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> |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 17 | #include "blk-cgroup.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | |
| 19 | /* |
| 20 | * tunables |
| 21 | */ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 22 | /* max queue in one round of service */ |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 23 | static const int cfq_quantum = 8; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 24 | static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 25 | /* maximum backwards seek, in KiB */ |
| 26 | static const int cfq_back_max = 16 * 1024; |
| 27 | /* penalty of a backwards seek */ |
| 28 | static const int cfq_back_penalty = 2; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 29 | static const int cfq_slice_sync = HZ / 10; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 30 | static int cfq_slice_async = HZ / 25; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 31 | static const int cfq_slice_async_rq = 2; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 32 | static int cfq_slice_idle = HZ / 125; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 33 | static const int cfq_target_latency = HZ * 3/10; /* 300 ms */ |
| 34 | static const int cfq_hist_divisor = 4; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 35 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 36 | /* |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 37 | * offset from end of service tree |
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 | #define CFQ_IDLE_DELAY (HZ / 5) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 40 | |
| 41 | /* |
| 42 | * below this threshold, we consider thinktime immediate |
| 43 | */ |
| 44 | #define CFQ_MIN_TT (2) |
| 45 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 46 | #define CFQ_SLICE_SCALE (5) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 47 | #define CFQ_HW_QUEUE_MIN (5) |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 48 | #define CFQ_SERVICE_SHIFT 12 |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 49 | |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 50 | #define CFQQ_SEEK_THR (sector_t)(8 * 100) |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 51 | #define CFQQ_CLOSE_THR (sector_t)(8 * 1024) |
Corrado Zoccolo | 41647e7 | 2010-02-27 19:45:40 +0100 | [diff] [blame] | 52 | #define CFQQ_SECT_THR_NONROT (sector_t)(2 * 32) |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 53 | #define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8) |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 54 | |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 55 | #define RQ_CIC(rq) \ |
| 56 | ((struct cfq_io_context *) (rq)->elevator_private) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 57 | #define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 59 | static struct kmem_cache *cfq_pool; |
| 60 | static struct kmem_cache *cfq_ioc_pool; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 62 | static DEFINE_PER_CPU(unsigned long, cfq_ioc_count); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 63 | static struct completion *ioc_gone; |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 64 | static DEFINE_SPINLOCK(ioc_gone_lock); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 65 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 66 | #define CFQ_PRIO_LISTS IOPRIO_BE_NR |
| 67 | #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 68 | #define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT) |
| 69 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 70 | #define sample_valid(samples) ((samples) > 80) |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 71 | #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] | 72 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 73 | /* |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 74 | * Most of our rbtree usage is for sorting with min extraction, so |
| 75 | * if we cache the leftmost node we don't have to walk down the tree |
| 76 | * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should |
| 77 | * move this into the elevator for the rq sorting as well. |
| 78 | */ |
| 79 | struct cfq_rb_root { |
| 80 | struct rb_root rb; |
| 81 | struct rb_node *left; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 82 | unsigned count; |
Richard Kennedy | 73e9ffd | 2010-03-01 10:50:20 +0100 | [diff] [blame] | 83 | unsigned total_weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 84 | u64 min_vdisktime; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 85 | struct rb_node *active; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 86 | }; |
Richard Kennedy | 73e9ffd | 2010-03-01 10:50:20 +0100 | [diff] [blame] | 87 | #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, .left = NULL, \ |
| 88 | .count = 0, .min_vdisktime = 0, } |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 89 | |
| 90 | /* |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 91 | * Per process-grouping structure |
| 92 | */ |
| 93 | struct cfq_queue { |
| 94 | /* reference count */ |
| 95 | atomic_t ref; |
| 96 | /* various state flags, see below */ |
| 97 | unsigned int flags; |
| 98 | /* parent cfq_data */ |
| 99 | struct cfq_data *cfqd; |
| 100 | /* service_tree member */ |
| 101 | struct rb_node rb_node; |
| 102 | /* service_tree key */ |
| 103 | unsigned long rb_key; |
| 104 | /* prio tree member */ |
| 105 | struct rb_node p_node; |
| 106 | /* prio tree root we belong to, if any */ |
| 107 | struct rb_root *p_root; |
| 108 | /* sorted list of pending requests */ |
| 109 | struct rb_root sort_list; |
| 110 | /* if fifo isn't expired, next request to serve */ |
| 111 | struct request *next_rq; |
| 112 | /* requests queued in sort_list */ |
| 113 | int queued[2]; |
| 114 | /* currently allocated requests */ |
| 115 | int allocated[2]; |
| 116 | /* fifo list of requests in sort_list */ |
| 117 | struct list_head fifo; |
| 118 | |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 119 | /* time when queue got scheduled in to dispatch first request. */ |
| 120 | unsigned long dispatch_start; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 121 | unsigned int allocated_slice; |
Richard Kennedy | c4081ba | 2010-02-22 13:49:24 +0100 | [diff] [blame] | 122 | unsigned int slice_dispatch; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 123 | /* time when first request from queue completed and slice started. */ |
| 124 | unsigned long slice_start; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 125 | unsigned long slice_end; |
| 126 | long slice_resid; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 127 | |
| 128 | /* pending metadata requests */ |
| 129 | int meta_pending; |
| 130 | /* number of requests that are on the dispatch list or inside driver */ |
| 131 | int dispatched; |
| 132 | |
| 133 | /* io prio of this group */ |
| 134 | unsigned short ioprio, org_ioprio; |
| 135 | unsigned short ioprio_class, org_ioprio_class; |
| 136 | |
Richard Kennedy | c4081ba | 2010-02-22 13:49:24 +0100 | [diff] [blame] | 137 | pid_t pid; |
| 138 | |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 139 | u32 seek_history; |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 140 | sector_t last_request_pos; |
| 141 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 142 | struct cfq_rb_root *service_tree; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 143 | struct cfq_queue *new_cfqq; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 144 | struct cfq_group *cfqg; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 145 | struct cfq_group *orig_cfqg; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 146 | }; |
| 147 | |
| 148 | /* |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 149 | * First index in the service_trees. |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 150 | * IDLE is handled separately, so it has negative index |
| 151 | */ |
| 152 | enum wl_prio_t { |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 153 | BE_WORKLOAD = 0, |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 154 | RT_WORKLOAD = 1, |
| 155 | IDLE_WORKLOAD = 2, |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 156 | }; |
| 157 | |
| 158 | /* |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 159 | * Second index in the service_trees. |
| 160 | */ |
| 161 | enum wl_type_t { |
| 162 | ASYNC_WORKLOAD = 0, |
| 163 | SYNC_NOIDLE_WORKLOAD = 1, |
| 164 | SYNC_WORKLOAD = 2 |
| 165 | }; |
| 166 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 167 | /* This is per cgroup per device grouping structure */ |
| 168 | struct cfq_group { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 169 | /* group service_tree member */ |
| 170 | struct rb_node rb_node; |
| 171 | |
| 172 | /* group service_tree key */ |
| 173 | u64 vdisktime; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 174 | unsigned int weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 175 | bool on_st; |
| 176 | |
| 177 | /* number of cfqq currently on this group */ |
| 178 | int nr_cfqq; |
| 179 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 180 | /* Per group busy queus average. Useful for workload slice calc. */ |
| 181 | unsigned int busy_queues_avg[2]; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 182 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 183 | * rr lists of queues with requests, onle rr for each priority class. |
| 184 | * Counts are embedded in the cfq_rb_root |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 185 | */ |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 186 | struct cfq_rb_root service_trees[2][3]; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 187 | struct cfq_rb_root service_tree_idle; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 188 | |
| 189 | unsigned long saved_workload_slice; |
| 190 | enum wl_type_t saved_workload; |
| 191 | enum wl_prio_t saved_serving_prio; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 192 | struct blkio_group blkg; |
| 193 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 194 | struct hlist_node cfqd_node; |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 195 | atomic_t ref; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 196 | #endif |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 197 | }; |
| 198 | |
| 199 | /* |
| 200 | * Per block device queue structure |
| 201 | */ |
| 202 | struct cfq_data { |
| 203 | struct request_queue *queue; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 204 | /* Root service tree for cfq_groups */ |
| 205 | struct cfq_rb_root grp_service_tree; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 206 | struct cfq_group root_group; |
| 207 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 208 | /* |
| 209 | * The priority currently being served |
| 210 | */ |
| 211 | enum wl_prio_t serving_prio; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 212 | enum wl_type_t serving_type; |
| 213 | unsigned long workload_expires; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 214 | struct cfq_group *serving_group; |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 215 | bool noidle_tree_requires_idle; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 216 | |
| 217 | /* |
| 218 | * Each priority tree is sorted by next_request position. These |
| 219 | * trees are used when determining if two or more queues are |
| 220 | * interleaving requests (see cfq_close_cooperator). |
| 221 | */ |
| 222 | struct rb_root prio_trees[CFQ_PRIO_LISTS]; |
| 223 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 224 | unsigned int busy_queues; |
| 225 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 226 | int rq_in_driver; |
| 227 | int rq_in_flight[2]; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 228 | |
| 229 | /* |
| 230 | * queue-depth detection |
| 231 | */ |
| 232 | int rq_queued; |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 233 | int hw_tag; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 234 | /* |
| 235 | * hw_tag can be |
| 236 | * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection) |
| 237 | * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth) |
| 238 | * 0 => no NCQ |
| 239 | */ |
| 240 | int hw_tag_est_depth; |
| 241 | unsigned int hw_tag_samples; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 242 | |
| 243 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 244 | * idle window management |
| 245 | */ |
| 246 | struct timer_list idle_slice_timer; |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 247 | struct work_struct unplug_work; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 248 | |
| 249 | struct cfq_queue *active_queue; |
| 250 | struct cfq_io_context *active_cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 251 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 252 | /* |
| 253 | * async queue for each priority case |
| 254 | */ |
| 255 | struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; |
| 256 | struct cfq_queue *async_idle_cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 257 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 258 | sector_t last_position; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | /* |
| 261 | * tunables, see top of file |
| 262 | */ |
| 263 | unsigned int cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 264 | unsigned int cfq_fifo_expire[2]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | unsigned int cfq_back_penalty; |
| 266 | unsigned int cfq_back_max; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 267 | unsigned int cfq_slice[2]; |
| 268 | unsigned int cfq_slice_async_rq; |
| 269 | unsigned int cfq_slice_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 270 | unsigned int cfq_latency; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 271 | unsigned int cfq_group_isolation; |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 272 | |
| 273 | struct list_head cic_list; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 275 | /* |
| 276 | * Fallback dummy cfqq for extreme OOM conditions |
| 277 | */ |
| 278 | struct cfq_queue oom_cfqq; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 279 | |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 280 | unsigned long last_delayed_sync; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 281 | |
| 282 | /* List of cfq groups being managed on this device*/ |
| 283 | struct hlist_head cfqg_list; |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 284 | struct rcu_head rcu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | }; |
| 286 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 287 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd); |
| 288 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 289 | static struct cfq_rb_root *service_tree_for(struct cfq_group *cfqg, |
| 290 | enum wl_prio_t prio, |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 291 | enum wl_type_t type) |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 292 | { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 293 | if (!cfqg) |
| 294 | return NULL; |
| 295 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 296 | if (prio == IDLE_WORKLOAD) |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 297 | return &cfqg->service_tree_idle; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 298 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 299 | return &cfqg->service_trees[prio][type]; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 300 | } |
| 301 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 302 | enum cfqq_state_flags { |
Jens Axboe | b0b8d74 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 303 | CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ |
| 304 | CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 305 | CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ |
Jens Axboe | b0b8d74 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 306 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ |
Jens Axboe | b0b8d74 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 307 | CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ |
| 308 | CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ |
| 309 | CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 310 | CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 311 | CFQ_CFQQ_FLAG_sync, /* synchronous queue */ |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 312 | CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 313 | CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */ |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 314 | CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 315 | CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 316 | }; |
| 317 | |
| 318 | #define CFQ_CFQQ_FNS(name) \ |
| 319 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ |
| 320 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 321 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 322 | } \ |
| 323 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ |
| 324 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 325 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 326 | } \ |
| 327 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ |
| 328 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 329 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 330 | } |
| 331 | |
| 332 | CFQ_CFQQ_FNS(on_rr); |
| 333 | CFQ_CFQQ_FNS(wait_request); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 334 | CFQ_CFQQ_FNS(must_dispatch); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 335 | CFQ_CFQQ_FNS(must_alloc_slice); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 336 | CFQ_CFQQ_FNS(fifo_expire); |
| 337 | CFQ_CFQQ_FNS(idle_window); |
| 338 | CFQ_CFQQ_FNS(prio_changed); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 339 | CFQ_CFQQ_FNS(slice_new); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 340 | CFQ_CFQQ_FNS(sync); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 341 | CFQ_CFQQ_FNS(coop); |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 342 | CFQ_CFQQ_FNS(split_coop); |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 343 | CFQ_CFQQ_FNS(deep); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 344 | CFQ_CFQQ_FNS(wait_busy); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 345 | #undef CFQ_CFQQ_FNS |
| 346 | |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 347 | #ifdef CONFIG_DEBUG_CFQ_IOSCHED |
| 348 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 349 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \ |
| 350 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ |
| 351 | blkg_path(&(cfqq)->cfqg->blkg), ##args); |
| 352 | |
| 353 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) \ |
| 354 | blk_add_trace_msg((cfqd)->queue, "%s " fmt, \ |
| 355 | blkg_path(&(cfqg)->blkg), ##args); \ |
| 356 | |
| 357 | #else |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 358 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 359 | blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args) |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 360 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0); |
| 361 | #endif |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 362 | #define cfq_log(cfqd, fmt, args...) \ |
| 363 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) |
| 364 | |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 365 | /* Traverses through cfq group service trees */ |
| 366 | #define for_each_cfqg_st(cfqg, i, j, st) \ |
| 367 | for (i = 0; i <= IDLE_WORKLOAD; i++) \ |
| 368 | for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\ |
| 369 | : &cfqg->service_tree_idle; \ |
| 370 | (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \ |
| 371 | (i == IDLE_WORKLOAD && j == 0); \ |
| 372 | j++, st = i < IDLE_WORKLOAD ? \ |
| 373 | &cfqg->service_trees[i][j]: NULL) \ |
| 374 | |
| 375 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 376 | static inline enum wl_prio_t cfqq_prio(struct cfq_queue *cfqq) |
| 377 | { |
| 378 | if (cfq_class_idle(cfqq)) |
| 379 | return IDLE_WORKLOAD; |
| 380 | if (cfq_class_rt(cfqq)) |
| 381 | return RT_WORKLOAD; |
| 382 | return BE_WORKLOAD; |
| 383 | } |
| 384 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 385 | |
| 386 | static enum wl_type_t cfqq_type(struct cfq_queue *cfqq) |
| 387 | { |
| 388 | if (!cfq_cfqq_sync(cfqq)) |
| 389 | return ASYNC_WORKLOAD; |
| 390 | if (!cfq_cfqq_idle_window(cfqq)) |
| 391 | return SYNC_NOIDLE_WORKLOAD; |
| 392 | return SYNC_WORKLOAD; |
| 393 | } |
| 394 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 395 | static inline int cfq_group_busy_queues_wl(enum wl_prio_t wl, |
| 396 | struct cfq_data *cfqd, |
| 397 | struct cfq_group *cfqg) |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 398 | { |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 399 | if (wl == IDLE_WORKLOAD) |
| 400 | return cfqg->service_tree_idle.count; |
| 401 | |
| 402 | return cfqg->service_trees[wl][ASYNC_WORKLOAD].count |
| 403 | + cfqg->service_trees[wl][SYNC_NOIDLE_WORKLOAD].count |
| 404 | + cfqg->service_trees[wl][SYNC_WORKLOAD].count; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 405 | } |
| 406 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 407 | static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, |
| 408 | struct cfq_group *cfqg) |
| 409 | { |
| 410 | return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count |
| 411 | + cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count; |
| 412 | } |
| 413 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 414 | static void cfq_dispatch_insert(struct request_queue *, struct request *); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 415 | static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 416 | struct io_context *, gfp_t); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 417 | static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *, |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 418 | struct io_context *); |
| 419 | |
| 420 | static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 421 | bool is_sync) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 422 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 423 | return cic->cfqq[is_sync]; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 424 | } |
| 425 | |
| 426 | static inline void cic_set_cfqq(struct cfq_io_context *cic, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 427 | struct cfq_queue *cfqq, bool is_sync) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 428 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 429 | cic->cfqq[is_sync] = cfqq; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 430 | } |
| 431 | |
| 432 | /* |
| 433 | * We regard a request as SYNC, if it's either a read or has the SYNC bit |
| 434 | * set (in which case it could also be direct WRITE). |
| 435 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 436 | static inline bool cfq_bio_sync(struct bio *bio) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 437 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 438 | return bio_data_dir(bio) == READ || bio_rw_flagged(bio, BIO_RW_SYNCIO); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 439 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | /* |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 442 | * scheduler run of queue, if there are requests pending and no one in the |
| 443 | * driver that will restart queueing |
| 444 | */ |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 445 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 446 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 447 | if (cfqd->busy_queues) { |
| 448 | cfq_log(cfqd, "schedule dispatch"); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 449 | kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 450 | } |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 451 | } |
| 452 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 453 | static int cfq_queue_empty(struct request_queue *q) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 454 | { |
| 455 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 456 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 457 | return !cfqd->rq_queued; |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 458 | } |
| 459 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | /* |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 461 | * Scale schedule slice based on io priority. Use the sync time slice only |
| 462 | * if a queue is marked sync and has sync io queued. A sync queue with async |
| 463 | * io only, should not get full sync slice length. |
| 464 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 465 | static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync, |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 466 | unsigned short prio) |
| 467 | { |
| 468 | const int base_slice = cfqd->cfq_slice[sync]; |
| 469 | |
| 470 | WARN_ON(prio >= IOPRIO_BE_NR); |
| 471 | |
| 472 | return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); |
| 473 | } |
| 474 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 475 | static inline int |
| 476 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 477 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 478 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 479 | } |
| 480 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 481 | static inline u64 cfq_scale_slice(unsigned long delta, struct cfq_group *cfqg) |
| 482 | { |
| 483 | u64 d = delta << CFQ_SERVICE_SHIFT; |
| 484 | |
| 485 | d = d * BLKIO_WEIGHT_DEFAULT; |
| 486 | do_div(d, cfqg->weight); |
| 487 | return d; |
| 488 | } |
| 489 | |
| 490 | static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime) |
| 491 | { |
| 492 | s64 delta = (s64)(vdisktime - min_vdisktime); |
| 493 | if (delta > 0) |
| 494 | min_vdisktime = vdisktime; |
| 495 | |
| 496 | return min_vdisktime; |
| 497 | } |
| 498 | |
| 499 | static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime) |
| 500 | { |
| 501 | s64 delta = (s64)(vdisktime - min_vdisktime); |
| 502 | if (delta < 0) |
| 503 | min_vdisktime = vdisktime; |
| 504 | |
| 505 | return min_vdisktime; |
| 506 | } |
| 507 | |
| 508 | static void update_min_vdisktime(struct cfq_rb_root *st) |
| 509 | { |
| 510 | u64 vdisktime = st->min_vdisktime; |
| 511 | struct cfq_group *cfqg; |
| 512 | |
| 513 | if (st->active) { |
| 514 | cfqg = rb_entry_cfqg(st->active); |
| 515 | vdisktime = cfqg->vdisktime; |
| 516 | } |
| 517 | |
| 518 | if (st->left) { |
| 519 | cfqg = rb_entry_cfqg(st->left); |
| 520 | vdisktime = min_vdisktime(vdisktime, cfqg->vdisktime); |
| 521 | } |
| 522 | |
| 523 | st->min_vdisktime = max_vdisktime(st->min_vdisktime, vdisktime); |
| 524 | } |
| 525 | |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 526 | /* |
| 527 | * get averaged number of queues of RT/BE priority. |
| 528 | * average is updated, with a formula that gives more weight to higher numbers, |
| 529 | * to quickly follows sudden increases and decrease slowly |
| 530 | */ |
| 531 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 532 | static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd, |
| 533 | struct cfq_group *cfqg, bool rt) |
Jens Axboe | 5869619 | 2009-10-28 09:27:07 +0100 | [diff] [blame] | 534 | { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 535 | unsigned min_q, max_q; |
| 536 | unsigned mult = cfq_hist_divisor - 1; |
| 537 | unsigned round = cfq_hist_divisor / 2; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 538 | unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg); |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 539 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 540 | min_q = min(cfqg->busy_queues_avg[rt], busy); |
| 541 | max_q = max(cfqg->busy_queues_avg[rt], busy); |
| 542 | cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) / |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 543 | cfq_hist_divisor; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 544 | return cfqg->busy_queues_avg[rt]; |
| 545 | } |
| 546 | |
| 547 | static inline unsigned |
| 548 | cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 549 | { |
| 550 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 551 | |
| 552 | return cfq_target_latency * cfqg->weight / st->total_weight; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 553 | } |
| 554 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 555 | static inline void |
| 556 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 557 | { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 558 | unsigned slice = cfq_prio_to_slice(cfqd, cfqq); |
| 559 | if (cfqd->cfq_latency) { |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 560 | /* |
| 561 | * interested queues (we consider only the ones with the same |
| 562 | * priority class in the cfq group) |
| 563 | */ |
| 564 | unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg, |
| 565 | cfq_class_rt(cfqq)); |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 566 | unsigned sync_slice = cfqd->cfq_slice[1]; |
| 567 | unsigned expect_latency = sync_slice * iq; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 568 | unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg); |
| 569 | |
| 570 | if (expect_latency > group_slice) { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 571 | unsigned base_low_slice = 2 * cfqd->cfq_slice_idle; |
| 572 | /* scale low_slice according to IO priority |
| 573 | * and sync vs async */ |
| 574 | unsigned low_slice = |
| 575 | min(slice, base_low_slice * slice / sync_slice); |
| 576 | /* the adapted slice value is scaled to fit all iqs |
| 577 | * into the target latency */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 578 | slice = max(slice * group_slice / expect_latency, |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 579 | low_slice); |
| 580 | } |
| 581 | } |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 582 | cfqq->slice_start = jiffies; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 583 | cfqq->slice_end = jiffies + slice; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 584 | cfqq->allocated_slice = slice; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 585 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 586 | } |
| 587 | |
| 588 | /* |
| 589 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end |
| 590 | * isn't valid until the first request from the dispatch is activated |
| 591 | * and the slice time set. |
| 592 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 593 | static inline bool cfq_slice_used(struct cfq_queue *cfqq) |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 594 | { |
| 595 | if (cfq_cfqq_slice_new(cfqq)) |
| 596 | return 0; |
| 597 | if (time_before(jiffies, cfqq->slice_end)) |
| 598 | return 0; |
| 599 | |
| 600 | return 1; |
| 601 | } |
| 602 | |
| 603 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 604 | * 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] | 605 | * 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] | 606 | * behind the head is penalized and only allowed to a certain extent. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 608 | static struct request * |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 609 | 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] | 610 | { |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 611 | sector_t s1, s2, d1 = 0, d2 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | unsigned long back_max; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 613 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ |
| 614 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ |
| 615 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 616 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 617 | if (rq1 == NULL || rq1 == rq2) |
| 618 | return rq2; |
| 619 | if (rq2 == NULL) |
| 620 | return rq1; |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 621 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 622 | if (rq_is_sync(rq1) && !rq_is_sync(rq2)) |
| 623 | return rq1; |
| 624 | else if (rq_is_sync(rq2) && !rq_is_sync(rq1)) |
| 625 | return rq2; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 626 | if (rq_is_meta(rq1) && !rq_is_meta(rq2)) |
| 627 | return rq1; |
| 628 | else if (rq_is_meta(rq2) && !rq_is_meta(rq1)) |
| 629 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 630 | |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 631 | s1 = blk_rq_pos(rq1); |
| 632 | s2 = blk_rq_pos(rq2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 633 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 634 | /* |
| 635 | * by definition, 1KiB is 2 sectors |
| 636 | */ |
| 637 | back_max = cfqd->cfq_back_max * 2; |
| 638 | |
| 639 | /* |
| 640 | * Strict one way elevator _except_ in the case where we allow |
| 641 | * short backward seeks which are biased as twice the cost of a |
| 642 | * similar forward seek. |
| 643 | */ |
| 644 | if (s1 >= last) |
| 645 | d1 = s1 - last; |
| 646 | else if (s1 + back_max >= last) |
| 647 | d1 = (last - s1) * cfqd->cfq_back_penalty; |
| 648 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 649 | wrap |= CFQ_RQ1_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | |
| 651 | if (s2 >= last) |
| 652 | d2 = s2 - last; |
| 653 | else if (s2 + back_max >= last) |
| 654 | d2 = (last - s2) * cfqd->cfq_back_penalty; |
| 655 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 656 | wrap |= CFQ_RQ2_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | |
| 658 | /* Found required data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 659 | |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 660 | /* |
| 661 | * By doing switch() on the bit mask "wrap" we avoid having to |
| 662 | * check two variables for all permutations: --> faster! |
| 663 | */ |
| 664 | switch (wrap) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 665 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 666 | if (d1 < d2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 667 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 668 | else if (d2 < d1) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 669 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 670 | else { |
| 671 | if (s1 >= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 672 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 673 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 674 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 675 | } |
| 676 | |
| 677 | case CFQ_RQ2_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 678 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 679 | case CFQ_RQ1_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 680 | return rq2; |
| 681 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 682 | default: |
| 683 | /* |
| 684 | * Since both rqs are wrapped, |
| 685 | * start with the one that's further behind head |
| 686 | * (--> only *one* back seek required), |
| 687 | * since back seek takes more time than forward. |
| 688 | */ |
| 689 | if (s1 <= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 690 | return rq1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 692 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | } |
| 694 | } |
| 695 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 696 | /* |
| 697 | * The below is leftmost cache rbtree addon |
| 698 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 699 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 700 | { |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 701 | /* Service tree is empty */ |
| 702 | if (!root->count) |
| 703 | return NULL; |
| 704 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 705 | if (!root->left) |
| 706 | root->left = rb_first(&root->rb); |
| 707 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 708 | if (root->left) |
| 709 | return rb_entry(root->left, struct cfq_queue, rb_node); |
| 710 | |
| 711 | return NULL; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 712 | } |
| 713 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 714 | static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root) |
| 715 | { |
| 716 | if (!root->left) |
| 717 | root->left = rb_first(&root->rb); |
| 718 | |
| 719 | if (root->left) |
| 720 | return rb_entry_cfqg(root->left); |
| 721 | |
| 722 | return NULL; |
| 723 | } |
| 724 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 725 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
| 726 | { |
| 727 | rb_erase(n, root); |
| 728 | RB_CLEAR_NODE(n); |
| 729 | } |
| 730 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 731 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) |
| 732 | { |
| 733 | if (root->left == n) |
| 734 | root->left = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 735 | rb_erase_init(n, &root->rb); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 736 | --root->count; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 737 | } |
| 738 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | /* |
| 740 | * would be nice to take fifo expire time into account as well |
| 741 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 742 | static struct request * |
| 743 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 744 | struct request *last) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 746 | struct rb_node *rbnext = rb_next(&last->rb_node); |
| 747 | struct rb_node *rbprev = rb_prev(&last->rb_node); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 748 | struct request *next = NULL, *prev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 749 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 750 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 751 | |
| 752 | if (rbprev) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 753 | prev = rb_entry_rq(rbprev); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 754 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | if (rbnext) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 756 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 757 | else { |
| 758 | rbnext = rb_first(&cfqq->sort_list); |
| 759 | if (rbnext && rbnext != &last->rb_node) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 760 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 761 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 763 | return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | } |
| 765 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 766 | static unsigned long cfq_slice_offset(struct cfq_data *cfqd, |
| 767 | struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 769 | /* |
| 770 | * just an approximation, should be ok. |
| 771 | */ |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 772 | return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - |
Jens Axboe | 464191c | 2009-11-30 09:38:13 +0100 | [diff] [blame] | 773 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 774 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 775 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 776 | static inline s64 |
| 777 | cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg) |
| 778 | { |
| 779 | return cfqg->vdisktime - st->min_vdisktime; |
| 780 | } |
| 781 | |
| 782 | static void |
| 783 | __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) |
| 784 | { |
| 785 | struct rb_node **node = &st->rb.rb_node; |
| 786 | struct rb_node *parent = NULL; |
| 787 | struct cfq_group *__cfqg; |
| 788 | s64 key = cfqg_key(st, cfqg); |
| 789 | int left = 1; |
| 790 | |
| 791 | while (*node != NULL) { |
| 792 | parent = *node; |
| 793 | __cfqg = rb_entry_cfqg(parent); |
| 794 | |
| 795 | if (key < cfqg_key(st, __cfqg)) |
| 796 | node = &parent->rb_left; |
| 797 | else { |
| 798 | node = &parent->rb_right; |
| 799 | left = 0; |
| 800 | } |
| 801 | } |
| 802 | |
| 803 | if (left) |
| 804 | st->left = &cfqg->rb_node; |
| 805 | |
| 806 | rb_link_node(&cfqg->rb_node, parent, node); |
| 807 | rb_insert_color(&cfqg->rb_node, &st->rb); |
| 808 | } |
| 809 | |
| 810 | static void |
| 811 | cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 812 | { |
| 813 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 814 | struct cfq_group *__cfqg; |
| 815 | struct rb_node *n; |
| 816 | |
| 817 | cfqg->nr_cfqq++; |
| 818 | if (cfqg->on_st) |
| 819 | return; |
| 820 | |
| 821 | /* |
| 822 | * Currently put the group at the end. Later implement something |
| 823 | * so that groups get lesser vtime based on their weights, so that |
| 824 | * if group does not loose all if it was not continously backlogged. |
| 825 | */ |
| 826 | n = rb_last(&st->rb); |
| 827 | if (n) { |
| 828 | __cfqg = rb_entry_cfqg(n); |
| 829 | cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY; |
| 830 | } else |
| 831 | cfqg->vdisktime = st->min_vdisktime; |
| 832 | |
| 833 | __cfq_group_service_tree_add(st, cfqg); |
| 834 | cfqg->on_st = true; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 835 | st->total_weight += cfqg->weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 836 | } |
| 837 | |
| 838 | static void |
| 839 | cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 840 | { |
| 841 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 842 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 843 | if (st->active == &cfqg->rb_node) |
| 844 | st->active = NULL; |
| 845 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 846 | BUG_ON(cfqg->nr_cfqq < 1); |
| 847 | cfqg->nr_cfqq--; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 848 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 849 | /* If there are other cfq queues under this group, don't delete it */ |
| 850 | if (cfqg->nr_cfqq) |
| 851 | return; |
| 852 | |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 853 | cfq_log_cfqg(cfqd, cfqg, "del_from_rr group"); |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 854 | cfqg->on_st = false; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 855 | st->total_weight -= cfqg->weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 856 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
| 857 | cfq_rb_erase(&cfqg->rb_node, st); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 858 | cfqg->saved_workload_slice = 0; |
Divyesh Shah | 9195291 | 2010-04-01 15:01:41 -0700 | [diff] [blame] | 859 | blkiocg_update_dequeue_stats(&cfqg->blkg, 1); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 860 | } |
| 861 | |
| 862 | static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq) |
| 863 | { |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 864 | unsigned int slice_used; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 865 | |
| 866 | /* |
| 867 | * Queue got expired before even a single request completed or |
| 868 | * got expired immediately after first request completion. |
| 869 | */ |
| 870 | if (!cfqq->slice_start || cfqq->slice_start == jiffies) { |
| 871 | /* |
| 872 | * Also charge the seek time incurred to the group, otherwise |
| 873 | * if there are mutiple queues in the group, each can dispatch |
| 874 | * a single request on seeky media and cause lots of seek time |
| 875 | * and group will never know it. |
| 876 | */ |
| 877 | slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start), |
| 878 | 1); |
| 879 | } else { |
| 880 | slice_used = jiffies - cfqq->slice_start; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 881 | if (slice_used > cfqq->allocated_slice) |
| 882 | slice_used = cfqq->allocated_slice; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 883 | } |
| 884 | |
Divyesh Shah | 9a0785b | 2010-04-01 15:01:04 -0700 | [diff] [blame] | 885 | cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u", slice_used); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 886 | return slice_used; |
| 887 | } |
| 888 | |
| 889 | static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 890 | struct cfq_queue *cfqq, bool forced) |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 891 | { |
| 892 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 893 | unsigned int used_sl, charge_sl; |
| 894 | int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) |
| 895 | - cfqg->service_tree_idle.count; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 896 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 897 | BUG_ON(nr_sync < 0); |
| 898 | used_sl = charge_sl = cfq_cfqq_slice_usage(cfqq); |
| 899 | |
| 900 | if (!cfq_cfqq_sync(cfqq) && !nr_sync) |
| 901 | charge_sl = cfqq->allocated_slice; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 902 | |
| 903 | /* Can't update vdisktime while group is on service tree */ |
| 904 | cfq_rb_erase(&cfqg->rb_node, st); |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 905 | cfqg->vdisktime += cfq_scale_slice(charge_sl, cfqg); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 906 | __cfq_group_service_tree_add(st, cfqg); |
| 907 | |
| 908 | /* This group is being expired. Save the context */ |
| 909 | if (time_after(cfqd->workload_expires, jiffies)) { |
| 910 | cfqg->saved_workload_slice = cfqd->workload_expires |
| 911 | - jiffies; |
| 912 | cfqg->saved_workload = cfqd->serving_type; |
| 913 | cfqg->saved_serving_prio = cfqd->serving_prio; |
| 914 | } else |
| 915 | cfqg->saved_workload_slice = 0; |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 916 | |
| 917 | cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime, |
| 918 | st->min_vdisktime); |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 919 | blkiocg_update_timeslice_used(&cfqg->blkg, used_sl); |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 920 | blkiocg_set_start_empty_time(&cfqg->blkg, forced); |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 921 | } |
| 922 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 923 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 924 | static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg) |
| 925 | { |
| 926 | if (blkg) |
| 927 | return container_of(blkg, struct cfq_group, blkg); |
| 928 | return NULL; |
| 929 | } |
| 930 | |
Vivek Goyal | f8d461d | 2009-12-03 12:59:52 -0500 | [diff] [blame] | 931 | void |
| 932 | cfq_update_blkio_group_weight(struct blkio_group *blkg, unsigned int weight) |
| 933 | { |
| 934 | cfqg_of_blkg(blkg)->weight = weight; |
| 935 | } |
| 936 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 937 | static struct cfq_group * |
| 938 | cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create) |
| 939 | { |
| 940 | struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); |
| 941 | struct cfq_group *cfqg = NULL; |
| 942 | void *key = cfqd; |
| 943 | int i, j; |
| 944 | struct cfq_rb_root *st; |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 945 | struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info; |
| 946 | unsigned int major, minor; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 947 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 948 | cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key)); |
Ricky Benitez | a74b2ad | 2010-04-05 18:22:17 +0200 | [diff] [blame] | 949 | if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) { |
| 950 | sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); |
| 951 | cfqg->blkg.dev = MKDEV(major, minor); |
| 952 | goto done; |
| 953 | } |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 954 | if (cfqg || !create) |
| 955 | goto done; |
| 956 | |
| 957 | cfqg = kzalloc_node(sizeof(*cfqg), GFP_ATOMIC, cfqd->queue->node); |
| 958 | if (!cfqg) |
| 959 | goto done; |
| 960 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 961 | for_each_cfqg_st(cfqg, i, j, st) |
| 962 | *st = CFQ_RB_ROOT; |
| 963 | RB_CLEAR_NODE(&cfqg->rb_node); |
Divyesh Shah | 84c124d | 2010-04-09 08:31:19 +0200 | [diff] [blame] | 964 | blkio_group_init(&cfqg->blkg); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 965 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 966 | /* |
| 967 | * Take the initial reference that will be released on destroy |
| 968 | * This can be thought of a joint reference by cgroup and |
| 969 | * elevator which will be dropped by either elevator exit |
| 970 | * or cgroup deletion path depending on who is exiting first. |
| 971 | */ |
| 972 | atomic_set(&cfqg->ref, 1); |
| 973 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 974 | /* Add group onto cgroup list */ |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 975 | sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); |
| 976 | blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd, |
| 977 | MKDEV(major, minor)); |
Gui Jianfeng | 34d0f17 | 2010-04-13 16:05:49 +0800 | [diff] [blame] | 978 | cfqg->weight = blkcg_get_weight(blkcg, cfqg->blkg.dev); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 979 | |
| 980 | /* Add group on cfqd list */ |
| 981 | hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list); |
| 982 | |
| 983 | done: |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 984 | return cfqg; |
| 985 | } |
| 986 | |
| 987 | /* |
| 988 | * Search for the cfq group current task belongs to. If create = 1, then also |
| 989 | * create the cfq group if it does not exist. request_queue lock must be held. |
| 990 | */ |
| 991 | static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create) |
| 992 | { |
| 993 | struct cgroup *cgroup; |
| 994 | struct cfq_group *cfqg = NULL; |
| 995 | |
| 996 | rcu_read_lock(); |
| 997 | cgroup = task_cgroup(current, blkio_subsys_id); |
| 998 | cfqg = cfq_find_alloc_cfqg(cfqd, cgroup, create); |
| 999 | if (!cfqg && create) |
| 1000 | cfqg = &cfqd->root_group; |
| 1001 | rcu_read_unlock(); |
| 1002 | return cfqg; |
| 1003 | } |
| 1004 | |
| 1005 | static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) |
| 1006 | { |
| 1007 | /* Currently, all async queues are mapped to root group */ |
| 1008 | if (!cfq_cfqq_sync(cfqq)) |
| 1009 | cfqg = &cfqq->cfqd->root_group; |
| 1010 | |
| 1011 | cfqq->cfqg = cfqg; |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1012 | /* cfqq reference on cfqg */ |
| 1013 | atomic_inc(&cfqq->cfqg->ref); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1014 | } |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1015 | |
| 1016 | static void cfq_put_cfqg(struct cfq_group *cfqg) |
| 1017 | { |
| 1018 | struct cfq_rb_root *st; |
| 1019 | int i, j; |
| 1020 | |
| 1021 | BUG_ON(atomic_read(&cfqg->ref) <= 0); |
| 1022 | if (!atomic_dec_and_test(&cfqg->ref)) |
| 1023 | return; |
| 1024 | for_each_cfqg_st(cfqg, i, j, st) |
| 1025 | BUG_ON(!RB_EMPTY_ROOT(&st->rb) || st->active != NULL); |
| 1026 | kfree(cfqg); |
| 1027 | } |
| 1028 | |
| 1029 | static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 1030 | { |
| 1031 | /* Something wrong if we are trying to remove same group twice */ |
| 1032 | BUG_ON(hlist_unhashed(&cfqg->cfqd_node)); |
| 1033 | |
| 1034 | hlist_del_init(&cfqg->cfqd_node); |
| 1035 | |
| 1036 | /* |
| 1037 | * Put the reference taken at the time of creation so that when all |
| 1038 | * queues are gone, group can be destroyed. |
| 1039 | */ |
| 1040 | cfq_put_cfqg(cfqg); |
| 1041 | } |
| 1042 | |
| 1043 | static void cfq_release_cfq_groups(struct cfq_data *cfqd) |
| 1044 | { |
| 1045 | struct hlist_node *pos, *n; |
| 1046 | struct cfq_group *cfqg; |
| 1047 | |
| 1048 | hlist_for_each_entry_safe(cfqg, pos, n, &cfqd->cfqg_list, cfqd_node) { |
| 1049 | /* |
| 1050 | * If cgroup removal path got to blk_group first and removed |
| 1051 | * it from cgroup list, then it will take care of destroying |
| 1052 | * cfqg also. |
| 1053 | */ |
| 1054 | if (!blkiocg_del_blkio_group(&cfqg->blkg)) |
| 1055 | cfq_destroy_cfqg(cfqd, cfqg); |
| 1056 | } |
| 1057 | } |
| 1058 | |
| 1059 | /* |
| 1060 | * Blk cgroup controller notification saying that blkio_group object is being |
| 1061 | * delinked as associated cgroup object is going away. That also means that |
| 1062 | * no new IO will come in this group. So get rid of this group as soon as |
| 1063 | * any pending IO in the group is finished. |
| 1064 | * |
| 1065 | * This function is called under rcu_read_lock(). key is the rcu protected |
| 1066 | * pointer. That means "key" is a valid cfq_data pointer as long as we are rcu |
| 1067 | * read lock. |
| 1068 | * |
| 1069 | * "key" was fetched from blkio_group under blkio_cgroup->lock. That means |
| 1070 | * it should not be NULL as even if elevator was exiting, cgroup deltion |
| 1071 | * path got to it first. |
| 1072 | */ |
| 1073 | void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg) |
| 1074 | { |
| 1075 | unsigned long flags; |
| 1076 | struct cfq_data *cfqd = key; |
| 1077 | |
| 1078 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 1079 | cfq_destroy_cfqg(cfqd, cfqg_of_blkg(blkg)); |
| 1080 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 1081 | } |
| 1082 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1083 | #else /* GROUP_IOSCHED */ |
| 1084 | static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create) |
| 1085 | { |
| 1086 | return &cfqd->root_group; |
| 1087 | } |
| 1088 | static inline void |
| 1089 | cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { |
| 1090 | cfqq->cfqg = cfqg; |
| 1091 | } |
| 1092 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1093 | static void cfq_release_cfq_groups(struct cfq_data *cfqd) {} |
| 1094 | static inline void cfq_put_cfqg(struct cfq_group *cfqg) {} |
| 1095 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1096 | #endif /* GROUP_IOSCHED */ |
| 1097 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1098 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1099 | * The cfqd->service_trees holds all pending cfq_queue's that have |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1100 | * requests waiting to be processed. It is sorted in the order that |
| 1101 | * we will service the queues. |
| 1102 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1103 | 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] | 1104 | bool add_front) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1105 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1106 | struct rb_node **p, *parent; |
| 1107 | struct cfq_queue *__cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1108 | unsigned long rb_key; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1109 | struct cfq_rb_root *service_tree; |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1110 | int left; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1111 | int new_cfqq = 1; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 1112 | int group_changed = 0; |
| 1113 | |
| 1114 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 1115 | if (!cfqd->cfq_group_isolation |
| 1116 | && cfqq_type(cfqq) == SYNC_NOIDLE_WORKLOAD |
| 1117 | && cfqq->cfqg && cfqq->cfqg != &cfqd->root_group) { |
| 1118 | /* Move this cfq to root group */ |
| 1119 | cfq_log_cfqq(cfqd, cfqq, "moving to root group"); |
| 1120 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) |
| 1121 | cfq_group_service_tree_del(cfqd, cfqq->cfqg); |
| 1122 | cfqq->orig_cfqg = cfqq->cfqg; |
| 1123 | cfqq->cfqg = &cfqd->root_group; |
| 1124 | atomic_inc(&cfqd->root_group.ref); |
| 1125 | group_changed = 1; |
| 1126 | } else if (!cfqd->cfq_group_isolation |
| 1127 | && cfqq_type(cfqq) == SYNC_WORKLOAD && cfqq->orig_cfqg) { |
| 1128 | /* cfqq is sequential now needs to go to its original group */ |
| 1129 | BUG_ON(cfqq->cfqg != &cfqd->root_group); |
| 1130 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) |
| 1131 | cfq_group_service_tree_del(cfqd, cfqq->cfqg); |
| 1132 | cfq_put_cfqg(cfqq->cfqg); |
| 1133 | cfqq->cfqg = cfqq->orig_cfqg; |
| 1134 | cfqq->orig_cfqg = NULL; |
| 1135 | group_changed = 1; |
| 1136 | cfq_log_cfqq(cfqd, cfqq, "moved to origin group"); |
| 1137 | } |
| 1138 | #endif |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1139 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1140 | service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq), |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 1141 | cfqq_type(cfqq)); |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1142 | if (cfq_class_idle(cfqq)) { |
| 1143 | rb_key = CFQ_IDLE_DELAY; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1144 | parent = rb_last(&service_tree->rb); |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1145 | if (parent && parent != &cfqq->rb_node) { |
| 1146 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 1147 | rb_key += __cfqq->rb_key; |
| 1148 | } else |
| 1149 | rb_key += jiffies; |
| 1150 | } else if (!add_front) { |
Jens Axboe | b9c8946 | 2009-10-06 20:53:44 +0200 | [diff] [blame] | 1151 | /* |
| 1152 | * Get our rb key offset. Subtract any residual slice |
| 1153 | * value carried from last service. A negative resid |
| 1154 | * count indicates slice overrun, and this should position |
| 1155 | * the next service time further away in the tree. |
| 1156 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1157 | rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; |
Jens Axboe | b9c8946 | 2009-10-06 20:53:44 +0200 | [diff] [blame] | 1158 | rb_key -= cfqq->slice_resid; |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1159 | cfqq->slice_resid = 0; |
Corrado Zoccolo | 48e025e | 2009-10-05 08:49:23 +0200 | [diff] [blame] | 1160 | } else { |
| 1161 | rb_key = -HZ; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1162 | __cfqq = cfq_rb_first(service_tree); |
Corrado Zoccolo | 48e025e | 2009-10-05 08:49:23 +0200 | [diff] [blame] | 1163 | rb_key += __cfqq ? __cfqq->rb_key : jiffies; |
| 1164 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1165 | |
| 1166 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1167 | new_cfqq = 0; |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 1168 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1169 | * same position, nothing more to do |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 1170 | */ |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1171 | if (rb_key == cfqq->rb_key && |
| 1172 | cfqq->service_tree == service_tree) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1173 | return; |
Jens Axboe | 53b0374 | 2006-07-28 09:48:51 +0200 | [diff] [blame] | 1174 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1175 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
| 1176 | cfqq->service_tree = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1177 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1178 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1179 | left = 1; |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1180 | parent = NULL; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1181 | cfqq->service_tree = service_tree; |
| 1182 | p = &service_tree->rb.rb_node; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1183 | while (*p) { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1184 | struct rb_node **n; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1185 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1186 | parent = *p; |
| 1187 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 1188 | |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 1189 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1190 | * sort by key, that represents service time. |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 1191 | */ |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1192 | if (time_before(rb_key, __cfqq->rb_key)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1193 | n = &(*p)->rb_left; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1194 | else { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1195 | n = &(*p)->rb_right; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1196 | left = 0; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1197 | } |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1198 | |
| 1199 | p = n; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1200 | } |
| 1201 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1202 | if (left) |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1203 | service_tree->left = &cfqq->rb_node; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1204 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1205 | cfqq->rb_key = rb_key; |
| 1206 | rb_link_node(&cfqq->rb_node, parent, p); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1207 | rb_insert_color(&cfqq->rb_node, &service_tree->rb); |
| 1208 | service_tree->count++; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 1209 | if ((add_front || !new_cfqq) && !group_changed) |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1210 | return; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1211 | cfq_group_service_tree_add(cfqd, cfqq->cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1212 | } |
| 1213 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1214 | static struct cfq_queue * |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1215 | cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, |
| 1216 | sector_t sector, struct rb_node **ret_parent, |
| 1217 | struct rb_node ***rb_link) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1218 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1219 | struct rb_node **p, *parent; |
| 1220 | struct cfq_queue *cfqq = NULL; |
| 1221 | |
| 1222 | parent = NULL; |
| 1223 | p = &root->rb_node; |
| 1224 | while (*p) { |
| 1225 | struct rb_node **n; |
| 1226 | |
| 1227 | parent = *p; |
| 1228 | cfqq = rb_entry(parent, struct cfq_queue, p_node); |
| 1229 | |
| 1230 | /* |
| 1231 | * Sort strictly based on sector. Smallest to the left, |
| 1232 | * largest to the right. |
| 1233 | */ |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1234 | if (sector > blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1235 | n = &(*p)->rb_right; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1236 | else if (sector < blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1237 | n = &(*p)->rb_left; |
| 1238 | else |
| 1239 | break; |
| 1240 | p = n; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1241 | cfqq = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1242 | } |
| 1243 | |
| 1244 | *ret_parent = parent; |
| 1245 | if (rb_link) |
| 1246 | *rb_link = p; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1247 | return cfqq; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1248 | } |
| 1249 | |
| 1250 | static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1251 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1252 | struct rb_node **p, *parent; |
| 1253 | struct cfq_queue *__cfqq; |
| 1254 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1255 | if (cfqq->p_root) { |
| 1256 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1257 | cfqq->p_root = NULL; |
| 1258 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1259 | |
| 1260 | if (cfq_class_idle(cfqq)) |
| 1261 | return; |
| 1262 | if (!cfqq->next_rq) |
| 1263 | return; |
| 1264 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1265 | cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1266 | __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, |
| 1267 | blk_rq_pos(cfqq->next_rq), &parent, &p); |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1268 | if (!__cfqq) { |
| 1269 | rb_link_node(&cfqq->p_node, parent, p); |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1270 | rb_insert_color(&cfqq->p_node, cfqq->p_root); |
| 1271 | } else |
| 1272 | cfqq->p_root = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1273 | } |
| 1274 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1275 | /* |
| 1276 | * Update cfqq's position in the service tree. |
| 1277 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1278 | 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] | 1279 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1280 | /* |
| 1281 | * Resorting requires the cfqq to be on the RR list already. |
| 1282 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1283 | if (cfq_cfqq_on_rr(cfqq)) { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1284 | cfq_service_tree_add(cfqd, cfqq, 0); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1285 | cfq_prio_tree_add(cfqd, cfqq); |
| 1286 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1287 | } |
| 1288 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1289 | /* |
| 1290 | * 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] | 1291 | * the pending list according to last request service |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1292 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1293 | 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] | 1294 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1295 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1296 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
| 1297 | cfq_mark_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1298 | cfqd->busy_queues++; |
| 1299 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1300 | cfq_resort_rr_list(cfqd, cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | } |
| 1302 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1303 | /* |
| 1304 | * Called when the cfqq no longer has requests pending, remove it from |
| 1305 | * the service tree. |
| 1306 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1307 | 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] | 1308 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1309 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1310 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
| 1311 | cfq_clear_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1312 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1313 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
| 1314 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
| 1315 | cfqq->service_tree = NULL; |
| 1316 | } |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1317 | if (cfqq->p_root) { |
| 1318 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1319 | cfqq->p_root = NULL; |
| 1320 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1321 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1322 | cfq_group_service_tree_del(cfqd, cfqq->cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1323 | BUG_ON(!cfqd->busy_queues); |
| 1324 | cfqd->busy_queues--; |
| 1325 | } |
| 1326 | |
| 1327 | /* |
| 1328 | * rb tree support functions |
| 1329 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1330 | static void cfq_del_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1331 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1332 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1333 | const int sync = rq_is_sync(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1334 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1335 | BUG_ON(!cfqq->queued[sync]); |
| 1336 | cfqq->queued[sync]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1338 | elv_rb_del(&cfqq->sort_list, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1339 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1340 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) { |
| 1341 | /* |
| 1342 | * Queue will be deleted from service tree when we actually |
| 1343 | * expire it later. Right now just remove it from prio tree |
| 1344 | * as it is empty. |
| 1345 | */ |
| 1346 | if (cfqq->p_root) { |
| 1347 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1348 | cfqq->p_root = NULL; |
| 1349 | } |
| 1350 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1351 | } |
| 1352 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1353 | static void cfq_add_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1354 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1355 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1356 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1357 | struct request *__alias, *prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1358 | |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1359 | cfqq->queued[rq_is_sync(rq)]++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1360 | |
| 1361 | /* |
| 1362 | * looks a little odd, but the first insert might return an alias. |
| 1363 | * if that happens, put the alias on the dispatch list |
| 1364 | */ |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1365 | while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1366 | cfq_dispatch_insert(cfqd->queue, __alias); |
Jens Axboe | 5fccbf6 | 2006-10-31 14:21:55 +0100 | [diff] [blame] | 1367 | |
| 1368 | if (!cfq_cfqq_on_rr(cfqq)) |
| 1369 | cfq_add_cfqq_rr(cfqd, cfqq); |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 1370 | |
| 1371 | /* |
| 1372 | * check if this request is a better next-serve candidate |
| 1373 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1374 | prev = cfqq->next_rq; |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1375 | 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] | 1376 | |
| 1377 | /* |
| 1378 | * adjust priority tree position, if ->next_rq changes |
| 1379 | */ |
| 1380 | if (prev != cfqq->next_rq) |
| 1381 | cfq_prio_tree_add(cfqd, cfqq); |
| 1382 | |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 1383 | BUG_ON(!cfqq->next_rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1384 | } |
| 1385 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1386 | 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] | 1387 | { |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1388 | elv_rb_del(&cfqq->sort_list, rq); |
| 1389 | cfqq->queued[rq_is_sync(rq)]--; |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 1390 | blkiocg_update_io_remove_stats(&cfqq->cfqg->blkg, rq_data_dir(rq), |
Divyesh Shah | cdc1184 | 2010-04-08 21:15:10 -0700 | [diff] [blame] | 1391 | rq_is_sync(rq)); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1392 | cfq_add_rq_rb(rq); |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 1393 | blkiocg_update_io_add_stats( |
Divyesh Shah | cdc1184 | 2010-04-08 21:15:10 -0700 | [diff] [blame] | 1394 | &cfqq->cfqg->blkg, &cfqq->cfqd->serving_group->blkg, |
| 1395 | rq_data_dir(rq), rq_is_sync(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | } |
| 1397 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1398 | static struct request * |
| 1399 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1400 | { |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1401 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1402 | struct cfq_io_context *cic; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1403 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1404 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1405 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1406 | if (!cic) |
| 1407 | return NULL; |
| 1408 | |
| 1409 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1410 | if (cfqq) { |
| 1411 | sector_t sector = bio->bi_sector + bio_sectors(bio); |
| 1412 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1413 | return elv_rb_find(&cfqq->sort_list, sector); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1414 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1415 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1416 | return NULL; |
| 1417 | } |
| 1418 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1419 | static void cfq_activate_request(struct request_queue *q, struct request *rq) |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1420 | { |
| 1421 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1422 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1423 | cfqd->rq_in_driver++; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1424 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1425 | cfqd->rq_in_driver); |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 1426 | |
Tejun Heo | 5b93629 | 2009-05-07 22:24:38 +0900 | [diff] [blame] | 1427 | cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1428 | } |
| 1429 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1430 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1431 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1432 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1433 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1434 | WARN_ON(!cfqd->rq_in_driver); |
| 1435 | cfqd->rq_in_driver--; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1436 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1437 | cfqd->rq_in_driver); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1438 | } |
| 1439 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1440 | static void cfq_remove_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1441 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1442 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1443 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1444 | if (cfqq->next_rq == rq) |
| 1445 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1446 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1447 | list_del_init(&rq->queuelist); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1448 | cfq_del_rq_rb(rq); |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 1449 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 1450 | cfqq->cfqd->rq_queued--; |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 1451 | blkiocg_update_io_remove_stats(&cfqq->cfqg->blkg, rq_data_dir(rq), |
Divyesh Shah | cdc1184 | 2010-04-08 21:15:10 -0700 | [diff] [blame] | 1452 | rq_is_sync(rq)); |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 1453 | if (rq_is_meta(rq)) { |
| 1454 | WARN_ON(!cfqq->meta_pending); |
| 1455 | cfqq->meta_pending--; |
| 1456 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1457 | } |
| 1458 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1459 | static int cfq_merge(struct request_queue *q, struct request **req, |
| 1460 | struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1461 | { |
| 1462 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1463 | struct request *__rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1464 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1465 | __rq = cfq_find_rq_fmerge(cfqd, bio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1466 | if (__rq && elv_rq_merge_ok(__rq, bio)) { |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 1467 | *req = __rq; |
| 1468 | return ELEVATOR_FRONT_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1469 | } |
| 1470 | |
| 1471 | return ELEVATOR_NO_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1472 | } |
| 1473 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1474 | static void cfq_merged_request(struct request_queue *q, struct request *req, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1475 | int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1476 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1477 | if (type == ELEVATOR_FRONT_MERGE) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1478 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1479 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1480 | cfq_reposition_rq_rb(cfqq, req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1481 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1482 | } |
| 1483 | |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 1484 | static void cfq_bio_merged(struct request_queue *q, struct request *req, |
| 1485 | struct bio *bio) |
| 1486 | { |
| 1487 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
| 1488 | blkiocg_update_io_merged_stats(&cfqq->cfqg->blkg, bio_data_dir(bio), |
| 1489 | cfq_bio_sync(bio)); |
| 1490 | } |
| 1491 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1492 | static void |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1493 | cfq_merged_requests(struct request_queue *q, struct request *rq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | struct request *next) |
| 1495 | { |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1496 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1497 | /* |
| 1498 | * reposition in fifo if next is older than rq |
| 1499 | */ |
| 1500 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1501 | time_before(rq_fifo_time(next), rq_fifo_time(rq))) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1502 | list_move(&rq->queuelist, &next->queuelist); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1503 | rq_set_fifo_time(rq, rq_fifo_time(next)); |
| 1504 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1505 | |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1506 | if (cfqq->next_rq == next) |
| 1507 | cfqq->next_rq = rq; |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1508 | cfq_remove_request(next); |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 1509 | blkiocg_update_io_merged_stats(&cfqq->cfqg->blkg, rq_data_dir(next), |
| 1510 | rq_is_sync(next)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1511 | } |
| 1512 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1513 | static int cfq_allow_merge(struct request_queue *q, struct request *rq, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1514 | struct bio *bio) |
| 1515 | { |
| 1516 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1517 | struct cfq_io_context *cic; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1518 | struct cfq_queue *cfqq; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1519 | |
| 1520 | /* |
Jens Axboe | ec8acb6 | 2007-01-02 18:32:11 +0100 | [diff] [blame] | 1521 | * Disallow merge of a sync bio into an async request. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1522 | */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1523 | if (cfq_bio_sync(bio) && !rq_is_sync(rq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1524 | return false; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1525 | |
| 1526 | /* |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 1527 | * Lookup the cfqq that this bio will be queued with. Allow |
| 1528 | * merge only if rq is queued there. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1529 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1530 | cic = cfq_cic_lookup(cfqd, current->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1531 | if (!cic) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1532 | return false; |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 1533 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1534 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1535 | return cfqq == RQ_CFQQ(rq); |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1536 | } |
| 1537 | |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1538 | static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1539 | { |
| 1540 | del_timer(&cfqd->idle_slice_timer); |
| 1541 | blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg); |
| 1542 | } |
| 1543 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1544 | static void __cfq_set_active_queue(struct cfq_data *cfqd, |
| 1545 | struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1546 | { |
| 1547 | if (cfqq) { |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 1548 | cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d", |
| 1549 | cfqd->serving_prio, cfqd->serving_type); |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 1550 | blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1551 | cfqq->slice_start = 0; |
| 1552 | cfqq->dispatch_start = jiffies; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 1553 | cfqq->allocated_slice = 0; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1554 | cfqq->slice_end = 0; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1555 | cfqq->slice_dispatch = 0; |
| 1556 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1557 | cfq_clear_cfqq_wait_request(cfqq); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 1558 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1559 | cfq_clear_cfqq_must_alloc_slice(cfqq); |
| 1560 | cfq_clear_cfqq_fifo_expire(cfqq); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 1561 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1562 | |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1563 | cfq_del_timer(cfqd, cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1564 | } |
| 1565 | |
| 1566 | cfqd->active_queue = cfqq; |
| 1567 | } |
| 1568 | |
| 1569 | /* |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1570 | * current cfqq expired its slice (or was too idle), select new one |
| 1571 | */ |
| 1572 | static void |
| 1573 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1574 | bool timed_out, bool forced) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1575 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1576 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); |
| 1577 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1578 | if (cfq_cfqq_wait_request(cfqq)) |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1579 | cfq_del_timer(cfqd, cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1580 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1581 | cfq_clear_cfqq_wait_request(cfqq); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 1582 | cfq_clear_cfqq_wait_busy(cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1583 | |
| 1584 | /* |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 1585 | * If this cfqq is shared between multiple processes, check to |
| 1586 | * make sure that those processes are still issuing I/Os within |
| 1587 | * the mean seek distance. If not, it may be time to break the |
| 1588 | * queues apart again. |
| 1589 | */ |
| 1590 | if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq)) |
| 1591 | cfq_mark_cfqq_split_coop(cfqq); |
| 1592 | |
| 1593 | /* |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1594 | * 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] | 1595 | */ |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1596 | if (timed_out && !cfq_cfqq_slice_new(cfqq)) { |
Jens Axboe | c5b680f | 2007-01-19 11:56:49 +1100 | [diff] [blame] | 1597 | cfqq->slice_resid = cfqq->slice_end - jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1598 | cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); |
| 1599 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1600 | |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1601 | cfq_group_served(cfqd, cfqq->cfqg, cfqq, forced); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1602 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1603 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 1604 | cfq_del_cfqq_rr(cfqd, cfqq); |
| 1605 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1606 | cfq_resort_rr_list(cfqd, cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1607 | |
| 1608 | if (cfqq == cfqd->active_queue) |
| 1609 | cfqd->active_queue = NULL; |
| 1610 | |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1611 | if (&cfqq->cfqg->rb_node == cfqd->grp_service_tree.active) |
| 1612 | cfqd->grp_service_tree.active = NULL; |
| 1613 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1614 | if (cfqd->active_cic) { |
| 1615 | put_io_context(cfqd->active_cic->ioc); |
| 1616 | cfqd->active_cic = NULL; |
| 1617 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1618 | } |
| 1619 | |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1620 | static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out, |
| 1621 | bool forced) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1622 | { |
| 1623 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 1624 | |
| 1625 | if (cfqq) |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1626 | __cfq_slice_expired(cfqd, cfqq, timed_out, forced); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1627 | } |
| 1628 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1629 | /* |
| 1630 | * Get next queue for service. Unless we have a queue preemption, |
| 1631 | * we'll simply select the first cfqq in the service tree. |
| 1632 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1633 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1634 | { |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1635 | struct cfq_rb_root *service_tree = |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1636 | service_tree_for(cfqd->serving_group, cfqd->serving_prio, |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 1637 | cfqd->serving_type); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1638 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1639 | if (!cfqd->rq_queued) |
| 1640 | return NULL; |
| 1641 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1642 | /* There is nothing to dispatch */ |
| 1643 | if (!service_tree) |
| 1644 | return NULL; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1645 | if (RB_EMPTY_ROOT(&service_tree->rb)) |
| 1646 | return NULL; |
| 1647 | return cfq_rb_first(service_tree); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1648 | } |
| 1649 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1650 | static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd) |
| 1651 | { |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1652 | struct cfq_group *cfqg; |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1653 | struct cfq_queue *cfqq; |
| 1654 | int i, j; |
| 1655 | struct cfq_rb_root *st; |
| 1656 | |
| 1657 | if (!cfqd->rq_queued) |
| 1658 | return NULL; |
| 1659 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1660 | cfqg = cfq_get_next_cfqg(cfqd); |
| 1661 | if (!cfqg) |
| 1662 | return NULL; |
| 1663 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1664 | for_each_cfqg_st(cfqg, i, j, st) |
| 1665 | if ((cfqq = cfq_rb_first(st)) != NULL) |
| 1666 | return cfqq; |
| 1667 | return NULL; |
| 1668 | } |
| 1669 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1670 | /* |
| 1671 | * Get and set a new active queue for service. |
| 1672 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1673 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, |
| 1674 | struct cfq_queue *cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1675 | { |
Jens Axboe | e00ef79 | 2009-11-04 08:54:55 +0100 | [diff] [blame] | 1676 | if (!cfqq) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1677 | cfqq = cfq_get_next_queue(cfqd); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1678 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1679 | __cfq_set_active_queue(cfqd, cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1680 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1681 | } |
| 1682 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1683 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, |
| 1684 | struct request *rq) |
| 1685 | { |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1686 | if (blk_rq_pos(rq) >= cfqd->last_position) |
| 1687 | return blk_rq_pos(rq) - cfqd->last_position; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1688 | else |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1689 | return cfqd->last_position - blk_rq_pos(rq); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1690 | } |
| 1691 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 1692 | 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] | 1693 | struct request *rq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1694 | { |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 1695 | return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1696 | } |
| 1697 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1698 | static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, |
| 1699 | struct cfq_queue *cur_cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1700 | { |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1701 | struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1702 | struct rb_node *parent, *node; |
| 1703 | struct cfq_queue *__cfqq; |
| 1704 | sector_t sector = cfqd->last_position; |
| 1705 | |
| 1706 | if (RB_EMPTY_ROOT(root)) |
| 1707 | return NULL; |
| 1708 | |
| 1709 | /* |
| 1710 | * First, if we find a request starting at the end of the last |
| 1711 | * request, choose it. |
| 1712 | */ |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1713 | __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1714 | if (__cfqq) |
| 1715 | return __cfqq; |
| 1716 | |
| 1717 | /* |
| 1718 | * If the exact sector wasn't found, the parent of the NULL leaf |
| 1719 | * will contain the closest sector. |
| 1720 | */ |
| 1721 | __cfqq = rb_entry(parent, struct cfq_queue, p_node); |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 1722 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1723 | return __cfqq; |
| 1724 | |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1725 | if (blk_rq_pos(__cfqq->next_rq) < sector) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1726 | node = rb_next(&__cfqq->p_node); |
| 1727 | else |
| 1728 | node = rb_prev(&__cfqq->p_node); |
| 1729 | if (!node) |
| 1730 | return NULL; |
| 1731 | |
| 1732 | __cfqq = rb_entry(node, struct cfq_queue, p_node); |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 1733 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1734 | return __cfqq; |
| 1735 | |
| 1736 | return NULL; |
| 1737 | } |
| 1738 | |
| 1739 | /* |
| 1740 | * cfqd - obvious |
| 1741 | * cur_cfqq - passed in so that we don't decide that the current queue is |
| 1742 | * closely cooperating with itself. |
| 1743 | * |
| 1744 | * So, basically we're assuming that that cur_cfqq has dispatched at least |
| 1745 | * one request, and that cfqd->last_position reflects a position on the disk |
| 1746 | * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid |
| 1747 | * assumption. |
| 1748 | */ |
| 1749 | static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 1750 | struct cfq_queue *cur_cfqq) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1751 | { |
| 1752 | struct cfq_queue *cfqq; |
| 1753 | |
Divyesh Shah | 39c01b2 | 2010-03-25 15:45:57 +0100 | [diff] [blame] | 1754 | if (cfq_class_idle(cur_cfqq)) |
| 1755 | return NULL; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1756 | if (!cfq_cfqq_sync(cur_cfqq)) |
| 1757 | return NULL; |
| 1758 | if (CFQQ_SEEKY(cur_cfqq)) |
| 1759 | return NULL; |
| 1760 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1761 | /* |
Gui Jianfeng | b9d8f4c | 2009-12-08 08:54:17 +0100 | [diff] [blame] | 1762 | * Don't search priority tree if it's the only queue in the group. |
| 1763 | */ |
| 1764 | if (cur_cfqq->cfqg->nr_cfqq == 1) |
| 1765 | return NULL; |
| 1766 | |
| 1767 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1768 | * We should notice if some of the queues are cooperating, eg |
| 1769 | * working closely on the same area of the disk. In that case, |
| 1770 | * we can group them together and don't waste time idling. |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1771 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1772 | cfqq = cfqq_close(cfqd, cur_cfqq); |
| 1773 | if (!cfqq) |
| 1774 | return NULL; |
| 1775 | |
Vivek Goyal | 8682e1f | 2009-12-03 12:59:50 -0500 | [diff] [blame] | 1776 | /* If new queue belongs to different cfq_group, don't choose it */ |
| 1777 | if (cur_cfqq->cfqg != cfqq->cfqg) |
| 1778 | return NULL; |
| 1779 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1780 | /* |
| 1781 | * It only makes sense to merge sync queues. |
| 1782 | */ |
| 1783 | if (!cfq_cfqq_sync(cfqq)) |
| 1784 | return NULL; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1785 | if (CFQQ_SEEKY(cfqq)) |
| 1786 | return NULL; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1787 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1788 | /* |
| 1789 | * Do not merge queues of different priority classes |
| 1790 | */ |
| 1791 | if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq)) |
| 1792 | return NULL; |
| 1793 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1794 | return cfqq; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1795 | } |
| 1796 | |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1797 | /* |
| 1798 | * Determine whether we should enforce idle window for this queue. |
| 1799 | */ |
| 1800 | |
| 1801 | static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1802 | { |
| 1803 | enum wl_prio_t prio = cfqq_prio(cfqq); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1804 | struct cfq_rb_root *service_tree = cfqq->service_tree; |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1805 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1806 | BUG_ON(!service_tree); |
| 1807 | BUG_ON(!service_tree->count); |
| 1808 | |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1809 | /* We never do for idle class queues. */ |
| 1810 | if (prio == IDLE_WORKLOAD) |
| 1811 | return false; |
| 1812 | |
| 1813 | /* We do for queues that were marked with idle window flag. */ |
Shaohua Li | 3c764b7 | 2009-12-04 13:12:06 +0100 | [diff] [blame] | 1814 | if (cfq_cfqq_idle_window(cfqq) && |
| 1815 | !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)) |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1816 | return true; |
| 1817 | |
| 1818 | /* |
| 1819 | * Otherwise, we do only if they are the last ones |
| 1820 | * in their service tree. |
| 1821 | */ |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 1822 | if (service_tree->count == 1 && cfq_cfqq_sync(cfqq)) |
| 1823 | return 1; |
| 1824 | cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", |
| 1825 | service_tree->count); |
| 1826 | return 0; |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1827 | } |
| 1828 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1829 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1830 | { |
Jens Axboe | 1792669 | 2007-01-19 11:59:30 +1100 | [diff] [blame] | 1831 | struct cfq_queue *cfqq = cfqd->active_queue; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1832 | struct cfq_io_context *cic; |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1833 | unsigned long sl; |
| 1834 | |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1835 | /* |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 1836 | * SSD device without seek penalty, disable idling. But only do so |
| 1837 | * for devices that support queuing, otherwise we still have a problem |
| 1838 | * with sync vs async workloads. |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1839 | */ |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 1840 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1841 | return; |
| 1842 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 1843 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1844 | WARN_ON(cfq_cfqq_slice_new(cfqq)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1845 | |
| 1846 | /* |
| 1847 | * idle is disabled, either manually or by past process history |
| 1848 | */ |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1849 | if (!cfqd->cfq_slice_idle || !cfq_should_idle(cfqd, cfqq)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1850 | return; |
| 1851 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1852 | /* |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 1853 | * still active requests from this queue, don't idle |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1854 | */ |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 1855 | if (cfqq->dispatched) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1856 | return; |
| 1857 | |
| 1858 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1859 | * task has exited, don't wait |
| 1860 | */ |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1861 | cic = cfqd->active_cic; |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 1862 | if (!cic || !atomic_read(&cic->ioc->nr_tasks)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1863 | return; |
| 1864 | |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 1865 | /* |
| 1866 | * If our average think time is larger than the remaining time |
| 1867 | * slice, then don't idle. This avoids overrunning the allotted |
| 1868 | * time slice. |
| 1869 | */ |
| 1870 | if (sample_valid(cic->ttime_samples) && |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 1871 | (cfqq->slice_end - jiffies < cic->ttime_mean)) { |
| 1872 | cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%d", |
| 1873 | cic->ttime_mean); |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 1874 | return; |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 1875 | } |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 1876 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1877 | cfq_mark_cfqq_wait_request(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1878 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1879 | sl = cfqd->cfq_slice_idle; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1880 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1881 | mod_timer(&cfqd->idle_slice_timer, jiffies + sl); |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1882 | blkiocg_update_set_idle_time_stats(&cfqq->cfqg->blkg); |
Jens Axboe | 9481ffd | 2009-04-15 12:14:13 +0200 | [diff] [blame] | 1883 | cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1884 | } |
| 1885 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1886 | /* |
| 1887 | * Move request from internal lists to the request queue dispatch list. |
| 1888 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1889 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1890 | { |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1891 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1892 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1893 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1894 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); |
| 1895 | |
Jeff Moyer | 06d2188 | 2009-09-11 17:08:59 +0200 | [diff] [blame] | 1896 | cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1897 | cfq_remove_request(rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1898 | cfqq->dispatched++; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1899 | elv_dispatch_sort(q, rq); |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1900 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1901 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++; |
Divyesh Shah | 84c124d | 2010-04-09 08:31:19 +0200 | [diff] [blame] | 1902 | blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq), |
| 1903 | rq_data_dir(rq), rq_is_sync(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1904 | } |
| 1905 | |
| 1906 | /* |
| 1907 | * return expired entry, or NULL to just start from scratch in rbtree |
| 1908 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1909 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1910 | { |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1911 | struct request *rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1912 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1913 | if (cfq_cfqq_fifo_expire(cfqq)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1914 | return NULL; |
Jens Axboe | cb88741 | 2007-01-19 12:01:16 +1100 | [diff] [blame] | 1915 | |
| 1916 | cfq_mark_cfqq_fifo_expire(cfqq); |
| 1917 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1918 | if (list_empty(&cfqq->fifo)) |
| 1919 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1920 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1921 | rq = rq_entry_fifo(cfqq->fifo.next); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1922 | if (time_before(jiffies, rq_fifo_time(rq))) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1923 | rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1924 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1925 | cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1926 | return rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1927 | } |
| 1928 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1929 | static inline int |
| 1930 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1931 | { |
| 1932 | const int base_rq = cfqd->cfq_slice_async_rq; |
| 1933 | |
| 1934 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); |
| 1935 | |
| 1936 | return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio)); |
| 1937 | } |
| 1938 | |
| 1939 | /* |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1940 | * Must be called with the queue_lock held. |
| 1941 | */ |
| 1942 | static int cfqq_process_refs(struct cfq_queue *cfqq) |
| 1943 | { |
| 1944 | int process_refs, io_refs; |
| 1945 | |
| 1946 | io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE]; |
| 1947 | process_refs = atomic_read(&cfqq->ref) - io_refs; |
| 1948 | BUG_ON(process_refs < 0); |
| 1949 | return process_refs; |
| 1950 | } |
| 1951 | |
| 1952 | static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) |
| 1953 | { |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1954 | int process_refs, new_process_refs; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1955 | struct cfq_queue *__cfqq; |
| 1956 | |
| 1957 | /* Avoid a circular list and skip interim queue merges */ |
| 1958 | while ((__cfqq = new_cfqq->new_cfqq)) { |
| 1959 | if (__cfqq == cfqq) |
| 1960 | return; |
| 1961 | new_cfqq = __cfqq; |
| 1962 | } |
| 1963 | |
| 1964 | process_refs = cfqq_process_refs(cfqq); |
| 1965 | /* |
| 1966 | * If the process for the cfqq has gone away, there is no |
| 1967 | * sense in merging the queues. |
| 1968 | */ |
| 1969 | if (process_refs == 0) |
| 1970 | return; |
| 1971 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1972 | /* |
| 1973 | * Merge in the direction of the lesser amount of work. |
| 1974 | */ |
| 1975 | new_process_refs = cfqq_process_refs(new_cfqq); |
| 1976 | if (new_process_refs >= process_refs) { |
| 1977 | cfqq->new_cfqq = new_cfqq; |
| 1978 | atomic_add(process_refs, &new_cfqq->ref); |
| 1979 | } else { |
| 1980 | new_cfqq->new_cfqq = cfqq; |
| 1981 | atomic_add(new_process_refs, &cfqq->ref); |
| 1982 | } |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1983 | } |
| 1984 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1985 | static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 1986 | struct cfq_group *cfqg, enum wl_prio_t prio) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1987 | { |
| 1988 | struct cfq_queue *queue; |
| 1989 | int i; |
| 1990 | bool key_valid = false; |
| 1991 | unsigned long lowest_key = 0; |
| 1992 | enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; |
| 1993 | |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 1994 | for (i = 0; i <= SYNC_WORKLOAD; ++i) { |
| 1995 | /* select the one with lowest rb_key */ |
| 1996 | queue = cfq_rb_first(service_tree_for(cfqg, prio, i)); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1997 | if (queue && |
| 1998 | (!key_valid || time_before(queue->rb_key, lowest_key))) { |
| 1999 | lowest_key = queue->rb_key; |
| 2000 | cur_best = i; |
| 2001 | key_valid = true; |
| 2002 | } |
| 2003 | } |
| 2004 | |
| 2005 | return cur_best; |
| 2006 | } |
| 2007 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2008 | 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] | 2009 | { |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2010 | unsigned slice; |
| 2011 | unsigned count; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2012 | struct cfq_rb_root *st; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2013 | unsigned group_slice; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2014 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2015 | if (!cfqg) { |
| 2016 | cfqd->serving_prio = IDLE_WORKLOAD; |
| 2017 | cfqd->workload_expires = jiffies + 1; |
| 2018 | return; |
| 2019 | } |
| 2020 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2021 | /* Choose next priority. RT > BE > IDLE */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2022 | if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2023 | cfqd->serving_prio = RT_WORKLOAD; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2024 | else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2025 | cfqd->serving_prio = BE_WORKLOAD; |
| 2026 | else { |
| 2027 | cfqd->serving_prio = IDLE_WORKLOAD; |
| 2028 | cfqd->workload_expires = jiffies + 1; |
| 2029 | return; |
| 2030 | } |
| 2031 | |
| 2032 | /* |
| 2033 | * For RT and BE, we have to choose also the type |
| 2034 | * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload |
| 2035 | * expiration time |
| 2036 | */ |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2037 | st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2038 | count = st->count; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2039 | |
| 2040 | /* |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2041 | * check workload expiration, and that we still have other queues ready |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2042 | */ |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2043 | if (count && !time_after(jiffies, cfqd->workload_expires)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2044 | return; |
| 2045 | |
| 2046 | /* otherwise select new workload type */ |
| 2047 | cfqd->serving_type = |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2048 | cfq_choose_wl(cfqd, cfqg, cfqd->serving_prio); |
| 2049 | st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2050 | count = st->count; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2051 | |
| 2052 | /* |
| 2053 | * the workload slice is computed as a fraction of target latency |
| 2054 | * proportional to the number of queues in that workload, over |
| 2055 | * all the queues in the same priority class |
| 2056 | */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2057 | group_slice = cfq_group_slice(cfqd, cfqg); |
| 2058 | |
| 2059 | slice = group_slice * count / |
| 2060 | max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_prio], |
| 2061 | cfq_group_busy_queues_wl(cfqd->serving_prio, cfqd, cfqg)); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2062 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 2063 | if (cfqd->serving_type == ASYNC_WORKLOAD) { |
| 2064 | unsigned int tmp; |
| 2065 | |
| 2066 | /* |
| 2067 | * Async queues are currently system wide. Just taking |
| 2068 | * proportion of queues with-in same group will lead to higher |
| 2069 | * async ratio system wide as generally root group is going |
| 2070 | * to have higher weight. A more accurate thing would be to |
| 2071 | * calculate system wide asnc/sync ratio. |
| 2072 | */ |
| 2073 | tmp = cfq_target_latency * cfqg_busy_async_queues(cfqd, cfqg); |
| 2074 | tmp = tmp/cfqd->busy_queues; |
| 2075 | slice = min_t(unsigned, slice, tmp); |
| 2076 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2077 | /* async workload slice is scaled down according to |
| 2078 | * the sync/async slice ratio. */ |
| 2079 | slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1]; |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 2080 | } else |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2081 | /* sync workload slice is at least 2 * cfq_slice_idle */ |
| 2082 | slice = max(slice, 2 * cfqd->cfq_slice_idle); |
| 2083 | |
| 2084 | slice = max_t(unsigned, slice, CFQ_MIN_TT); |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 2085 | cfq_log(cfqd, "workload slice:%d", slice); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2086 | cfqd->workload_expires = jiffies + slice; |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 2087 | cfqd->noidle_tree_requires_idle = false; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2088 | } |
| 2089 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2090 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) |
| 2091 | { |
| 2092 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 2093 | struct cfq_group *cfqg; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2094 | |
| 2095 | if (RB_EMPTY_ROOT(&st->rb)) |
| 2096 | return NULL; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 2097 | cfqg = cfq_rb_first_group(st); |
| 2098 | st->active = &cfqg->rb_node; |
| 2099 | update_min_vdisktime(st); |
| 2100 | return cfqg; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2101 | } |
| 2102 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2103 | static void cfq_choose_cfqg(struct cfq_data *cfqd) |
| 2104 | { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2105 | struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); |
| 2106 | |
| 2107 | cfqd->serving_group = cfqg; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 2108 | |
| 2109 | /* Restore the workload type data */ |
| 2110 | if (cfqg->saved_workload_slice) { |
| 2111 | cfqd->workload_expires = jiffies + cfqg->saved_workload_slice; |
| 2112 | cfqd->serving_type = cfqg->saved_workload; |
| 2113 | cfqd->serving_prio = cfqg->saved_serving_prio; |
Gui Jianfeng | 66ae291 | 2009-12-15 10:08:45 +0100 | [diff] [blame] | 2114 | } else |
| 2115 | cfqd->workload_expires = jiffies - 1; |
| 2116 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2117 | choose_service_tree(cfqd, cfqg); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2118 | } |
| 2119 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2120 | /* |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2121 | * Select a queue for service. If we have a current active queue, |
| 2122 | * 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] | 2123 | */ |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2124 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2125 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2126 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2127 | |
| 2128 | cfqq = cfqd->active_queue; |
| 2129 | if (!cfqq) |
| 2130 | goto new_queue; |
| 2131 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2132 | if (!cfqd->rq_queued) |
| 2133 | return NULL; |
Vivek Goyal | c244bb5 | 2009-12-08 17:52:57 -0500 | [diff] [blame] | 2134 | |
| 2135 | /* |
| 2136 | * We were waiting for group to get backlogged. Expire the queue |
| 2137 | */ |
| 2138 | if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 2139 | goto expire; |
| 2140 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2141 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2142 | * 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] | 2143 | */ |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2144 | if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) { |
| 2145 | /* |
| 2146 | * If slice had not expired at the completion of last request |
| 2147 | * we might not have turned on wait_busy flag. Don't expire |
| 2148 | * the queue yet. Allow the group to get backlogged. |
| 2149 | * |
| 2150 | * The very fact that we have used the slice, that means we |
| 2151 | * have been idling all along on this queue and it should be |
| 2152 | * ok to wait for this request to complete. |
| 2153 | */ |
Vivek Goyal | 82bbbf2 | 2009-12-10 19:25:41 +0100 | [diff] [blame] | 2154 | if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list) |
| 2155 | && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { |
| 2156 | cfqq = NULL; |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2157 | goto keep_queue; |
Vivek Goyal | 82bbbf2 | 2009-12-10 19:25:41 +0100 | [diff] [blame] | 2158 | } else |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2159 | goto expire; |
| 2160 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2161 | |
| 2162 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2163 | * The active queue has requests and isn't expired, allow it to |
| 2164 | * dispatch. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2165 | */ |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 2166 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2167 | goto keep_queue; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2168 | |
| 2169 | /* |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2170 | * If another queue has a request waiting within our mean seek |
| 2171 | * distance, let it run. The expire code will check for close |
| 2172 | * cooperators and put the close queue at the front of the service |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2173 | * tree. If possible, merge the expiring queue with the new cfqq. |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2174 | */ |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 2175 | new_cfqq = cfq_close_cooperator(cfqd, cfqq); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2176 | if (new_cfqq) { |
| 2177 | if (!cfqq->new_cfqq) |
| 2178 | cfq_setup_merge(cfqq, new_cfqq); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2179 | goto expire; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2180 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2181 | |
| 2182 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2183 | * No requests pending. If the active queue still has requests in |
| 2184 | * flight or is idling for a new request, allow either of these |
| 2185 | * conditions to happen (or time out) before selecting a new queue. |
| 2186 | */ |
Jens Axboe | cc19747 | 2007-04-20 20:45:39 +0200 | [diff] [blame] | 2187 | if (timer_pending(&cfqd->idle_slice_timer) || |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 2188 | (cfqq->dispatched && cfq_should_idle(cfqd, cfqq))) { |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2189 | cfqq = NULL; |
| 2190 | goto keep_queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2191 | } |
| 2192 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2193 | expire: |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 2194 | cfq_slice_expired(cfqd, 0, false); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2195 | new_queue: |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2196 | /* |
| 2197 | * Current queue expired. Check if we have to switch to a new |
| 2198 | * service tree |
| 2199 | */ |
| 2200 | if (!new_cfqq) |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2201 | cfq_choose_cfqg(cfqd); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2202 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2203 | cfqq = cfq_set_active_queue(cfqd, new_cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2204 | keep_queue: |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2205 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2206 | } |
| 2207 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2208 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2209 | { |
| 2210 | int dispatched = 0; |
| 2211 | |
| 2212 | while (cfqq->next_rq) { |
| 2213 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); |
| 2214 | dispatched++; |
| 2215 | } |
| 2216 | |
| 2217 | BUG_ON(!list_empty(&cfqq->fifo)); |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2218 | |
| 2219 | /* By default cfqq is not expired if it is empty. Do it explicitly */ |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 2220 | __cfq_slice_expired(cfqq->cfqd, cfqq, 0, true); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2221 | return dispatched; |
| 2222 | } |
| 2223 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2224 | /* |
| 2225 | * Drain our current requests. Used for barriers and when switching |
| 2226 | * io schedulers on-the-fly. |
| 2227 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2228 | static int cfq_forced_dispatch(struct cfq_data *cfqd) |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2229 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 2230 | struct cfq_queue *cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2231 | int dispatched = 0; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2232 | |
Divyesh Shah | 3440c49 | 2010-04-09 09:29:57 +0200 | [diff] [blame] | 2233 | /* Expire the timeslice of the current active queue first */ |
Divyesh Shah | 28baf44 | 2010-04-14 11:22:38 +0200 | [diff] [blame^] | 2234 | cfq_slice_expired(cfqd, 0, true); |
Divyesh Shah | 3440c49 | 2010-04-09 09:29:57 +0200 | [diff] [blame] | 2235 | while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) { |
| 2236 | __cfq_set_active_queue(cfqd, cfqq); |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2237 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); |
Divyesh Shah | 3440c49 | 2010-04-09 09:29:57 +0200 | [diff] [blame] | 2238 | } |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2239 | |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2240 | BUG_ON(cfqd->busy_queues); |
| 2241 | |
Jeff Moyer | 6923715 | 2009-06-12 15:29:30 +0200 | [diff] [blame] | 2242 | cfq_log(cfqd, "forced_dispatch=%d", dispatched); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2243 | return dispatched; |
| 2244 | } |
| 2245 | |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2246 | static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, |
| 2247 | struct cfq_queue *cfqq) |
| 2248 | { |
| 2249 | /* the queue hasn't finished any request, can't estimate */ |
| 2250 | if (cfq_cfqq_slice_new(cfqq)) |
| 2251 | return 1; |
| 2252 | if (time_after(jiffies + cfqd->cfq_slice_idle * cfqq->dispatched, |
| 2253 | cfqq->slice_end)) |
| 2254 | return 1; |
| 2255 | |
| 2256 | return 0; |
| 2257 | } |
| 2258 | |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2259 | 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] | 2260 | { |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2261 | unsigned int max_dispatch; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2262 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2263 | /* |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2264 | * Drain async requests before we start sync IO |
| 2265 | */ |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 2266 | 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] | 2267 | return false; |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2268 | |
| 2269 | /* |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2270 | * If this is an async queue and we have sync IO in flight, let it wait |
| 2271 | */ |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 2272 | if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2273 | return false; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2274 | |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2275 | max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2276 | if (cfq_class_idle(cfqq)) |
| 2277 | max_dispatch = 1; |
| 2278 | |
| 2279 | /* |
| 2280 | * Does this cfqq already have too much IO in flight? |
| 2281 | */ |
| 2282 | if (cfqq->dispatched >= max_dispatch) { |
| 2283 | /* |
| 2284 | * idle queue must always only have a single IO in flight |
| 2285 | */ |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2286 | if (cfq_class_idle(cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2287 | return false; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2288 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2289 | /* |
| 2290 | * We have other queues, don't allow more IO from this one |
| 2291 | */ |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2292 | if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2293 | return false; |
Jens Axboe | 9ede209 | 2007-01-19 12:11:44 +1100 | [diff] [blame] | 2294 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2295 | /* |
Shaohua Li | 474b18c | 2009-12-03 12:58:05 +0100 | [diff] [blame] | 2296 | * Sole queue user, no limit |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2297 | */ |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2298 | if (cfqd->busy_queues == 1) |
| 2299 | max_dispatch = -1; |
| 2300 | else |
| 2301 | /* |
| 2302 | * Normally we start throttling cfqq when cfq_quantum/2 |
| 2303 | * requests have been dispatched. But we can drive |
| 2304 | * deeper queue depths at the beginning of slice |
| 2305 | * subjected to upper limit of cfq_quantum. |
| 2306 | * */ |
| 2307 | max_dispatch = cfqd->cfq_quantum; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2308 | } |
| 2309 | |
| 2310 | /* |
| 2311 | * Async queues must wait a bit before being allowed dispatch. |
| 2312 | * We also ramp up the dispatch depth gradually for async IO, |
| 2313 | * based on the last sync IO we serviced |
| 2314 | */ |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2315 | if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 2316 | unsigned long last_sync = jiffies - cfqd->last_delayed_sync; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2317 | unsigned int depth; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2318 | |
Jens Axboe | 61f0c1d | 2009-10-03 19:46:03 +0200 | [diff] [blame] | 2319 | depth = last_sync / cfqd->cfq_slice[1]; |
Jens Axboe | e00c54c | 2009-10-04 20:36:19 +0200 | [diff] [blame] | 2320 | if (!depth && !cfqq->dispatched) |
| 2321 | depth = 1; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2322 | if (depth < max_dispatch) |
| 2323 | max_dispatch = depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2324 | } |
| 2325 | |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2326 | /* |
| 2327 | * If we're below the current max, allow a dispatch |
| 2328 | */ |
| 2329 | return cfqq->dispatched < max_dispatch; |
| 2330 | } |
| 2331 | |
| 2332 | /* |
| 2333 | * Dispatch a request from cfqq, moving them to the request queue |
| 2334 | * dispatch list. |
| 2335 | */ |
| 2336 | static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2337 | { |
| 2338 | struct request *rq; |
| 2339 | |
| 2340 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); |
| 2341 | |
| 2342 | if (!cfq_may_dispatch(cfqd, cfqq)) |
| 2343 | return false; |
| 2344 | |
| 2345 | /* |
| 2346 | * follow expired path, else get first next available |
| 2347 | */ |
| 2348 | rq = cfq_check_fifo(cfqq); |
| 2349 | if (!rq) |
| 2350 | rq = cfqq->next_rq; |
| 2351 | |
| 2352 | /* |
| 2353 | * insert request into driver dispatch list |
| 2354 | */ |
| 2355 | cfq_dispatch_insert(cfqd->queue, rq); |
| 2356 | |
| 2357 | if (!cfqd->active_cic) { |
| 2358 | struct cfq_io_context *cic = RQ_CIC(rq); |
| 2359 | |
| 2360 | atomic_long_inc(&cic->ioc->refcount); |
| 2361 | cfqd->active_cic = cic; |
| 2362 | } |
| 2363 | |
| 2364 | return true; |
| 2365 | } |
| 2366 | |
| 2367 | /* |
| 2368 | * Find the cfqq that we need to service and move a request from that to the |
| 2369 | * dispatch list |
| 2370 | */ |
| 2371 | static int cfq_dispatch_requests(struct request_queue *q, int force) |
| 2372 | { |
| 2373 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 2374 | struct cfq_queue *cfqq; |
| 2375 | |
| 2376 | if (!cfqd->busy_queues) |
| 2377 | return 0; |
| 2378 | |
| 2379 | if (unlikely(force)) |
| 2380 | return cfq_forced_dispatch(cfqd); |
| 2381 | |
| 2382 | cfqq = cfq_select_queue(cfqd); |
| 2383 | if (!cfqq) |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2384 | return 0; |
| 2385 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2386 | /* |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2387 | * Dispatch a request from this cfqq, if it is allowed |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2388 | */ |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2389 | if (!cfq_dispatch_request(cfqd, cfqq)) |
| 2390 | return 0; |
| 2391 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2392 | cfqq->slice_dispatch++; |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 2393 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2394 | |
| 2395 | /* |
| 2396 | * expire an async queue immediately if it has used up its slice. idle |
| 2397 | * queue always expire after 1 dispatch round. |
| 2398 | */ |
| 2399 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && |
| 2400 | cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || |
| 2401 | cfq_class_idle(cfqq))) { |
| 2402 | cfqq->slice_end = jiffies + 1; |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 2403 | cfq_slice_expired(cfqd, 0, false); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2404 | } |
| 2405 | |
Shan Wei | b217a90 | 2009-09-01 10:06:42 +0200 | [diff] [blame] | 2406 | cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2407 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2408 | } |
| 2409 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2410 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2411 | * task holds one reference to the queue, dropped when task exits. each rq |
| 2412 | * 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] | 2413 | * |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2414 | * 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] | 2415 | * queue lock must be held here. |
| 2416 | */ |
| 2417 | static void cfq_put_queue(struct cfq_queue *cfqq) |
| 2418 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2419 | struct cfq_data *cfqd = cfqq->cfqd; |
Vivek Goyal | 878eadd | 2009-12-07 19:37:15 +0100 | [diff] [blame] | 2420 | struct cfq_group *cfqg, *orig_cfqg; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2421 | |
| 2422 | BUG_ON(atomic_read(&cfqq->ref) <= 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2423 | |
| 2424 | if (!atomic_dec_and_test(&cfqq->ref)) |
| 2425 | return; |
| 2426 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2427 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2428 | BUG_ON(rb_first(&cfqq->sort_list)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2429 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2430 | cfqg = cfqq->cfqg; |
Vivek Goyal | 878eadd | 2009-12-07 19:37:15 +0100 | [diff] [blame] | 2431 | orig_cfqg = cfqq->orig_cfqg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2432 | |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2433 | if (unlikely(cfqd->active_queue == cfqq)) { |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 2434 | __cfq_slice_expired(cfqd, cfqq, 0, false); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2435 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2436 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2437 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2438 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2439 | kmem_cache_free(cfq_pool, cfqq); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2440 | cfq_put_cfqg(cfqg); |
Vivek Goyal | 878eadd | 2009-12-07 19:37:15 +0100 | [diff] [blame] | 2441 | if (orig_cfqg) |
| 2442 | cfq_put_cfqg(orig_cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2443 | } |
| 2444 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2445 | /* |
| 2446 | * Must always be called with the rcu_read_lock() held |
| 2447 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 2448 | static void |
| 2449 | __call_for_each_cic(struct io_context *ioc, |
| 2450 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 2451 | { |
| 2452 | struct cfq_io_context *cic; |
| 2453 | struct hlist_node *n; |
| 2454 | |
| 2455 | hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list) |
| 2456 | func(ioc, cic); |
| 2457 | } |
| 2458 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2459 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2460 | * Call func for each cic attached to this ioc. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2461 | */ |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2462 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2463 | call_for_each_cic(struct io_context *ioc, |
| 2464 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 2465 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2466 | rcu_read_lock(); |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 2467 | __call_for_each_cic(ioc, func); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2468 | rcu_read_unlock(); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2469 | } |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2470 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2471 | static void cfq_cic_free_rcu(struct rcu_head *head) |
| 2472 | { |
| 2473 | struct cfq_io_context *cic; |
| 2474 | |
| 2475 | cic = container_of(head, struct cfq_io_context, rcu_head); |
| 2476 | |
| 2477 | kmem_cache_free(cfq_ioc_pool, cic); |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2478 | elv_ioc_count_dec(cfq_ioc_count); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2479 | |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 2480 | if (ioc_gone) { |
| 2481 | /* |
| 2482 | * CFQ scheduler is exiting, grab exit lock and check |
| 2483 | * the pending io context count. If it hits zero, |
| 2484 | * complete ioc_gone and set it back to NULL |
| 2485 | */ |
| 2486 | spin_lock(&ioc_gone_lock); |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2487 | if (ioc_gone && !elv_ioc_count_read(cfq_ioc_count)) { |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 2488 | complete(ioc_gone); |
| 2489 | ioc_gone = NULL; |
| 2490 | } |
| 2491 | spin_unlock(&ioc_gone_lock); |
| 2492 | } |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2493 | } |
| 2494 | |
| 2495 | static void cfq_cic_free(struct cfq_io_context *cic) |
| 2496 | { |
| 2497 | call_rcu(&cic->rcu_head, cfq_cic_free_rcu); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2498 | } |
| 2499 | |
| 2500 | static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic) |
| 2501 | { |
| 2502 | unsigned long flags; |
| 2503 | |
| 2504 | BUG_ON(!cic->dead_key); |
| 2505 | |
| 2506 | spin_lock_irqsave(&ioc->lock, flags); |
| 2507 | radix_tree_delete(&ioc->radix_root, cic->dead_key); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2508 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2509 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 2510 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2511 | cfq_cic_free(cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2512 | } |
| 2513 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2514 | /* |
| 2515 | * Must be called with rcu_read_lock() held or preemption otherwise disabled. |
| 2516 | * Only two callers of this - ->dtor() which is called with the rcu_read_lock(), |
| 2517 | * and ->trim() which is called with the task lock held |
| 2518 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2519 | static void cfq_free_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2520 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2521 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2522 | * ioc->refcount is zero here, or we are called from elv_unregister(), |
| 2523 | * so no more cic's are allowed to be linked into this ioc. So it |
| 2524 | * should be ok to iterate over the known list, we will see all cic's |
| 2525 | * since no new ones are added. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2526 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 2527 | __call_for_each_cic(ioc, cic_free_func); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2528 | } |
| 2529 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2530 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2531 | { |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2532 | struct cfq_queue *__cfqq, *next; |
| 2533 | |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2534 | if (unlikely(cfqq == cfqd->active_queue)) { |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 2535 | __cfq_slice_expired(cfqd, cfqq, 0, false); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2536 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2537 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2538 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2539 | /* |
| 2540 | * If this queue was scheduled to merge with another queue, be |
| 2541 | * sure to drop the reference taken on that queue (and others in |
| 2542 | * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. |
| 2543 | */ |
| 2544 | __cfqq = cfqq->new_cfqq; |
| 2545 | while (__cfqq) { |
| 2546 | if (__cfqq == cfqq) { |
| 2547 | WARN(1, "cfqq->new_cfqq loop detected\n"); |
| 2548 | break; |
| 2549 | } |
| 2550 | next = __cfqq->new_cfqq; |
| 2551 | cfq_put_queue(__cfqq); |
| 2552 | __cfqq = next; |
| 2553 | } |
| 2554 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2555 | cfq_put_queue(cfqq); |
| 2556 | } |
| 2557 | |
| 2558 | static void __cfq_exit_single_io_context(struct cfq_data *cfqd, |
| 2559 | struct cfq_io_context *cic) |
| 2560 | { |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 2561 | struct io_context *ioc = cic->ioc; |
| 2562 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2563 | list_del_init(&cic->queue_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2564 | |
| 2565 | /* |
| 2566 | * Make sure key == NULL is seen for dead queues |
| 2567 | */ |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2568 | smp_wmb(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2569 | cic->dead_key = (unsigned long) cic->key; |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2570 | cic->key = NULL; |
| 2571 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 2572 | if (ioc->ioc_data == cic) |
| 2573 | rcu_assign_pointer(ioc->ioc_data, NULL); |
| 2574 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2575 | if (cic->cfqq[BLK_RW_ASYNC]) { |
| 2576 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]); |
| 2577 | cic->cfqq[BLK_RW_ASYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2578 | } |
| 2579 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2580 | if (cic->cfqq[BLK_RW_SYNC]) { |
| 2581 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_SYNC]); |
| 2582 | cic->cfqq[BLK_RW_SYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2583 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2584 | } |
| 2585 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2586 | static void cfq_exit_single_io_context(struct io_context *ioc, |
| 2587 | struct cfq_io_context *cic) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2588 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 2589 | struct cfq_data *cfqd = cic->key; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2590 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2591 | if (cfqd) { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2592 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2593 | unsigned long flags; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2594 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2595 | spin_lock_irqsave(q->queue_lock, flags); |
Jens Axboe | 62c1fe9 | 2008-12-15 21:19:25 +0100 | [diff] [blame] | 2596 | |
| 2597 | /* |
| 2598 | * Ensure we get a fresh copy of the ->key to prevent |
| 2599 | * race between exiting task and queue |
| 2600 | */ |
| 2601 | smp_read_barrier_depends(); |
| 2602 | if (cic->key) |
| 2603 | __cfq_exit_single_io_context(cfqd, cic); |
| 2604 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2605 | spin_unlock_irqrestore(q->queue_lock, flags); |
Al Viro | 12a0573 | 2006-03-18 13:38:01 -0500 | [diff] [blame] | 2606 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2607 | } |
| 2608 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2609 | /* |
| 2610 | * The process that ioc belongs to has exited, we need to clean up |
| 2611 | * and put the internal structures we have that belongs to that process. |
| 2612 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2613 | static void cfq_exit_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2614 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2615 | call_for_each_cic(ioc, cfq_exit_single_io_context); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2616 | } |
| 2617 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2618 | static struct cfq_io_context * |
Al Viro | 8267e26 | 2005-10-21 03:20:53 -0400 | [diff] [blame] | 2619 | cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2620 | { |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 2621 | struct cfq_io_context *cic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2622 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2623 | cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO, |
| 2624 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2625 | if (cic) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2626 | cic->last_end_request = jiffies; |
Jens Axboe | 553698f | 2006-06-14 19:11:57 +0200 | [diff] [blame] | 2627 | INIT_LIST_HEAD(&cic->queue_list); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2628 | INIT_HLIST_NODE(&cic->cic_list); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2629 | cic->dtor = cfq_free_io_context; |
| 2630 | cic->exit = cfq_exit_io_context; |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2631 | elv_ioc_count_inc(cfq_ioc_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2632 | } |
| 2633 | |
| 2634 | return cic; |
| 2635 | } |
| 2636 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2637 | 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] | 2638 | { |
| 2639 | struct task_struct *tsk = current; |
| 2640 | int ioprio_class; |
| 2641 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2642 | if (!cfq_cfqq_prio_changed(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2643 | return; |
| 2644 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2645 | ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2646 | switch (ioprio_class) { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2647 | default: |
| 2648 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); |
| 2649 | case IOPRIO_CLASS_NONE: |
| 2650 | /* |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 2651 | * no prio set, inherit CPU scheduling settings |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2652 | */ |
| 2653 | cfqq->ioprio = task_nice_ioprio(tsk); |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 2654 | cfqq->ioprio_class = task_nice_ioclass(tsk); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2655 | break; |
| 2656 | case IOPRIO_CLASS_RT: |
| 2657 | cfqq->ioprio = task_ioprio(ioc); |
| 2658 | cfqq->ioprio_class = IOPRIO_CLASS_RT; |
| 2659 | break; |
| 2660 | case IOPRIO_CLASS_BE: |
| 2661 | cfqq->ioprio = task_ioprio(ioc); |
| 2662 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 2663 | break; |
| 2664 | case IOPRIO_CLASS_IDLE: |
| 2665 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; |
| 2666 | cfqq->ioprio = 7; |
| 2667 | cfq_clear_cfqq_idle_window(cfqq); |
| 2668 | break; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2669 | } |
| 2670 | |
| 2671 | /* |
| 2672 | * keep track of original prio settings in case we have to temporarily |
| 2673 | * elevate the priority of this queue |
| 2674 | */ |
| 2675 | cfqq->org_ioprio = cfqq->ioprio; |
| 2676 | cfqq->org_ioprio_class = cfqq->ioprio_class; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2677 | cfq_clear_cfqq_prio_changed(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2678 | } |
| 2679 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2680 | static void changed_ioprio(struct io_context *ioc, struct cfq_io_context *cic) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2681 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 2682 | struct cfq_data *cfqd = cic->key; |
| 2683 | struct cfq_queue *cfqq; |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 2684 | unsigned long flags; |
Jens Axboe | 35e6077 | 2006-06-14 09:10:45 +0200 | [diff] [blame] | 2685 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2686 | if (unlikely(!cfqd)) |
| 2687 | return; |
| 2688 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 2689 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2690 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2691 | cfqq = cic->cfqq[BLK_RW_ASYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2692 | if (cfqq) { |
| 2693 | struct cfq_queue *new_cfqq; |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2694 | new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->ioc, |
| 2695 | GFP_ATOMIC); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2696 | if (new_cfqq) { |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2697 | cic->cfqq[BLK_RW_ASYNC] = new_cfqq; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2698 | cfq_put_queue(cfqq); |
| 2699 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2700 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2701 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2702 | cfqq = cic->cfqq[BLK_RW_SYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2703 | if (cfqq) |
| 2704 | cfq_mark_cfqq_prio_changed(cfqq); |
| 2705 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 2706 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2707 | } |
| 2708 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2709 | static void cfq_ioc_set_ioprio(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2710 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2711 | call_for_each_cic(ioc, changed_ioprio); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2712 | ioc->ioprio_changed = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2713 | } |
| 2714 | |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 2715 | 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] | 2716 | pid_t pid, bool is_sync) |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 2717 | { |
| 2718 | RB_CLEAR_NODE(&cfqq->rb_node); |
| 2719 | RB_CLEAR_NODE(&cfqq->p_node); |
| 2720 | INIT_LIST_HEAD(&cfqq->fifo); |
| 2721 | |
| 2722 | atomic_set(&cfqq->ref, 0); |
| 2723 | cfqq->cfqd = cfqd; |
| 2724 | |
| 2725 | cfq_mark_cfqq_prio_changed(cfqq); |
| 2726 | |
| 2727 | if (is_sync) { |
| 2728 | if (!cfq_class_idle(cfqq)) |
| 2729 | cfq_mark_cfqq_idle_window(cfqq); |
| 2730 | cfq_mark_cfqq_sync(cfqq); |
| 2731 | } |
| 2732 | cfqq->pid = pid; |
| 2733 | } |
| 2734 | |
Vivek Goyal | 2461033 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 2735 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 2736 | static void changed_cgroup(struct io_context *ioc, struct cfq_io_context *cic) |
| 2737 | { |
| 2738 | struct cfq_queue *sync_cfqq = cic_to_cfqq(cic, 1); |
| 2739 | struct cfq_data *cfqd = cic->key; |
| 2740 | unsigned long flags; |
| 2741 | struct request_queue *q; |
| 2742 | |
| 2743 | if (unlikely(!cfqd)) |
| 2744 | return; |
| 2745 | |
| 2746 | q = cfqd->queue; |
| 2747 | |
| 2748 | spin_lock_irqsave(q->queue_lock, flags); |
| 2749 | |
| 2750 | if (sync_cfqq) { |
| 2751 | /* |
| 2752 | * Drop reference to sync queue. A new sync queue will be |
| 2753 | * assigned in new group upon arrival of a fresh request. |
| 2754 | */ |
| 2755 | cfq_log_cfqq(cfqd, sync_cfqq, "changed cgroup"); |
| 2756 | cic_set_cfqq(cic, NULL, 1); |
| 2757 | cfq_put_queue(sync_cfqq); |
| 2758 | } |
| 2759 | |
| 2760 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2761 | } |
| 2762 | |
| 2763 | static void cfq_ioc_set_cgroup(struct io_context *ioc) |
| 2764 | { |
| 2765 | call_for_each_cic(ioc, changed_cgroup); |
| 2766 | ioc->cgroup_changed = 0; |
| 2767 | } |
| 2768 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ |
| 2769 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2770 | static struct cfq_queue * |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2771 | cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2772 | struct io_context *ioc, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2773 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2774 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2775 | struct cfq_io_context *cic; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2776 | struct cfq_group *cfqg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2777 | |
| 2778 | retry: |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2779 | cfqg = cfq_get_cfqg(cfqd, 1); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2780 | cic = cfq_cic_lookup(cfqd, ioc); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2781 | /* cic always exists here */ |
| 2782 | cfqq = cic_to_cfqq(cic, is_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2783 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2784 | /* |
| 2785 | * Always try a new alloc if we fell back to the OOM cfqq |
| 2786 | * originally, since it should just be a temporary situation. |
| 2787 | */ |
| 2788 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
| 2789 | cfqq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2790 | if (new_cfqq) { |
| 2791 | cfqq = new_cfqq; |
| 2792 | new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2793 | } else if (gfp_mask & __GFP_WAIT) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2794 | spin_unlock_irq(cfqd->queue->queue_lock); |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2795 | new_cfqq = kmem_cache_alloc_node(cfq_pool, |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2796 | gfp_mask | __GFP_ZERO, |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2797 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2798 | spin_lock_irq(cfqd->queue->queue_lock); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2799 | if (new_cfqq) |
| 2800 | goto retry; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2801 | } else { |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2802 | cfqq = kmem_cache_alloc_node(cfq_pool, |
| 2803 | gfp_mask | __GFP_ZERO, |
| 2804 | cfqd->queue->node); |
Kiyoshi Ueda | db3b584 | 2005-06-17 16:15:10 +0200 | [diff] [blame] | 2805 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2806 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2807 | if (cfqq) { |
| 2808 | cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); |
| 2809 | cfq_init_prio_data(cfqq, ioc); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2810 | cfq_link_cfqq_cfqg(cfqq, cfqg); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2811 | cfq_log_cfqq(cfqd, cfqq, "alloced"); |
| 2812 | } else |
| 2813 | cfqq = &cfqd->oom_cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2814 | } |
| 2815 | |
| 2816 | if (new_cfqq) |
| 2817 | kmem_cache_free(cfq_pool, new_cfqq); |
| 2818 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2819 | return cfqq; |
| 2820 | } |
| 2821 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2822 | static struct cfq_queue ** |
| 2823 | cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) |
| 2824 | { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2825 | switch (ioprio_class) { |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2826 | case IOPRIO_CLASS_RT: |
| 2827 | return &cfqd->async_cfqq[0][ioprio]; |
| 2828 | case IOPRIO_CLASS_BE: |
| 2829 | return &cfqd->async_cfqq[1][ioprio]; |
| 2830 | case IOPRIO_CLASS_IDLE: |
| 2831 | return &cfqd->async_idle_cfqq; |
| 2832 | default: |
| 2833 | BUG(); |
| 2834 | } |
| 2835 | } |
| 2836 | |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2837 | static struct cfq_queue * |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2838 | 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] | 2839 | gfp_t gfp_mask) |
| 2840 | { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2841 | const int ioprio = task_ioprio(ioc); |
| 2842 | const int ioprio_class = task_ioprio_class(ioc); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2843 | struct cfq_queue **async_cfqq = NULL; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2844 | struct cfq_queue *cfqq = NULL; |
| 2845 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2846 | if (!is_sync) { |
| 2847 | async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); |
| 2848 | cfqq = *async_cfqq; |
| 2849 | } |
| 2850 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2851 | if (!cfqq) |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2852 | cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2853 | |
| 2854 | /* |
| 2855 | * pin the queue now that it's allocated, scheduler exit will prune it |
| 2856 | */ |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2857 | if (!is_sync && !(*async_cfqq)) { |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2858 | atomic_inc(&cfqq->ref); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2859 | *async_cfqq = cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2860 | } |
| 2861 | |
| 2862 | atomic_inc(&cfqq->ref); |
| 2863 | return cfqq; |
| 2864 | } |
| 2865 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2866 | /* |
| 2867 | * We drop cfq io contexts lazily, so we may find a dead one. |
| 2868 | */ |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2869 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2870 | cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc, |
| 2871 | struct cfq_io_context *cic) |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2872 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2873 | unsigned long flags; |
| 2874 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2875 | WARN_ON(!list_empty(&cic->queue_list)); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2876 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2877 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2878 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 2879 | BUG_ON(ioc->ioc_data == cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2880 | |
| 2881 | radix_tree_delete(&ioc->radix_root, (unsigned long) cfqd); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2882 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2883 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 2884 | |
| 2885 | cfq_cic_free(cic); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2886 | } |
| 2887 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2888 | static struct cfq_io_context * |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2889 | cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2890 | { |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2891 | struct cfq_io_context *cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2892 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2893 | void *k; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2894 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2895 | if (unlikely(!ioc)) |
| 2896 | return NULL; |
| 2897 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2898 | rcu_read_lock(); |
| 2899 | |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2900 | /* |
| 2901 | * we maintain a last-hit cache, to avoid browsing over the tree |
| 2902 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2903 | cic = rcu_dereference(ioc->ioc_data); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2904 | if (cic && cic->key == cfqd) { |
| 2905 | rcu_read_unlock(); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2906 | return cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2907 | } |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2908 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2909 | do { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2910 | cic = radix_tree_lookup(&ioc->radix_root, (unsigned long) cfqd); |
| 2911 | rcu_read_unlock(); |
| 2912 | if (!cic) |
| 2913 | break; |
OGAWA Hirofumi | be3b075 | 2006-04-18 19:18:31 +0200 | [diff] [blame] | 2914 | /* ->key must be copied to avoid race with cfq_exit_queue() */ |
| 2915 | k = cic->key; |
| 2916 | if (unlikely(!k)) { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2917 | cfq_drop_dead_cic(cfqd, ioc, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2918 | rcu_read_lock(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2919 | continue; |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2920 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2921 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2922 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2923 | rcu_assign_pointer(ioc->ioc_data, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2924 | spin_unlock_irqrestore(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2925 | break; |
| 2926 | } while (1); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2927 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2928 | return cic; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2929 | } |
| 2930 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2931 | /* |
| 2932 | * Add cic into ioc, using cfqd as the search key. This enables us to lookup |
| 2933 | * the process specific cfq io context when entered from the block layer. |
| 2934 | * Also adds the cic to a per-cfqd list, used when this queue is removed. |
| 2935 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2936 | static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, |
| 2937 | struct cfq_io_context *cic, gfp_t gfp_mask) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2938 | { |
Jens Axboe | 0261d68 | 2006-10-30 19:07:48 +0100 | [diff] [blame] | 2939 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2940 | int ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2941 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2942 | ret = radix_tree_preload(gfp_mask); |
| 2943 | if (!ret) { |
| 2944 | cic->ioc = ioc; |
| 2945 | cic->key = cfqd; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2946 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2947 | spin_lock_irqsave(&ioc->lock, flags); |
| 2948 | ret = radix_tree_insert(&ioc->radix_root, |
| 2949 | (unsigned long) cfqd, cic); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2950 | if (!ret) |
| 2951 | hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2952 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 2953 | |
| 2954 | radix_tree_preload_end(); |
| 2955 | |
| 2956 | if (!ret) { |
| 2957 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 2958 | list_add(&cic->queue_list, &cfqd->cic_list); |
| 2959 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2960 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2961 | } |
| 2962 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2963 | if (ret) |
| 2964 | printk(KERN_ERR "cfq: cic link failed!\n"); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2965 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2966 | return ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2967 | } |
| 2968 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2969 | /* |
| 2970 | * Setup general io context and cfq io context. There can be several cfq |
| 2971 | * io contexts per general io context, if this process is doing io to more |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2972 | * than one device managed by cfq. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2973 | */ |
| 2974 | static struct cfq_io_context * |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2975 | cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2976 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2977 | struct io_context *ioc = NULL; |
| 2978 | struct cfq_io_context *cic; |
| 2979 | |
| 2980 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 2981 | |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 2982 | ioc = get_io_context(gfp_mask, cfqd->queue->node); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2983 | if (!ioc) |
| 2984 | return NULL; |
| 2985 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2986 | cic = cfq_cic_lookup(cfqd, ioc); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2987 | if (cic) |
| 2988 | goto out; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2989 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2990 | cic = cfq_alloc_io_context(cfqd, gfp_mask); |
| 2991 | if (cic == NULL) |
| 2992 | goto err; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2993 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2994 | if (cfq_cic_link(cfqd, ioc, cic, gfp_mask)) |
| 2995 | goto err_free; |
| 2996 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2997 | out: |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2998 | smp_read_barrier_depends(); |
| 2999 | if (unlikely(ioc->ioprio_changed)) |
| 3000 | cfq_ioc_set_ioprio(ioc); |
| 3001 | |
Vivek Goyal | 2461033 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 3002 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 3003 | if (unlikely(ioc->cgroup_changed)) |
| 3004 | cfq_ioc_set_cgroup(ioc); |
| 3005 | #endif |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3006 | return cic; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 3007 | err_free: |
| 3008 | cfq_cic_free(cic); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3009 | err: |
| 3010 | put_io_context(ioc); |
| 3011 | return NULL; |
| 3012 | } |
| 3013 | |
| 3014 | static void |
| 3015 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic) |
| 3016 | { |
Jens Axboe | aaf1228 | 2007-01-19 11:30:16 +1100 | [diff] [blame] | 3017 | unsigned long elapsed = jiffies - cic->last_end_request; |
| 3018 | unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3019 | |
| 3020 | cic->ttime_samples = (7*cic->ttime_samples + 256) / 8; |
| 3021 | cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8; |
| 3022 | cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples; |
| 3023 | } |
| 3024 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3025 | static void |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3026 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3027 | struct request *rq) |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3028 | { |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 3029 | sector_t sdist = 0; |
Corrado Zoccolo | 41647e7 | 2010-02-27 19:45:40 +0100 | [diff] [blame] | 3030 | sector_t n_sec = blk_rq_sectors(rq); |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 3031 | if (cfqq->last_request_pos) { |
| 3032 | if (cfqq->last_request_pos < blk_rq_pos(rq)) |
| 3033 | sdist = blk_rq_pos(rq) - cfqq->last_request_pos; |
| 3034 | else |
| 3035 | sdist = cfqq->last_request_pos - blk_rq_pos(rq); |
| 3036 | } |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3037 | |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 3038 | cfqq->seek_history <<= 1; |
Corrado Zoccolo | 41647e7 | 2010-02-27 19:45:40 +0100 | [diff] [blame] | 3039 | if (blk_queue_nonrot(cfqd->queue)) |
| 3040 | cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT); |
| 3041 | else |
| 3042 | cfqq->seek_history |= (sdist > CFQQ_SEEK_THR); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3043 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3044 | |
| 3045 | /* |
| 3046 | * Disable idle window if the process thinks too long or seeks so much that |
| 3047 | * it doesn't matter |
| 3048 | */ |
| 3049 | static void |
| 3050 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 3051 | struct cfq_io_context *cic) |
| 3052 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3053 | int old_idle, enable_idle; |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 3054 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 3055 | /* |
| 3056 | * Don't idle for async or idle io prio class |
| 3057 | */ |
| 3058 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 3059 | return; |
| 3060 | |
Jens Axboe | c265a7f | 2008-06-26 13:49:33 +0200 | [diff] [blame] | 3061 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3062 | |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3063 | if (cfqq->queued[0] + cfqq->queued[1] >= 4) |
| 3064 | cfq_mark_cfqq_deep(cfqq); |
| 3065 | |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 3066 | if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle || |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 3067 | (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq))) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3068 | enable_idle = 0; |
| 3069 | else if (sample_valid(cic->ttime_samples)) { |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 3070 | if (cic->ttime_mean > cfqd->cfq_slice_idle) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3071 | enable_idle = 0; |
| 3072 | else |
| 3073 | enable_idle = 1; |
| 3074 | } |
| 3075 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3076 | if (old_idle != enable_idle) { |
| 3077 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); |
| 3078 | if (enable_idle) |
| 3079 | cfq_mark_cfqq_idle_window(cfqq); |
| 3080 | else |
| 3081 | cfq_clear_cfqq_idle_window(cfqq); |
| 3082 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3083 | } |
| 3084 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3085 | /* |
| 3086 | * Check if new_cfqq should preempt the currently active queue. Return 0 for |
| 3087 | * no or if we aren't sure, a 1 will cause a preempt. |
| 3088 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3089 | static bool |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3090 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3091 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3092 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3093 | struct cfq_queue *cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3094 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3095 | cfqq = cfqd->active_queue; |
| 3096 | if (!cfqq) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3097 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3098 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3099 | if (cfq_class_idle(new_cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3100 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3101 | |
| 3102 | if (cfq_class_idle(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3103 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3104 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3105 | /* |
Divyesh Shah | 875feb6 | 2010-01-06 18:58:20 -0800 | [diff] [blame] | 3106 | * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice. |
| 3107 | */ |
| 3108 | if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq)) |
| 3109 | return false; |
| 3110 | |
| 3111 | /* |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3112 | * if the new request is sync, but the currently running queue is |
| 3113 | * not, let the sync request have priority. |
| 3114 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3115 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3116 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3117 | |
Vivek Goyal | 8682e1f | 2009-12-03 12:59:50 -0500 | [diff] [blame] | 3118 | if (new_cfqq->cfqg != cfqq->cfqg) |
| 3119 | return false; |
| 3120 | |
| 3121 | if (cfq_slice_used(cfqq)) |
| 3122 | return true; |
| 3123 | |
| 3124 | /* Allow preemption only if we are idling on sync-noidle tree */ |
| 3125 | if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD && |
| 3126 | cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD && |
| 3127 | new_cfqq->service_tree->count == 2 && |
| 3128 | RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 3129 | return true; |
| 3130 | |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3131 | /* |
| 3132 | * So both queues are sync. Let the new request get disk time if |
| 3133 | * it's a metadata request and the current queue is doing regular IO. |
| 3134 | */ |
| 3135 | if (rq_is_meta(rq) && !cfqq->meta_pending) |
Jens Axboe | e6ec4fe | 2009-11-03 20:21:35 +0100 | [diff] [blame] | 3136 | return true; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3137 | |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3138 | /* |
| 3139 | * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. |
| 3140 | */ |
| 3141 | if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3142 | return true; |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3143 | |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3144 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3145 | return false; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3146 | |
| 3147 | /* |
| 3148 | * if this request is as-good as one we would expect from the |
| 3149 | * current cfqq, let it preempt |
| 3150 | */ |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 3151 | if (cfq_rq_close(cfqd, cfqq, rq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3152 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3153 | |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3154 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3155 | } |
| 3156 | |
| 3157 | /* |
| 3158 | * cfqq preempts the active queue. if we allowed preempt with no slice left, |
| 3159 | * let it have half of its nominal slice. |
| 3160 | */ |
| 3161 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 3162 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3163 | cfq_log_cfqq(cfqd, cfqq, "preempt"); |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 3164 | cfq_slice_expired(cfqd, 1, false); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3165 | |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 3166 | /* |
| 3167 | * Put the new queue at the front of the of the current list, |
| 3168 | * so we know that it will be selected next. |
| 3169 | */ |
| 3170 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 3171 | |
| 3172 | cfq_service_tree_add(cfqd, cfqq, 1); |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 3173 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3174 | cfqq->slice_end = 0; |
| 3175 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3176 | } |
| 3177 | |
| 3178 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3179 | * 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] | 3180 | * something we should do about it |
| 3181 | */ |
| 3182 | static void |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3183 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 3184 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3185 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3186 | struct cfq_io_context *cic = RQ_CIC(rq); |
Jens Axboe | 12e9fdd | 2006-06-01 10:09:56 +0200 | [diff] [blame] | 3187 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3188 | cfqd->rq_queued++; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3189 | if (rq_is_meta(rq)) |
| 3190 | cfqq->meta_pending++; |
| 3191 | |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 3192 | cfq_update_io_thinktime(cfqd, cic); |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3193 | cfq_update_io_seektime(cfqd, cfqq, rq); |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 3194 | cfq_update_idle_window(cfqd, cfqq, cic); |
| 3195 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3196 | cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3197 | |
| 3198 | if (cfqq == cfqd->active_queue) { |
| 3199 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 3200 | * Remember that we saw a request from this process, but |
| 3201 | * don't start queuing just yet. Otherwise we risk seeing lots |
| 3202 | * of tiny requests, because we disrupt the normal plugging |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3203 | * and merging. If the request is already larger than a single |
| 3204 | * page, let it rip immediately. For that case we assume that |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 3205 | * merging is already done. Ditto for a busy system that |
| 3206 | * has other work pending, don't risk delaying until the |
| 3207 | * idle timer unplug to continue working. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3208 | */ |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3209 | if (cfq_cfqq_wait_request(cfqq)) { |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 3210 | if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE || |
| 3211 | cfqd->busy_queues > 1) { |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 3212 | cfq_del_timer(cfqd, cfqq); |
Gui Jianfeng | 554554f | 2009-12-10 09:38:39 +0100 | [diff] [blame] | 3213 | cfq_clear_cfqq_wait_request(cfqq); |
Vivek Goyal | bf79193 | 2009-12-03 12:59:37 -0500 | [diff] [blame] | 3214 | __blk_run_queue(cfqd->queue); |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 3215 | } else { |
| 3216 | blkiocg_update_idle_time_stats( |
| 3217 | &cfqq->cfqg->blkg); |
Vivek Goyal | bf79193 | 2009-12-03 12:59:37 -0500 | [diff] [blame] | 3218 | cfq_mark_cfqq_must_dispatch(cfqq); |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 3219 | } |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3220 | } |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3221 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3222 | /* |
| 3223 | * not the active queue - expire current slice if it is |
| 3224 | * idle and has expired it's mean thinktime or this new queue |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3225 | * has some old slice time left and is of higher priority or |
| 3226 | * this new queue is RT and the current one is BE |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3227 | */ |
| 3228 | cfq_preempt_queue(cfqd, cfqq); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 3229 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3230 | } |
| 3231 | } |
| 3232 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3233 | static void cfq_insert_request(struct request_queue *q, struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3234 | { |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3235 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3236 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3237 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3238 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 3239 | cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3240 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 3241 | 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] | 3242 | list_add_tail(&rq->queuelist, &cfqq->fifo); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 3243 | cfq_add_rq_rb(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3244 | |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 3245 | blkiocg_update_io_add_stats(&cfqq->cfqg->blkg, |
Divyesh Shah | cdc1184 | 2010-04-08 21:15:10 -0700 | [diff] [blame] | 3246 | &cfqd->serving_group->blkg, rq_data_dir(rq), |
| 3247 | rq_is_sync(rq)); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3248 | cfq_rq_enqueued(cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3249 | } |
| 3250 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3251 | /* |
| 3252 | * Update hw_tag based on peak queue depth over 50 samples under |
| 3253 | * sufficient load. |
| 3254 | */ |
| 3255 | static void cfq_update_hw_tag(struct cfq_data *cfqd) |
| 3256 | { |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3257 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 3258 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3259 | if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth) |
| 3260 | cfqd->hw_tag_est_depth = cfqd->rq_in_driver; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3261 | |
| 3262 | if (cfqd->hw_tag == 1) |
| 3263 | return; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3264 | |
| 3265 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3266 | cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3267 | return; |
| 3268 | |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3269 | /* |
| 3270 | * If active queue hasn't enough requests and can idle, cfq might not |
| 3271 | * dispatch sufficient requests to hardware. Don't zero hw_tag in this |
| 3272 | * case |
| 3273 | */ |
| 3274 | if (cfqq && cfq_cfqq_idle_window(cfqq) && |
| 3275 | cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] < |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3276 | CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN) |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3277 | return; |
| 3278 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3279 | if (cfqd->hw_tag_samples++ < 50) |
| 3280 | return; |
| 3281 | |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3282 | if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3283 | cfqd->hw_tag = 1; |
| 3284 | else |
| 3285 | cfqd->hw_tag = 0; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3286 | } |
| 3287 | |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3288 | static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 3289 | { |
| 3290 | struct cfq_io_context *cic = cfqd->active_cic; |
| 3291 | |
| 3292 | /* If there are other queues in the group, don't wait */ |
| 3293 | if (cfqq->cfqg->nr_cfqq > 1) |
| 3294 | return false; |
| 3295 | |
| 3296 | if (cfq_slice_used(cfqq)) |
| 3297 | return true; |
| 3298 | |
| 3299 | /* if slice left is less than think time, wait busy */ |
| 3300 | if (cic && sample_valid(cic->ttime_samples) |
| 3301 | && (cfqq->slice_end - jiffies < cic->ttime_mean)) |
| 3302 | return true; |
| 3303 | |
| 3304 | /* |
| 3305 | * If think times is less than a jiffy than ttime_mean=0 and above |
| 3306 | * will not be true. It might happen that slice has not expired yet |
| 3307 | * but will expire soon (4-5 ns) during select_queue(). To cover the |
| 3308 | * case where think time is less than a jiffy, mark the queue wait |
| 3309 | * busy if only 1 jiffy is left in the slice. |
| 3310 | */ |
| 3311 | if (cfqq->slice_end - jiffies == 1) |
| 3312 | return true; |
| 3313 | |
| 3314 | return false; |
| 3315 | } |
| 3316 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3317 | static void cfq_completed_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3318 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3319 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3320 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 3321 | const int sync = rq_is_sync(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3322 | unsigned long now; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3323 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3324 | now = jiffies; |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 3325 | cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", !!rq_noidle(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3326 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3327 | cfq_update_hw_tag(cfqd); |
| 3328 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3329 | WARN_ON(!cfqd->rq_in_driver); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3330 | WARN_ON(!cfqq->dispatched); |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3331 | cfqd->rq_in_driver--; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3332 | cfqq->dispatched--; |
Divyesh Shah | 84c124d | 2010-04-09 08:31:19 +0200 | [diff] [blame] | 3333 | blkiocg_update_completion_stats(&cfqq->cfqg->blkg, rq_start_time_ns(rq), |
| 3334 | rq_io_start_time_ns(rq), rq_data_dir(rq), |
| 3335 | rq_is_sync(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3336 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3337 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 3338 | |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 3339 | if (sync) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3340 | RQ_CIC(rq)->last_end_request = now; |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 3341 | if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) |
| 3342 | cfqd->last_delayed_sync = now; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 3343 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3344 | |
| 3345 | /* |
| 3346 | * If this is the active queue, check if it needs to be expired, |
| 3347 | * or if we want to idle in case it has no pending requests. |
| 3348 | */ |
| 3349 | if (cfqd->active_queue == cfqq) { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3350 | const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); |
| 3351 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3352 | if (cfq_cfqq_slice_new(cfqq)) { |
| 3353 | cfq_set_prio_slice(cfqd, cfqq); |
| 3354 | cfq_clear_cfqq_slice_new(cfqq); |
| 3355 | } |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3356 | |
| 3357 | /* |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3358 | * Should we wait for next request to come in before we expire |
| 3359 | * the queue. |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3360 | */ |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3361 | if (cfq_should_wait_busy(cfqd, cfqq)) { |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3362 | cfqq->slice_end = jiffies + cfqd->cfq_slice_idle; |
| 3363 | cfq_mark_cfqq_wait_busy(cfqq); |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 3364 | cfq_log_cfqq(cfqd, cfqq, "will busy wait"); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3365 | } |
| 3366 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3367 | /* |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3368 | * Idling is not enabled on: |
| 3369 | * - expired queues |
| 3370 | * - idle-priority queues |
| 3371 | * - async queues |
| 3372 | * - queues with still some requests queued |
| 3373 | * - when there is a close cooperator |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3374 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 3375 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 3376 | cfq_slice_expired(cfqd, 1, false); |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3377 | else if (sync && cfqq_empty && |
| 3378 | !cfq_close_cooperator(cfqd, cfqq)) { |
| 3379 | cfqd->noidle_tree_requires_idle |= !rq_noidle(rq); |
| 3380 | /* |
| 3381 | * Idling is enabled for SYNC_WORKLOAD. |
| 3382 | * SYNC_NOIDLE_WORKLOAD idles at the end of the tree |
| 3383 | * only if we processed at least one !rq_noidle request |
| 3384 | */ |
| 3385 | if (cfqd->serving_type == SYNC_WORKLOAD |
Vivek Goyal | c04645e | 2009-12-03 12:59:56 -0500 | [diff] [blame] | 3386 | || cfqd->noidle_tree_requires_idle |
| 3387 | || cfqq->cfqg->nr_cfqq == 1) |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3388 | cfq_arm_slice_timer(cfqd); |
| 3389 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3390 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3391 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3392 | if (!cfqd->rq_in_driver) |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3393 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3394 | } |
| 3395 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3396 | /* |
| 3397 | * we temporarily boost lower priority queues if they are holding fs exclusive |
| 3398 | * resources. they are boosted to normal prio (CLASS_BE/4) |
| 3399 | */ |
| 3400 | static void cfq_prio_boost(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3401 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3402 | if (has_fs_excl()) { |
| 3403 | /* |
| 3404 | * boost idle prio on transactions that would lock out other |
| 3405 | * users of the filesystem |
| 3406 | */ |
| 3407 | if (cfq_class_idle(cfqq)) |
| 3408 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 3409 | if (cfqq->ioprio > IOPRIO_NORM) |
| 3410 | cfqq->ioprio = IOPRIO_NORM; |
| 3411 | } else { |
| 3412 | /* |
Corrado Zoccolo | dddb745 | 2009-11-02 10:40:37 +0100 | [diff] [blame] | 3413 | * unboost the queue (if needed) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3414 | */ |
Corrado Zoccolo | dddb745 | 2009-11-02 10:40:37 +0100 | [diff] [blame] | 3415 | cfqq->ioprio_class = cfqq->org_ioprio_class; |
| 3416 | cfqq->ioprio = cfqq->org_ioprio; |
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 | } |
| 3419 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3420 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3421 | { |
Jens Axboe | 1b379d8 | 2009-08-11 08:26:11 +0200 | [diff] [blame] | 3422 | if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3423 | cfq_mark_cfqq_must_alloc_slice(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3424 | return ELV_MQUEUE_MUST; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3425 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3426 | |
| 3427 | return ELV_MQUEUE_MAY; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3428 | } |
| 3429 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3430 | static int cfq_may_queue(struct request_queue *q, int rw) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3431 | { |
| 3432 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 3433 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3434 | struct cfq_io_context *cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3435 | struct cfq_queue *cfqq; |
| 3436 | |
| 3437 | /* |
| 3438 | * don't force setup of a queue from here, as a call to may_queue |
| 3439 | * does not necessarily imply that a request actually will be queued. |
| 3440 | * so just lookup a possibly existing queue, or return 'may queue' |
| 3441 | * if that fails |
| 3442 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 3443 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3444 | if (!cic) |
| 3445 | return ELV_MQUEUE_MAY; |
| 3446 | |
Jens Axboe | b0b78f8 | 2009-04-08 10:56:08 +0200 | [diff] [blame] | 3447 | cfqq = cic_to_cfqq(cic, rw_is_sync(rw)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3448 | if (cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 3449 | cfq_init_prio_data(cfqq, cic->ioc); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3450 | cfq_prio_boost(cfqq); |
| 3451 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3452 | return __cfq_may_queue(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3453 | } |
| 3454 | |
| 3455 | return ELV_MQUEUE_MAY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3456 | } |
| 3457 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3458 | /* |
| 3459 | * queue lock held here |
| 3460 | */ |
Jens Axboe | bb37b94 | 2006-12-01 10:42:33 +0100 | [diff] [blame] | 3461 | static void cfq_put_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3462 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3463 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3464 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3465 | if (cfqq) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3466 | const int rw = rq_data_dir(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3467 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3468 | BUG_ON(!cfqq->allocated[rw]); |
| 3469 | cfqq->allocated[rw]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3470 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3471 | put_io_context(RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3472 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3473 | rq->elevator_private = NULL; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3474 | rq->elevator_private2 = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3475 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3476 | cfq_put_queue(cfqq); |
| 3477 | } |
| 3478 | } |
| 3479 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3480 | static struct cfq_queue * |
| 3481 | cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_context *cic, |
| 3482 | struct cfq_queue *cfqq) |
| 3483 | { |
| 3484 | cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq); |
| 3485 | cic_set_cfqq(cic, cfqq->new_cfqq, 1); |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 3486 | cfq_mark_cfqq_coop(cfqq->new_cfqq); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3487 | cfq_put_queue(cfqq); |
| 3488 | return cic_to_cfqq(cic, 1); |
| 3489 | } |
| 3490 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3491 | /* |
| 3492 | * Returns NULL if a new cfqq should be allocated, or the old cfqq if this |
| 3493 | * was the last process referring to said cfqq. |
| 3494 | */ |
| 3495 | static struct cfq_queue * |
| 3496 | split_cfqq(struct cfq_io_context *cic, struct cfq_queue *cfqq) |
| 3497 | { |
| 3498 | if (cfqq_process_refs(cfqq) == 1) { |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3499 | cfqq->pid = current->pid; |
| 3500 | cfq_clear_cfqq_coop(cfqq); |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 3501 | cfq_clear_cfqq_split_coop(cfqq); |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3502 | return cfqq; |
| 3503 | } |
| 3504 | |
| 3505 | cic_set_cfqq(cic, NULL, 1); |
| 3506 | cfq_put_queue(cfqq); |
| 3507 | return NULL; |
| 3508 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3509 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3510 | * Allocate cfq data structures associated with this request. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3511 | */ |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3512 | static int |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3513 | 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] | 3514 | { |
| 3515 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 3516 | struct cfq_io_context *cic; |
| 3517 | const int rw = rq_data_dir(rq); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3518 | const bool is_sync = rq_is_sync(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3519 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3520 | unsigned long flags; |
| 3521 | |
| 3522 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 3523 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3524 | cic = cfq_get_io_context(cfqd, gfp_mask); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3525 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3526 | spin_lock_irqsave(q->queue_lock, flags); |
| 3527 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3528 | if (!cic) |
| 3529 | goto queue_fail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3530 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3531 | new_queue: |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3532 | cfqq = cic_to_cfqq(cic, is_sync); |
Vivek Goyal | 32f2e80 | 2009-07-09 22:13:16 +0200 | [diff] [blame] | 3533 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 3534 | cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3535 | cic_set_cfqq(cic, cfqq, is_sync); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3536 | } else { |
| 3537 | /* |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3538 | * If the queue was seeky for too long, break it apart. |
| 3539 | */ |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 3540 | if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) { |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3541 | cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq"); |
| 3542 | cfqq = split_cfqq(cic, cfqq); |
| 3543 | if (!cfqq) |
| 3544 | goto new_queue; |
| 3545 | } |
| 3546 | |
| 3547 | /* |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3548 | * Check to see if this queue is scheduled to merge with |
| 3549 | * another, closely cooperating queue. The merging of |
| 3550 | * queues happens here as it must be done in process context. |
| 3551 | * The reference on new_cfqq was taken in merge_cfqqs. |
| 3552 | */ |
| 3553 | if (cfqq->new_cfqq) |
| 3554 | cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3555 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3556 | |
| 3557 | cfqq->allocated[rw]++; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3558 | atomic_inc(&cfqq->ref); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3559 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3560 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 3561 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3562 | rq->elevator_private = cic; |
| 3563 | rq->elevator_private2 = cfqq; |
| 3564 | return 0; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3565 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3566 | queue_fail: |
| 3567 | if (cic) |
| 3568 | put_io_context(cic->ioc); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3569 | |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3570 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3571 | spin_unlock_irqrestore(q->queue_lock, flags); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3572 | cfq_log(cfqd, "set_request fail"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3573 | return 1; |
| 3574 | } |
| 3575 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 3576 | static void cfq_kick_queue(struct work_struct *work) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3577 | { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 3578 | struct cfq_data *cfqd = |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3579 | container_of(work, struct cfq_data, unplug_work); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3580 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3581 | |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 3582 | spin_lock_irq(q->queue_lock); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 3583 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 3584 | spin_unlock_irq(q->queue_lock); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3585 | } |
| 3586 | |
| 3587 | /* |
| 3588 | * Timer running if the active_queue is currently idling inside its time slice |
| 3589 | */ |
| 3590 | static void cfq_idle_slice_timer(unsigned long data) |
| 3591 | { |
| 3592 | struct cfq_data *cfqd = (struct cfq_data *) data; |
| 3593 | struct cfq_queue *cfqq; |
| 3594 | unsigned long flags; |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 3595 | int timed_out = 1; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3596 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3597 | cfq_log(cfqd, "idle timer fired"); |
| 3598 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3599 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 3600 | |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 3601 | cfqq = cfqd->active_queue; |
| 3602 | if (cfqq) { |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 3603 | timed_out = 0; |
| 3604 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3605 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 3606 | * We saw a request before the queue expired, let it through |
| 3607 | */ |
| 3608 | if (cfq_cfqq_must_dispatch(cfqq)) |
| 3609 | goto out_kick; |
| 3610 | |
| 3611 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3612 | * expired |
| 3613 | */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3614 | if (cfq_slice_used(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3615 | goto expire; |
| 3616 | |
| 3617 | /* |
| 3618 | * only expire and reinvoke request handler, if there are |
| 3619 | * other queues with pending requests |
| 3620 | */ |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3621 | if (!cfqd->busy_queues) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3622 | goto out_cont; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3623 | |
| 3624 | /* |
| 3625 | * not expired and it has a request pending, let it dispatch |
| 3626 | */ |
Jens Axboe | 75e5098 | 2009-04-07 08:56:14 +0200 | [diff] [blame] | 3627 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3628 | goto out_kick; |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3629 | |
| 3630 | /* |
| 3631 | * Queue depth flag is reset only when the idle didn't succeed |
| 3632 | */ |
| 3633 | cfq_clear_cfqq_deep(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3634 | } |
| 3635 | expire: |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 3636 | cfq_slice_expired(cfqd, timed_out, false); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3637 | out_kick: |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3638 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3639 | out_cont: |
| 3640 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 3641 | } |
| 3642 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3643 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) |
| 3644 | { |
| 3645 | del_timer_sync(&cfqd->idle_slice_timer); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3646 | cancel_work_sync(&cfqd->unplug_work); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3647 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3648 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3649 | static void cfq_put_async_queues(struct cfq_data *cfqd) |
| 3650 | { |
| 3651 | int i; |
| 3652 | |
| 3653 | for (i = 0; i < IOPRIO_BE_NR; i++) { |
| 3654 | if (cfqd->async_cfqq[0][i]) |
| 3655 | cfq_put_queue(cfqd->async_cfqq[0][i]); |
| 3656 | if (cfqd->async_cfqq[1][i]) |
| 3657 | cfq_put_queue(cfqd->async_cfqq[1][i]); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3658 | } |
Oleg Nesterov | 2389d1e | 2007-11-05 08:58:05 +0100 | [diff] [blame] | 3659 | |
| 3660 | if (cfqd->async_idle_cfqq) |
| 3661 | cfq_put_queue(cfqd->async_idle_cfqq); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3662 | } |
| 3663 | |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 3664 | static void cfq_cfqd_free(struct rcu_head *head) |
| 3665 | { |
| 3666 | kfree(container_of(head, struct cfq_data, rcu)); |
| 3667 | } |
| 3668 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3669 | static void cfq_exit_queue(struct elevator_queue *e) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3670 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3671 | struct cfq_data *cfqd = e->elevator_data; |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3672 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3673 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3674 | cfq_shutdown_timer_wq(cfqd); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3675 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3676 | spin_lock_irq(q->queue_lock); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3677 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3678 | if (cfqd->active_queue) |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 3679 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0, false); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3680 | |
| 3681 | while (!list_empty(&cfqd->cic_list)) { |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3682 | struct cfq_io_context *cic = list_entry(cfqd->cic_list.next, |
| 3683 | struct cfq_io_context, |
| 3684 | queue_list); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3685 | |
| 3686 | __cfq_exit_single_io_context(cfqd, cic); |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3687 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3688 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3689 | cfq_put_async_queues(cfqd); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3690 | cfq_release_cfq_groups(cfqd); |
| 3691 | blkiocg_del_blkio_group(&cfqd->root_group.blkg); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 3692 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3693 | spin_unlock_irq(q->queue_lock); |
Al Viro | a90d742 | 2006-03-18 12:05:37 -0500 | [diff] [blame] | 3694 | |
| 3695 | cfq_shutdown_timer_wq(cfqd); |
| 3696 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3697 | /* Wait for cfqg->blkg->key accessors to exit their grace periods. */ |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 3698 | call_rcu(&cfqd->rcu, cfq_cfqd_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3699 | } |
| 3700 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3701 | static void *cfq_init_queue(struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3702 | { |
| 3703 | struct cfq_data *cfqd; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 3704 | int i, j; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3705 | struct cfq_group *cfqg; |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 3706 | struct cfq_rb_root *st; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3707 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 3708 | cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3709 | if (!cfqd) |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 3710 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3711 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 3712 | /* Init root service tree */ |
| 3713 | cfqd->grp_service_tree = CFQ_RB_ROOT; |
| 3714 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3715 | /* Init root group */ |
| 3716 | cfqg = &cfqd->root_group; |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 3717 | for_each_cfqg_st(cfqg, i, j, st) |
| 3718 | *st = CFQ_RB_ROOT; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 3719 | RB_CLEAR_NODE(&cfqg->rb_node); |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 3720 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 3721 | /* Give preference to root group over other groups */ |
| 3722 | cfqg->weight = 2*BLKIO_WEIGHT_DEFAULT; |
| 3723 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 3724 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3725 | /* |
| 3726 | * Take a reference to root group which we never drop. This is just |
| 3727 | * to make sure that cfq_put_cfqg() does not try to kfree root group |
| 3728 | */ |
| 3729 | atomic_set(&cfqg->ref, 1); |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 3730 | blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, (void *)cfqd, |
| 3731 | 0); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 3732 | #endif |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 3733 | /* |
| 3734 | * Not strictly needed (since RB_ROOT just clears the node and we |
| 3735 | * zeroed cfqd on alloc), but better be safe in case someone decides |
| 3736 | * to add magic to the rb code |
| 3737 | */ |
| 3738 | for (i = 0; i < CFQ_PRIO_LISTS; i++) |
| 3739 | cfqd->prio_trees[i] = RB_ROOT; |
| 3740 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 3741 | /* |
| 3742 | * Our fallback cfqq if cfq_find_alloc_queue() runs into OOM issues. |
| 3743 | * Grab a permanent reference to it, so that the normal code flow |
| 3744 | * will not attempt to free it. |
| 3745 | */ |
| 3746 | cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); |
| 3747 | atomic_inc(&cfqd->oom_cfqq.ref); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3748 | cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 3749 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3750 | INIT_LIST_HEAD(&cfqd->cic_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3751 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3752 | cfqd->queue = q; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3753 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3754 | init_timer(&cfqd->idle_slice_timer); |
| 3755 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; |
| 3756 | cfqd->idle_slice_timer.data = (unsigned long) cfqd; |
| 3757 | |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3758 | INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3759 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3760 | cfqd->cfq_quantum = cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3761 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |
| 3762 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3763 | cfqd->cfq_back_max = cfq_back_max; |
| 3764 | cfqd->cfq_back_penalty = cfq_back_penalty; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3765 | cfqd->cfq_slice[0] = cfq_slice_async; |
| 3766 | cfqd->cfq_slice[1] = cfq_slice_sync; |
| 3767 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; |
| 3768 | cfqd->cfq_slice_idle = cfq_slice_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3769 | cfqd->cfq_latency = 1; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3770 | cfqd->cfq_group_isolation = 0; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3771 | cfqd->hw_tag = -1; |
Corrado Zoccolo | edc7113 | 2009-12-09 20:56:04 +0100 | [diff] [blame] | 3772 | /* |
| 3773 | * we optimistically start assuming sync ops weren't delayed in last |
| 3774 | * second, in order to have larger depth for async operations. |
| 3775 | */ |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 3776 | cfqd->last_delayed_sync = jiffies - HZ; |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 3777 | INIT_RCU_HEAD(&cfqd->rcu); |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 3778 | return cfqd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3779 | } |
| 3780 | |
| 3781 | static void cfq_slab_kill(void) |
| 3782 | { |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 3783 | /* |
| 3784 | * Caller already ensured that pending RCU callbacks are completed, |
| 3785 | * so we should have no busy allocations at this point. |
| 3786 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3787 | if (cfq_pool) |
| 3788 | kmem_cache_destroy(cfq_pool); |
| 3789 | if (cfq_ioc_pool) |
| 3790 | kmem_cache_destroy(cfq_ioc_pool); |
| 3791 | } |
| 3792 | |
| 3793 | static int __init cfq_slab_setup(void) |
| 3794 | { |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame] | 3795 | cfq_pool = KMEM_CACHE(cfq_queue, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3796 | if (!cfq_pool) |
| 3797 | goto fail; |
| 3798 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 3799 | cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3800 | if (!cfq_ioc_pool) |
| 3801 | goto fail; |
| 3802 | |
| 3803 | return 0; |
| 3804 | fail: |
| 3805 | cfq_slab_kill(); |
| 3806 | return -ENOMEM; |
| 3807 | } |
| 3808 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3809 | /* |
| 3810 | * sysfs parts below --> |
| 3811 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3812 | static ssize_t |
| 3813 | cfq_var_show(unsigned int var, char *page) |
| 3814 | { |
| 3815 | return sprintf(page, "%d\n", var); |
| 3816 | } |
| 3817 | |
| 3818 | static ssize_t |
| 3819 | cfq_var_store(unsigned int *var, const char *page, size_t count) |
| 3820 | { |
| 3821 | char *p = (char *) page; |
| 3822 | |
| 3823 | *var = simple_strtoul(p, &p, 10); |
| 3824 | return count; |
| 3825 | } |
| 3826 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3827 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3828 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3829 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3830 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3831 | unsigned int __data = __VAR; \ |
| 3832 | if (__CONV) \ |
| 3833 | __data = jiffies_to_msecs(__data); \ |
| 3834 | return cfq_var_show(__data, (page)); \ |
| 3835 | } |
| 3836 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3837 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); |
| 3838 | 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] | 3839 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); |
| 3840 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3841 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); |
| 3842 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); |
| 3843 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); |
| 3844 | 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] | 3845 | SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3846 | SHOW_FUNCTION(cfq_group_isolation_show, cfqd->cfq_group_isolation, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3847 | #undef SHOW_FUNCTION |
| 3848 | |
| 3849 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3850 | 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] | 3851 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3852 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3853 | unsigned int __data; \ |
| 3854 | int ret = cfq_var_store(&__data, (page), count); \ |
| 3855 | if (__data < (MIN)) \ |
| 3856 | __data = (MIN); \ |
| 3857 | else if (__data > (MAX)) \ |
| 3858 | __data = (MAX); \ |
| 3859 | if (__CONV) \ |
| 3860 | *(__PTR) = msecs_to_jiffies(__data); \ |
| 3861 | else \ |
| 3862 | *(__PTR) = __data; \ |
| 3863 | return ret; \ |
| 3864 | } |
| 3865 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 3866 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, |
| 3867 | UINT_MAX, 1); |
| 3868 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, |
| 3869 | UINT_MAX, 1); |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3870 | 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] | 3871 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, |
| 3872 | UINT_MAX, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3873 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); |
| 3874 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); |
| 3875 | 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] | 3876 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, |
| 3877 | UINT_MAX, 0); |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3878 | STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3879 | STORE_FUNCTION(cfq_group_isolation_store, &cfqd->cfq_group_isolation, 0, 1, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3880 | #undef STORE_FUNCTION |
| 3881 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3882 | #define CFQ_ATTR(name) \ |
| 3883 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3884 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3885 | static struct elv_fs_entry cfq_attrs[] = { |
| 3886 | CFQ_ATTR(quantum), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3887 | CFQ_ATTR(fifo_expire_sync), |
| 3888 | CFQ_ATTR(fifo_expire_async), |
| 3889 | CFQ_ATTR(back_seek_max), |
| 3890 | CFQ_ATTR(back_seek_penalty), |
| 3891 | CFQ_ATTR(slice_sync), |
| 3892 | CFQ_ATTR(slice_async), |
| 3893 | CFQ_ATTR(slice_async_rq), |
| 3894 | CFQ_ATTR(slice_idle), |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3895 | CFQ_ATTR(low_latency), |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3896 | CFQ_ATTR(group_isolation), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3897 | __ATTR_NULL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3898 | }; |
| 3899 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3900 | static struct elevator_type iosched_cfq = { |
| 3901 | .ops = { |
| 3902 | .elevator_merge_fn = cfq_merge, |
| 3903 | .elevator_merged_fn = cfq_merged_request, |
| 3904 | .elevator_merge_req_fn = cfq_merged_requests, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 3905 | .elevator_allow_merge_fn = cfq_allow_merge, |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 3906 | .elevator_bio_merged_fn = cfq_bio_merged, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3907 | .elevator_dispatch_fn = cfq_dispatch_requests, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3908 | .elevator_add_req_fn = cfq_insert_request, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3909 | .elevator_activate_req_fn = cfq_activate_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3910 | .elevator_deactivate_req_fn = cfq_deactivate_request, |
| 3911 | .elevator_queue_empty_fn = cfq_queue_empty, |
| 3912 | .elevator_completed_req_fn = cfq_completed_request, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 3913 | .elevator_former_req_fn = elv_rb_former_request, |
| 3914 | .elevator_latter_req_fn = elv_rb_latter_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3915 | .elevator_set_req_fn = cfq_set_request, |
| 3916 | .elevator_put_req_fn = cfq_put_request, |
| 3917 | .elevator_may_queue_fn = cfq_may_queue, |
| 3918 | .elevator_init_fn = cfq_init_queue, |
| 3919 | .elevator_exit_fn = cfq_exit_queue, |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 3920 | .trim = cfq_free_io_context, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3921 | }, |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3922 | .elevator_attrs = cfq_attrs, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3923 | .elevator_name = "cfq", |
| 3924 | .elevator_owner = THIS_MODULE, |
| 3925 | }; |
| 3926 | |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3927 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 3928 | static struct blkio_policy_type blkio_policy_cfq = { |
| 3929 | .ops = { |
| 3930 | .blkio_unlink_group_fn = cfq_unlink_blkio_group, |
| 3931 | .blkio_update_group_weight_fn = cfq_update_blkio_group_weight, |
| 3932 | }, |
| 3933 | }; |
| 3934 | #else |
| 3935 | static struct blkio_policy_type blkio_policy_cfq; |
| 3936 | #endif |
| 3937 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3938 | static int __init cfq_init(void) |
| 3939 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3940 | /* |
| 3941 | * could be 0 on HZ < 1000 setups |
| 3942 | */ |
| 3943 | if (!cfq_slice_async) |
| 3944 | cfq_slice_async = 1; |
| 3945 | if (!cfq_slice_idle) |
| 3946 | cfq_slice_idle = 1; |
| 3947 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3948 | if (cfq_slab_setup()) |
| 3949 | return -ENOMEM; |
| 3950 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 3951 | elv_register(&iosched_cfq); |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3952 | blkio_policy_register(&blkio_policy_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3953 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 3954 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3955 | } |
| 3956 | |
| 3957 | static void __exit cfq_exit(void) |
| 3958 | { |
Peter Zijlstra | 6e9a473 | 2006-09-30 23:28:10 -0700 | [diff] [blame] | 3959 | DECLARE_COMPLETION_ONSTACK(all_gone); |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3960 | blkio_policy_unregister(&blkio_policy_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3961 | elv_unregister(&iosched_cfq); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 3962 | ioc_gone = &all_gone; |
OGAWA Hirofumi | fba8227 | 2006-04-18 09:44:06 +0200 | [diff] [blame] | 3963 | /* ioc_gone's update must be visible before reading ioc_count */ |
| 3964 | smp_wmb(); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 3965 | |
| 3966 | /* |
| 3967 | * this also protects us from entering cfq_slab_kill() with |
| 3968 | * pending RCU callbacks |
| 3969 | */ |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 3970 | if (elv_ioc_count_read(cfq_ioc_count)) |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 3971 | wait_for_completion(&all_gone); |
Christoph Hellwig | 83521d3 | 2005-10-30 15:01:39 -0800 | [diff] [blame] | 3972 | cfq_slab_kill(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3973 | } |
| 3974 | |
| 3975 | module_init(cfq_init); |
| 3976 | module_exit(cfq_exit); |
| 3977 | |
| 3978 | MODULE_AUTHOR("Jens Axboe"); |
| 3979 | MODULE_LICENSE("GPL"); |
| 3980 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |