
| 2705 | __cfq_slice_expired(cfqd, cfqq, 0); |
| 2706 | cfq_schedule_dispatch(cfqd); |
| 2707 | } |
| 2708 | |
| 2709 | cfq_put_cooperator(cfqq); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2710 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2711 | cfq_put_queue(cfqq); |
| 2712 | } |
| 2713 | |
Tejun Heo | 9b84cac | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 2714 | static void cfq_init_icq(struct io_cq *icq) |
| 2715 | { |
| 2716 | struct cfq_io_cq *cic = icq_to_cic(icq); |
| 2717 | |
| 2718 | cic->ttime.last_end_request = jiffies; |
| 2719 | } |
| 2720 | |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2721 | static void cfq_exit_icq(struct io_cq *icq) |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2722 | { |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2723 | struct cfq_io_cq *cic = icq_to_cic(icq); |
Tejun Heo | 283287a | 2011-12-14 00:33:38 +0100 | [diff] [blame] | 2724 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 2725 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2726 | if (cic->cfqq[BLK_RW_ASYNC]) { |
| 2727 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]); |
| 2728 | cic->cfqq[BLK_RW_ASYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2729 | } |
| 2730 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2731 | if (cic->cfqq[BLK_RW_SYNC]) { |
| 2732 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_SYNC]); |
| 2733 | cic->cfqq[BLK_RW_SYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2734 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2735 | } |
| 2736 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2737 | static void cfq_init_prio_data(struct cfq_queue *cfqq, struct io_context *ioc) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2738 | { |
| 2739 | struct task_struct *tsk = current; |
| 2740 | int ioprio_class; |
| 2741 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2742 | if (!cfq_cfqq_prio_changed(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2743 | return; |
| 2744 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2745 | ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2746 | switch (ioprio_class) { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2747 | default: |
| 2748 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); |
| 2749 | case IOPRIO_CLASS_NONE: |
| 2750 | /* |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 2751 | * no prio set, inherit CPU scheduling settings |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2752 | */ |
| 2753 | cfqq->ioprio = task_nice_ioprio(tsk); |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 2754 | cfqq->ioprio_class = task_nice_ioclass(tsk); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2755 | break; |
| 2756 | case IOPRIO_CLASS_RT: |
| 2757 | cfqq->ioprio = task_ioprio(ioc); |
| 2758 | cfqq->ioprio_class = IOPRIO_CLASS_RT; |
| 2759 | break; |
| 2760 | case IOPRIO_CLASS_BE: |
| 2761 | cfqq->ioprio = task_ioprio(ioc); |
| 2762 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 2763 | break; |
| 2764 | case IOPRIO_CLASS_IDLE: |
| 2765 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; |
| 2766 | cfqq->ioprio = 7; |
| 2767 | cfq_clear_cfqq_idle_window(cfqq); |
| 2768 | break; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2769 | } |
| 2770 | |
| 2771 | /* |
| 2772 | * keep track of original prio settings in case we have to temporarily |
| 2773 | * elevate the priority of this queue |
| 2774 | */ |
| 2775 | cfqq->org_ioprio = cfqq->ioprio; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2776 | cfq_clear_cfqq_prio_changed(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2777 | } |
| 2778 | |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2779 | static void changed_ioprio(struct cfq_io_cq *cic) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2780 | { |
Konstantin Khlebnikov | bca4b91 | 2010-05-20 23:21:34 +0400 | [diff] [blame] | 2781 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 2782 | struct cfq_queue *cfqq; |
Jens Axboe | 35e6077 | 2006-06-14 09:10:45 +0200 | [diff] [blame] | 2783 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2784 | if (unlikely(!cfqd)) |
| 2785 | return; |
| 2786 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2787 | cfqq = cic->cfqq[BLK_RW_ASYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2788 | if (cfqq) { |
| 2789 | struct cfq_queue *new_cfqq; |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2790 | new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->icq.ioc, |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2791 | GFP_ATOMIC); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2792 | if (new_cfqq) { |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2793 | cic->cfqq[BLK_RW_ASYNC] = new_cfqq; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2794 | cfq_put_queue(cfqq); |
| 2795 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2796 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2797 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2798 | cfqq = cic->cfqq[BLK_RW_SYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2799 | if (cfqq) |
| 2800 | cfq_mark_cfqq_prio_changed(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2801 | } |
| 2802 | |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 2803 | static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2804 | pid_t pid, bool is_sync) |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 2805 | { |
| 2806 | RB_CLEAR_NODE(&cfqq->rb_node); |
| 2807 | RB_CLEAR_NODE(&cfqq->p_node); |
| 2808 | INIT_LIST_HEAD(&cfqq->fifo); |
| 2809 | |
Shaohua Li | 30d7b94 | 2011-01-07 08:46:59 +0100 | [diff] [blame] | 2810 | cfqq->ref = 0; |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 2811 | cfqq->cfqd = cfqd; |
| 2812 | |
| 2813 | cfq_mark_cfqq_prio_changed(cfqq); |
| 2814 | |
| 2815 | if (is_sync) { |
| 2816 | if (!cfq_class_idle(cfqq)) |
| 2817 | cfq_mark_cfqq_idle_window(cfqq); |
| 2818 | cfq_mark_cfqq_sync(cfqq); |
| 2819 | } |
| 2820 | cfqq->pid = pid; |
| 2821 | } |
| 2822 | |
Vivek Goyal | 2461033 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 2823 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2824 | static void changed_cgroup(struct cfq_io_cq *cic) |
Vivek Goyal | 2461033 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 2825 | { |
| 2826 | struct cfq_queue *sync_cfqq = cic_to_cfqq(cic, 1); |
Konstantin Khlebnikov | bca4b91 | 2010-05-20 23:21:34 +0400 | [diff] [blame] | 2827 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
Vivek Goyal | 2461033 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 2828 | struct request_queue *q; |
| 2829 | |
| 2830 | if (unlikely(!cfqd)) |
| 2831 | return; |
| 2832 | |
| 2833 | q = cfqd->queue; |
| 2834 | |
Vivek Goyal | 2461033 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 2835 | if (sync_cfqq) { |
| 2836 | /* |
| 2837 | * Drop reference to sync queue. A new sync queue will be |
| 2838 | * assigned in new group upon arrival of a fresh request. |
| 2839 | */ |
| 2840 | cfq_log_cfqq(cfqd, sync_cfqq, "changed cgroup"); |
| 2841 | cic_set_cfqq(cic, NULL, 1); |
| 2842 | cfq_put_queue(sync_cfqq); |
| 2843 | } |
Vivek Goyal | 2461033 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 2844 | } |
Vivek Goyal | 2461033 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 2845 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ |
| 2846 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2847 | static struct cfq_queue * |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2848 | cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2849 | struct io_context *ioc, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2850 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2851 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2852 | struct cfq_io_cq *cic; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2853 | struct cfq_group *cfqg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2854 | |
| 2855 | retry: |
Vivek Goyal | 3e59cf9 | 2011-05-19 15:38:21 -0400 | [diff] [blame] | 2856 | cfqg = cfq_get_cfqg(cfqd); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2857 | cic = cfq_cic_lookup(cfqd, ioc); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2858 | /* cic always exists here */ |
| 2859 | cfqq = cic_to_cfqq(cic, is_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2860 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2861 | /* |
| 2862 | * Always try a new alloc if we fell back to the OOM cfqq |
| 2863 | * originally, since it should just be a temporary situation. |
| 2864 | */ |
| 2865 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
| 2866 | cfqq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2867 | if (new_cfqq) { |
| 2868 | cfqq = new_cfqq; |
| 2869 | new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2870 | } else if (gfp_mask & __GFP_WAIT) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2871 | spin_unlock_irq(cfqd->queue->queue_lock); |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2872 | new_cfqq = kmem_cache_alloc_node(cfq_pool, |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2873 | gfp_mask | __GFP_ZERO, |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2874 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2875 | spin_lock_irq(cfqd->queue->queue_lock); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2876 | if (new_cfqq) |
| 2877 | goto retry; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2878 | } else { |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2879 | cfqq = kmem_cache_alloc_node(cfq_pool, |
| 2880 | gfp_mask | __GFP_ZERO, |
| 2881 | cfqd->queue->node); |
Kiyoshi Ueda | db3b584 | 2005-06-17 16:15:10 +0200 | [diff] [blame] | 2882 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2883 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2884 | if (cfqq) { |
| 2885 | cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); |
| 2886 | cfq_init_prio_data(cfqq, ioc); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2887 | cfq_link_cfqq_cfqg(cfqq, cfqg); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2888 | cfq_log_cfqq(cfqd, cfqq, "alloced"); |
| 2889 | } else |
| 2890 | cfqq = &cfqd->oom_cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2891 | } |
| 2892 | |
| 2893 | if (new_cfqq) |
| 2894 | kmem_cache_free(cfq_pool, new_cfqq); |
| 2895 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2896 | return cfqq; |
| 2897 | } |
| 2898 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2899 | static struct cfq_queue ** |
| 2900 | cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) |
| 2901 | { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2902 | switch (ioprio_class) { |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2903 | case IOPRIO_CLASS_RT: |
| 2904 | return &cfqd->async_cfqq[0][ioprio]; |
| 2905 | case IOPRIO_CLASS_BE: |
| 2906 | return &cfqd->async_cfqq[1][ioprio]; |
| 2907 | case IOPRIO_CLASS_IDLE: |
| 2908 | return &cfqd->async_idle_cfqq; |
| 2909 | default: |
| 2910 | BUG(); |
| 2911 | } |
| 2912 | } |
| 2913 | |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2914 | static struct cfq_queue * |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2915 | cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc, |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2916 | gfp_t gfp_mask) |
| 2917 | { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2918 | const int ioprio = task_ioprio(ioc); |
| 2919 | const int ioprio_class = task_ioprio_class(ioc); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2920 | struct cfq_queue **async_cfqq = NULL; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2921 | struct cfq_queue *cfqq = NULL; |
| 2922 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2923 | if (!is_sync) { |
| 2924 | async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); |
| 2925 | cfqq = *async_cfqq; |
| 2926 | } |
| 2927 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2928 | if (!cfqq) |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2929 | cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2930 | |
| 2931 | /* |
| 2932 | * pin the queue now that it's allocated, scheduler exit will prune it |
| 2933 | */ |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2934 | if (!is_sync && !(*async_cfqq)) { |
Shaohua Li | 30d7b94 | 2011-01-07 08:46:59 +0100 | [diff] [blame] | 2935 | cfqq->ref++; |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2936 | *async_cfqq = cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2937 | } |
| 2938 | |
Shaohua Li | 30d7b94 | 2011-01-07 08:46:59 +0100 | [diff] [blame] | 2939 | cfqq->ref++; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2940 | return cfqq; |
| 2941 | } |
| 2942 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2943 | static void |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 2944 | __cfq_update_io_thinktime(struct cfq_ttime *ttime, unsigned long slice_idle) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2945 | { |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 2946 | unsigned long elapsed = jiffies - ttime->last_end_request; |
| 2947 | elapsed = min(elapsed, 2UL * slice_idle); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2948 | |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 2949 | ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8; |
| 2950 | ttime->ttime_total = (7*ttime->ttime_total + 256*elapsed) / 8; |
| 2951 | ttime->ttime_mean = (ttime->ttime_total + 128) / ttime->ttime_samples; |
| 2952 | } |
| 2953 | |
| 2954 | static void |
| 2955 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2956 | struct cfq_io_cq *cic) |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 2957 | { |
Shaohua Li | f5f2b6c | 2011-07-12 14:24:55 +0200 | [diff] [blame] | 2958 | if (cfq_cfqq_sync(cfqq)) { |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 2959 | __cfq_update_io_thinktime(&cic->ttime, cfqd->cfq_slice_idle); |
Shaohua Li | f5f2b6c | 2011-07-12 14:24:55 +0200 | [diff] [blame] | 2960 | __cfq_update_io_thinktime(&cfqq->service_tree->ttime, |
| 2961 | cfqd->cfq_slice_idle); |
| 2962 | } |
Shaohua Li | 7700fc4 | 2011-07-12 14:24:56 +0200 | [diff] [blame] | 2963 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 2964 | __cfq_update_io_thinktime(&cfqq->cfqg->ttime, cfqd->cfq_group_idle); |
| 2965 | #endif |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2966 | } |
| 2967 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 2968 | static void |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 2969 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2970 | struct request *rq) |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 2971 | { |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 2972 | sector_t sdist = 0; |
Corrado Zoccolo | 41647e7 | 2010-02-27 19:45:40 +0100 | [diff] [blame] | 2973 | sector_t n_sec = blk_rq_sectors(rq); |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 2974 | if (cfqq->last_request_pos) { |
| 2975 | if (cfqq->last_request_pos < blk_rq_pos(rq)) |
| 2976 | sdist = blk_rq_pos(rq) - cfqq->last_request_pos; |
| 2977 | else |
| 2978 | sdist = cfqq->last_request_pos - blk_rq_pos(rq); |
| 2979 | } |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 2980 | |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 2981 | cfqq->seek_history <<= 1; |
Corrado Zoccolo | 41647e7 | 2010-02-27 19:45:40 +0100 | [diff] [blame] | 2982 | if (blk_queue_nonrot(cfqd->queue)) |
| 2983 | cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT); |
| 2984 | else |
| 2985 | cfqq->seek_history |= (sdist > CFQQ_SEEK_THR); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 2986 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2987 | |
| 2988 | /* |
| 2989 | * Disable idle window if the process thinks too long or seeks so much that |
| 2990 | * it doesn't matter |
| 2991 | */ |
| 2992 | static void |
| 2993 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 2994 | struct cfq_io_cq *cic) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2995 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2996 | int old_idle, enable_idle; |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 2997 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 2998 | /* |
| 2999 | * Don't idle for async or idle io prio class |
| 3000 | */ |
| 3001 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 3002 | return; |
| 3003 | |
Jens Axboe | c265a7f | 2008-06-26 13:49:33 +0200 | [diff] [blame] | 3004 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3005 | |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3006 | if (cfqq->queued[0] + cfqq->queued[1] >= 4) |
| 3007 | cfq_mark_cfqq_deep(cfqq); |
| 3008 | |
Corrado Zoccolo | 749ef9f | 2010-09-20 15:24:50 +0200 | [diff] [blame] | 3009 | if (cfqq->next_rq && (cfqq->next_rq->cmd_flags & REQ_NOIDLE)) |
| 3010 | enable_idle = 0; |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3011 | else if (!atomic_read(&cic->icq.ioc->nr_tasks) || |
| 3012 | !cfqd->cfq_slice_idle || |
| 3013 | (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq))) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3014 | enable_idle = 0; |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 3015 | else if (sample_valid(cic->ttime.ttime_samples)) { |
| 3016 | if (cic->ttime.ttime_mean > cfqd->cfq_slice_idle) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3017 | enable_idle = 0; |
| 3018 | else |
| 3019 | enable_idle = 1; |
| 3020 | } |
| 3021 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3022 | if (old_idle != enable_idle) { |
| 3023 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); |
| 3024 | if (enable_idle) |
| 3025 | cfq_mark_cfqq_idle_window(cfqq); |
| 3026 | else |
| 3027 | cfq_clear_cfqq_idle_window(cfqq); |
| 3028 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3029 | } |
| 3030 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3031 | /* |
| 3032 | * Check if new_cfqq should preempt the currently active queue. Return 0 for |
| 3033 | * no or if we aren't sure, a 1 will cause a preempt. |
| 3034 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3035 | static bool |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3036 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3037 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3038 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3039 | struct cfq_queue *cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3040 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3041 | cfqq = cfqd->active_queue; |
| 3042 | if (!cfqq) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3043 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3044 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3045 | if (cfq_class_idle(new_cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3046 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3047 | |
| 3048 | if (cfq_class_idle(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3049 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3050 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3051 | /* |
Divyesh Shah | 875feb6 | 2010-01-06 18:58:20 -0800 | [diff] [blame] | 3052 | * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice. |
| 3053 | */ |
| 3054 | if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq)) |
| 3055 | return false; |
| 3056 | |
| 3057 | /* |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3058 | * if the new request is sync, but the currently running queue is |
| 3059 | * not, let the sync request have priority. |
| 3060 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3061 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3062 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3063 | |
Vivek Goyal | 8682e1f | 2009-12-03 12:59:50 -0500 | [diff] [blame] | 3064 | if (new_cfqq->cfqg != cfqq->cfqg) |
| 3065 | return false; |
| 3066 | |
| 3067 | if (cfq_slice_used(cfqq)) |
| 3068 | return true; |
| 3069 | |
| 3070 | /* Allow preemption only if we are idling on sync-noidle tree */ |
| 3071 | if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD && |
| 3072 | cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD && |
| 3073 | new_cfqq->service_tree->count == 2 && |
| 3074 | RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 3075 | return true; |
| 3076 | |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3077 | /* |
Jens Axboe | b53d1ed | 2011-08-19 08:34:48 +0200 | [diff] [blame] | 3078 | * So both queues are sync. Let the new request get disk time if |
| 3079 | * it's a metadata request and the current queue is doing regular IO. |
| 3080 | */ |
Christoph Hellwig | 65299a3 | 2011-08-23 14:50:29 +0200 | [diff] [blame] | 3081 | if ((rq->cmd_flags & REQ_PRIO) && !cfqq->prio_pending) |
Jens Axboe | b53d1ed | 2011-08-19 08:34:48 +0200 | [diff] [blame] | 3082 | return true; |
| 3083 | |
| 3084 | /* |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3085 | * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. |
| 3086 | */ |
| 3087 | if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3088 | return true; |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3089 | |
Shaohua Li | d2d59e1 | 2010-11-08 15:01:03 +0100 | [diff] [blame] | 3090 | /* An idle queue should not be idle now for some reason */ |
| 3091 | if (RB_EMPTY_ROOT(&cfqq->sort_list) && !cfq_should_idle(cfqd, cfqq)) |
| 3092 | return true; |
| 3093 | |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3094 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3095 | return false; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3096 | |
| 3097 | /* |
| 3098 | * if this request is as-good as one we would expect from the |
| 3099 | * current cfqq, let it preempt |
| 3100 | */ |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 3101 | if (cfq_rq_close(cfqd, cfqq, rq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3102 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3103 | |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3104 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3105 | } |
| 3106 | |
| 3107 | /* |
| 3108 | * cfqq preempts the active queue. if we allowed preempt with no slice left, |
| 3109 | * let it have half of its nominal slice. |
| 3110 | */ |
| 3111 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 3112 | { |
Shaohua Li | df0793a | 2012-01-19 09:20:09 +0100 | [diff] [blame] | 3113 | enum wl_type_t old_type = cfqq_type(cfqd->active_queue); |
| 3114 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3115 | cfq_log_cfqq(cfqd, cfqq, "preempt"); |
Shaohua Li | df0793a | 2012-01-19 09:20:09 +0100 | [diff] [blame] | 3116 | cfq_slice_expired(cfqd, 1); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3117 | |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 3118 | /* |
Shaohua Li | f8ae6e3 | 2011-01-14 08:41:02 +0100 | [diff] [blame] | 3119 | * workload type is changed, don't save slice, otherwise preempt |
| 3120 | * doesn't happen |
| 3121 | */ |
Shaohua Li | df0793a | 2012-01-19 09:20:09 +0100 | [diff] [blame] | 3122 | if (old_type != cfqq_type(cfqq)) |
Shaohua Li | f8ae6e3 | 2011-01-14 08:41:02 +0100 | [diff] [blame] | 3123 | cfqq->cfqg->saved_workload_slice = 0; |
| 3124 | |
| 3125 | /* |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 3126 | * Put the new queue at the front of the of the current list, |
| 3127 | * so we know that it will be selected next. |
| 3128 | */ |
| 3129 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 3130 | |
| 3131 | cfq_service_tree_add(cfqd, cfqq, 1); |
Justin TerAvest | eda5e0c | 2011-03-22 21:26:49 +0100 | [diff] [blame] | 3132 | |
Justin TerAvest | 62a37f6 | 2011-03-23 08:25:44 +0100 | [diff] [blame] | 3133 | cfqq->slice_end = 0; |
| 3134 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3135 | } |
| 3136 | |
| 3137 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3138 | * Called when a new fs request (rq) is added (to cfqq). Check if there's |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3139 | * something we should do about it |
| 3140 | */ |
| 3141 | static void |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3142 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 3143 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3144 | { |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3145 | struct cfq_io_cq *cic = RQ_CIC(rq); |
Jens Axboe | 12e9fdd | 2006-06-01 10:09:56 +0200 | [diff] [blame] | 3146 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3147 | cfqd->rq_queued++; |
Christoph Hellwig | 65299a3 | 2011-08-23 14:50:29 +0200 | [diff] [blame] | 3148 | if (rq->cmd_flags & REQ_PRIO) |
| 3149 | cfqq->prio_pending++; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3150 | |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 3151 | cfq_update_io_thinktime(cfqd, cfqq, cic); |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3152 | cfq_update_io_seektime(cfqd, cfqq, rq); |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 3153 | cfq_update_idle_window(cfqd, cfqq, cic); |
| 3154 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3155 | cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3156 | |
| 3157 | if (cfqq == cfqd->active_queue) { |
| 3158 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 3159 | * Remember that we saw a request from this process, but |
| 3160 | * don't start queuing just yet. Otherwise we risk seeing lots |
| 3161 | * of tiny requests, because we disrupt the normal plugging |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3162 | * and merging. If the request is already larger than a single |
| 3163 | * page, let it rip immediately. For that case we assume that |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 3164 | * merging is already done. Ditto for a busy system that |
| 3165 | * has other work pending, don't risk delaying until the |
| 3166 | * idle timer unplug to continue working. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3167 | */ |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3168 | if (cfq_cfqq_wait_request(cfqq)) { |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 3169 | if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE || |
| 3170 | cfqd->busy_queues > 1) { |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 3171 | cfq_del_timer(cfqd, cfqq); |
Gui Jianfeng | 554554f | 2009-12-10 09:38:39 +0100 | [diff] [blame] | 3172 | cfq_clear_cfqq_wait_request(cfqq); |
Christoph Hellwig | 24ecfbe | 2011-04-18 11:41:33 +0200 | [diff] [blame] | 3173 | __blk_run_queue(cfqd->queue); |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 3174 | } else { |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 3175 | cfq_blkiocg_update_idle_time_stats( |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 3176 | &cfqq->cfqg->blkg); |
Vivek Goyal | bf79193 | 2009-12-03 12:59:37 -0500 | [diff] [blame] | 3177 | cfq_mark_cfqq_must_dispatch(cfqq); |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 3178 | } |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3179 | } |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3180 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3181 | /* |
| 3182 | * not the active queue - expire current slice if it is |
| 3183 | * idle and has expired it's mean thinktime or this new queue |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3184 | * has some old slice time left and is of higher priority or |
| 3185 | * this new queue is RT and the current one is BE |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3186 | */ |
| 3187 | cfq_preempt_queue(cfqd, cfqq); |
Christoph Hellwig | 24ecfbe | 2011-04-18 11:41:33 +0200 | [diff] [blame] | 3188 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3189 | } |
| 3190 | } |
| 3191 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3192 | static void cfq_insert_request(struct request_queue *q, struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3193 | { |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3194 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3195 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3196 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3197 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3198 | cfq_init_prio_data(cfqq, RQ_CIC(rq)->icq.ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3199 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 3200 | rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3201 | list_add_tail(&rq->queuelist, &cfqq->fifo); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 3202 | cfq_add_rq_rb(rq); |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 3203 | cfq_blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg, |
Divyesh Shah | cdc1184 | 2010-04-08 21:15:10 -0700 | [diff] [blame] | 3204 | &cfqd->serving_group->blkg, rq_data_dir(rq), |
| 3205 | rq_is_sync(rq)); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3206 | cfq_rq_enqueued(cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3207 | } |
| 3208 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3209 | /* |
| 3210 | * Update hw_tag based on peak queue depth over 50 samples under |
| 3211 | * sufficient load. |
| 3212 | */ |
| 3213 | static void cfq_update_hw_tag(struct cfq_data *cfqd) |
| 3214 | { |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3215 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 3216 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3217 | if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth) |
| 3218 | cfqd->hw_tag_est_depth = cfqd->rq_in_driver; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3219 | |
| 3220 | if (cfqd->hw_tag == 1) |
| 3221 | return; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3222 | |
| 3223 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3224 | cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3225 | return; |
| 3226 | |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3227 | /* |
| 3228 | * If active queue hasn't enough requests and can idle, cfq might not |
| 3229 | * dispatch sufficient requests to hardware. Don't zero hw_tag in this |
| 3230 | * case |
| 3231 | */ |
| 3232 | if (cfqq && cfq_cfqq_idle_window(cfqq) && |
| 3233 | cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] < |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3234 | CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN) |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3235 | return; |
| 3236 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3237 | if (cfqd->hw_tag_samples++ < 50) |
| 3238 | return; |
| 3239 | |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3240 | if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3241 | cfqd->hw_tag = 1; |
| 3242 | else |
| 3243 | cfqd->hw_tag = 0; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3244 | } |
| 3245 | |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3246 | static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 3247 | { |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3248 | struct cfq_io_cq *cic = cfqd->active_cic; |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3249 | |
Justin TerAvest | 02a8f01 | 2011-02-09 14:20:03 +0100 | [diff] [blame] | 3250 | /* If the queue already has requests, don't wait */ |
| 3251 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 3252 | return false; |
| 3253 | |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3254 | /* If there are other queues in the group, don't wait */ |
| 3255 | if (cfqq->cfqg->nr_cfqq > 1) |
| 3256 | return false; |
| 3257 | |
Shaohua Li | 7700fc4 | 2011-07-12 14:24:56 +0200 | [diff] [blame] | 3258 | /* the only queue in the group, but think time is big */ |
| 3259 | if (cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) |
| 3260 | return false; |
| 3261 | |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3262 | if (cfq_slice_used(cfqq)) |
| 3263 | return true; |
| 3264 | |
| 3265 | /* if slice left is less than think time, wait busy */ |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 3266 | if (cic && sample_valid(cic->ttime.ttime_samples) |
| 3267 | && (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3268 | return true; |
| 3269 | |
| 3270 | /* |
| 3271 | * If think times is less than a jiffy than ttime_mean=0 and above |
| 3272 | * will not be true. It might happen that slice has not expired yet |
| 3273 | * but will expire soon (4-5 ns) during select_queue(). To cover the |
| 3274 | * case where think time is less than a jiffy, mark the queue wait |
| 3275 | * busy if only 1 jiffy is left in the slice. |
| 3276 | */ |
| 3277 | if (cfqq->slice_end - jiffies == 1) |
| 3278 | return true; |
| 3279 | |
| 3280 | return false; |
| 3281 | } |
| 3282 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3283 | static void cfq_completed_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3284 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3285 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3286 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 3287 | const int sync = rq_is_sync(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3288 | unsigned long now; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3289 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3290 | now = jiffies; |
Christoph Hellwig | 33659eb | 2010-08-07 18:17:56 +0200 | [diff] [blame] | 3291 | cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", |
| 3292 | !!(rq->cmd_flags & REQ_NOIDLE)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3293 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3294 | cfq_update_hw_tag(cfqd); |
| 3295 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3296 | WARN_ON(!cfqd->rq_in_driver); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3297 | WARN_ON(!cfqq->dispatched); |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3298 | cfqd->rq_in_driver--; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3299 | cfqq->dispatched--; |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 3300 | (RQ_CFQG(rq))->dispatched--; |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 3301 | cfq_blkiocg_update_completion_stats(&cfqq->cfqg->blkg, |
| 3302 | rq_start_time_ns(rq), rq_io_start_time_ns(rq), |
| 3303 | rq_data_dir(rq), rq_is_sync(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3304 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3305 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 3306 | |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 3307 | if (sync) { |
Shaohua Li | f5f2b6c | 2011-07-12 14:24:55 +0200 | [diff] [blame] | 3308 | struct cfq_rb_root *service_tree; |
| 3309 | |
Shaohua Li | 383cd72 | 2011-07-12 14:24:35 +0200 | [diff] [blame] | 3310 | RQ_CIC(rq)->ttime.last_end_request = now; |
Shaohua Li | f5f2b6c | 2011-07-12 14:24:55 +0200 | [diff] [blame] | 3311 | |
| 3312 | if (cfq_cfqq_on_rr(cfqq)) |
| 3313 | service_tree = cfqq->service_tree; |
| 3314 | else |
| 3315 | service_tree = service_tree_for(cfqq->cfqg, |
| 3316 | cfqq_prio(cfqq), cfqq_type(cfqq)); |
| 3317 | service_tree->ttime.last_end_request = now; |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 3318 | if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) |
| 3319 | cfqd->last_delayed_sync = now; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 3320 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3321 | |
Shaohua Li | 7700fc4 | 2011-07-12 14:24:56 +0200 | [diff] [blame] | 3322 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 3323 | cfqq->cfqg->ttime.last_end_request = now; |
| 3324 | #endif |
| 3325 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3326 | /* |
| 3327 | * If this is the active queue, check if it needs to be expired, |
| 3328 | * or if we want to idle in case it has no pending requests. |
| 3329 | */ |
| 3330 | if (cfqd->active_queue == cfqq) { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3331 | const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); |
| 3332 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3333 | if (cfq_cfqq_slice_new(cfqq)) { |
| 3334 | cfq_set_prio_slice(cfqd, cfqq); |
| 3335 | cfq_clear_cfqq_slice_new(cfqq); |
| 3336 | } |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3337 | |
| 3338 | /* |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3339 | * Should we wait for next request to come in before we expire |
| 3340 | * the queue. |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3341 | */ |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3342 | if (cfq_should_wait_busy(cfqd, cfqq)) { |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 3343 | unsigned long extend_sl = cfqd->cfq_slice_idle; |
| 3344 | if (!cfqd->cfq_slice_idle) |
| 3345 | extend_sl = cfqd->cfq_group_idle; |
| 3346 | cfqq->slice_end = jiffies + extend_sl; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3347 | cfq_mark_cfqq_wait_busy(cfqq); |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 3348 | cfq_log_cfqq(cfqd, cfqq, "will busy wait"); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3349 | } |
| 3350 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3351 | /* |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3352 | * Idling is not enabled on: |
| 3353 | * - expired queues |
| 3354 | * - idle-priority queues |
| 3355 | * - async queues |
| 3356 | * - queues with still some requests queued |
| 3357 | * - when there is a close cooperator |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3358 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 3359 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 3360 | cfq_slice_expired(cfqd, 1); |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3361 | else if (sync && cfqq_empty && |
| 3362 | !cfq_close_cooperator(cfqd, cfqq)) { |
Corrado Zoccolo | 749ef9f | 2010-09-20 15:24:50 +0200 | [diff] [blame] | 3363 | cfq_arm_slice_timer(cfqd); |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3364 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3365 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3366 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3367 | if (!cfqd->rq_in_driver) |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3368 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3369 | } |
| 3370 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3371 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3372 | { |
Jens Axboe | 1b379d8 | 2009-08-11 08:26:11 +0200 | [diff] [blame] | 3373 | if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3374 | cfq_mark_cfqq_must_alloc_slice(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3375 | return ELV_MQUEUE_MUST; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3376 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3377 | |
| 3378 | return ELV_MQUEUE_MAY; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3379 | } |
| 3380 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3381 | static int cfq_may_queue(struct request_queue *q, int rw) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3382 | { |
| 3383 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 3384 | struct task_struct *tsk = current; |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3385 | struct cfq_io_cq *cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3386 | struct cfq_queue *cfqq; |
| 3387 | |
| 3388 | /* |
| 3389 | * don't force setup of a queue from here, as a call to may_queue |
| 3390 | * does not necessarily imply that a request actually will be queued. |
| 3391 | * so just lookup a possibly existing queue, or return 'may queue' |
| 3392 | * if that fails |
| 3393 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 3394 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3395 | if (!cic) |
| 3396 | return ELV_MQUEUE_MAY; |
| 3397 | |
Jens Axboe | b0b78f8 | 2009-04-08 10:56:08 +0200 | [diff] [blame] | 3398 | cfqq = cic_to_cfqq(cic, rw_is_sync(rw)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3399 | if (cfqq) { |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3400 | cfq_init_prio_data(cfqq, cic->icq.ioc); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3401 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3402 | return __cfq_may_queue(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3403 | } |
| 3404 | |
| 3405 | return ELV_MQUEUE_MAY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3406 | } |
| 3407 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3408 | /* |
| 3409 | * queue lock held here |
| 3410 | */ |
Jens Axboe | bb37b94 | 2006-12-01 10:42:33 +0100 | [diff] [blame] | 3411 | static void cfq_put_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3412 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3413 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3414 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3415 | if (cfqq) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3416 | const int rw = rq_data_dir(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3417 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3418 | BUG_ON(!cfqq->allocated[rw]); |
| 3419 | cfqq->allocated[rw]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3420 | |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 3421 | /* Put down rq reference on cfqg */ |
| 3422 | cfq_put_cfqg(RQ_CFQG(rq)); |
Tejun Heo | a612fdd | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3423 | rq->elv.priv[0] = NULL; |
| 3424 | rq->elv.priv[1] = NULL; |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 3425 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3426 | cfq_put_queue(cfqq); |
| 3427 | } |
| 3428 | } |
| 3429 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3430 | static struct cfq_queue * |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3431 | cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_cq *cic, |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3432 | struct cfq_queue *cfqq) |
| 3433 | { |
| 3434 | cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq); |
| 3435 | cic_set_cfqq(cic, cfqq->new_cfqq, 1); |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 3436 | cfq_mark_cfqq_coop(cfqq->new_cfqq); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3437 | cfq_put_queue(cfqq); |
| 3438 | return cic_to_cfqq(cic, 1); |
| 3439 | } |
| 3440 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3441 | /* |
| 3442 | * Returns NULL if a new cfqq should be allocated, or the old cfqq if this |
| 3443 | * was the last process referring to said cfqq. |
| 3444 | */ |
| 3445 | static struct cfq_queue * |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3446 | split_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq) |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3447 | { |
| 3448 | if (cfqq_process_refs(cfqq) == 1) { |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3449 | cfqq->pid = current->pid; |
| 3450 | cfq_clear_cfqq_coop(cfqq); |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 3451 | cfq_clear_cfqq_split_coop(cfqq); |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3452 | return cfqq; |
| 3453 | } |
| 3454 | |
| 3455 | cic_set_cfqq(cic, NULL, 1); |
Shaohua Li | d02a2c0 | 2010-05-25 10:16:53 +0200 | [diff] [blame] | 3456 | |
| 3457 | cfq_put_cooperator(cfqq); |
| 3458 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3459 | cfq_put_queue(cfqq); |
| 3460 | return NULL; |
| 3461 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3462 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3463 | * Allocate cfq data structures associated with this request. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3464 | */ |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3465 | static int |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3466 | cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3467 | { |
| 3468 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Tejun Heo | f1f8cc9 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3469 | struct cfq_io_cq *cic = icq_to_cic(rq->elv.icq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3470 | const int rw = rq_data_dir(rq); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3471 | const bool is_sync = rq_is_sync(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3472 | struct cfq_queue *cfqq; |
Tejun Heo | d705ae6 | 2012-02-15 09:45:49 +0100 | [diff] [blame^] | 3473 | unsigned int changed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3474 | |
| 3475 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 3476 | |
Tejun Heo | 216284c | 2011-12-14 00:33:38 +0100 | [diff] [blame] | 3477 | spin_lock_irq(q->queue_lock); |
Tejun Heo | f1f8cc9 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3478 | |
| 3479 | /* handle changed notifications */ |
Tejun Heo | d705ae6 | 2012-02-15 09:45:49 +0100 | [diff] [blame^] | 3480 | changed = icq_get_changed(&cic->icq); |
| 3481 | if (unlikely(changed & ICQ_IOPRIO_CHANGED)) |
| 3482 | changed_ioprio(cic); |
Tejun Heo | f1f8cc9 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3483 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
Tejun Heo | d705ae6 | 2012-02-15 09:45:49 +0100 | [diff] [blame^] | 3484 | if (unlikely(changed & ICQ_CGROUP_CHANGED)) |
| 3485 | changed_cgroup(cic); |
Tejun Heo | f1f8cc9 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3486 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3487 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3488 | new_queue: |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3489 | cfqq = cic_to_cfqq(cic, is_sync); |
Vivek Goyal | 32f2e80 | 2009-07-09 22:13:16 +0200 | [diff] [blame] | 3490 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
Tejun Heo | c586980 | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3491 | cfqq = cfq_get_queue(cfqd, is_sync, cic->icq.ioc, gfp_mask); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3492 | cic_set_cfqq(cic, cfqq, is_sync); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3493 | } else { |
| 3494 | /* |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3495 | * If the queue was seeky for too long, break it apart. |
| 3496 | */ |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 3497 | if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) { |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3498 | cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq"); |
| 3499 | cfqq = split_cfqq(cic, cfqq); |
| 3500 | if (!cfqq) |
| 3501 | goto new_queue; |
| 3502 | } |
| 3503 | |
| 3504 | /* |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3505 | * Check to see if this queue is scheduled to merge with |
| 3506 | * another, closely cooperating queue. The merging of |
| 3507 | * queues happens here as it must be done in process context. |
| 3508 | * The reference on new_cfqq was taken in merge_cfqqs. |
| 3509 | */ |
| 3510 | if (cfqq->new_cfqq) |
| 3511 | cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3512 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3513 | |
| 3514 | cfqq->allocated[rw]++; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3515 | |
Jens Axboe | 6fae9c2 | 2011-03-01 15:04:39 -0500 | [diff] [blame] | 3516 | cfqq->ref++; |
Tejun Heo | a612fdd | 2011-12-14 00:33:41 +0100 | [diff] [blame] | 3517 | rq->elv.priv[0] = cfqq; |
| 3518 | rq->elv.priv[1] = cfq_ref_get_cfqg(cfqq->cfqg); |
Tejun Heo | 216284c | 2011-12-14 00:33:38 +0100 | [diff] [blame] | 3519 | spin_unlock_irq(q->queue_lock); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3520 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3521 | } |
| 3522 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 3523 | static void cfq_kick_queue(struct work_struct *work) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3524 | { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 3525 | struct cfq_data *cfqd = |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3526 | container_of(work, struct cfq_data, unplug_work); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3527 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3528 | |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 3529 | spin_lock_irq(q->queue_lock); |
Christoph Hellwig | 24ecfbe | 2011-04-18 11:41:33 +0200 | [diff] [blame] | 3530 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 3531 | spin_unlock_irq(q->queue_lock); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3532 | } |
| 3533 | |
| 3534 | /* |
| 3535 | * Timer running if the active_queue is currently idling inside its time slice |
| 3536 | */ |
| 3537 | static void cfq_idle_slice_timer(unsigned long data) |
| 3538 | { |
| 3539 | struct cfq_data *cfqd = (struct cfq_data *) data; |
| 3540 | struct cfq_queue *cfqq; |
| 3541 | unsigned long flags; |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 3542 | int timed_out = 1; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3543 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3544 | cfq_log(cfqd, "idle timer fired"); |
| 3545 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3546 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 3547 | |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 3548 | cfqq = cfqd->active_queue; |
| 3549 | if (cfqq) { |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 3550 | timed_out = 0; |
| 3551 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3552 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 3553 | * We saw a request before the queue expired, let it through |
| 3554 | */ |
| 3555 | if (cfq_cfqq_must_dispatch(cfqq)) |
| 3556 | goto out_kick; |
| 3557 | |
| 3558 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3559 | * expired |
| 3560 | */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3561 | if (cfq_slice_used(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3562 | goto expire; |
| 3563 | |
| 3564 | /* |
| 3565 | * only expire and reinvoke request handler, if there are |
| 3566 | * other queues with pending requests |
| 3567 | */ |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3568 | if (!cfqd->busy_queues) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3569 | goto out_cont; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3570 | |
| 3571 | /* |
| 3572 | * not expired and it has a request pending, let it dispatch |
| 3573 | */ |
Jens Axboe | 75e5098 | 2009-04-07 08:56:14 +0200 | [diff] [blame] | 3574 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3575 | goto out_kick; |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3576 | |
| 3577 | /* |
| 3578 | * Queue depth flag is reset only when the idle didn't succeed |
| 3579 | */ |
| 3580 | cfq_clear_cfqq_deep(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3581 | } |
| 3582 | expire: |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 3583 | cfq_slice_expired(cfqd, timed_out); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3584 | out_kick: |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3585 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3586 | out_cont: |
| 3587 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 3588 | } |
| 3589 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3590 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) |
| 3591 | { |
| 3592 | del_timer_sync(&cfqd->idle_slice_timer); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3593 | cancel_work_sync(&cfqd->unplug_work); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3594 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3595 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3596 | static void cfq_put_async_queues(struct cfq_data *cfqd) |
| 3597 | { |
| 3598 | int i; |
| 3599 | |
| 3600 | for (i = 0; i < IOPRIO_BE_NR; i++) { |
| 3601 | if (cfqd->async_cfqq[0][i]) |
| 3602 | cfq_put_queue(cfqd->async_cfqq[0][i]); |
| 3603 | if (cfqd->async_cfqq[1][i]) |
| 3604 | cfq_put_queue(cfqd->async_cfqq[1][i]); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3605 | } |
Oleg Nesterov | 2389d1e | 2007-11-05 08:58:05 +0100 | [diff] [blame] | 3606 | |
| 3607 | if (cfqd->async_idle_cfqq) |
| 3608 | cfq_put_queue(cfqd->async_idle_cfqq); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3609 | } |
| 3610 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3611 | static void cfq_exit_queue(struct elevator_queue *e) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3612 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3613 | struct cfq_data *cfqd = e->elevator_data; |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3614 | struct request_queue *q = cfqd->queue; |
Vivek Goyal | 56edf7d | 2011-05-19 15:38:22 -0400 | [diff] [blame] | 3615 | bool wait = false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3616 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3617 | cfq_shutdown_timer_wq(cfqd); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3618 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3619 | spin_lock_irq(q->queue_lock); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3620 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3621 | if (cfqd->active_queue) |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 3622 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3623 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3624 | cfq_put_async_queues(cfqd); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3625 | cfq_release_cfq_groups(cfqd); |
Vivek Goyal | 56edf7d | 2011-05-19 15:38:22 -0400 | [diff] [blame] | 3626 | |
| 3627 | /* |
| 3628 | * If there are groups which we could not unlink from blkcg list, |
| 3629 | * wait for a rcu period for them to be freed. |
| 3630 | */ |
| 3631 | if (cfqd->nr_blkcg_linked_grps) |
| 3632 | wait = true; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 3633 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3634 | spin_unlock_irq(q->queue_lock); |
Al Viro | a90d742 | 2006-03-18 12:05:37 -0500 | [diff] [blame] | 3635 | |
| 3636 | cfq_shutdown_timer_wq(cfqd); |
| 3637 | |
Vivek Goyal | 56edf7d | 2011-05-19 15:38:22 -0400 | [diff] [blame] | 3638 | /* |
| 3639 | * Wait for cfqg->blkg->key accessors to exit their grace periods. |
| 3640 | * Do this wait only if there are other unlinked groups out |
| 3641 | * there. This can happen if cgroup deletion path claimed the |
| 3642 | * responsibility of cleaning up a group before queue cleanup code |
| 3643 | * get to the group. |
| 3644 | * |
| 3645 | * Do not call synchronize_rcu() unconditionally as there are drivers |
| 3646 | * which create/delete request queue hundreds of times during scan/boot |
| 3647 | * and synchronize_rcu() can take significant time and slow down boot. |
| 3648 | */ |
| 3649 | if (wait) |
| 3650 | synchronize_rcu(); |
Vivek Goyal | 2abae55 | 2011-05-23 10:02:19 +0200 | [diff] [blame] | 3651 | |
| 3652 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 3653 | /* Free up per cpu stats for root group */ |
| 3654 | free_percpu(cfqd->root_group.blkg.stats_cpu); |
| 3655 | #endif |
Vivek Goyal | 56edf7d | 2011-05-19 15:38:22 -0400 | [diff] [blame] | 3656 | kfree(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3657 | } |
| 3658 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3659 | static void *cfq_init_queue(struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3660 | { |
| 3661 | struct cfq_data *cfqd; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 3662 | int i, j; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3663 | struct cfq_group *cfqg; |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 3664 | struct cfq_rb_root *st; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3665 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 3666 | cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); |
Tejun Heo | a73f730 | 2011-12-14 00:33:37 +0100 | [diff] [blame] | 3667 | if (!cfqd) |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 3668 | return NULL; |
Konstantin Khlebnikov | 80b15c7 | 2010-05-20 23:21:41 +0400 | [diff] [blame] | 3669 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 3670 | /* Init root service tree */ |
| 3671 | cfqd->grp_service_tree = CFQ_RB_ROOT; |
| 3672 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3673 | /* Init root group */ |
| 3674 | cfqg = &cfqd->root_group; |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 3675 | for_each_cfqg_st(cfqg, i, j, st) |
| 3676 | *st = CFQ_RB_ROOT; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 3677 | RB_CLEAR_NODE(&cfqg->rb_node); |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 3678 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 3679 | /* Give preference to root group over other groups */ |
| 3680 | cfqg->weight = 2*BLKIO_WEIGHT_DEFAULT; |
| 3681 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 3682 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3683 | /* |
Vivek Goyal | 56edf7d | 2011-05-19 15:38:22 -0400 | [diff] [blame] | 3684 | * Set root group reference to 2. One reference will be dropped when |
| 3685 | * all groups on cfqd->cfqg_list are being deleted during queue exit. |
| 3686 | * Other reference will remain there as we don't want to delete this |
| 3687 | * group as it is statically allocated and gets destroyed when |
| 3688 | * throtl_data goes away. |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3689 | */ |
Vivek Goyal | 56edf7d | 2011-05-19 15:38:22 -0400 | [diff] [blame] | 3690 | cfqg->ref = 2; |
Vivek Goyal | 5624a4e | 2011-05-19 15:38:28 -0400 | [diff] [blame] | 3691 | |
| 3692 | if (blkio_alloc_blkg_stats(&cfqg->blkg)) { |
| 3693 | kfree(cfqg); |
| 3694 | kfree(cfqd); |
| 3695 | return NULL; |
| 3696 | } |
| 3697 | |
Vivek Goyal | dcf097b | 2010-04-22 11:54:52 -0400 | [diff] [blame] | 3698 | rcu_read_lock(); |
Vivek Goyal | 5624a4e | 2011-05-19 15:38:28 -0400 | [diff] [blame] | 3699 | |
Vivek Goyal | e98ef89 | 2010-06-18 10:39:47 -0400 | [diff] [blame] | 3700 | cfq_blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, |
| 3701 | (void *)cfqd, 0); |
Vivek Goyal | dcf097b | 2010-04-22 11:54:52 -0400 | [diff] [blame] | 3702 | rcu_read_unlock(); |
Vivek Goyal | 56edf7d | 2011-05-19 15:38:22 -0400 | [diff] [blame] | 3703 | cfqd->nr_blkcg_linked_grps++; |
| 3704 | |
| 3705 | /* Add group on cfqd->cfqg_list */ |
| 3706 | hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 3707 | #endif |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 3708 | /* |
| 3709 | * Not strictly needed (since RB_ROOT just clears the node and we |
| 3710 | * zeroed cfqd on alloc), but better be safe in case someone decides |
| 3711 | * to add magic to the rb code |
| 3712 | */ |
| 3713 | for (i = 0; i < CFQ_PRIO_LISTS; i++) |
| 3714 | cfqd->prio_trees[i] = RB_ROOT; |
| 3715 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 3716 | /* |
| 3717 | * Our fallback cfqq if cfq_find_alloc_queue() runs into OOM issues. |
| 3718 | * Grab a permanent reference to it, so that the normal code flow |
| 3719 | * will not attempt to free it. |
| 3720 | */ |
| 3721 | cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); |
Shaohua Li | 30d7b94 | 2011-01-07 08:46:59 +0100 | [diff] [blame] | 3722 | cfqd->oom_cfqq.ref++; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3723 | cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 3724 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3725 | cfqd->queue = q; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3726 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3727 | init_timer(&cfqd->idle_slice_timer); |
| 3728 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; |
| 3729 | cfqd->idle_slice_timer.data = (unsigned long) cfqd; |
| 3730 | |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3731 | INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3732 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3733 | cfqd->cfq_quantum = cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3734 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |
| 3735 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3736 | cfqd->cfq_back_max = cfq_back_max; |
| 3737 | cfqd->cfq_back_penalty = cfq_back_penalty; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3738 | cfqd->cfq_slice[0] = cfq_slice_async; |
| 3739 | cfqd->cfq_slice[1] = cfq_slice_sync; |
| 3740 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; |
| 3741 | cfqd->cfq_slice_idle = cfq_slice_idle; |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 3742 | cfqd->cfq_group_idle = cfq_group_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3743 | cfqd->cfq_latency = 1; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3744 | cfqd->hw_tag = -1; |
Corrado Zoccolo | edc7113 | 2009-12-09 20:56:04 +0100 | [diff] [blame] | 3745 | /* |
| 3746 | * we optimistically start assuming sync ops weren't delayed in last |
| 3747 | * second, in order to have larger depth for async operations. |
| 3748 | */ |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 3749 | cfqd->last_delayed_sync = jiffies - HZ; |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 3750 | return cfqd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3751 | } |
| 3752 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3753 | /* |
| 3754 | * sysfs parts below --> |
| 3755 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3756 | static ssize_t |
| 3757 | cfq_var_show(unsigned int var, char *page) |
| 3758 | { |
| 3759 | return sprintf(page, "%d\n", var); |
| 3760 | } |
| 3761 | |
| 3762 | static ssize_t |
| 3763 | cfq_var_store(unsigned int *var, const char *page, size_t count) |
| 3764 | { |
| 3765 | char *p = (char *) page; |
| 3766 | |
| 3767 | *var = simple_strtoul(p, &p, 10); |
| 3768 | return count; |
| 3769 | } |
| 3770 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3771 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3772 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3773 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3774 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3775 | unsigned int __data = __VAR; \ |
| 3776 | if (__CONV) \ |
| 3777 | __data = jiffies_to_msecs(__data); \ |
| 3778 | return cfq_var_show(__data, (page)); \ |
| 3779 | } |
| 3780 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3781 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); |
| 3782 | SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1); |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3783 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); |
| 3784 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3785 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 3786 | SHOW_FUNCTION(cfq_group_idle_show, cfqd->cfq_group_idle, 1); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3787 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); |
| 3788 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); |
| 3789 | SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3790 | SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3791 | #undef SHOW_FUNCTION |
| 3792 | |
| 3793 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3794 | static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3795 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3796 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3797 | unsigned int __data; \ |
| 3798 | int ret = cfq_var_store(&__data, (page), count); \ |
| 3799 | if (__data < (MIN)) \ |
| 3800 | __data = (MIN); \ |
| 3801 | else if (__data > (MAX)) \ |
| 3802 | __data = (MAX); \ |
| 3803 | if (__CONV) \ |
| 3804 | *(__PTR) = msecs_to_jiffies(__data); \ |
| 3805 | else \ |
| 3806 | *(__PTR) = __data; \ |
| 3807 | return ret; \ |
| 3808 | } |
| 3809 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 3810 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, |
| 3811 | UINT_MAX, 1); |
| 3812 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, |
| 3813 | UINT_MAX, 1); |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3814 | STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 3815 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, |
| 3816 | UINT_MAX, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3817 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 3818 | STORE_FUNCTION(cfq_group_idle_store, &cfqd->cfq_group_idle, 0, UINT_MAX, 1); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3819 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); |
| 3820 | STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 3821 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, |
| 3822 | UINT_MAX, 0); |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3823 | STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3824 | #undef STORE_FUNCTION |
| 3825 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3826 | #define CFQ_ATTR(name) \ |
| 3827 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3828 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3829 | static struct elv_fs_entry cfq_attrs[] = { |
| 3830 | CFQ_ATTR(quantum), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3831 | CFQ_ATTR(fifo_expire_sync), |
| 3832 | CFQ_ATTR(fifo_expire_async), |
| 3833 | CFQ_ATTR(back_seek_max), |
| 3834 | CFQ_ATTR(back_seek_penalty), |
| 3835 | CFQ_ATTR(slice_sync), |
| 3836 | CFQ_ATTR(slice_async), |
| 3837 | CFQ_ATTR(slice_async_rq), |
| 3838 | CFQ_ATTR(slice_idle), |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 3839 | CFQ_ATTR(group_idle), |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3840 | CFQ_ATTR(low_latency), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3841 | __ATTR_NULL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3842 | }; |
| 3843 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3844 | static struct elevator_type iosched_cfq = { |
| 3845 | .ops = { |
| 3846 | .elevator_merge_fn = cfq_merge, |
| 3847 | .elevator_merged_fn = cfq_merged_request, |
| 3848 | .elevator_merge_req_fn = cfq_merged_requests, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 3849 | .elevator_allow_merge_fn = cfq_allow_merge, |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 3850 | .elevator_bio_merged_fn = cfq_bio_merged, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3851 | .elevator_dispatch_fn = cfq_dispatch_requests, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3852 | .elevator_add_req_fn = cfq_insert_request, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3853 | .elevator_activate_req_fn = cfq_activate_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3854 | .elevator_deactivate_req_fn = cfq_deactivate_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3855 | .elevator_completed_req_fn = cfq_completed_request, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 3856 | .elevator_former_req_fn = elv_rb_former_request, |
| 3857 | .elevator_latter_req_fn = elv_rb_latter_request, |
Tejun Heo | 9b84cac | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3858 | .elevator_init_icq_fn = cfq_init_icq, |
Tejun Heo | 7e5a879 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3859 | .elevator_exit_icq_fn = cfq_exit_icq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3860 | .elevator_set_req_fn = cfq_set_request, |
| 3861 | .elevator_put_req_fn = cfq_put_request, |
| 3862 | .elevator_may_queue_fn = cfq_may_queue, |
| 3863 | .elevator_init_fn = cfq_init_queue, |
| 3864 | .elevator_exit_fn = cfq_exit_queue, |
| 3865 | }, |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3866 | .icq_size = sizeof(struct cfq_io_cq), |
| 3867 | .icq_align = __alignof__(struct cfq_io_cq), |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3868 | .elevator_attrs = cfq_attrs, |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3869 | .elevator_name = "cfq", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3870 | .elevator_owner = THIS_MODULE, |
| 3871 | }; |
| 3872 | |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3873 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 3874 | static struct blkio_policy_type blkio_policy_cfq = { |
| 3875 | .ops = { |
| 3876 | .blkio_unlink_group_fn = cfq_unlink_blkio_group, |
| 3877 | .blkio_update_group_weight_fn = cfq_update_blkio_group_weight, |
| 3878 | }, |
Vivek Goyal | 062a644 | 2010-09-15 17:06:33 -0400 | [diff] [blame] | 3879 | .plid = BLKIO_POLICY_PROP, |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3880 | }; |
| 3881 | #else |
| 3882 | static struct blkio_policy_type blkio_policy_cfq; |
| 3883 | #endif |
| 3884 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3885 | static int __init cfq_init(void) |
| 3886 | { |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3887 | int ret; |
| 3888 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3889 | /* |
| 3890 | * could be 0 on HZ < 1000 setups |
| 3891 | */ |
| 3892 | if (!cfq_slice_async) |
| 3893 | cfq_slice_async = 1; |
| 3894 | if (!cfq_slice_idle) |
| 3895 | cfq_slice_idle = 1; |
| 3896 | |
Vivek Goyal | 80bdf0c | 2010-08-23 12:24:26 +0200 | [diff] [blame] | 3897 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 3898 | if (!cfq_group_idle) |
| 3899 | cfq_group_idle = 1; |
| 3900 | #else |
| 3901 | cfq_group_idle = 0; |
| 3902 | #endif |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3903 | cfq_pool = KMEM_CACHE(cfq_queue, 0); |
| 3904 | if (!cfq_pool) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3905 | return -ENOMEM; |
| 3906 | |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3907 | ret = elv_register(&iosched_cfq); |
| 3908 | if (ret) { |
| 3909 | kmem_cache_destroy(cfq_pool); |
| 3910 | return ret; |
| 3911 | } |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3912 | |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3913 | blkio_policy_register(&blkio_policy_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3914 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 3915 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3916 | } |
| 3917 | |
| 3918 | static void __exit cfq_exit(void) |
| 3919 | { |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3920 | blkio_policy_unregister(&blkio_policy_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3921 | elv_unregister(&iosched_cfq); |
Tejun Heo | 3d3c237 | 2011-12-14 00:33:42 +0100 | [diff] [blame] | 3922 | kmem_cache_destroy(cfq_pool); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3923 | } |
| 3924 | |
| 3925 | module_init(cfq_init); |
| 3926 | module_exit(cfq_exit); |
| 3927 | |
| 3928 | MODULE_AUTHOR("Jens Axboe"); |
| 3929 | MODULE_LICENSE("GPL"); |
| 3930 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |