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) |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 58 | #define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elevator_private3) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 60 | static struct kmem_cache *cfq_pool; |
| 61 | static struct kmem_cache *cfq_ioc_pool; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 63 | static DEFINE_PER_CPU(unsigned long, cfq_ioc_count); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 64 | static struct completion *ioc_gone; |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 65 | static DEFINE_SPINLOCK(ioc_gone_lock); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 66 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 67 | #define CFQ_PRIO_LISTS IOPRIO_BE_NR |
| 68 | #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 69 | #define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT) |
| 70 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 71 | #define sample_valid(samples) ((samples) > 80) |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 72 | #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] | 73 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 74 | /* |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 75 | * Most of our rbtree usage is for sorting with min extraction, so |
| 76 | * if we cache the leftmost node we don't have to walk down the tree |
| 77 | * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should |
| 78 | * move this into the elevator for the rq sorting as well. |
| 79 | */ |
| 80 | struct cfq_rb_root { |
| 81 | struct rb_root rb; |
| 82 | struct rb_node *left; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 83 | unsigned count; |
Richard Kennedy | 73e9ffd | 2010-03-01 10:50:20 +0100 | [diff] [blame] | 84 | unsigned total_weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 85 | u64 min_vdisktime; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 86 | struct rb_node *active; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 87 | }; |
Richard Kennedy | 73e9ffd | 2010-03-01 10:50:20 +0100 | [diff] [blame] | 88 | #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, .left = NULL, \ |
| 89 | .count = 0, .min_vdisktime = 0, } |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 90 | |
| 91 | /* |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 92 | * Per process-grouping structure |
| 93 | */ |
| 94 | struct cfq_queue { |
| 95 | /* reference count */ |
| 96 | atomic_t ref; |
| 97 | /* various state flags, see below */ |
| 98 | unsigned int flags; |
| 99 | /* parent cfq_data */ |
| 100 | struct cfq_data *cfqd; |
| 101 | /* service_tree member */ |
| 102 | struct rb_node rb_node; |
| 103 | /* service_tree key */ |
| 104 | unsigned long rb_key; |
| 105 | /* prio tree member */ |
| 106 | struct rb_node p_node; |
| 107 | /* prio tree root we belong to, if any */ |
| 108 | struct rb_root *p_root; |
| 109 | /* sorted list of pending requests */ |
| 110 | struct rb_root sort_list; |
| 111 | /* if fifo isn't expired, next request to serve */ |
| 112 | struct request *next_rq; |
| 113 | /* requests queued in sort_list */ |
| 114 | int queued[2]; |
| 115 | /* currently allocated requests */ |
| 116 | int allocated[2]; |
| 117 | /* fifo list of requests in sort_list */ |
| 118 | struct list_head fifo; |
| 119 | |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 120 | /* time when queue got scheduled in to dispatch first request. */ |
| 121 | unsigned long dispatch_start; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 122 | unsigned int allocated_slice; |
Richard Kennedy | c4081ba | 2010-02-22 13:49:24 +0100 | [diff] [blame] | 123 | unsigned int slice_dispatch; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 124 | /* time when first request from queue completed and slice started. */ |
| 125 | unsigned long slice_start; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 126 | unsigned long slice_end; |
| 127 | long slice_resid; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 128 | |
| 129 | /* pending metadata requests */ |
| 130 | int meta_pending; |
| 131 | /* number of requests that are on the dispatch list or inside driver */ |
| 132 | int dispatched; |
| 133 | |
| 134 | /* io prio of this group */ |
| 135 | unsigned short ioprio, org_ioprio; |
| 136 | unsigned short ioprio_class, org_ioprio_class; |
| 137 | |
Richard Kennedy | c4081ba | 2010-02-22 13:49:24 +0100 | [diff] [blame] | 138 | pid_t pid; |
| 139 | |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 140 | u32 seek_history; |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 141 | sector_t last_request_pos; |
| 142 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 143 | struct cfq_rb_root *service_tree; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 144 | struct cfq_queue *new_cfqq; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 145 | struct cfq_group *cfqg; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 146 | struct cfq_group *orig_cfqg; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 147 | }; |
| 148 | |
| 149 | /* |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 150 | * First index in the service_trees. |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 151 | * IDLE is handled separately, so it has negative index |
| 152 | */ |
| 153 | enum wl_prio_t { |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 154 | BE_WORKLOAD = 0, |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 155 | RT_WORKLOAD = 1, |
| 156 | IDLE_WORKLOAD = 2, |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 157 | }; |
| 158 | |
| 159 | /* |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 160 | * Second index in the service_trees. |
| 161 | */ |
| 162 | enum wl_type_t { |
| 163 | ASYNC_WORKLOAD = 0, |
| 164 | SYNC_NOIDLE_WORKLOAD = 1, |
| 165 | SYNC_WORKLOAD = 2 |
| 166 | }; |
| 167 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 168 | /* This is per cgroup per device grouping structure */ |
| 169 | struct cfq_group { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 170 | /* group service_tree member */ |
| 171 | struct rb_node rb_node; |
| 172 | |
| 173 | /* group service_tree key */ |
| 174 | u64 vdisktime; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 175 | unsigned int weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 176 | bool on_st; |
| 177 | |
| 178 | /* number of cfqq currently on this group */ |
| 179 | int nr_cfqq; |
| 180 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 181 | /* Per group busy queus average. Useful for workload slice calc. */ |
| 182 | unsigned int busy_queues_avg[2]; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 183 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 184 | * rr lists of queues with requests, onle rr for each priority class. |
| 185 | * Counts are embedded in the cfq_rb_root |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 186 | */ |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 187 | struct cfq_rb_root service_trees[2][3]; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 188 | struct cfq_rb_root service_tree_idle; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 189 | |
| 190 | unsigned long saved_workload_slice; |
| 191 | enum wl_type_t saved_workload; |
| 192 | enum wl_prio_t saved_serving_prio; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 193 | struct blkio_group blkg; |
| 194 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 195 | struct hlist_node cfqd_node; |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 196 | atomic_t ref; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 197 | #endif |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 198 | }; |
| 199 | |
| 200 | /* |
| 201 | * Per block device queue structure |
| 202 | */ |
| 203 | struct cfq_data { |
| 204 | struct request_queue *queue; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 205 | /* Root service tree for cfq_groups */ |
| 206 | struct cfq_rb_root grp_service_tree; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 207 | struct cfq_group root_group; |
| 208 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 209 | /* |
| 210 | * The priority currently being served |
| 211 | */ |
| 212 | enum wl_prio_t serving_prio; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 213 | enum wl_type_t serving_type; |
| 214 | unsigned long workload_expires; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 215 | struct cfq_group *serving_group; |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 216 | bool noidle_tree_requires_idle; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 217 | |
| 218 | /* |
| 219 | * Each priority tree is sorted by next_request position. These |
| 220 | * trees are used when determining if two or more queues are |
| 221 | * interleaving requests (see cfq_close_cooperator). |
| 222 | */ |
| 223 | struct rb_root prio_trees[CFQ_PRIO_LISTS]; |
| 224 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 225 | unsigned int busy_queues; |
| 226 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 227 | int rq_in_driver; |
| 228 | int rq_in_flight[2]; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 229 | |
| 230 | /* |
| 231 | * queue-depth detection |
| 232 | */ |
| 233 | int rq_queued; |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 234 | int hw_tag; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 235 | /* |
| 236 | * hw_tag can be |
| 237 | * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection) |
| 238 | * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth) |
| 239 | * 0 => no NCQ |
| 240 | */ |
| 241 | int hw_tag_est_depth; |
| 242 | unsigned int hw_tag_samples; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 243 | |
| 244 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 245 | * idle window management |
| 246 | */ |
| 247 | struct timer_list idle_slice_timer; |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 248 | struct work_struct unplug_work; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 249 | |
| 250 | struct cfq_queue *active_queue; |
| 251 | struct cfq_io_context *active_cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 252 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 253 | /* |
| 254 | * async queue for each priority case |
| 255 | */ |
| 256 | struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; |
| 257 | struct cfq_queue *async_idle_cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 258 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 259 | sector_t last_position; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | /* |
| 262 | * tunables, see top of file |
| 263 | */ |
| 264 | unsigned int cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 265 | unsigned int cfq_fifo_expire[2]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | unsigned int cfq_back_penalty; |
| 267 | unsigned int cfq_back_max; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 268 | unsigned int cfq_slice[2]; |
| 269 | unsigned int cfq_slice_async_rq; |
| 270 | unsigned int cfq_slice_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 271 | unsigned int cfq_latency; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 272 | unsigned int cfq_group_isolation; |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 273 | |
| 274 | struct list_head cic_list; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 276 | /* |
| 277 | * Fallback dummy cfqq for extreme OOM conditions |
| 278 | */ |
| 279 | struct cfq_queue oom_cfqq; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 280 | |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 281 | unsigned long last_delayed_sync; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 282 | |
| 283 | /* List of cfq groups being managed on this device*/ |
| 284 | struct hlist_head cfqg_list; |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 285 | struct rcu_head rcu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | }; |
| 287 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 288 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd); |
| 289 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 290 | static struct cfq_rb_root *service_tree_for(struct cfq_group *cfqg, |
| 291 | enum wl_prio_t prio, |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 292 | enum wl_type_t type) |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 293 | { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 294 | if (!cfqg) |
| 295 | return NULL; |
| 296 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 297 | if (prio == IDLE_WORKLOAD) |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 298 | return &cfqg->service_tree_idle; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 299 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 300 | return &cfqg->service_trees[prio][type]; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 301 | } |
| 302 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 303 | enum cfqq_state_flags { |
Jens Axboe | b0b8d749 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 304 | CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ |
| 305 | CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 306 | CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ |
Jens Axboe | b0b8d749 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 307 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ |
Jens Axboe | b0b8d749 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 308 | CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ |
| 309 | CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ |
| 310 | CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 311 | CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 312 | CFQ_CFQQ_FLAG_sync, /* synchronous queue */ |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 313 | CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 314 | CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */ |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 315 | CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 316 | CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 317 | }; |
| 318 | |
| 319 | #define CFQ_CFQQ_FNS(name) \ |
| 320 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ |
| 321 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 322 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 323 | } \ |
| 324 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ |
| 325 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 326 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 327 | } \ |
| 328 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ |
| 329 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 330 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 331 | } |
| 332 | |
| 333 | CFQ_CFQQ_FNS(on_rr); |
| 334 | CFQ_CFQQ_FNS(wait_request); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 335 | CFQ_CFQQ_FNS(must_dispatch); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 336 | CFQ_CFQQ_FNS(must_alloc_slice); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 337 | CFQ_CFQQ_FNS(fifo_expire); |
| 338 | CFQ_CFQQ_FNS(idle_window); |
| 339 | CFQ_CFQQ_FNS(prio_changed); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 340 | CFQ_CFQQ_FNS(slice_new); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 341 | CFQ_CFQQ_FNS(sync); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 342 | CFQ_CFQQ_FNS(coop); |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 343 | CFQ_CFQQ_FNS(split_coop); |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 344 | CFQ_CFQQ_FNS(deep); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 345 | CFQ_CFQQ_FNS(wait_busy); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 346 | #undef CFQ_CFQQ_FNS |
| 347 | |
Vivek Goyal | afc24d4 | 2010-04-26 19:27:56 +0200 | [diff] [blame] | 348 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 349 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 350 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \ |
| 351 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ |
| 352 | blkg_path(&(cfqq)->cfqg->blkg), ##args); |
| 353 | |
| 354 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) \ |
| 355 | blk_add_trace_msg((cfqd)->queue, "%s " fmt, \ |
| 356 | blkg_path(&(cfqg)->blkg), ##args); \ |
| 357 | |
| 358 | #else |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 359 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 360 | blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args) |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 361 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0); |
| 362 | #endif |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 363 | #define cfq_log(cfqd, fmt, args...) \ |
| 364 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) |
| 365 | |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 366 | /* Traverses through cfq group service trees */ |
| 367 | #define for_each_cfqg_st(cfqg, i, j, st) \ |
| 368 | for (i = 0; i <= IDLE_WORKLOAD; i++) \ |
| 369 | for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\ |
| 370 | : &cfqg->service_tree_idle; \ |
| 371 | (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \ |
| 372 | (i == IDLE_WORKLOAD && j == 0); \ |
| 373 | j++, st = i < IDLE_WORKLOAD ? \ |
| 374 | &cfqg->service_trees[i][j]: NULL) \ |
| 375 | |
| 376 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 377 | static inline enum wl_prio_t cfqq_prio(struct cfq_queue *cfqq) |
| 378 | { |
| 379 | if (cfq_class_idle(cfqq)) |
| 380 | return IDLE_WORKLOAD; |
| 381 | if (cfq_class_rt(cfqq)) |
| 382 | return RT_WORKLOAD; |
| 383 | return BE_WORKLOAD; |
| 384 | } |
| 385 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 386 | |
| 387 | static enum wl_type_t cfqq_type(struct cfq_queue *cfqq) |
| 388 | { |
| 389 | if (!cfq_cfqq_sync(cfqq)) |
| 390 | return ASYNC_WORKLOAD; |
| 391 | if (!cfq_cfqq_idle_window(cfqq)) |
| 392 | return SYNC_NOIDLE_WORKLOAD; |
| 393 | return SYNC_WORKLOAD; |
| 394 | } |
| 395 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 396 | static inline int cfq_group_busy_queues_wl(enum wl_prio_t wl, |
| 397 | struct cfq_data *cfqd, |
| 398 | struct cfq_group *cfqg) |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 399 | { |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 400 | if (wl == IDLE_WORKLOAD) |
| 401 | return cfqg->service_tree_idle.count; |
| 402 | |
| 403 | return cfqg->service_trees[wl][ASYNC_WORKLOAD].count |
| 404 | + cfqg->service_trees[wl][SYNC_NOIDLE_WORKLOAD].count |
| 405 | + cfqg->service_trees[wl][SYNC_WORKLOAD].count; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 406 | } |
| 407 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 408 | static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, |
| 409 | struct cfq_group *cfqg) |
| 410 | { |
| 411 | return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count |
| 412 | + cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count; |
| 413 | } |
| 414 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 415 | static void cfq_dispatch_insert(struct request_queue *, struct request *); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 416 | static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 417 | struct io_context *, gfp_t); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 418 | static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *, |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 419 | struct io_context *); |
| 420 | |
| 421 | 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] | 422 | bool is_sync) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 423 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 424 | return cic->cfqq[is_sync]; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 425 | } |
| 426 | |
| 427 | static inline void cic_set_cfqq(struct cfq_io_context *cic, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 428 | struct cfq_queue *cfqq, bool is_sync) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 429 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 430 | cic->cfqq[is_sync] = cfqq; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 431 | } |
| 432 | |
| 433 | /* |
| 434 | * We regard a request as SYNC, if it's either a read or has the SYNC bit |
| 435 | * set (in which case it could also be direct WRITE). |
| 436 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 437 | static inline bool cfq_bio_sync(struct bio *bio) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 438 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 439 | 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] | 440 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | /* |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 443 | * scheduler run of queue, if there are requests pending and no one in the |
| 444 | * driver that will restart queueing |
| 445 | */ |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 446 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 447 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 448 | if (cfqd->busy_queues) { |
| 449 | cfq_log(cfqd, "schedule dispatch"); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 450 | kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 451 | } |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 452 | } |
| 453 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 454 | static int cfq_queue_empty(struct request_queue *q) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 455 | { |
| 456 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 457 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 458 | return !cfqd->rq_queued; |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 459 | } |
| 460 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | /* |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 462 | * Scale schedule slice based on io priority. Use the sync time slice only |
| 463 | * if a queue is marked sync and has sync io queued. A sync queue with async |
| 464 | * io only, should not get full sync slice length. |
| 465 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 466 | static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync, |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 467 | unsigned short prio) |
| 468 | { |
| 469 | const int base_slice = cfqd->cfq_slice[sync]; |
| 470 | |
| 471 | WARN_ON(prio >= IOPRIO_BE_NR); |
| 472 | |
| 473 | return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); |
| 474 | } |
| 475 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 476 | static inline int |
| 477 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 478 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 479 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 480 | } |
| 481 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 482 | static inline u64 cfq_scale_slice(unsigned long delta, struct cfq_group *cfqg) |
| 483 | { |
| 484 | u64 d = delta << CFQ_SERVICE_SHIFT; |
| 485 | |
| 486 | d = d * BLKIO_WEIGHT_DEFAULT; |
| 487 | do_div(d, cfqg->weight); |
| 488 | return d; |
| 489 | } |
| 490 | |
| 491 | static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime) |
| 492 | { |
| 493 | s64 delta = (s64)(vdisktime - min_vdisktime); |
| 494 | if (delta > 0) |
| 495 | min_vdisktime = vdisktime; |
| 496 | |
| 497 | return min_vdisktime; |
| 498 | } |
| 499 | |
| 500 | static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime) |
| 501 | { |
| 502 | s64 delta = (s64)(vdisktime - min_vdisktime); |
| 503 | if (delta < 0) |
| 504 | min_vdisktime = vdisktime; |
| 505 | |
| 506 | return min_vdisktime; |
| 507 | } |
| 508 | |
| 509 | static void update_min_vdisktime(struct cfq_rb_root *st) |
| 510 | { |
| 511 | u64 vdisktime = st->min_vdisktime; |
| 512 | struct cfq_group *cfqg; |
| 513 | |
| 514 | if (st->active) { |
| 515 | cfqg = rb_entry_cfqg(st->active); |
| 516 | vdisktime = cfqg->vdisktime; |
| 517 | } |
| 518 | |
| 519 | if (st->left) { |
| 520 | cfqg = rb_entry_cfqg(st->left); |
| 521 | vdisktime = min_vdisktime(vdisktime, cfqg->vdisktime); |
| 522 | } |
| 523 | |
| 524 | st->min_vdisktime = max_vdisktime(st->min_vdisktime, vdisktime); |
| 525 | } |
| 526 | |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 527 | /* |
| 528 | * get averaged number of queues of RT/BE priority. |
| 529 | * average is updated, with a formula that gives more weight to higher numbers, |
| 530 | * to quickly follows sudden increases and decrease slowly |
| 531 | */ |
| 532 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 533 | static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd, |
| 534 | struct cfq_group *cfqg, bool rt) |
Jens Axboe | 5869619c | 2009-10-28 09:27:07 +0100 | [diff] [blame] | 535 | { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 536 | unsigned min_q, max_q; |
| 537 | unsigned mult = cfq_hist_divisor - 1; |
| 538 | unsigned round = cfq_hist_divisor / 2; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 539 | unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg); |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 540 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 541 | min_q = min(cfqg->busy_queues_avg[rt], busy); |
| 542 | max_q = max(cfqg->busy_queues_avg[rt], busy); |
| 543 | cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) / |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 544 | cfq_hist_divisor; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 545 | return cfqg->busy_queues_avg[rt]; |
| 546 | } |
| 547 | |
| 548 | static inline unsigned |
| 549 | cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 550 | { |
| 551 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 552 | |
| 553 | return cfq_target_latency * cfqg->weight / st->total_weight; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 554 | } |
| 555 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 556 | static inline void |
| 557 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 558 | { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 559 | unsigned slice = cfq_prio_to_slice(cfqd, cfqq); |
| 560 | if (cfqd->cfq_latency) { |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 561 | /* |
| 562 | * interested queues (we consider only the ones with the same |
| 563 | * priority class in the cfq group) |
| 564 | */ |
| 565 | unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg, |
| 566 | cfq_class_rt(cfqq)); |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 567 | unsigned sync_slice = cfqd->cfq_slice[1]; |
| 568 | unsigned expect_latency = sync_slice * iq; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 569 | unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg); |
| 570 | |
| 571 | if (expect_latency > group_slice) { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 572 | unsigned base_low_slice = 2 * cfqd->cfq_slice_idle; |
| 573 | /* scale low_slice according to IO priority |
| 574 | * and sync vs async */ |
| 575 | unsigned low_slice = |
| 576 | min(slice, base_low_slice * slice / sync_slice); |
| 577 | /* the adapted slice value is scaled to fit all iqs |
| 578 | * into the target latency */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 579 | slice = max(slice * group_slice / expect_latency, |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 580 | low_slice); |
| 581 | } |
| 582 | } |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 583 | cfqq->slice_start = jiffies; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 584 | cfqq->slice_end = jiffies + slice; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 585 | cfqq->allocated_slice = slice; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 586 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 587 | } |
| 588 | |
| 589 | /* |
| 590 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end |
| 591 | * isn't valid until the first request from the dispatch is activated |
| 592 | * and the slice time set. |
| 593 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 594 | static inline bool cfq_slice_used(struct cfq_queue *cfqq) |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 595 | { |
| 596 | if (cfq_cfqq_slice_new(cfqq)) |
| 597 | return 0; |
| 598 | if (time_before(jiffies, cfqq->slice_end)) |
| 599 | return 0; |
| 600 | |
| 601 | return 1; |
| 602 | } |
| 603 | |
| 604 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 605 | * 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] | 606 | * 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] | 607 | * behind the head is penalized and only allowed to a certain extent. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 609 | static struct request * |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 610 | 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] | 611 | { |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 612 | sector_t s1, s2, d1 = 0, d2 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | unsigned long back_max; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 614 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ |
| 615 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ |
| 616 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 618 | if (rq1 == NULL || rq1 == rq2) |
| 619 | return rq2; |
| 620 | if (rq2 == NULL) |
| 621 | return rq1; |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 622 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 623 | if (rq_is_sync(rq1) && !rq_is_sync(rq2)) |
| 624 | return rq1; |
| 625 | else if (rq_is_sync(rq2) && !rq_is_sync(rq1)) |
| 626 | return rq2; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 627 | if (rq_is_meta(rq1) && !rq_is_meta(rq2)) |
| 628 | return rq1; |
| 629 | else if (rq_is_meta(rq2) && !rq_is_meta(rq1)) |
| 630 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 632 | s1 = blk_rq_pos(rq1); |
| 633 | s2 = blk_rq_pos(rq2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 634 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 635 | /* |
| 636 | * by definition, 1KiB is 2 sectors |
| 637 | */ |
| 638 | back_max = cfqd->cfq_back_max * 2; |
| 639 | |
| 640 | /* |
| 641 | * Strict one way elevator _except_ in the case where we allow |
| 642 | * short backward seeks which are biased as twice the cost of a |
| 643 | * similar forward seek. |
| 644 | */ |
| 645 | if (s1 >= last) |
| 646 | d1 = s1 - last; |
| 647 | else if (s1 + back_max >= last) |
| 648 | d1 = (last - s1) * cfqd->cfq_back_penalty; |
| 649 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 650 | wrap |= CFQ_RQ1_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | |
| 652 | if (s2 >= last) |
| 653 | d2 = s2 - last; |
| 654 | else if (s2 + back_max >= last) |
| 655 | d2 = (last - s2) * cfqd->cfq_back_penalty; |
| 656 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 657 | wrap |= CFQ_RQ2_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 658 | |
| 659 | /* Found required data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 661 | /* |
| 662 | * By doing switch() on the bit mask "wrap" we avoid having to |
| 663 | * check two variables for all permutations: --> faster! |
| 664 | */ |
| 665 | switch (wrap) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 666 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 667 | if (d1 < d2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 668 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 669 | else if (d2 < d1) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 670 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 671 | else { |
| 672 | if (s1 >= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 673 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 674 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 675 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 676 | } |
| 677 | |
| 678 | case CFQ_RQ2_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 679 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 680 | case CFQ_RQ1_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 681 | return rq2; |
| 682 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 683 | default: |
| 684 | /* |
| 685 | * Since both rqs are wrapped, |
| 686 | * start with the one that's further behind head |
| 687 | * (--> only *one* back seek required), |
| 688 | * since back seek takes more time than forward. |
| 689 | */ |
| 690 | if (s1 <= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 691 | return rq1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 693 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 694 | } |
| 695 | } |
| 696 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 697 | /* |
| 698 | * The below is leftmost cache rbtree addon |
| 699 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 700 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 701 | { |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 702 | /* Service tree is empty */ |
| 703 | if (!root->count) |
| 704 | return NULL; |
| 705 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 706 | if (!root->left) |
| 707 | root->left = rb_first(&root->rb); |
| 708 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 709 | if (root->left) |
| 710 | return rb_entry(root->left, struct cfq_queue, rb_node); |
| 711 | |
| 712 | return NULL; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 713 | } |
| 714 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 715 | static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root) |
| 716 | { |
| 717 | if (!root->left) |
| 718 | root->left = rb_first(&root->rb); |
| 719 | |
| 720 | if (root->left) |
| 721 | return rb_entry_cfqg(root->left); |
| 722 | |
| 723 | return NULL; |
| 724 | } |
| 725 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 726 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
| 727 | { |
| 728 | rb_erase(n, root); |
| 729 | RB_CLEAR_NODE(n); |
| 730 | } |
| 731 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 732 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) |
| 733 | { |
| 734 | if (root->left == n) |
| 735 | root->left = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 736 | rb_erase_init(n, &root->rb); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 737 | --root->count; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 738 | } |
| 739 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 740 | /* |
| 741 | * would be nice to take fifo expire time into account as well |
| 742 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 743 | static struct request * |
| 744 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 745 | struct request *last) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 747 | struct rb_node *rbnext = rb_next(&last->rb_node); |
| 748 | struct rb_node *rbprev = rb_prev(&last->rb_node); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 749 | struct request *next = NULL, *prev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 750 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 751 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 752 | |
| 753 | if (rbprev) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 754 | prev = rb_entry_rq(rbprev); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 755 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | if (rbnext) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 757 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 758 | else { |
| 759 | rbnext = rb_first(&cfqq->sort_list); |
| 760 | if (rbnext && rbnext != &last->rb_node) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 761 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 762 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 764 | return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | } |
| 766 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 767 | static unsigned long cfq_slice_offset(struct cfq_data *cfqd, |
| 768 | struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 769 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 770 | /* |
| 771 | * just an approximation, should be ok. |
| 772 | */ |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 773 | return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - |
Jens Axboe | 464191c | 2009-11-30 09:38:13 +0100 | [diff] [blame] | 774 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 775 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 777 | static inline s64 |
| 778 | cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg) |
| 779 | { |
| 780 | return cfqg->vdisktime - st->min_vdisktime; |
| 781 | } |
| 782 | |
| 783 | static void |
| 784 | __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) |
| 785 | { |
| 786 | struct rb_node **node = &st->rb.rb_node; |
| 787 | struct rb_node *parent = NULL; |
| 788 | struct cfq_group *__cfqg; |
| 789 | s64 key = cfqg_key(st, cfqg); |
| 790 | int left = 1; |
| 791 | |
| 792 | while (*node != NULL) { |
| 793 | parent = *node; |
| 794 | __cfqg = rb_entry_cfqg(parent); |
| 795 | |
| 796 | if (key < cfqg_key(st, __cfqg)) |
| 797 | node = &parent->rb_left; |
| 798 | else { |
| 799 | node = &parent->rb_right; |
| 800 | left = 0; |
| 801 | } |
| 802 | } |
| 803 | |
| 804 | if (left) |
| 805 | st->left = &cfqg->rb_node; |
| 806 | |
| 807 | rb_link_node(&cfqg->rb_node, parent, node); |
| 808 | rb_insert_color(&cfqg->rb_node, &st->rb); |
| 809 | } |
| 810 | |
| 811 | static void |
| 812 | cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 813 | { |
| 814 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 815 | struct cfq_group *__cfqg; |
| 816 | struct rb_node *n; |
| 817 | |
| 818 | cfqg->nr_cfqq++; |
| 819 | if (cfqg->on_st) |
| 820 | return; |
| 821 | |
| 822 | /* |
| 823 | * Currently put the group at the end. Later implement something |
| 824 | * so that groups get lesser vtime based on their weights, so that |
| 825 | * if group does not loose all if it was not continously backlogged. |
| 826 | */ |
| 827 | n = rb_last(&st->rb); |
| 828 | if (n) { |
| 829 | __cfqg = rb_entry_cfqg(n); |
| 830 | cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY; |
| 831 | } else |
| 832 | cfqg->vdisktime = st->min_vdisktime; |
| 833 | |
| 834 | __cfq_group_service_tree_add(st, cfqg); |
| 835 | cfqg->on_st = true; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 836 | st->total_weight += cfqg->weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 837 | } |
| 838 | |
| 839 | static void |
| 840 | cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 841 | { |
| 842 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 843 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 844 | if (st->active == &cfqg->rb_node) |
| 845 | st->active = NULL; |
| 846 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 847 | BUG_ON(cfqg->nr_cfqq < 1); |
| 848 | cfqg->nr_cfqq--; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 849 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 850 | /* If there are other cfq queues under this group, don't delete it */ |
| 851 | if (cfqg->nr_cfqq) |
| 852 | return; |
| 853 | |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 854 | cfq_log_cfqg(cfqd, cfqg, "del_from_rr group"); |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 855 | cfqg->on_st = false; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 856 | st->total_weight -= cfqg->weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 857 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
| 858 | cfq_rb_erase(&cfqg->rb_node, st); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 859 | cfqg->saved_workload_slice = 0; |
Divyesh Shah | 9195291 | 2010-04-01 15:01:41 -0700 | [diff] [blame] | 860 | blkiocg_update_dequeue_stats(&cfqg->blkg, 1); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 861 | } |
| 862 | |
| 863 | static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq) |
| 864 | { |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 865 | unsigned int slice_used; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 866 | |
| 867 | /* |
| 868 | * Queue got expired before even a single request completed or |
| 869 | * got expired immediately after first request completion. |
| 870 | */ |
| 871 | if (!cfqq->slice_start || cfqq->slice_start == jiffies) { |
| 872 | /* |
| 873 | * Also charge the seek time incurred to the group, otherwise |
| 874 | * if there are mutiple queues in the group, each can dispatch |
| 875 | * a single request on seeky media and cause lots of seek time |
| 876 | * and group will never know it. |
| 877 | */ |
| 878 | slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start), |
| 879 | 1); |
| 880 | } else { |
| 881 | slice_used = jiffies - cfqq->slice_start; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 882 | if (slice_used > cfqq->allocated_slice) |
| 883 | slice_used = cfqq->allocated_slice; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 884 | } |
| 885 | |
Divyesh Shah | 9a0785b | 2010-04-01 15:01:04 -0700 | [diff] [blame] | 886 | cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u", slice_used); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 887 | return slice_used; |
| 888 | } |
| 889 | |
| 890 | static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 891 | struct cfq_queue *cfqq) |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 892 | { |
| 893 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 894 | unsigned int used_sl, charge_sl; |
| 895 | int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) |
| 896 | - cfqg->service_tree_idle.count; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 897 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 898 | BUG_ON(nr_sync < 0); |
| 899 | used_sl = charge_sl = cfq_cfqq_slice_usage(cfqq); |
| 900 | |
| 901 | if (!cfq_cfqq_sync(cfqq) && !nr_sync) |
| 902 | charge_sl = cfqq->allocated_slice; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 903 | |
| 904 | /* Can't update vdisktime while group is on service tree */ |
| 905 | cfq_rb_erase(&cfqg->rb_node, st); |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 906 | cfqg->vdisktime += cfq_scale_slice(charge_sl, cfqg); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 907 | __cfq_group_service_tree_add(st, cfqg); |
| 908 | |
| 909 | /* This group is being expired. Save the context */ |
| 910 | if (time_after(cfqd->workload_expires, jiffies)) { |
| 911 | cfqg->saved_workload_slice = cfqd->workload_expires |
| 912 | - jiffies; |
| 913 | cfqg->saved_workload = cfqd->serving_type; |
| 914 | cfqg->saved_serving_prio = cfqd->serving_prio; |
| 915 | } else |
| 916 | cfqg->saved_workload_slice = 0; |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 917 | |
| 918 | cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime, |
| 919 | st->min_vdisktime); |
Divyesh Shah | 303a3ac | 2010-04-01 15:01:24 -0700 | [diff] [blame] | 920 | blkiocg_update_timeslice_used(&cfqg->blkg, used_sl); |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 921 | blkiocg_set_start_empty_time(&cfqg->blkg); |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 922 | } |
| 923 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 924 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 925 | static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg) |
| 926 | { |
| 927 | if (blkg) |
| 928 | return container_of(blkg, struct cfq_group, blkg); |
| 929 | return NULL; |
| 930 | } |
| 931 | |
Vivek Goyal | f8d461d | 2009-12-03 12:59:52 -0500 | [diff] [blame] | 932 | void |
| 933 | cfq_update_blkio_group_weight(struct blkio_group *blkg, unsigned int weight) |
| 934 | { |
| 935 | cfqg_of_blkg(blkg)->weight = weight; |
| 936 | } |
| 937 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 938 | static struct cfq_group * |
| 939 | cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create) |
| 940 | { |
| 941 | struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); |
| 942 | struct cfq_group *cfqg = NULL; |
| 943 | void *key = cfqd; |
| 944 | int i, j; |
| 945 | struct cfq_rb_root *st; |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 946 | struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info; |
| 947 | unsigned int major, minor; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 948 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 949 | cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key)); |
Ricky Benitez | a74b2ad | 2010-04-05 18:22:17 +0200 | [diff] [blame] | 950 | if (cfqg && !cfqg->blkg.dev && bdi->dev && dev_name(bdi->dev)) { |
| 951 | sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); |
| 952 | cfqg->blkg.dev = MKDEV(major, minor); |
| 953 | goto done; |
| 954 | } |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 955 | if (cfqg || !create) |
| 956 | goto done; |
| 957 | |
| 958 | cfqg = kzalloc_node(sizeof(*cfqg), GFP_ATOMIC, cfqd->queue->node); |
| 959 | if (!cfqg) |
| 960 | goto done; |
| 961 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 962 | for_each_cfqg_st(cfqg, i, j, st) |
| 963 | *st = CFQ_RB_ROOT; |
| 964 | RB_CLEAR_NODE(&cfqg->rb_node); |
| 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 | |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1005 | static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg) |
| 1006 | { |
| 1007 | atomic_inc(&cfqg->ref); |
| 1008 | return cfqg; |
| 1009 | } |
| 1010 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1011 | static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) |
| 1012 | { |
| 1013 | /* Currently, all async queues are mapped to root group */ |
| 1014 | if (!cfq_cfqq_sync(cfqq)) |
| 1015 | cfqg = &cfqq->cfqd->root_group; |
| 1016 | |
| 1017 | cfqq->cfqg = cfqg; |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1018 | /* cfqq reference on cfqg */ |
| 1019 | atomic_inc(&cfqq->cfqg->ref); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1020 | } |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1021 | |
| 1022 | static void cfq_put_cfqg(struct cfq_group *cfqg) |
| 1023 | { |
| 1024 | struct cfq_rb_root *st; |
| 1025 | int i, j; |
| 1026 | |
| 1027 | BUG_ON(atomic_read(&cfqg->ref) <= 0); |
| 1028 | if (!atomic_dec_and_test(&cfqg->ref)) |
| 1029 | return; |
| 1030 | for_each_cfqg_st(cfqg, i, j, st) |
| 1031 | BUG_ON(!RB_EMPTY_ROOT(&st->rb) || st->active != NULL); |
| 1032 | kfree(cfqg); |
| 1033 | } |
| 1034 | |
| 1035 | static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 1036 | { |
| 1037 | /* Something wrong if we are trying to remove same group twice */ |
| 1038 | BUG_ON(hlist_unhashed(&cfqg->cfqd_node)); |
| 1039 | |
| 1040 | hlist_del_init(&cfqg->cfqd_node); |
| 1041 | |
| 1042 | /* |
| 1043 | * Put the reference taken at the time of creation so that when all |
| 1044 | * queues are gone, group can be destroyed. |
| 1045 | */ |
| 1046 | cfq_put_cfqg(cfqg); |
| 1047 | } |
| 1048 | |
| 1049 | static void cfq_release_cfq_groups(struct cfq_data *cfqd) |
| 1050 | { |
| 1051 | struct hlist_node *pos, *n; |
| 1052 | struct cfq_group *cfqg; |
| 1053 | |
| 1054 | hlist_for_each_entry_safe(cfqg, pos, n, &cfqd->cfqg_list, cfqd_node) { |
| 1055 | /* |
| 1056 | * If cgroup removal path got to blk_group first and removed |
| 1057 | * it from cgroup list, then it will take care of destroying |
| 1058 | * cfqg also. |
| 1059 | */ |
| 1060 | if (!blkiocg_del_blkio_group(&cfqg->blkg)) |
| 1061 | cfq_destroy_cfqg(cfqd, cfqg); |
| 1062 | } |
| 1063 | } |
| 1064 | |
| 1065 | /* |
| 1066 | * Blk cgroup controller notification saying that blkio_group object is being |
| 1067 | * delinked as associated cgroup object is going away. That also means that |
| 1068 | * no new IO will come in this group. So get rid of this group as soon as |
| 1069 | * any pending IO in the group is finished. |
| 1070 | * |
| 1071 | * This function is called under rcu_read_lock(). key is the rcu protected |
| 1072 | * pointer. That means "key" is a valid cfq_data pointer as long as we are rcu |
| 1073 | * read lock. |
| 1074 | * |
| 1075 | * "key" was fetched from blkio_group under blkio_cgroup->lock. That means |
| 1076 | * it should not be NULL as even if elevator was exiting, cgroup deltion |
| 1077 | * path got to it first. |
| 1078 | */ |
| 1079 | void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg) |
| 1080 | { |
| 1081 | unsigned long flags; |
| 1082 | struct cfq_data *cfqd = key; |
| 1083 | |
| 1084 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 1085 | cfq_destroy_cfqg(cfqd, cfqg_of_blkg(blkg)); |
| 1086 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 1087 | } |
| 1088 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1089 | #else /* GROUP_IOSCHED */ |
| 1090 | static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create) |
| 1091 | { |
| 1092 | return &cfqd->root_group; |
| 1093 | } |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1094 | |
| 1095 | static inline struct cfq_group *cfq_ref_get_cfqg(struct cfq_group *cfqg) |
| 1096 | { |
Dmitry Monakhov | 50eaeb3 | 2010-04-28 19:50:33 +0200 | [diff] [blame] | 1097 | return cfqg; |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1098 | } |
| 1099 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1100 | static inline void |
| 1101 | cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { |
| 1102 | cfqq->cfqg = cfqg; |
| 1103 | } |
| 1104 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1105 | static void cfq_release_cfq_groups(struct cfq_data *cfqd) {} |
| 1106 | static inline void cfq_put_cfqg(struct cfq_group *cfqg) {} |
| 1107 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1108 | #endif /* GROUP_IOSCHED */ |
| 1109 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1110 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1111 | * The cfqd->service_trees holds all pending cfq_queue's that have |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1112 | * requests waiting to be processed. It is sorted in the order that |
| 1113 | * we will service the queues. |
| 1114 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1115 | 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] | 1116 | bool add_front) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1117 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1118 | struct rb_node **p, *parent; |
| 1119 | struct cfq_queue *__cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1120 | unsigned long rb_key; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1121 | struct cfq_rb_root *service_tree; |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1122 | int left; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1123 | int new_cfqq = 1; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 1124 | int group_changed = 0; |
| 1125 | |
| 1126 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 1127 | if (!cfqd->cfq_group_isolation |
| 1128 | && cfqq_type(cfqq) == SYNC_NOIDLE_WORKLOAD |
| 1129 | && cfqq->cfqg && cfqq->cfqg != &cfqd->root_group) { |
| 1130 | /* Move this cfq to root group */ |
| 1131 | cfq_log_cfqq(cfqd, cfqq, "moving to root group"); |
| 1132 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) |
| 1133 | cfq_group_service_tree_del(cfqd, cfqq->cfqg); |
| 1134 | cfqq->orig_cfqg = cfqq->cfqg; |
| 1135 | cfqq->cfqg = &cfqd->root_group; |
| 1136 | atomic_inc(&cfqd->root_group.ref); |
| 1137 | group_changed = 1; |
| 1138 | } else if (!cfqd->cfq_group_isolation |
| 1139 | && cfqq_type(cfqq) == SYNC_WORKLOAD && cfqq->orig_cfqg) { |
| 1140 | /* cfqq is sequential now needs to go to its original group */ |
| 1141 | BUG_ON(cfqq->cfqg != &cfqd->root_group); |
| 1142 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) |
| 1143 | cfq_group_service_tree_del(cfqd, cfqq->cfqg); |
| 1144 | cfq_put_cfqg(cfqq->cfqg); |
| 1145 | cfqq->cfqg = cfqq->orig_cfqg; |
| 1146 | cfqq->orig_cfqg = NULL; |
| 1147 | group_changed = 1; |
| 1148 | cfq_log_cfqq(cfqd, cfqq, "moved to origin group"); |
| 1149 | } |
| 1150 | #endif |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1151 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1152 | service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq), |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 1153 | cfqq_type(cfqq)); |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1154 | if (cfq_class_idle(cfqq)) { |
| 1155 | rb_key = CFQ_IDLE_DELAY; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1156 | parent = rb_last(&service_tree->rb); |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1157 | if (parent && parent != &cfqq->rb_node) { |
| 1158 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 1159 | rb_key += __cfqq->rb_key; |
| 1160 | } else |
| 1161 | rb_key += jiffies; |
| 1162 | } else if (!add_front) { |
Jens Axboe | b9c8946 | 2009-10-06 20:53:44 +0200 | [diff] [blame] | 1163 | /* |
| 1164 | * Get our rb key offset. Subtract any residual slice |
| 1165 | * value carried from last service. A negative resid |
| 1166 | * count indicates slice overrun, and this should position |
| 1167 | * the next service time further away in the tree. |
| 1168 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1169 | rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; |
Jens Axboe | b9c8946 | 2009-10-06 20:53:44 +0200 | [diff] [blame] | 1170 | rb_key -= cfqq->slice_resid; |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1171 | cfqq->slice_resid = 0; |
Corrado Zoccolo | 48e025e | 2009-10-05 08:49:23 +0200 | [diff] [blame] | 1172 | } else { |
| 1173 | rb_key = -HZ; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1174 | __cfqq = cfq_rb_first(service_tree); |
Corrado Zoccolo | 48e025e | 2009-10-05 08:49:23 +0200 | [diff] [blame] | 1175 | rb_key += __cfqq ? __cfqq->rb_key : jiffies; |
| 1176 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1177 | |
| 1178 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1179 | new_cfqq = 0; |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 1180 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1181 | * same position, nothing more to do |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 1182 | */ |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1183 | if (rb_key == cfqq->rb_key && |
| 1184 | cfqq->service_tree == service_tree) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1185 | return; |
Jens Axboe | 53b03744 | 2006-07-28 09:48:51 +0200 | [diff] [blame] | 1186 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1187 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
| 1188 | cfqq->service_tree = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1189 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1190 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1191 | left = 1; |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1192 | parent = NULL; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1193 | cfqq->service_tree = service_tree; |
| 1194 | p = &service_tree->rb.rb_node; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1195 | while (*p) { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1196 | struct rb_node **n; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1197 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1198 | parent = *p; |
| 1199 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 1200 | |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 1201 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1202 | * sort by key, that represents service time. |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 1203 | */ |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1204 | if (time_before(rb_key, __cfqq->rb_key)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1205 | n = &(*p)->rb_left; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1206 | else { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1207 | n = &(*p)->rb_right; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1208 | left = 0; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1209 | } |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1210 | |
| 1211 | p = n; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1212 | } |
| 1213 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1214 | if (left) |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1215 | service_tree->left = &cfqq->rb_node; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1216 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1217 | cfqq->rb_key = rb_key; |
| 1218 | rb_link_node(&cfqq->rb_node, parent, p); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1219 | rb_insert_color(&cfqq->rb_node, &service_tree->rb); |
| 1220 | service_tree->count++; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 1221 | if ((add_front || !new_cfqq) && !group_changed) |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1222 | return; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1223 | cfq_group_service_tree_add(cfqd, cfqq->cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1224 | } |
| 1225 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1226 | static struct cfq_queue * |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1227 | cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, |
| 1228 | sector_t sector, struct rb_node **ret_parent, |
| 1229 | struct rb_node ***rb_link) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1230 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1231 | struct rb_node **p, *parent; |
| 1232 | struct cfq_queue *cfqq = NULL; |
| 1233 | |
| 1234 | parent = NULL; |
| 1235 | p = &root->rb_node; |
| 1236 | while (*p) { |
| 1237 | struct rb_node **n; |
| 1238 | |
| 1239 | parent = *p; |
| 1240 | cfqq = rb_entry(parent, struct cfq_queue, p_node); |
| 1241 | |
| 1242 | /* |
| 1243 | * Sort strictly based on sector. Smallest to the left, |
| 1244 | * largest to the right. |
| 1245 | */ |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1246 | if (sector > blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1247 | n = &(*p)->rb_right; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1248 | else if (sector < blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1249 | n = &(*p)->rb_left; |
| 1250 | else |
| 1251 | break; |
| 1252 | p = n; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1253 | cfqq = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1254 | } |
| 1255 | |
| 1256 | *ret_parent = parent; |
| 1257 | if (rb_link) |
| 1258 | *rb_link = p; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1259 | return cfqq; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1260 | } |
| 1261 | |
| 1262 | static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1263 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1264 | struct rb_node **p, *parent; |
| 1265 | struct cfq_queue *__cfqq; |
| 1266 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1267 | if (cfqq->p_root) { |
| 1268 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1269 | cfqq->p_root = NULL; |
| 1270 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1271 | |
| 1272 | if (cfq_class_idle(cfqq)) |
| 1273 | return; |
| 1274 | if (!cfqq->next_rq) |
| 1275 | return; |
| 1276 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1277 | cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1278 | __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, |
| 1279 | blk_rq_pos(cfqq->next_rq), &parent, &p); |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1280 | if (!__cfqq) { |
| 1281 | rb_link_node(&cfqq->p_node, parent, p); |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1282 | rb_insert_color(&cfqq->p_node, cfqq->p_root); |
| 1283 | } else |
| 1284 | cfqq->p_root = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1285 | } |
| 1286 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1287 | /* |
| 1288 | * Update cfqq's position in the service tree. |
| 1289 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1290 | 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] | 1291 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1292 | /* |
| 1293 | * Resorting requires the cfqq to be on the RR list already. |
| 1294 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1295 | if (cfq_cfqq_on_rr(cfqq)) { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1296 | cfq_service_tree_add(cfqd, cfqq, 0); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1297 | cfq_prio_tree_add(cfqd, cfqq); |
| 1298 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1299 | } |
| 1300 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | /* |
| 1302 | * 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] | 1303 | * the pending list according to last request service |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1304 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1305 | 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] | 1306 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1307 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1308 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
| 1309 | cfq_mark_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1310 | cfqd->busy_queues++; |
| 1311 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1312 | cfq_resort_rr_list(cfqd, cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1313 | } |
| 1314 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1315 | /* |
| 1316 | * Called when the cfqq no longer has requests pending, remove it from |
| 1317 | * the service tree. |
| 1318 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1319 | 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] | 1320 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1321 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1322 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
| 1323 | cfq_clear_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1324 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1325 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
| 1326 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
| 1327 | cfqq->service_tree = NULL; |
| 1328 | } |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1329 | if (cfqq->p_root) { |
| 1330 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1331 | cfqq->p_root = NULL; |
| 1332 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1333 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1334 | cfq_group_service_tree_del(cfqd, cfqq->cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1335 | BUG_ON(!cfqd->busy_queues); |
| 1336 | cfqd->busy_queues--; |
| 1337 | } |
| 1338 | |
| 1339 | /* |
| 1340 | * rb tree support functions |
| 1341 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1342 | static void cfq_del_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1344 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1345 | const int sync = rq_is_sync(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1346 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1347 | BUG_ON(!cfqq->queued[sync]); |
| 1348 | cfqq->queued[sync]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1349 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1350 | elv_rb_del(&cfqq->sort_list, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1351 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1352 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) { |
| 1353 | /* |
| 1354 | * Queue will be deleted from service tree when we actually |
| 1355 | * expire it later. Right now just remove it from prio tree |
| 1356 | * as it is empty. |
| 1357 | */ |
| 1358 | if (cfqq->p_root) { |
| 1359 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1360 | cfqq->p_root = NULL; |
| 1361 | } |
| 1362 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1363 | } |
| 1364 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1365 | static void cfq_add_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1366 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1367 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1368 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1369 | struct request *__alias, *prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1370 | |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1371 | cfqq->queued[rq_is_sync(rq)]++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1372 | |
| 1373 | /* |
| 1374 | * looks a little odd, but the first insert might return an alias. |
| 1375 | * if that happens, put the alias on the dispatch list |
| 1376 | */ |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1377 | while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1378 | cfq_dispatch_insert(cfqd->queue, __alias); |
Jens Axboe | 5fccbf6 | 2006-10-31 14:21:55 +0100 | [diff] [blame] | 1379 | |
| 1380 | if (!cfq_cfqq_on_rr(cfqq)) |
| 1381 | cfq_add_cfqq_rr(cfqd, cfqq); |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 1382 | |
| 1383 | /* |
| 1384 | * check if this request is a better next-serve candidate |
| 1385 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1386 | prev = cfqq->next_rq; |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1387 | 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] | 1388 | |
| 1389 | /* |
| 1390 | * adjust priority tree position, if ->next_rq changes |
| 1391 | */ |
| 1392 | if (prev != cfqq->next_rq) |
| 1393 | cfq_prio_tree_add(cfqd, cfqq); |
| 1394 | |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 1395 | BUG_ON(!cfqq->next_rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | } |
| 1397 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1398 | 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] | 1399 | { |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1400 | elv_rb_del(&cfqq->sort_list, rq); |
| 1401 | cfqq->queued[rq_is_sync(rq)]--; |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1402 | blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, rq_data_dir(rq), |
Divyesh Shah | cdc1184 | 2010-04-08 21:15:10 -0700 | [diff] [blame] | 1403 | rq_is_sync(rq)); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1404 | cfq_add_rq_rb(rq); |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1405 | blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg, |
| 1406 | &cfqq->cfqd->serving_group->blkg, rq_data_dir(rq), |
| 1407 | rq_is_sync(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1408 | } |
| 1409 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1410 | static struct request * |
| 1411 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1412 | { |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1413 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1414 | struct cfq_io_context *cic; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1415 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1416 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1417 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1418 | if (!cic) |
| 1419 | return NULL; |
| 1420 | |
| 1421 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1422 | if (cfqq) { |
| 1423 | sector_t sector = bio->bi_sector + bio_sectors(bio); |
| 1424 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1425 | return elv_rb_find(&cfqq->sort_list, sector); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1426 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1427 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1428 | return NULL; |
| 1429 | } |
| 1430 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1431 | static void cfq_activate_request(struct request_queue *q, struct request *rq) |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1432 | { |
| 1433 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1434 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 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), "activate rq, drv=%d", |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1437 | cfqd->rq_in_driver); |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 1438 | |
Tejun Heo | 5b93629 | 2009-05-07 22:24:38 +0900 | [diff] [blame] | 1439 | cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1440 | } |
| 1441 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1442 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1443 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1444 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1445 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1446 | WARN_ON(!cfqd->rq_in_driver); |
| 1447 | cfqd->rq_in_driver--; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1448 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1449 | cfqd->rq_in_driver); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1450 | } |
| 1451 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1452 | static void cfq_remove_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1453 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1454 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1455 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1456 | if (cfqq->next_rq == rq) |
| 1457 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1458 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1459 | list_del_init(&rq->queuelist); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1460 | cfq_del_rq_rb(rq); |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 1461 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 1462 | cfqq->cfqd->rq_queued--; |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1463 | blkiocg_update_io_remove_stats(&(RQ_CFQG(rq))->blkg, rq_data_dir(rq), |
Divyesh Shah | cdc1184 | 2010-04-08 21:15:10 -0700 | [diff] [blame] | 1464 | rq_is_sync(rq)); |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 1465 | if (rq_is_meta(rq)) { |
| 1466 | WARN_ON(!cfqq->meta_pending); |
| 1467 | cfqq->meta_pending--; |
| 1468 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1469 | } |
| 1470 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1471 | static int cfq_merge(struct request_queue *q, struct request **req, |
| 1472 | struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1473 | { |
| 1474 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1475 | struct request *__rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1476 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1477 | __rq = cfq_find_rq_fmerge(cfqd, bio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1478 | if (__rq && elv_rq_merge_ok(__rq, bio)) { |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 1479 | *req = __rq; |
| 1480 | return ELEVATOR_FRONT_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1481 | } |
| 1482 | |
| 1483 | return ELEVATOR_NO_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1484 | } |
| 1485 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1486 | static void cfq_merged_request(struct request_queue *q, struct request *req, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1487 | int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1488 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1489 | if (type == ELEVATOR_FRONT_MERGE) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1490 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1491 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1492 | cfq_reposition_rq_rb(cfqq, req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1493 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | } |
| 1495 | |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 1496 | static void cfq_bio_merged(struct request_queue *q, struct request *req, |
| 1497 | struct bio *bio) |
| 1498 | { |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1499 | blkiocg_update_io_merged_stats(&(RQ_CFQG(req))->blkg, bio_data_dir(bio), |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 1500 | cfq_bio_sync(bio)); |
| 1501 | } |
| 1502 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1503 | static void |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1504 | cfq_merged_requests(struct request_queue *q, struct request *rq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1505 | struct request *next) |
| 1506 | { |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1507 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1508 | /* |
| 1509 | * reposition in fifo if next is older than rq |
| 1510 | */ |
| 1511 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1512 | time_before(rq_fifo_time(next), rq_fifo_time(rq))) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1513 | list_move(&rq->queuelist, &next->queuelist); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1514 | rq_set_fifo_time(rq, rq_fifo_time(next)); |
| 1515 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1516 | |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1517 | if (cfqq->next_rq == next) |
| 1518 | cfqq->next_rq = rq; |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1519 | cfq_remove_request(next); |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 1520 | blkiocg_update_io_merged_stats(&(RQ_CFQG(rq))->blkg, rq_data_dir(next), |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 1521 | rq_is_sync(next)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1522 | } |
| 1523 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1524 | static int cfq_allow_merge(struct request_queue *q, struct request *rq, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1525 | struct bio *bio) |
| 1526 | { |
| 1527 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1528 | struct cfq_io_context *cic; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1529 | struct cfq_queue *cfqq; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1530 | |
| 1531 | /* |
Jens Axboe | ec8acb6 | 2007-01-02 18:32:11 +0100 | [diff] [blame] | 1532 | * Disallow merge of a sync bio into an async request. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1533 | */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1534 | if (cfq_bio_sync(bio) && !rq_is_sync(rq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1535 | return false; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1536 | |
| 1537 | /* |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 1538 | * Lookup the cfqq that this bio will be queued with. Allow |
| 1539 | * merge only if rq is queued there. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1540 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1541 | cic = cfq_cic_lookup(cfqd, current->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1542 | if (!cic) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1543 | return false; |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 1544 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1545 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1546 | return cfqq == RQ_CFQQ(rq); |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1547 | } |
| 1548 | |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1549 | static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1550 | { |
| 1551 | del_timer(&cfqd->idle_slice_timer); |
| 1552 | blkiocg_update_idle_time_stats(&cfqq->cfqg->blkg); |
| 1553 | } |
| 1554 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1555 | static void __cfq_set_active_queue(struct cfq_data *cfqd, |
| 1556 | struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1557 | { |
| 1558 | if (cfqq) { |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 1559 | cfq_log_cfqq(cfqd, cfqq, "set_active wl_prio:%d wl_type:%d", |
| 1560 | cfqd->serving_prio, cfqd->serving_type); |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 1561 | blkiocg_update_avg_queue_size_stats(&cfqq->cfqg->blkg); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1562 | cfqq->slice_start = 0; |
| 1563 | cfqq->dispatch_start = jiffies; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 1564 | cfqq->allocated_slice = 0; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1565 | cfqq->slice_end = 0; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1566 | cfqq->slice_dispatch = 0; |
| 1567 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1568 | cfq_clear_cfqq_wait_request(cfqq); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 1569 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1570 | cfq_clear_cfqq_must_alloc_slice(cfqq); |
| 1571 | cfq_clear_cfqq_fifo_expire(cfqq); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 1572 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1573 | |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1574 | cfq_del_timer(cfqd, cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1575 | } |
| 1576 | |
| 1577 | cfqd->active_queue = cfqq; |
| 1578 | } |
| 1579 | |
| 1580 | /* |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1581 | * current cfqq expired its slice (or was too idle), select new one |
| 1582 | */ |
| 1583 | static void |
| 1584 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 1585 | bool timed_out) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1586 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1587 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); |
| 1588 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1589 | if (cfq_cfqq_wait_request(cfqq)) |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1590 | cfq_del_timer(cfqd, cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1591 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1592 | cfq_clear_cfqq_wait_request(cfqq); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 1593 | cfq_clear_cfqq_wait_busy(cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1594 | |
| 1595 | /* |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 1596 | * If this cfqq is shared between multiple processes, check to |
| 1597 | * make sure that those processes are still issuing I/Os within |
| 1598 | * the mean seek distance. If not, it may be time to break the |
| 1599 | * queues apart again. |
| 1600 | */ |
| 1601 | if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq)) |
| 1602 | cfq_mark_cfqq_split_coop(cfqq); |
| 1603 | |
| 1604 | /* |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1605 | * 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] | 1606 | */ |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1607 | if (timed_out && !cfq_cfqq_slice_new(cfqq)) { |
Jens Axboe | c5b680f | 2007-01-19 11:56:49 +1100 | [diff] [blame] | 1608 | cfqq->slice_resid = cfqq->slice_end - jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1609 | cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); |
| 1610 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1611 | |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 1612 | cfq_group_served(cfqd, cfqq->cfqg, cfqq); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1613 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1614 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 1615 | cfq_del_cfqq_rr(cfqd, cfqq); |
| 1616 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1617 | cfq_resort_rr_list(cfqd, cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1618 | |
| 1619 | if (cfqq == cfqd->active_queue) |
| 1620 | cfqd->active_queue = NULL; |
| 1621 | |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1622 | if (&cfqq->cfqg->rb_node == cfqd->grp_service_tree.active) |
| 1623 | cfqd->grp_service_tree.active = NULL; |
| 1624 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1625 | if (cfqd->active_cic) { |
| 1626 | put_io_context(cfqd->active_cic->ioc); |
| 1627 | cfqd->active_cic = NULL; |
| 1628 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1629 | } |
| 1630 | |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 1631 | static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1632 | { |
| 1633 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 1634 | |
| 1635 | if (cfqq) |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 1636 | __cfq_slice_expired(cfqd, cfqq, timed_out); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1637 | } |
| 1638 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1639 | /* |
| 1640 | * Get next queue for service. Unless we have a queue preemption, |
| 1641 | * we'll simply select the first cfqq in the service tree. |
| 1642 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1643 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1644 | { |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1645 | struct cfq_rb_root *service_tree = |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1646 | service_tree_for(cfqd->serving_group, cfqd->serving_prio, |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 1647 | cfqd->serving_type); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1648 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1649 | if (!cfqd->rq_queued) |
| 1650 | return NULL; |
| 1651 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1652 | /* There is nothing to dispatch */ |
| 1653 | if (!service_tree) |
| 1654 | return NULL; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1655 | if (RB_EMPTY_ROOT(&service_tree->rb)) |
| 1656 | return NULL; |
| 1657 | return cfq_rb_first(service_tree); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1658 | } |
| 1659 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1660 | static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd) |
| 1661 | { |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1662 | struct cfq_group *cfqg; |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1663 | struct cfq_queue *cfqq; |
| 1664 | int i, j; |
| 1665 | struct cfq_rb_root *st; |
| 1666 | |
| 1667 | if (!cfqd->rq_queued) |
| 1668 | return NULL; |
| 1669 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1670 | cfqg = cfq_get_next_cfqg(cfqd); |
| 1671 | if (!cfqg) |
| 1672 | return NULL; |
| 1673 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1674 | for_each_cfqg_st(cfqg, i, j, st) |
| 1675 | if ((cfqq = cfq_rb_first(st)) != NULL) |
| 1676 | return cfqq; |
| 1677 | return NULL; |
| 1678 | } |
| 1679 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1680 | /* |
| 1681 | * Get and set a new active queue for service. |
| 1682 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1683 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, |
| 1684 | struct cfq_queue *cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1685 | { |
Jens Axboe | e00ef79 | 2009-11-04 08:54:55 +0100 | [diff] [blame] | 1686 | if (!cfqq) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1687 | cfqq = cfq_get_next_queue(cfqd); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1688 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1689 | __cfq_set_active_queue(cfqd, cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1690 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1691 | } |
| 1692 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1693 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, |
| 1694 | struct request *rq) |
| 1695 | { |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1696 | if (blk_rq_pos(rq) >= cfqd->last_position) |
| 1697 | return blk_rq_pos(rq) - cfqd->last_position; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1698 | else |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1699 | return cfqd->last_position - blk_rq_pos(rq); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1700 | } |
| 1701 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 1702 | 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] | 1703 | struct request *rq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1704 | { |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 1705 | return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1706 | } |
| 1707 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1708 | static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, |
| 1709 | struct cfq_queue *cur_cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1710 | { |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1711 | struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1712 | struct rb_node *parent, *node; |
| 1713 | struct cfq_queue *__cfqq; |
| 1714 | sector_t sector = cfqd->last_position; |
| 1715 | |
| 1716 | if (RB_EMPTY_ROOT(root)) |
| 1717 | return NULL; |
| 1718 | |
| 1719 | /* |
| 1720 | * First, if we find a request starting at the end of the last |
| 1721 | * request, choose it. |
| 1722 | */ |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1723 | __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1724 | if (__cfqq) |
| 1725 | return __cfqq; |
| 1726 | |
| 1727 | /* |
| 1728 | * If the exact sector wasn't found, the parent of the NULL leaf |
| 1729 | * will contain the closest sector. |
| 1730 | */ |
| 1731 | __cfqq = rb_entry(parent, struct cfq_queue, p_node); |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 1732 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1733 | return __cfqq; |
| 1734 | |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1735 | if (blk_rq_pos(__cfqq->next_rq) < sector) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1736 | node = rb_next(&__cfqq->p_node); |
| 1737 | else |
| 1738 | node = rb_prev(&__cfqq->p_node); |
| 1739 | if (!node) |
| 1740 | return NULL; |
| 1741 | |
| 1742 | __cfqq = rb_entry(node, struct cfq_queue, p_node); |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 1743 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1744 | return __cfqq; |
| 1745 | |
| 1746 | return NULL; |
| 1747 | } |
| 1748 | |
| 1749 | /* |
| 1750 | * cfqd - obvious |
| 1751 | * cur_cfqq - passed in so that we don't decide that the current queue is |
| 1752 | * closely cooperating with itself. |
| 1753 | * |
| 1754 | * So, basically we're assuming that that cur_cfqq has dispatched at least |
| 1755 | * one request, and that cfqd->last_position reflects a position on the disk |
| 1756 | * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid |
| 1757 | * assumption. |
| 1758 | */ |
| 1759 | static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 1760 | struct cfq_queue *cur_cfqq) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1761 | { |
| 1762 | struct cfq_queue *cfqq; |
| 1763 | |
Divyesh Shah | 39c01b2 | 2010-03-25 15:45:57 +0100 | [diff] [blame] | 1764 | if (cfq_class_idle(cur_cfqq)) |
| 1765 | return NULL; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1766 | if (!cfq_cfqq_sync(cur_cfqq)) |
| 1767 | return NULL; |
| 1768 | if (CFQQ_SEEKY(cur_cfqq)) |
| 1769 | return NULL; |
| 1770 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1771 | /* |
Gui Jianfeng | b9d8f4c | 2009-12-08 08:54:17 +0100 | [diff] [blame] | 1772 | * Don't search priority tree if it's the only queue in the group. |
| 1773 | */ |
| 1774 | if (cur_cfqq->cfqg->nr_cfqq == 1) |
| 1775 | return NULL; |
| 1776 | |
| 1777 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1778 | * We should notice if some of the queues are cooperating, eg |
| 1779 | * working closely on the same area of the disk. In that case, |
| 1780 | * we can group them together and don't waste time idling. |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1781 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1782 | cfqq = cfqq_close(cfqd, cur_cfqq); |
| 1783 | if (!cfqq) |
| 1784 | return NULL; |
| 1785 | |
Vivek Goyal | 8682e1f | 2009-12-03 12:59:50 -0500 | [diff] [blame] | 1786 | /* If new queue belongs to different cfq_group, don't choose it */ |
| 1787 | if (cur_cfqq->cfqg != cfqq->cfqg) |
| 1788 | return NULL; |
| 1789 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1790 | /* |
| 1791 | * It only makes sense to merge sync queues. |
| 1792 | */ |
| 1793 | if (!cfq_cfqq_sync(cfqq)) |
| 1794 | return NULL; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1795 | if (CFQQ_SEEKY(cfqq)) |
| 1796 | return NULL; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1797 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1798 | /* |
| 1799 | * Do not merge queues of different priority classes |
| 1800 | */ |
| 1801 | if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq)) |
| 1802 | return NULL; |
| 1803 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1804 | return cfqq; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1805 | } |
| 1806 | |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1807 | /* |
| 1808 | * Determine whether we should enforce idle window for this queue. |
| 1809 | */ |
| 1810 | |
| 1811 | static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1812 | { |
| 1813 | enum wl_prio_t prio = cfqq_prio(cfqq); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1814 | struct cfq_rb_root *service_tree = cfqq->service_tree; |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1815 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1816 | BUG_ON(!service_tree); |
| 1817 | BUG_ON(!service_tree->count); |
| 1818 | |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1819 | /* We never do for idle class queues. */ |
| 1820 | if (prio == IDLE_WORKLOAD) |
| 1821 | return false; |
| 1822 | |
| 1823 | /* We do for queues that were marked with idle window flag. */ |
Shaohua Li | 3c764b7 | 2009-12-04 13:12:06 +0100 | [diff] [blame] | 1824 | if (cfq_cfqq_idle_window(cfqq) && |
| 1825 | !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)) |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1826 | return true; |
| 1827 | |
| 1828 | /* |
| 1829 | * Otherwise, we do only if they are the last ones |
| 1830 | * in their service tree. |
| 1831 | */ |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 1832 | if (service_tree->count == 1 && cfq_cfqq_sync(cfqq)) |
| 1833 | return 1; |
| 1834 | cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", |
| 1835 | service_tree->count); |
| 1836 | return 0; |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1837 | } |
| 1838 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1839 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1840 | { |
Jens Axboe | 1792669 | 2007-01-19 11:59:30 +1100 | [diff] [blame] | 1841 | struct cfq_queue *cfqq = cfqd->active_queue; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1842 | struct cfq_io_context *cic; |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1843 | unsigned long sl; |
| 1844 | |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1845 | /* |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 1846 | * SSD device without seek penalty, disable idling. But only do so |
| 1847 | * for devices that support queuing, otherwise we still have a problem |
| 1848 | * with sync vs async workloads. |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1849 | */ |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 1850 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1851 | return; |
| 1852 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 1853 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1854 | WARN_ON(cfq_cfqq_slice_new(cfqq)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1855 | |
| 1856 | /* |
| 1857 | * idle is disabled, either manually or by past process history |
| 1858 | */ |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1859 | if (!cfqd->cfq_slice_idle || !cfq_should_idle(cfqd, cfqq)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1860 | return; |
| 1861 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1862 | /* |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 1863 | * still active requests from this queue, don't idle |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1864 | */ |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 1865 | if (cfqq->dispatched) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1866 | return; |
| 1867 | |
| 1868 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1869 | * task has exited, don't wait |
| 1870 | */ |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1871 | cic = cfqd->active_cic; |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 1872 | if (!cic || !atomic_read(&cic->ioc->nr_tasks)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1873 | return; |
| 1874 | |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 1875 | /* |
| 1876 | * If our average think time is larger than the remaining time |
| 1877 | * slice, then don't idle. This avoids overrunning the allotted |
| 1878 | * time slice. |
| 1879 | */ |
| 1880 | if (sample_valid(cic->ttime_samples) && |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 1881 | (cfqq->slice_end - jiffies < cic->ttime_mean)) { |
| 1882 | cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%d", |
| 1883 | cic->ttime_mean); |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 1884 | return; |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 1885 | } |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 1886 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1887 | cfq_mark_cfqq_wait_request(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1888 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1889 | sl = cfqd->cfq_slice_idle; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1890 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1891 | mod_timer(&cfqd->idle_slice_timer, jiffies + sl); |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 1892 | blkiocg_update_set_idle_time_stats(&cfqq->cfqg->blkg); |
Jens Axboe | 9481ffd | 2009-04-15 12:14:13 +0200 | [diff] [blame] | 1893 | cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1894 | } |
| 1895 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1896 | /* |
| 1897 | * Move request from internal lists to the request queue dispatch list. |
| 1898 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1899 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1900 | { |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1901 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1902 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1903 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1904 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); |
| 1905 | |
Jeff Moyer | 06d2188 | 2009-09-11 17:08:59 +0200 | [diff] [blame] | 1906 | cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1907 | cfq_remove_request(rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1908 | cfqq->dispatched++; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1909 | elv_dispatch_sort(q, rq); |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1910 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 1911 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++; |
Divyesh Shah | 84c124d | 2010-04-09 08:31:19 +0200 | [diff] [blame] | 1912 | blkiocg_update_dispatch_stats(&cfqq->cfqg->blkg, blk_rq_bytes(rq), |
| 1913 | rq_data_dir(rq), rq_is_sync(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1914 | } |
| 1915 | |
| 1916 | /* |
| 1917 | * return expired entry, or NULL to just start from scratch in rbtree |
| 1918 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1919 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1920 | { |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1921 | struct request *rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1922 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1923 | if (cfq_cfqq_fifo_expire(cfqq)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1924 | return NULL; |
Jens Axboe | cb88741 | 2007-01-19 12:01:16 +1100 | [diff] [blame] | 1925 | |
| 1926 | cfq_mark_cfqq_fifo_expire(cfqq); |
| 1927 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1928 | if (list_empty(&cfqq->fifo)) |
| 1929 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1930 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1931 | rq = rq_entry_fifo(cfqq->fifo.next); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1932 | if (time_before(jiffies, rq_fifo_time(rq))) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1933 | rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1934 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1935 | cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1936 | return rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1937 | } |
| 1938 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1939 | static inline int |
| 1940 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1941 | { |
| 1942 | const int base_rq = cfqd->cfq_slice_async_rq; |
| 1943 | |
| 1944 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); |
| 1945 | |
| 1946 | return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio)); |
| 1947 | } |
| 1948 | |
| 1949 | /* |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1950 | * Must be called with the queue_lock held. |
| 1951 | */ |
| 1952 | static int cfqq_process_refs(struct cfq_queue *cfqq) |
| 1953 | { |
| 1954 | int process_refs, io_refs; |
| 1955 | |
| 1956 | io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE]; |
| 1957 | process_refs = atomic_read(&cfqq->ref) - io_refs; |
| 1958 | BUG_ON(process_refs < 0); |
| 1959 | return process_refs; |
| 1960 | } |
| 1961 | |
| 1962 | static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) |
| 1963 | { |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1964 | int process_refs, new_process_refs; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1965 | struct cfq_queue *__cfqq; |
| 1966 | |
| 1967 | /* Avoid a circular list and skip interim queue merges */ |
| 1968 | while ((__cfqq = new_cfqq->new_cfqq)) { |
| 1969 | if (__cfqq == cfqq) |
| 1970 | return; |
| 1971 | new_cfqq = __cfqq; |
| 1972 | } |
| 1973 | |
| 1974 | process_refs = cfqq_process_refs(cfqq); |
| 1975 | /* |
| 1976 | * If the process for the cfqq has gone away, there is no |
| 1977 | * sense in merging the queues. |
| 1978 | */ |
| 1979 | if (process_refs == 0) |
| 1980 | return; |
| 1981 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1982 | /* |
| 1983 | * Merge in the direction of the lesser amount of work. |
| 1984 | */ |
| 1985 | new_process_refs = cfqq_process_refs(new_cfqq); |
| 1986 | if (new_process_refs >= process_refs) { |
| 1987 | cfqq->new_cfqq = new_cfqq; |
| 1988 | atomic_add(process_refs, &new_cfqq->ref); |
| 1989 | } else { |
| 1990 | new_cfqq->new_cfqq = cfqq; |
| 1991 | atomic_add(new_process_refs, &cfqq->ref); |
| 1992 | } |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1993 | } |
| 1994 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1995 | static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 1996 | struct cfq_group *cfqg, enum wl_prio_t prio) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1997 | { |
| 1998 | struct cfq_queue *queue; |
| 1999 | int i; |
| 2000 | bool key_valid = false; |
| 2001 | unsigned long lowest_key = 0; |
| 2002 | enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; |
| 2003 | |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2004 | for (i = 0; i <= SYNC_WORKLOAD; ++i) { |
| 2005 | /* select the one with lowest rb_key */ |
| 2006 | queue = cfq_rb_first(service_tree_for(cfqg, prio, i)); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2007 | if (queue && |
| 2008 | (!key_valid || time_before(queue->rb_key, lowest_key))) { |
| 2009 | lowest_key = queue->rb_key; |
| 2010 | cur_best = i; |
| 2011 | key_valid = true; |
| 2012 | } |
| 2013 | } |
| 2014 | |
| 2015 | return cur_best; |
| 2016 | } |
| 2017 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2018 | 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] | 2019 | { |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2020 | unsigned slice; |
| 2021 | unsigned count; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2022 | struct cfq_rb_root *st; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2023 | unsigned group_slice; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2024 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2025 | if (!cfqg) { |
| 2026 | cfqd->serving_prio = IDLE_WORKLOAD; |
| 2027 | cfqd->workload_expires = jiffies + 1; |
| 2028 | return; |
| 2029 | } |
| 2030 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2031 | /* Choose next priority. RT > BE > IDLE */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2032 | if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2033 | cfqd->serving_prio = RT_WORKLOAD; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2034 | else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2035 | cfqd->serving_prio = BE_WORKLOAD; |
| 2036 | else { |
| 2037 | cfqd->serving_prio = IDLE_WORKLOAD; |
| 2038 | cfqd->workload_expires = jiffies + 1; |
| 2039 | return; |
| 2040 | } |
| 2041 | |
| 2042 | /* |
| 2043 | * For RT and BE, we have to choose also the type |
| 2044 | * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload |
| 2045 | * expiration time |
| 2046 | */ |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2047 | st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2048 | count = st->count; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2049 | |
| 2050 | /* |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2051 | * check workload expiration, and that we still have other queues ready |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2052 | */ |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2053 | if (count && !time_after(jiffies, cfqd->workload_expires)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2054 | return; |
| 2055 | |
| 2056 | /* otherwise select new workload type */ |
| 2057 | cfqd->serving_type = |
Vivek Goyal | 65b32a5 | 2009-12-16 17:52:59 -0500 | [diff] [blame] | 2058 | cfq_choose_wl(cfqd, cfqg, cfqd->serving_prio); |
| 2059 | st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2060 | count = st->count; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2061 | |
| 2062 | /* |
| 2063 | * the workload slice is computed as a fraction of target latency |
| 2064 | * proportional to the number of queues in that workload, over |
| 2065 | * all the queues in the same priority class |
| 2066 | */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2067 | group_slice = cfq_group_slice(cfqd, cfqg); |
| 2068 | |
| 2069 | slice = group_slice * count / |
| 2070 | max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_prio], |
| 2071 | cfq_group_busy_queues_wl(cfqd->serving_prio, cfqd, cfqg)); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2072 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 2073 | if (cfqd->serving_type == ASYNC_WORKLOAD) { |
| 2074 | unsigned int tmp; |
| 2075 | |
| 2076 | /* |
| 2077 | * Async queues are currently system wide. Just taking |
| 2078 | * proportion of queues with-in same group will lead to higher |
| 2079 | * async ratio system wide as generally root group is going |
| 2080 | * to have higher weight. A more accurate thing would be to |
| 2081 | * calculate system wide asnc/sync ratio. |
| 2082 | */ |
| 2083 | tmp = cfq_target_latency * cfqg_busy_async_queues(cfqd, cfqg); |
| 2084 | tmp = tmp/cfqd->busy_queues; |
| 2085 | slice = min_t(unsigned, slice, tmp); |
| 2086 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2087 | /* async workload slice is scaled down according to |
| 2088 | * the sync/async slice ratio. */ |
| 2089 | slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1]; |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 2090 | } else |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2091 | /* sync workload slice is at least 2 * cfq_slice_idle */ |
| 2092 | slice = max(slice, 2 * cfqd->cfq_slice_idle); |
| 2093 | |
| 2094 | slice = max_t(unsigned, slice, CFQ_MIN_TT); |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 2095 | cfq_log(cfqd, "workload slice:%d", slice); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2096 | cfqd->workload_expires = jiffies + slice; |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 2097 | cfqd->noidle_tree_requires_idle = false; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2098 | } |
| 2099 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2100 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) |
| 2101 | { |
| 2102 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 2103 | struct cfq_group *cfqg; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2104 | |
| 2105 | if (RB_EMPTY_ROOT(&st->rb)) |
| 2106 | return NULL; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 2107 | cfqg = cfq_rb_first_group(st); |
| 2108 | st->active = &cfqg->rb_node; |
| 2109 | update_min_vdisktime(st); |
| 2110 | return cfqg; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2111 | } |
| 2112 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2113 | static void cfq_choose_cfqg(struct cfq_data *cfqd) |
| 2114 | { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2115 | struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); |
| 2116 | |
| 2117 | cfqd->serving_group = cfqg; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 2118 | |
| 2119 | /* Restore the workload type data */ |
| 2120 | if (cfqg->saved_workload_slice) { |
| 2121 | cfqd->workload_expires = jiffies + cfqg->saved_workload_slice; |
| 2122 | cfqd->serving_type = cfqg->saved_workload; |
| 2123 | cfqd->serving_prio = cfqg->saved_serving_prio; |
Gui Jianfeng | 66ae291 | 2009-12-15 10:08:45 +0100 | [diff] [blame] | 2124 | } else |
| 2125 | cfqd->workload_expires = jiffies - 1; |
| 2126 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2127 | choose_service_tree(cfqd, cfqg); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2128 | } |
| 2129 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2130 | /* |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2131 | * Select a queue for service. If we have a current active queue, |
| 2132 | * 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] | 2133 | */ |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2134 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2135 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2136 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2137 | |
| 2138 | cfqq = cfqd->active_queue; |
| 2139 | if (!cfqq) |
| 2140 | goto new_queue; |
| 2141 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2142 | if (!cfqd->rq_queued) |
| 2143 | return NULL; |
Vivek Goyal | c244bb5 | 2009-12-08 17:52:57 -0500 | [diff] [blame] | 2144 | |
| 2145 | /* |
| 2146 | * We were waiting for group to get backlogged. Expire the queue |
| 2147 | */ |
| 2148 | if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 2149 | goto expire; |
| 2150 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2151 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2152 | * 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] | 2153 | */ |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2154 | if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) { |
| 2155 | /* |
| 2156 | * If slice had not expired at the completion of last request |
| 2157 | * we might not have turned on wait_busy flag. Don't expire |
| 2158 | * the queue yet. Allow the group to get backlogged. |
| 2159 | * |
| 2160 | * The very fact that we have used the slice, that means we |
| 2161 | * have been idling all along on this queue and it should be |
| 2162 | * ok to wait for this request to complete. |
| 2163 | */ |
Vivek Goyal | 82bbbf2 | 2009-12-10 19:25:41 +0100 | [diff] [blame] | 2164 | if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list) |
| 2165 | && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { |
| 2166 | cfqq = NULL; |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2167 | goto keep_queue; |
Vivek Goyal | 82bbbf2 | 2009-12-10 19:25:41 +0100 | [diff] [blame] | 2168 | } else |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2169 | goto expire; |
| 2170 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2171 | |
| 2172 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2173 | * The active queue has requests and isn't expired, allow it to |
| 2174 | * dispatch. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2175 | */ |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 2176 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2177 | goto keep_queue; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2178 | |
| 2179 | /* |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2180 | * If another queue has a request waiting within our mean seek |
| 2181 | * distance, let it run. The expire code will check for close |
| 2182 | * cooperators and put the close queue at the front of the service |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2183 | * tree. If possible, merge the expiring queue with the new cfqq. |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2184 | */ |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 2185 | new_cfqq = cfq_close_cooperator(cfqd, cfqq); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2186 | if (new_cfqq) { |
| 2187 | if (!cfqq->new_cfqq) |
| 2188 | cfq_setup_merge(cfqq, new_cfqq); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2189 | goto expire; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2190 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2191 | |
| 2192 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2193 | * No requests pending. If the active queue still has requests in |
| 2194 | * flight or is idling for a new request, allow either of these |
| 2195 | * conditions to happen (or time out) before selecting a new queue. |
| 2196 | */ |
Jens Axboe | cc19747 | 2007-04-20 20:45:39 +0200 | [diff] [blame] | 2197 | if (timer_pending(&cfqd->idle_slice_timer) || |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 2198 | (cfqq->dispatched && cfq_should_idle(cfqd, cfqq))) { |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2199 | cfqq = NULL; |
| 2200 | goto keep_queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2201 | } |
| 2202 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2203 | expire: |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2204 | cfq_slice_expired(cfqd, 0); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2205 | new_queue: |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2206 | /* |
| 2207 | * Current queue expired. Check if we have to switch to a new |
| 2208 | * service tree |
| 2209 | */ |
| 2210 | if (!new_cfqq) |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2211 | cfq_choose_cfqg(cfqd); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2212 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2213 | cfqq = cfq_set_active_queue(cfqd, new_cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2214 | keep_queue: |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2215 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2216 | } |
| 2217 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2218 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2219 | { |
| 2220 | int dispatched = 0; |
| 2221 | |
| 2222 | while (cfqq->next_rq) { |
| 2223 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); |
| 2224 | dispatched++; |
| 2225 | } |
| 2226 | |
| 2227 | BUG_ON(!list_empty(&cfqq->fifo)); |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2228 | |
| 2229 | /* By default cfqq is not expired if it is empty. Do it explicitly */ |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2230 | __cfq_slice_expired(cfqq->cfqd, cfqq, 0); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2231 | return dispatched; |
| 2232 | } |
| 2233 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2234 | /* |
| 2235 | * Drain our current requests. Used for barriers and when switching |
| 2236 | * io schedulers on-the-fly. |
| 2237 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2238 | static int cfq_forced_dispatch(struct cfq_data *cfqd) |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2239 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 2240 | struct cfq_queue *cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2241 | int dispatched = 0; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2242 | |
Divyesh Shah | 3440c49 | 2010-04-09 09:29:57 +0200 | [diff] [blame] | 2243 | /* Expire the timeslice of the current active queue first */ |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2244 | cfq_slice_expired(cfqd, 0); |
Divyesh Shah | 3440c49 | 2010-04-09 09:29:57 +0200 | [diff] [blame] | 2245 | while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) { |
| 2246 | __cfq_set_active_queue(cfqd, cfqq); |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2247 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); |
Divyesh Shah | 3440c49 | 2010-04-09 09:29:57 +0200 | [diff] [blame] | 2248 | } |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2249 | |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2250 | BUG_ON(cfqd->busy_queues); |
| 2251 | |
Jeff Moyer | 6923715 | 2009-06-12 15:29:30 +0200 | [diff] [blame] | 2252 | cfq_log(cfqd, "forced_dispatch=%d", dispatched); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2253 | return dispatched; |
| 2254 | } |
| 2255 | |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2256 | static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, |
| 2257 | struct cfq_queue *cfqq) |
| 2258 | { |
| 2259 | /* the queue hasn't finished any request, can't estimate */ |
| 2260 | if (cfq_cfqq_slice_new(cfqq)) |
| 2261 | return 1; |
| 2262 | if (time_after(jiffies + cfqd->cfq_slice_idle * cfqq->dispatched, |
| 2263 | cfqq->slice_end)) |
| 2264 | return 1; |
| 2265 | |
| 2266 | return 0; |
| 2267 | } |
| 2268 | |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2269 | 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] | 2270 | { |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2271 | unsigned int max_dispatch; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2272 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2273 | /* |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2274 | * Drain async requests before we start sync IO |
| 2275 | */ |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 2276 | 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] | 2277 | return false; |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2278 | |
| 2279 | /* |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2280 | * If this is an async queue and we have sync IO in flight, let it wait |
| 2281 | */ |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 2282 | if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2283 | return false; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2284 | |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2285 | max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2286 | if (cfq_class_idle(cfqq)) |
| 2287 | max_dispatch = 1; |
| 2288 | |
| 2289 | /* |
| 2290 | * Does this cfqq already have too much IO in flight? |
| 2291 | */ |
| 2292 | if (cfqq->dispatched >= max_dispatch) { |
| 2293 | /* |
| 2294 | * idle queue must always only have a single IO in flight |
| 2295 | */ |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2296 | if (cfq_class_idle(cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2297 | return false; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2298 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2299 | /* |
| 2300 | * We have other queues, don't allow more IO from this one |
| 2301 | */ |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2302 | if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2303 | return false; |
Jens Axboe | 9ede209 | 2007-01-19 12:11:44 +1100 | [diff] [blame] | 2304 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2305 | /* |
Shaohua Li | 474b18c | 2009-12-03 12:58:05 +0100 | [diff] [blame] | 2306 | * Sole queue user, no limit |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2307 | */ |
Shaohua Li | abc3c74 | 2010-03-01 09:20:54 +0100 | [diff] [blame] | 2308 | if (cfqd->busy_queues == 1) |
| 2309 | max_dispatch = -1; |
| 2310 | else |
| 2311 | /* |
| 2312 | * Normally we start throttling cfqq when cfq_quantum/2 |
| 2313 | * requests have been dispatched. But we can drive |
| 2314 | * deeper queue depths at the beginning of slice |
| 2315 | * subjected to upper limit of cfq_quantum. |
| 2316 | * */ |
| 2317 | max_dispatch = cfqd->cfq_quantum; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2318 | } |
| 2319 | |
| 2320 | /* |
| 2321 | * Async queues must wait a bit before being allowed dispatch. |
| 2322 | * We also ramp up the dispatch depth gradually for async IO, |
| 2323 | * based on the last sync IO we serviced |
| 2324 | */ |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2325 | if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 2326 | unsigned long last_sync = jiffies - cfqd->last_delayed_sync; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2327 | unsigned int depth; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2328 | |
Jens Axboe | 61f0c1d | 2009-10-03 19:46:03 +0200 | [diff] [blame] | 2329 | depth = last_sync / cfqd->cfq_slice[1]; |
Jens Axboe | e00c54c | 2009-10-04 20:36:19 +0200 | [diff] [blame] | 2330 | if (!depth && !cfqq->dispatched) |
| 2331 | depth = 1; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2332 | if (depth < max_dispatch) |
| 2333 | max_dispatch = depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2334 | } |
| 2335 | |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2336 | /* |
| 2337 | * If we're below the current max, allow a dispatch |
| 2338 | */ |
| 2339 | return cfqq->dispatched < max_dispatch; |
| 2340 | } |
| 2341 | |
| 2342 | /* |
| 2343 | * Dispatch a request from cfqq, moving them to the request queue |
| 2344 | * dispatch list. |
| 2345 | */ |
| 2346 | static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2347 | { |
| 2348 | struct request *rq; |
| 2349 | |
| 2350 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); |
| 2351 | |
| 2352 | if (!cfq_may_dispatch(cfqd, cfqq)) |
| 2353 | return false; |
| 2354 | |
| 2355 | /* |
| 2356 | * follow expired path, else get first next available |
| 2357 | */ |
| 2358 | rq = cfq_check_fifo(cfqq); |
| 2359 | if (!rq) |
| 2360 | rq = cfqq->next_rq; |
| 2361 | |
| 2362 | /* |
| 2363 | * insert request into driver dispatch list |
| 2364 | */ |
| 2365 | cfq_dispatch_insert(cfqd->queue, rq); |
| 2366 | |
| 2367 | if (!cfqd->active_cic) { |
| 2368 | struct cfq_io_context *cic = RQ_CIC(rq); |
| 2369 | |
| 2370 | atomic_long_inc(&cic->ioc->refcount); |
| 2371 | cfqd->active_cic = cic; |
| 2372 | } |
| 2373 | |
| 2374 | return true; |
| 2375 | } |
| 2376 | |
| 2377 | /* |
| 2378 | * Find the cfqq that we need to service and move a request from that to the |
| 2379 | * dispatch list |
| 2380 | */ |
| 2381 | static int cfq_dispatch_requests(struct request_queue *q, int force) |
| 2382 | { |
| 2383 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 2384 | struct cfq_queue *cfqq; |
| 2385 | |
| 2386 | if (!cfqd->busy_queues) |
| 2387 | return 0; |
| 2388 | |
| 2389 | if (unlikely(force)) |
| 2390 | return cfq_forced_dispatch(cfqd); |
| 2391 | |
| 2392 | cfqq = cfq_select_queue(cfqd); |
| 2393 | if (!cfqq) |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2394 | return 0; |
| 2395 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2396 | /* |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2397 | * Dispatch a request from this cfqq, if it is allowed |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2398 | */ |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2399 | if (!cfq_dispatch_request(cfqd, cfqq)) |
| 2400 | return 0; |
| 2401 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2402 | cfqq->slice_dispatch++; |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 2403 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2404 | |
| 2405 | /* |
| 2406 | * expire an async queue immediately if it has used up its slice. idle |
| 2407 | * queue always expire after 1 dispatch round. |
| 2408 | */ |
| 2409 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && |
| 2410 | cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || |
| 2411 | cfq_class_idle(cfqq))) { |
| 2412 | cfqq->slice_end = jiffies + 1; |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2413 | cfq_slice_expired(cfqd, 0); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2414 | } |
| 2415 | |
Shan Wei | b217a90 | 2009-09-01 10:06:42 +0200 | [diff] [blame] | 2416 | cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2417 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2418 | } |
| 2419 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2420 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2421 | * task holds one reference to the queue, dropped when task exits. each rq |
| 2422 | * 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] | 2423 | * |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2424 | * 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] | 2425 | * queue lock must be held here. |
| 2426 | */ |
| 2427 | static void cfq_put_queue(struct cfq_queue *cfqq) |
| 2428 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2429 | struct cfq_data *cfqd = cfqq->cfqd; |
Vivek Goyal | 878eadd | 2009-12-07 19:37:15 +0100 | [diff] [blame] | 2430 | struct cfq_group *cfqg, *orig_cfqg; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2431 | |
| 2432 | BUG_ON(atomic_read(&cfqq->ref) <= 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2433 | |
| 2434 | if (!atomic_dec_and_test(&cfqq->ref)) |
| 2435 | return; |
| 2436 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2437 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2438 | BUG_ON(rb_first(&cfqq->sort_list)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2439 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2440 | cfqg = cfqq->cfqg; |
Vivek Goyal | 878eadd | 2009-12-07 19:37:15 +0100 | [diff] [blame] | 2441 | orig_cfqg = cfqq->orig_cfqg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2442 | |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2443 | if (unlikely(cfqd->active_queue == cfqq)) { |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2444 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2445 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2446 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2447 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2448 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2449 | kmem_cache_free(cfq_pool, cfqq); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2450 | cfq_put_cfqg(cfqg); |
Vivek Goyal | 878eadd | 2009-12-07 19:37:15 +0100 | [diff] [blame] | 2451 | if (orig_cfqg) |
| 2452 | cfq_put_cfqg(orig_cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2453 | } |
| 2454 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2455 | /* |
| 2456 | * Must always be called with the rcu_read_lock() held |
| 2457 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 2458 | static void |
| 2459 | __call_for_each_cic(struct io_context *ioc, |
| 2460 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 2461 | { |
| 2462 | struct cfq_io_context *cic; |
| 2463 | struct hlist_node *n; |
| 2464 | |
| 2465 | hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list) |
| 2466 | func(ioc, cic); |
| 2467 | } |
| 2468 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2469 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2470 | * Call func for each cic attached to this ioc. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2471 | */ |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2472 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2473 | call_for_each_cic(struct io_context *ioc, |
| 2474 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 2475 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2476 | rcu_read_lock(); |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 2477 | __call_for_each_cic(ioc, func); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2478 | rcu_read_unlock(); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2479 | } |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2480 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2481 | static void cfq_cic_free_rcu(struct rcu_head *head) |
| 2482 | { |
| 2483 | struct cfq_io_context *cic; |
| 2484 | |
| 2485 | cic = container_of(head, struct cfq_io_context, rcu_head); |
| 2486 | |
| 2487 | kmem_cache_free(cfq_ioc_pool, cic); |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2488 | elv_ioc_count_dec(cfq_ioc_count); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2489 | |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 2490 | if (ioc_gone) { |
| 2491 | /* |
| 2492 | * CFQ scheduler is exiting, grab exit lock and check |
| 2493 | * the pending io context count. If it hits zero, |
| 2494 | * complete ioc_gone and set it back to NULL |
| 2495 | */ |
| 2496 | spin_lock(&ioc_gone_lock); |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2497 | if (ioc_gone && !elv_ioc_count_read(cfq_ioc_count)) { |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 2498 | complete(ioc_gone); |
| 2499 | ioc_gone = NULL; |
| 2500 | } |
| 2501 | spin_unlock(&ioc_gone_lock); |
| 2502 | } |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2503 | } |
| 2504 | |
| 2505 | static void cfq_cic_free(struct cfq_io_context *cic) |
| 2506 | { |
| 2507 | call_rcu(&cic->rcu_head, cfq_cic_free_rcu); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2508 | } |
| 2509 | |
| 2510 | static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic) |
| 2511 | { |
| 2512 | unsigned long flags; |
| 2513 | |
| 2514 | BUG_ON(!cic->dead_key); |
| 2515 | |
| 2516 | spin_lock_irqsave(&ioc->lock, flags); |
| 2517 | radix_tree_delete(&ioc->radix_root, cic->dead_key); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2518 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2519 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 2520 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2521 | cfq_cic_free(cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2522 | } |
| 2523 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2524 | /* |
| 2525 | * Must be called with rcu_read_lock() held or preemption otherwise disabled. |
| 2526 | * Only two callers of this - ->dtor() which is called with the rcu_read_lock(), |
| 2527 | * and ->trim() which is called with the task lock held |
| 2528 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2529 | static void cfq_free_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2530 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2531 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2532 | * ioc->refcount is zero here, or we are called from elv_unregister(), |
| 2533 | * so no more cic's are allowed to be linked into this ioc. So it |
| 2534 | * should be ok to iterate over the known list, we will see all cic's |
| 2535 | * since no new ones are added. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2536 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 2537 | __call_for_each_cic(ioc, cic_free_func); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2538 | } |
| 2539 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2540 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2541 | { |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2542 | struct cfq_queue *__cfqq, *next; |
| 2543 | |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2544 | if (unlikely(cfqq == cfqd->active_queue)) { |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 2545 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2546 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2547 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2548 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2549 | /* |
| 2550 | * If this queue was scheduled to merge with another queue, be |
| 2551 | * sure to drop the reference taken on that queue (and others in |
| 2552 | * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. |
| 2553 | */ |
| 2554 | __cfqq = cfqq->new_cfqq; |
| 2555 | while (__cfqq) { |
| 2556 | if (__cfqq == cfqq) { |
| 2557 | WARN(1, "cfqq->new_cfqq loop detected\n"); |
| 2558 | break; |
| 2559 | } |
| 2560 | next = __cfqq->new_cfqq; |
| 2561 | cfq_put_queue(__cfqq); |
| 2562 | __cfqq = next; |
| 2563 | } |
| 2564 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2565 | cfq_put_queue(cfqq); |
| 2566 | } |
| 2567 | |
| 2568 | static void __cfq_exit_single_io_context(struct cfq_data *cfqd, |
| 2569 | struct cfq_io_context *cic) |
| 2570 | { |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 2571 | struct io_context *ioc = cic->ioc; |
| 2572 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2573 | list_del_init(&cic->queue_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2574 | |
| 2575 | /* |
| 2576 | * Make sure key == NULL is seen for dead queues |
| 2577 | */ |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2578 | smp_wmb(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2579 | cic->dead_key = (unsigned long) cic->key; |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2580 | cic->key = NULL; |
| 2581 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 2582 | if (ioc->ioc_data == cic) |
| 2583 | rcu_assign_pointer(ioc->ioc_data, NULL); |
| 2584 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2585 | if (cic->cfqq[BLK_RW_ASYNC]) { |
| 2586 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]); |
| 2587 | cic->cfqq[BLK_RW_ASYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2588 | } |
| 2589 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2590 | if (cic->cfqq[BLK_RW_SYNC]) { |
| 2591 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_SYNC]); |
| 2592 | cic->cfqq[BLK_RW_SYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2593 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2594 | } |
| 2595 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2596 | static void cfq_exit_single_io_context(struct io_context *ioc, |
| 2597 | struct cfq_io_context *cic) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2598 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 2599 | struct cfq_data *cfqd = cic->key; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2600 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2601 | if (cfqd) { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2602 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2603 | unsigned long flags; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2604 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2605 | spin_lock_irqsave(q->queue_lock, flags); |
Jens Axboe | 62c1fe9 | 2008-12-15 21:19:25 +0100 | [diff] [blame] | 2606 | |
| 2607 | /* |
| 2608 | * Ensure we get a fresh copy of the ->key to prevent |
| 2609 | * race between exiting task and queue |
| 2610 | */ |
| 2611 | smp_read_barrier_depends(); |
| 2612 | if (cic->key) |
| 2613 | __cfq_exit_single_io_context(cfqd, cic); |
| 2614 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2615 | spin_unlock_irqrestore(q->queue_lock, flags); |
Al Viro | 12a0573 | 2006-03-18 13:38:01 -0500 | [diff] [blame] | 2616 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2617 | } |
| 2618 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2619 | /* |
| 2620 | * The process that ioc belongs to has exited, we need to clean up |
| 2621 | * and put the internal structures we have that belongs to that process. |
| 2622 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2623 | static void cfq_exit_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2624 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2625 | call_for_each_cic(ioc, cfq_exit_single_io_context); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2626 | } |
| 2627 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2628 | static struct cfq_io_context * |
Al Viro | 8267e26 | 2005-10-21 03:20:53 -0400 | [diff] [blame] | 2629 | cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2630 | { |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 2631 | struct cfq_io_context *cic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2632 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2633 | cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO, |
| 2634 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2635 | if (cic) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2636 | cic->last_end_request = jiffies; |
Jens Axboe | 553698f | 2006-06-14 19:11:57 +0200 | [diff] [blame] | 2637 | INIT_LIST_HEAD(&cic->queue_list); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2638 | INIT_HLIST_NODE(&cic->cic_list); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2639 | cic->dtor = cfq_free_io_context; |
| 2640 | cic->exit = cfq_exit_io_context; |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2641 | elv_ioc_count_inc(cfq_ioc_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2642 | } |
| 2643 | |
| 2644 | return cic; |
| 2645 | } |
| 2646 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2647 | 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] | 2648 | { |
| 2649 | struct task_struct *tsk = current; |
| 2650 | int ioprio_class; |
| 2651 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2652 | if (!cfq_cfqq_prio_changed(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2653 | return; |
| 2654 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2655 | ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2656 | switch (ioprio_class) { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2657 | default: |
| 2658 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); |
| 2659 | case IOPRIO_CLASS_NONE: |
| 2660 | /* |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 2661 | * no prio set, inherit CPU scheduling settings |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2662 | */ |
| 2663 | cfqq->ioprio = task_nice_ioprio(tsk); |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 2664 | cfqq->ioprio_class = task_nice_ioclass(tsk); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2665 | break; |
| 2666 | case IOPRIO_CLASS_RT: |
| 2667 | cfqq->ioprio = task_ioprio(ioc); |
| 2668 | cfqq->ioprio_class = IOPRIO_CLASS_RT; |
| 2669 | break; |
| 2670 | case IOPRIO_CLASS_BE: |
| 2671 | cfqq->ioprio = task_ioprio(ioc); |
| 2672 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 2673 | break; |
| 2674 | case IOPRIO_CLASS_IDLE: |
| 2675 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; |
| 2676 | cfqq->ioprio = 7; |
| 2677 | cfq_clear_cfqq_idle_window(cfqq); |
| 2678 | break; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2679 | } |
| 2680 | |
| 2681 | /* |
| 2682 | * keep track of original prio settings in case we have to temporarily |
| 2683 | * elevate the priority of this queue |
| 2684 | */ |
| 2685 | cfqq->org_ioprio = cfqq->ioprio; |
| 2686 | cfqq->org_ioprio_class = cfqq->ioprio_class; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2687 | cfq_clear_cfqq_prio_changed(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2688 | } |
| 2689 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2690 | 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] | 2691 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 2692 | struct cfq_data *cfqd = cic->key; |
| 2693 | struct cfq_queue *cfqq; |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 2694 | unsigned long flags; |
Jens Axboe | 35e6077 | 2006-06-14 09:10:45 +0200 | [diff] [blame] | 2695 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2696 | if (unlikely(!cfqd)) |
| 2697 | return; |
| 2698 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 2699 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2700 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2701 | cfqq = cic->cfqq[BLK_RW_ASYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2702 | if (cfqq) { |
| 2703 | struct cfq_queue *new_cfqq; |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2704 | new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->ioc, |
| 2705 | GFP_ATOMIC); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2706 | if (new_cfqq) { |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2707 | cic->cfqq[BLK_RW_ASYNC] = new_cfqq; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2708 | cfq_put_queue(cfqq); |
| 2709 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2710 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2711 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2712 | cfqq = cic->cfqq[BLK_RW_SYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2713 | if (cfqq) |
| 2714 | cfq_mark_cfqq_prio_changed(cfqq); |
| 2715 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 2716 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2717 | } |
| 2718 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2719 | static void cfq_ioc_set_ioprio(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2720 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2721 | call_for_each_cic(ioc, changed_ioprio); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2722 | ioc->ioprio_changed = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2723 | } |
| 2724 | |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 2725 | 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] | 2726 | pid_t pid, bool is_sync) |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 2727 | { |
| 2728 | RB_CLEAR_NODE(&cfqq->rb_node); |
| 2729 | RB_CLEAR_NODE(&cfqq->p_node); |
| 2730 | INIT_LIST_HEAD(&cfqq->fifo); |
| 2731 | |
| 2732 | atomic_set(&cfqq->ref, 0); |
| 2733 | cfqq->cfqd = cfqd; |
| 2734 | |
| 2735 | cfq_mark_cfqq_prio_changed(cfqq); |
| 2736 | |
| 2737 | if (is_sync) { |
| 2738 | if (!cfq_class_idle(cfqq)) |
| 2739 | cfq_mark_cfqq_idle_window(cfqq); |
| 2740 | cfq_mark_cfqq_sync(cfqq); |
| 2741 | } |
| 2742 | cfqq->pid = pid; |
| 2743 | } |
| 2744 | |
Vivek Goyal | 24610333 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 2745 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 2746 | static void changed_cgroup(struct io_context *ioc, struct cfq_io_context *cic) |
| 2747 | { |
| 2748 | struct cfq_queue *sync_cfqq = cic_to_cfqq(cic, 1); |
| 2749 | struct cfq_data *cfqd = cic->key; |
| 2750 | unsigned long flags; |
| 2751 | struct request_queue *q; |
| 2752 | |
| 2753 | if (unlikely(!cfqd)) |
| 2754 | return; |
| 2755 | |
| 2756 | q = cfqd->queue; |
| 2757 | |
| 2758 | spin_lock_irqsave(q->queue_lock, flags); |
| 2759 | |
| 2760 | if (sync_cfqq) { |
| 2761 | /* |
| 2762 | * Drop reference to sync queue. A new sync queue will be |
| 2763 | * assigned in new group upon arrival of a fresh request. |
| 2764 | */ |
| 2765 | cfq_log_cfqq(cfqd, sync_cfqq, "changed cgroup"); |
| 2766 | cic_set_cfqq(cic, NULL, 1); |
| 2767 | cfq_put_queue(sync_cfqq); |
| 2768 | } |
| 2769 | |
| 2770 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2771 | } |
| 2772 | |
| 2773 | static void cfq_ioc_set_cgroup(struct io_context *ioc) |
| 2774 | { |
| 2775 | call_for_each_cic(ioc, changed_cgroup); |
| 2776 | ioc->cgroup_changed = 0; |
| 2777 | } |
| 2778 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ |
| 2779 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2780 | static struct cfq_queue * |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2781 | cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2782 | struct io_context *ioc, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2783 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2784 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2785 | struct cfq_io_context *cic; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2786 | struct cfq_group *cfqg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2787 | |
| 2788 | retry: |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2789 | cfqg = cfq_get_cfqg(cfqd, 1); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2790 | cic = cfq_cic_lookup(cfqd, ioc); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2791 | /* cic always exists here */ |
| 2792 | cfqq = cic_to_cfqq(cic, is_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2793 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2794 | /* |
| 2795 | * Always try a new alloc if we fell back to the OOM cfqq |
| 2796 | * originally, since it should just be a temporary situation. |
| 2797 | */ |
| 2798 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
| 2799 | cfqq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2800 | if (new_cfqq) { |
| 2801 | cfqq = new_cfqq; |
| 2802 | new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2803 | } else if (gfp_mask & __GFP_WAIT) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2804 | spin_unlock_irq(cfqd->queue->queue_lock); |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2805 | new_cfqq = kmem_cache_alloc_node(cfq_pool, |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2806 | gfp_mask | __GFP_ZERO, |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2807 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2808 | spin_lock_irq(cfqd->queue->queue_lock); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2809 | if (new_cfqq) |
| 2810 | goto retry; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2811 | } else { |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2812 | cfqq = kmem_cache_alloc_node(cfq_pool, |
| 2813 | gfp_mask | __GFP_ZERO, |
| 2814 | cfqd->queue->node); |
Kiyoshi Ueda | db3b584 | 2005-06-17 16:15:10 +0200 | [diff] [blame] | 2815 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2816 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2817 | if (cfqq) { |
| 2818 | cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); |
| 2819 | cfq_init_prio_data(cfqq, ioc); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2820 | cfq_link_cfqq_cfqg(cfqq, cfqg); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2821 | cfq_log_cfqq(cfqd, cfqq, "alloced"); |
| 2822 | } else |
| 2823 | cfqq = &cfqd->oom_cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2824 | } |
| 2825 | |
| 2826 | if (new_cfqq) |
| 2827 | kmem_cache_free(cfq_pool, new_cfqq); |
| 2828 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2829 | return cfqq; |
| 2830 | } |
| 2831 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2832 | static struct cfq_queue ** |
| 2833 | cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) |
| 2834 | { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2835 | switch (ioprio_class) { |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2836 | case IOPRIO_CLASS_RT: |
| 2837 | return &cfqd->async_cfqq[0][ioprio]; |
| 2838 | case IOPRIO_CLASS_BE: |
| 2839 | return &cfqd->async_cfqq[1][ioprio]; |
| 2840 | case IOPRIO_CLASS_IDLE: |
| 2841 | return &cfqd->async_idle_cfqq; |
| 2842 | default: |
| 2843 | BUG(); |
| 2844 | } |
| 2845 | } |
| 2846 | |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2847 | static struct cfq_queue * |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2848 | 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] | 2849 | gfp_t gfp_mask) |
| 2850 | { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2851 | const int ioprio = task_ioprio(ioc); |
| 2852 | const int ioprio_class = task_ioprio_class(ioc); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2853 | struct cfq_queue **async_cfqq = NULL; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2854 | struct cfq_queue *cfqq = NULL; |
| 2855 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2856 | if (!is_sync) { |
| 2857 | async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); |
| 2858 | cfqq = *async_cfqq; |
| 2859 | } |
| 2860 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2861 | if (!cfqq) |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2862 | cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2863 | |
| 2864 | /* |
| 2865 | * pin the queue now that it's allocated, scheduler exit will prune it |
| 2866 | */ |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2867 | if (!is_sync && !(*async_cfqq)) { |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2868 | atomic_inc(&cfqq->ref); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2869 | *async_cfqq = cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2870 | } |
| 2871 | |
| 2872 | atomic_inc(&cfqq->ref); |
| 2873 | return cfqq; |
| 2874 | } |
| 2875 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2876 | /* |
| 2877 | * We drop cfq io contexts lazily, so we may find a dead one. |
| 2878 | */ |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2879 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2880 | cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc, |
| 2881 | struct cfq_io_context *cic) |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2882 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2883 | unsigned long flags; |
| 2884 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2885 | WARN_ON(!list_empty(&cic->queue_list)); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2886 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2887 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2888 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 2889 | BUG_ON(ioc->ioc_data == cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2890 | |
| 2891 | radix_tree_delete(&ioc->radix_root, (unsigned long) cfqd); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2892 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2893 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 2894 | |
| 2895 | cfq_cic_free(cic); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2896 | } |
| 2897 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2898 | static struct cfq_io_context * |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2899 | cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2900 | { |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2901 | struct cfq_io_context *cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2902 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2903 | void *k; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2904 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2905 | if (unlikely(!ioc)) |
| 2906 | return NULL; |
| 2907 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2908 | rcu_read_lock(); |
| 2909 | |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2910 | /* |
| 2911 | * we maintain a last-hit cache, to avoid browsing over the tree |
| 2912 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2913 | cic = rcu_dereference(ioc->ioc_data); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2914 | if (cic && cic->key == cfqd) { |
| 2915 | rcu_read_unlock(); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2916 | return cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2917 | } |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2918 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2919 | do { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2920 | cic = radix_tree_lookup(&ioc->radix_root, (unsigned long) cfqd); |
| 2921 | rcu_read_unlock(); |
| 2922 | if (!cic) |
| 2923 | break; |
OGAWA Hirofumi | be3b075 | 2006-04-18 19:18:31 +0200 | [diff] [blame] | 2924 | /* ->key must be copied to avoid race with cfq_exit_queue() */ |
| 2925 | k = cic->key; |
| 2926 | if (unlikely(!k)) { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2927 | cfq_drop_dead_cic(cfqd, ioc, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2928 | rcu_read_lock(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2929 | continue; |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2930 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2931 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2932 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2933 | rcu_assign_pointer(ioc->ioc_data, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2934 | spin_unlock_irqrestore(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2935 | break; |
| 2936 | } while (1); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2937 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2938 | return cic; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2939 | } |
| 2940 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2941 | /* |
| 2942 | * Add cic into ioc, using cfqd as the search key. This enables us to lookup |
| 2943 | * the process specific cfq io context when entered from the block layer. |
| 2944 | * Also adds the cic to a per-cfqd list, used when this queue is removed. |
| 2945 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2946 | static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, |
| 2947 | struct cfq_io_context *cic, gfp_t gfp_mask) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2948 | { |
Jens Axboe | 0261d68 | 2006-10-30 19:07:48 +0100 | [diff] [blame] | 2949 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2950 | int ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2951 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2952 | ret = radix_tree_preload(gfp_mask); |
| 2953 | if (!ret) { |
| 2954 | cic->ioc = ioc; |
| 2955 | cic->key = cfqd; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2956 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2957 | spin_lock_irqsave(&ioc->lock, flags); |
| 2958 | ret = radix_tree_insert(&ioc->radix_root, |
| 2959 | (unsigned long) cfqd, cic); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2960 | if (!ret) |
| 2961 | hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2962 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 2963 | |
| 2964 | radix_tree_preload_end(); |
| 2965 | |
| 2966 | if (!ret) { |
| 2967 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 2968 | list_add(&cic->queue_list, &cfqd->cic_list); |
| 2969 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2970 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2971 | } |
| 2972 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2973 | if (ret) |
| 2974 | printk(KERN_ERR "cfq: cic link failed!\n"); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2975 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2976 | return ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2977 | } |
| 2978 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2979 | /* |
| 2980 | * Setup general io context and cfq io context. There can be several cfq |
| 2981 | * 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] | 2982 | * than one device managed by cfq. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2983 | */ |
| 2984 | static struct cfq_io_context * |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2985 | cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2986 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2987 | struct io_context *ioc = NULL; |
| 2988 | struct cfq_io_context *cic; |
| 2989 | |
| 2990 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 2991 | |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 2992 | ioc = get_io_context(gfp_mask, cfqd->queue->node); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2993 | if (!ioc) |
| 2994 | return NULL; |
| 2995 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2996 | cic = cfq_cic_lookup(cfqd, ioc); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2997 | if (cic) |
| 2998 | goto out; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2999 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3000 | cic = cfq_alloc_io_context(cfqd, gfp_mask); |
| 3001 | if (cic == NULL) |
| 3002 | goto err; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3003 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 3004 | if (cfq_cic_link(cfqd, ioc, cic, gfp_mask)) |
| 3005 | goto err_free; |
| 3006 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3007 | out: |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 3008 | smp_read_barrier_depends(); |
| 3009 | if (unlikely(ioc->ioprio_changed)) |
| 3010 | cfq_ioc_set_ioprio(ioc); |
| 3011 | |
Vivek Goyal | 24610333 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 3012 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 3013 | if (unlikely(ioc->cgroup_changed)) |
| 3014 | cfq_ioc_set_cgroup(ioc); |
| 3015 | #endif |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3016 | return cic; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 3017 | err_free: |
| 3018 | cfq_cic_free(cic); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3019 | err: |
| 3020 | put_io_context(ioc); |
| 3021 | return NULL; |
| 3022 | } |
| 3023 | |
| 3024 | static void |
| 3025 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic) |
| 3026 | { |
Jens Axboe | aaf1228 | 2007-01-19 11:30:16 +1100 | [diff] [blame] | 3027 | unsigned long elapsed = jiffies - cic->last_end_request; |
| 3028 | unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3029 | |
| 3030 | cic->ttime_samples = (7*cic->ttime_samples + 256) / 8; |
| 3031 | cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8; |
| 3032 | cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples; |
| 3033 | } |
| 3034 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3035 | static void |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3036 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3037 | struct request *rq) |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3038 | { |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 3039 | sector_t sdist = 0; |
Corrado Zoccolo | 41647e7 | 2010-02-27 19:45:40 +0100 | [diff] [blame] | 3040 | sector_t n_sec = blk_rq_sectors(rq); |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 3041 | if (cfqq->last_request_pos) { |
| 3042 | if (cfqq->last_request_pos < blk_rq_pos(rq)) |
| 3043 | sdist = blk_rq_pos(rq) - cfqq->last_request_pos; |
| 3044 | else |
| 3045 | sdist = cfqq->last_request_pos - blk_rq_pos(rq); |
| 3046 | } |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3047 | |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 3048 | cfqq->seek_history <<= 1; |
Corrado Zoccolo | 41647e7 | 2010-02-27 19:45:40 +0100 | [diff] [blame] | 3049 | if (blk_queue_nonrot(cfqd->queue)) |
| 3050 | cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT); |
| 3051 | else |
| 3052 | cfqq->seek_history |= (sdist > CFQQ_SEEK_THR); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3053 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3054 | |
| 3055 | /* |
| 3056 | * Disable idle window if the process thinks too long or seeks so much that |
| 3057 | * it doesn't matter |
| 3058 | */ |
| 3059 | static void |
| 3060 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 3061 | struct cfq_io_context *cic) |
| 3062 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3063 | int old_idle, enable_idle; |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 3064 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 3065 | /* |
| 3066 | * Don't idle for async or idle io prio class |
| 3067 | */ |
| 3068 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 3069 | return; |
| 3070 | |
Jens Axboe | c265a7f | 2008-06-26 13:49:33 +0200 | [diff] [blame] | 3071 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3072 | |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3073 | if (cfqq->queued[0] + cfqq->queued[1] >= 4) |
| 3074 | cfq_mark_cfqq_deep(cfqq); |
| 3075 | |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 3076 | if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle || |
Corrado Zoccolo | 3dde36d | 2010-02-27 19:45:39 +0100 | [diff] [blame] | 3077 | (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq))) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3078 | enable_idle = 0; |
| 3079 | else if (sample_valid(cic->ttime_samples)) { |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 3080 | if (cic->ttime_mean > cfqd->cfq_slice_idle) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3081 | enable_idle = 0; |
| 3082 | else |
| 3083 | enable_idle = 1; |
| 3084 | } |
| 3085 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3086 | if (old_idle != enable_idle) { |
| 3087 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); |
| 3088 | if (enable_idle) |
| 3089 | cfq_mark_cfqq_idle_window(cfqq); |
| 3090 | else |
| 3091 | cfq_clear_cfqq_idle_window(cfqq); |
| 3092 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3093 | } |
| 3094 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3095 | /* |
| 3096 | * Check if new_cfqq should preempt the currently active queue. Return 0 for |
| 3097 | * no or if we aren't sure, a 1 will cause a preempt. |
| 3098 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3099 | static bool |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3100 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3101 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3102 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3103 | struct cfq_queue *cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3104 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3105 | cfqq = cfqd->active_queue; |
| 3106 | if (!cfqq) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3107 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3108 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3109 | if (cfq_class_idle(new_cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3110 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3111 | |
| 3112 | if (cfq_class_idle(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3113 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3114 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3115 | /* |
Divyesh Shah | 875feb6 | 2010-01-06 18:58:20 -0800 | [diff] [blame] | 3116 | * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice. |
| 3117 | */ |
| 3118 | if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq)) |
| 3119 | return false; |
| 3120 | |
| 3121 | /* |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3122 | * if the new request is sync, but the currently running queue is |
| 3123 | * not, let the sync request have priority. |
| 3124 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3125 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3126 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3127 | |
Vivek Goyal | 8682e1f | 2009-12-03 12:59:50 -0500 | [diff] [blame] | 3128 | if (new_cfqq->cfqg != cfqq->cfqg) |
| 3129 | return false; |
| 3130 | |
| 3131 | if (cfq_slice_used(cfqq)) |
| 3132 | return true; |
| 3133 | |
| 3134 | /* Allow preemption only if we are idling on sync-noidle tree */ |
| 3135 | if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD && |
| 3136 | cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD && |
| 3137 | new_cfqq->service_tree->count == 2 && |
| 3138 | RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 3139 | return true; |
| 3140 | |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3141 | /* |
| 3142 | * So both queues are sync. Let the new request get disk time if |
| 3143 | * it's a metadata request and the current queue is doing regular IO. |
| 3144 | */ |
| 3145 | if (rq_is_meta(rq) && !cfqq->meta_pending) |
Jens Axboe | e6ec4fe | 2009-11-03 20:21:35 +0100 | [diff] [blame] | 3146 | return true; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3147 | |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3148 | /* |
| 3149 | * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. |
| 3150 | */ |
| 3151 | if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3152 | return true; |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3153 | |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3154 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3155 | return false; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3156 | |
| 3157 | /* |
| 3158 | * if this request is as-good as one we would expect from the |
| 3159 | * current cfqq, let it preempt |
| 3160 | */ |
Shaohua Li | e9ce335 | 2010-03-19 08:03:04 +0100 | [diff] [blame] | 3161 | if (cfq_rq_close(cfqd, cfqq, rq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3162 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3163 | |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3164 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3165 | } |
| 3166 | |
| 3167 | /* |
| 3168 | * cfqq preempts the active queue. if we allowed preempt with no slice left, |
| 3169 | * let it have half of its nominal slice. |
| 3170 | */ |
| 3171 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 3172 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3173 | cfq_log_cfqq(cfqd, cfqq, "preempt"); |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 3174 | cfq_slice_expired(cfqd, 1); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3175 | |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 3176 | /* |
| 3177 | * Put the new queue at the front of the of the current list, |
| 3178 | * so we know that it will be selected next. |
| 3179 | */ |
| 3180 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 3181 | |
| 3182 | cfq_service_tree_add(cfqd, cfqq, 1); |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 3183 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3184 | cfqq->slice_end = 0; |
| 3185 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3186 | } |
| 3187 | |
| 3188 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3189 | * 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] | 3190 | * something we should do about it |
| 3191 | */ |
| 3192 | static void |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3193 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 3194 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3195 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3196 | struct cfq_io_context *cic = RQ_CIC(rq); |
Jens Axboe | 12e9fdd | 2006-06-01 10:09:56 +0200 | [diff] [blame] | 3197 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3198 | cfqd->rq_queued++; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3199 | if (rq_is_meta(rq)) |
| 3200 | cfqq->meta_pending++; |
| 3201 | |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 3202 | cfq_update_io_thinktime(cfqd, cic); |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3203 | cfq_update_io_seektime(cfqd, cfqq, rq); |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 3204 | cfq_update_idle_window(cfqd, cfqq, cic); |
| 3205 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3206 | cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3207 | |
| 3208 | if (cfqq == cfqd->active_queue) { |
| 3209 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 3210 | * Remember that we saw a request from this process, but |
| 3211 | * don't start queuing just yet. Otherwise we risk seeing lots |
| 3212 | * of tiny requests, because we disrupt the normal plugging |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3213 | * and merging. If the request is already larger than a single |
| 3214 | * page, let it rip immediately. For that case we assume that |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 3215 | * merging is already done. Ditto for a busy system that |
| 3216 | * has other work pending, don't risk delaying until the |
| 3217 | * idle timer unplug to continue working. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3218 | */ |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3219 | if (cfq_cfqq_wait_request(cfqq)) { |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 3220 | if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE || |
| 3221 | cfqd->busy_queues > 1) { |
Divyesh Shah | 812df48 | 2010-04-08 21:15:35 -0700 | [diff] [blame] | 3222 | cfq_del_timer(cfqd, cfqq); |
Gui Jianfeng | 554554f | 2009-12-10 09:38:39 +0100 | [diff] [blame] | 3223 | cfq_clear_cfqq_wait_request(cfqq); |
Vivek Goyal | bf791937 | 2009-12-03 12:59:37 -0500 | [diff] [blame] | 3224 | __blk_run_queue(cfqd->queue); |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 3225 | } else { |
| 3226 | blkiocg_update_idle_time_stats( |
| 3227 | &cfqq->cfqg->blkg); |
Vivek Goyal | bf791937 | 2009-12-03 12:59:37 -0500 | [diff] [blame] | 3228 | cfq_mark_cfqq_must_dispatch(cfqq); |
Divyesh Shah | a11cdaa | 2010-04-13 19:59:17 +0200 | [diff] [blame] | 3229 | } |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3230 | } |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3231 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3232 | /* |
| 3233 | * not the active queue - expire current slice if it is |
| 3234 | * idle and has expired it's mean thinktime or this new queue |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3235 | * has some old slice time left and is of higher priority or |
| 3236 | * this new queue is RT and the current one is BE |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3237 | */ |
| 3238 | cfq_preempt_queue(cfqd, cfqq); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 3239 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3240 | } |
| 3241 | } |
| 3242 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3243 | static void cfq_insert_request(struct request_queue *q, struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3244 | { |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3245 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3246 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3247 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3248 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 3249 | cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3250 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 3251 | 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] | 3252 | list_add_tail(&rq->queuelist, &cfqq->fifo); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 3253 | cfq_add_rq_rb(rq); |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 3254 | blkiocg_update_io_add_stats(&(RQ_CFQG(rq))->blkg, |
Divyesh Shah | cdc1184 | 2010-04-08 21:15:10 -0700 | [diff] [blame] | 3255 | &cfqd->serving_group->blkg, rq_data_dir(rq), |
| 3256 | rq_is_sync(rq)); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3257 | cfq_rq_enqueued(cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3258 | } |
| 3259 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3260 | /* |
| 3261 | * Update hw_tag based on peak queue depth over 50 samples under |
| 3262 | * sufficient load. |
| 3263 | */ |
| 3264 | static void cfq_update_hw_tag(struct cfq_data *cfqd) |
| 3265 | { |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3266 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 3267 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3268 | if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth) |
| 3269 | cfqd->hw_tag_est_depth = cfqd->rq_in_driver; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3270 | |
| 3271 | if (cfqd->hw_tag == 1) |
| 3272 | return; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3273 | |
| 3274 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3275 | cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3276 | return; |
| 3277 | |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3278 | /* |
| 3279 | * If active queue hasn't enough requests and can idle, cfq might not |
| 3280 | * dispatch sufficient requests to hardware. Don't zero hw_tag in this |
| 3281 | * case |
| 3282 | */ |
| 3283 | if (cfqq && cfq_cfqq_idle_window(cfqq) && |
| 3284 | cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] < |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3285 | CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN) |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3286 | return; |
| 3287 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3288 | if (cfqd->hw_tag_samples++ < 50) |
| 3289 | return; |
| 3290 | |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3291 | if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3292 | cfqd->hw_tag = 1; |
| 3293 | else |
| 3294 | cfqd->hw_tag = 0; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3295 | } |
| 3296 | |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3297 | static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 3298 | { |
| 3299 | struct cfq_io_context *cic = cfqd->active_cic; |
| 3300 | |
| 3301 | /* If there are other queues in the group, don't wait */ |
| 3302 | if (cfqq->cfqg->nr_cfqq > 1) |
| 3303 | return false; |
| 3304 | |
| 3305 | if (cfq_slice_used(cfqq)) |
| 3306 | return true; |
| 3307 | |
| 3308 | /* if slice left is less than think time, wait busy */ |
| 3309 | if (cic && sample_valid(cic->ttime_samples) |
| 3310 | && (cfqq->slice_end - jiffies < cic->ttime_mean)) |
| 3311 | return true; |
| 3312 | |
| 3313 | /* |
| 3314 | * If think times is less than a jiffy than ttime_mean=0 and above |
| 3315 | * will not be true. It might happen that slice has not expired yet |
| 3316 | * but will expire soon (4-5 ns) during select_queue(). To cover the |
| 3317 | * case where think time is less than a jiffy, mark the queue wait |
| 3318 | * busy if only 1 jiffy is left in the slice. |
| 3319 | */ |
| 3320 | if (cfqq->slice_end - jiffies == 1) |
| 3321 | return true; |
| 3322 | |
| 3323 | return false; |
| 3324 | } |
| 3325 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3326 | static void cfq_completed_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3327 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3328 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3329 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 3330 | const int sync = rq_is_sync(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3331 | unsigned long now; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3332 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3333 | now = jiffies; |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 3334 | cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", !!rq_noidle(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3335 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3336 | cfq_update_hw_tag(cfqd); |
| 3337 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3338 | WARN_ON(!cfqd->rq_in_driver); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3339 | WARN_ON(!cfqq->dispatched); |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3340 | cfqd->rq_in_driver--; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3341 | cfqq->dispatched--; |
Divyesh Shah | 84c124d | 2010-04-09 08:31:19 +0200 | [diff] [blame] | 3342 | blkiocg_update_completion_stats(&cfqq->cfqg->blkg, rq_start_time_ns(rq), |
| 3343 | rq_io_start_time_ns(rq), rq_data_dir(rq), |
| 3344 | rq_is_sync(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3345 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3346 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 3347 | |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 3348 | if (sync) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3349 | RQ_CIC(rq)->last_end_request = now; |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 3350 | if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) |
| 3351 | cfqd->last_delayed_sync = now; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 3352 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3353 | |
| 3354 | /* |
| 3355 | * If this is the active queue, check if it needs to be expired, |
| 3356 | * or if we want to idle in case it has no pending requests. |
| 3357 | */ |
| 3358 | if (cfqd->active_queue == cfqq) { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3359 | const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); |
| 3360 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3361 | if (cfq_cfqq_slice_new(cfqq)) { |
| 3362 | cfq_set_prio_slice(cfqd, cfqq); |
| 3363 | cfq_clear_cfqq_slice_new(cfqq); |
| 3364 | } |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3365 | |
| 3366 | /* |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3367 | * Should we wait for next request to come in before we expire |
| 3368 | * the queue. |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3369 | */ |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3370 | if (cfq_should_wait_busy(cfqd, cfqq)) { |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3371 | cfqq->slice_end = jiffies + cfqd->cfq_slice_idle; |
| 3372 | cfq_mark_cfqq_wait_busy(cfqq); |
Divyesh Shah | b1ffe73 | 2010-03-25 15:45:03 +0100 | [diff] [blame] | 3373 | cfq_log_cfqq(cfqd, cfqq, "will busy wait"); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3374 | } |
| 3375 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3376 | /* |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3377 | * Idling is not enabled on: |
| 3378 | * - expired queues |
| 3379 | * - idle-priority queues |
| 3380 | * - async queues |
| 3381 | * - queues with still some requests queued |
| 3382 | * - when there is a close cooperator |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3383 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 3384 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 3385 | cfq_slice_expired(cfqd, 1); |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3386 | else if (sync && cfqq_empty && |
| 3387 | !cfq_close_cooperator(cfqd, cfqq)) { |
| 3388 | cfqd->noidle_tree_requires_idle |= !rq_noidle(rq); |
| 3389 | /* |
| 3390 | * Idling is enabled for SYNC_WORKLOAD. |
| 3391 | * SYNC_NOIDLE_WORKLOAD idles at the end of the tree |
| 3392 | * only if we processed at least one !rq_noidle request |
| 3393 | */ |
| 3394 | if (cfqd->serving_type == SYNC_WORKLOAD |
Vivek Goyal | c04645e | 2009-12-03 12:59:56 -0500 | [diff] [blame] | 3395 | || cfqd->noidle_tree_requires_idle |
| 3396 | || cfqq->cfqg->nr_cfqq == 1) |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3397 | cfq_arm_slice_timer(cfqd); |
| 3398 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3399 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3400 | |
Corrado Zoccolo | 53c583d | 2010-02-28 19:45:05 +0100 | [diff] [blame] | 3401 | if (!cfqd->rq_in_driver) |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3402 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3403 | } |
| 3404 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3405 | /* |
| 3406 | * we temporarily boost lower priority queues if they are holding fs exclusive |
| 3407 | * resources. they are boosted to normal prio (CLASS_BE/4) |
| 3408 | */ |
| 3409 | static void cfq_prio_boost(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3410 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3411 | if (has_fs_excl()) { |
| 3412 | /* |
| 3413 | * boost idle prio on transactions that would lock out other |
| 3414 | * users of the filesystem |
| 3415 | */ |
| 3416 | if (cfq_class_idle(cfqq)) |
| 3417 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 3418 | if (cfqq->ioprio > IOPRIO_NORM) |
| 3419 | cfqq->ioprio = IOPRIO_NORM; |
| 3420 | } else { |
| 3421 | /* |
Corrado Zoccolo | dddb745 | 2009-11-02 10:40:37 +0100 | [diff] [blame] | 3422 | * unboost the queue (if needed) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3423 | */ |
Corrado Zoccolo | dddb745 | 2009-11-02 10:40:37 +0100 | [diff] [blame] | 3424 | cfqq->ioprio_class = cfqq->org_ioprio_class; |
| 3425 | cfqq->ioprio = cfqq->org_ioprio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3426 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3427 | } |
| 3428 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3429 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3430 | { |
Jens Axboe | 1b379d8 | 2009-08-11 08:26:11 +0200 | [diff] [blame] | 3431 | if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3432 | cfq_mark_cfqq_must_alloc_slice(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3433 | return ELV_MQUEUE_MUST; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3434 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3435 | |
| 3436 | return ELV_MQUEUE_MAY; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3437 | } |
| 3438 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3439 | static int cfq_may_queue(struct request_queue *q, int rw) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3440 | { |
| 3441 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 3442 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3443 | struct cfq_io_context *cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3444 | struct cfq_queue *cfqq; |
| 3445 | |
| 3446 | /* |
| 3447 | * don't force setup of a queue from here, as a call to may_queue |
| 3448 | * does not necessarily imply that a request actually will be queued. |
| 3449 | * so just lookup a possibly existing queue, or return 'may queue' |
| 3450 | * if that fails |
| 3451 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 3452 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3453 | if (!cic) |
| 3454 | return ELV_MQUEUE_MAY; |
| 3455 | |
Jens Axboe | b0b78f8 | 2009-04-08 10:56:08 +0200 | [diff] [blame] | 3456 | cfqq = cic_to_cfqq(cic, rw_is_sync(rw)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3457 | if (cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 3458 | cfq_init_prio_data(cfqq, cic->ioc); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3459 | cfq_prio_boost(cfqq); |
| 3460 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3461 | return __cfq_may_queue(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3462 | } |
| 3463 | |
| 3464 | return ELV_MQUEUE_MAY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3465 | } |
| 3466 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3467 | /* |
| 3468 | * queue lock held here |
| 3469 | */ |
Jens Axboe | bb37b94 | 2006-12-01 10:42:33 +0100 | [diff] [blame] | 3470 | static void cfq_put_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3471 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3472 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3473 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3474 | if (cfqq) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3475 | const int rw = rq_data_dir(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3476 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3477 | BUG_ON(!cfqq->allocated[rw]); |
| 3478 | cfqq->allocated[rw]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3479 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3480 | put_io_context(RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3481 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3482 | rq->elevator_private = NULL; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3483 | rq->elevator_private2 = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3484 | |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 3485 | /* Put down rq reference on cfqg */ |
| 3486 | cfq_put_cfqg(RQ_CFQG(rq)); |
| 3487 | rq->elevator_private3 = NULL; |
| 3488 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3489 | cfq_put_queue(cfqq); |
| 3490 | } |
| 3491 | } |
| 3492 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3493 | static struct cfq_queue * |
| 3494 | cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_context *cic, |
| 3495 | struct cfq_queue *cfqq) |
| 3496 | { |
| 3497 | cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq); |
| 3498 | cic_set_cfqq(cic, cfqq->new_cfqq, 1); |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 3499 | cfq_mark_cfqq_coop(cfqq->new_cfqq); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3500 | cfq_put_queue(cfqq); |
| 3501 | return cic_to_cfqq(cic, 1); |
| 3502 | } |
| 3503 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3504 | /* |
| 3505 | * Returns NULL if a new cfqq should be allocated, or the old cfqq if this |
| 3506 | * was the last process referring to said cfqq. |
| 3507 | */ |
| 3508 | static struct cfq_queue * |
| 3509 | split_cfqq(struct cfq_io_context *cic, struct cfq_queue *cfqq) |
| 3510 | { |
| 3511 | if (cfqq_process_refs(cfqq) == 1) { |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3512 | cfqq->pid = current->pid; |
| 3513 | cfq_clear_cfqq_coop(cfqq); |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 3514 | cfq_clear_cfqq_split_coop(cfqq); |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3515 | return cfqq; |
| 3516 | } |
| 3517 | |
| 3518 | cic_set_cfqq(cic, NULL, 1); |
| 3519 | cfq_put_queue(cfqq); |
| 3520 | return NULL; |
| 3521 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3522 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3523 | * Allocate cfq data structures associated with this request. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3524 | */ |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3525 | static int |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3526 | 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] | 3527 | { |
| 3528 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 3529 | struct cfq_io_context *cic; |
| 3530 | const int rw = rq_data_dir(rq); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3531 | const bool is_sync = rq_is_sync(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3532 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3533 | unsigned long flags; |
| 3534 | |
| 3535 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 3536 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3537 | cic = cfq_get_io_context(cfqd, gfp_mask); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3538 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3539 | spin_lock_irqsave(q->queue_lock, flags); |
| 3540 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3541 | if (!cic) |
| 3542 | goto queue_fail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3543 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3544 | new_queue: |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3545 | cfqq = cic_to_cfqq(cic, is_sync); |
Vivek Goyal | 32f2e80 | 2009-07-09 22:13:16 +0200 | [diff] [blame] | 3546 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 3547 | cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3548 | cic_set_cfqq(cic, cfqq, is_sync); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3549 | } else { |
| 3550 | /* |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3551 | * If the queue was seeky for too long, break it apart. |
| 3552 | */ |
Shaohua Li | ae54abe | 2010-02-05 13:11:45 +0100 | [diff] [blame] | 3553 | if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) { |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3554 | cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq"); |
| 3555 | cfqq = split_cfqq(cic, cfqq); |
| 3556 | if (!cfqq) |
| 3557 | goto new_queue; |
| 3558 | } |
| 3559 | |
| 3560 | /* |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3561 | * Check to see if this queue is scheduled to merge with |
| 3562 | * another, closely cooperating queue. The merging of |
| 3563 | * queues happens here as it must be done in process context. |
| 3564 | * The reference on new_cfqq was taken in merge_cfqqs. |
| 3565 | */ |
| 3566 | if (cfqq->new_cfqq) |
| 3567 | cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3568 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3569 | |
| 3570 | cfqq->allocated[rw]++; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3571 | atomic_inc(&cfqq->ref); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3572 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3573 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 3574 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3575 | rq->elevator_private = cic; |
| 3576 | rq->elevator_private2 = cfqq; |
Vivek Goyal | 7f1dc8a | 2010-04-21 17:44:16 +0200 | [diff] [blame] | 3577 | rq->elevator_private3 = cfq_ref_get_cfqg(cfqq->cfqg); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3578 | return 0; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3579 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3580 | queue_fail: |
| 3581 | if (cic) |
| 3582 | put_io_context(cic->ioc); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3583 | |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3584 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3585 | spin_unlock_irqrestore(q->queue_lock, flags); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3586 | cfq_log(cfqd, "set_request fail"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3587 | return 1; |
| 3588 | } |
| 3589 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 3590 | static void cfq_kick_queue(struct work_struct *work) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3591 | { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 3592 | struct cfq_data *cfqd = |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3593 | container_of(work, struct cfq_data, unplug_work); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3594 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3595 | |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 3596 | spin_lock_irq(q->queue_lock); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 3597 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 3598 | spin_unlock_irq(q->queue_lock); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3599 | } |
| 3600 | |
| 3601 | /* |
| 3602 | * Timer running if the active_queue is currently idling inside its time slice |
| 3603 | */ |
| 3604 | static void cfq_idle_slice_timer(unsigned long data) |
| 3605 | { |
| 3606 | struct cfq_data *cfqd = (struct cfq_data *) data; |
| 3607 | struct cfq_queue *cfqq; |
| 3608 | unsigned long flags; |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 3609 | int timed_out = 1; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3610 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3611 | cfq_log(cfqd, "idle timer fired"); |
| 3612 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3613 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 3614 | |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 3615 | cfqq = cfqd->active_queue; |
| 3616 | if (cfqq) { |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 3617 | timed_out = 0; |
| 3618 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3619 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 3620 | * We saw a request before the queue expired, let it through |
| 3621 | */ |
| 3622 | if (cfq_cfqq_must_dispatch(cfqq)) |
| 3623 | goto out_kick; |
| 3624 | |
| 3625 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3626 | * expired |
| 3627 | */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3628 | if (cfq_slice_used(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3629 | goto expire; |
| 3630 | |
| 3631 | /* |
| 3632 | * only expire and reinvoke request handler, if there are |
| 3633 | * other queues with pending requests |
| 3634 | */ |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3635 | if (!cfqd->busy_queues) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3636 | goto out_cont; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3637 | |
| 3638 | /* |
| 3639 | * not expired and it has a request pending, let it dispatch |
| 3640 | */ |
Jens Axboe | 75e5098 | 2009-04-07 08:56:14 +0200 | [diff] [blame] | 3641 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3642 | goto out_kick; |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3643 | |
| 3644 | /* |
| 3645 | * Queue depth flag is reset only when the idle didn't succeed |
| 3646 | */ |
| 3647 | cfq_clear_cfqq_deep(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3648 | } |
| 3649 | expire: |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 3650 | cfq_slice_expired(cfqd, timed_out); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3651 | out_kick: |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3652 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3653 | out_cont: |
| 3654 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 3655 | } |
| 3656 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3657 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) |
| 3658 | { |
| 3659 | del_timer_sync(&cfqd->idle_slice_timer); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3660 | cancel_work_sync(&cfqd->unplug_work); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3661 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3662 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3663 | static void cfq_put_async_queues(struct cfq_data *cfqd) |
| 3664 | { |
| 3665 | int i; |
| 3666 | |
| 3667 | for (i = 0; i < IOPRIO_BE_NR; i++) { |
| 3668 | if (cfqd->async_cfqq[0][i]) |
| 3669 | cfq_put_queue(cfqd->async_cfqq[0][i]); |
| 3670 | if (cfqd->async_cfqq[1][i]) |
| 3671 | cfq_put_queue(cfqd->async_cfqq[1][i]); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3672 | } |
Oleg Nesterov | 2389d1e | 2007-11-05 08:58:05 +0100 | [diff] [blame] | 3673 | |
| 3674 | if (cfqd->async_idle_cfqq) |
| 3675 | cfq_put_queue(cfqd->async_idle_cfqq); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3676 | } |
| 3677 | |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 3678 | static void cfq_cfqd_free(struct rcu_head *head) |
| 3679 | { |
| 3680 | kfree(container_of(head, struct cfq_data, rcu)); |
| 3681 | } |
| 3682 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3683 | static void cfq_exit_queue(struct elevator_queue *e) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3684 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3685 | struct cfq_data *cfqd = e->elevator_data; |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3686 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3687 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3688 | cfq_shutdown_timer_wq(cfqd); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3689 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3690 | spin_lock_irq(q->queue_lock); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3691 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3692 | if (cfqd->active_queue) |
Vivek Goyal | e5ff082 | 2010-04-26 19:25:11 +0200 | [diff] [blame] | 3693 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3694 | |
| 3695 | while (!list_empty(&cfqd->cic_list)) { |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3696 | struct cfq_io_context *cic = list_entry(cfqd->cic_list.next, |
| 3697 | struct cfq_io_context, |
| 3698 | queue_list); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3699 | |
| 3700 | __cfq_exit_single_io_context(cfqd, cic); |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3701 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3702 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3703 | cfq_put_async_queues(cfqd); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3704 | cfq_release_cfq_groups(cfqd); |
| 3705 | blkiocg_del_blkio_group(&cfqd->root_group.blkg); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 3706 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3707 | spin_unlock_irq(q->queue_lock); |
Al Viro | a90d742 | 2006-03-18 12:05:37 -0500 | [diff] [blame] | 3708 | |
| 3709 | cfq_shutdown_timer_wq(cfqd); |
| 3710 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3711 | /* Wait for cfqg->blkg->key accessors to exit their grace periods. */ |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 3712 | call_rcu(&cfqd->rcu, cfq_cfqd_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3713 | } |
| 3714 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3715 | static void *cfq_init_queue(struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3716 | { |
| 3717 | struct cfq_data *cfqd; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 3718 | int i, j; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3719 | struct cfq_group *cfqg; |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 3720 | struct cfq_rb_root *st; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3721 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 3722 | cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3723 | if (!cfqd) |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 3724 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3725 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 3726 | /* Init root service tree */ |
| 3727 | cfqd->grp_service_tree = CFQ_RB_ROOT; |
| 3728 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3729 | /* Init root group */ |
| 3730 | cfqg = &cfqd->root_group; |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 3731 | for_each_cfqg_st(cfqg, i, j, st) |
| 3732 | *st = CFQ_RB_ROOT; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 3733 | RB_CLEAR_NODE(&cfqg->rb_node); |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 3734 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 3735 | /* Give preference to root group over other groups */ |
| 3736 | cfqg->weight = 2*BLKIO_WEIGHT_DEFAULT; |
| 3737 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 3738 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3739 | /* |
| 3740 | * Take a reference to root group which we never drop. This is just |
| 3741 | * to make sure that cfq_put_cfqg() does not try to kfree root group |
| 3742 | */ |
| 3743 | atomic_set(&cfqg->ref, 1); |
Vivek Goyal | dcf097b | 2010-04-22 11:54:52 -0400 | [diff] [blame] | 3744 | rcu_read_lock(); |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 3745 | blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, (void *)cfqd, |
| 3746 | 0); |
Vivek Goyal | dcf097b | 2010-04-22 11:54:52 -0400 | [diff] [blame] | 3747 | rcu_read_unlock(); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 3748 | #endif |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 3749 | /* |
| 3750 | * Not strictly needed (since RB_ROOT just clears the node and we |
| 3751 | * zeroed cfqd on alloc), but better be safe in case someone decides |
| 3752 | * to add magic to the rb code |
| 3753 | */ |
| 3754 | for (i = 0; i < CFQ_PRIO_LISTS; i++) |
| 3755 | cfqd->prio_trees[i] = RB_ROOT; |
| 3756 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 3757 | /* |
| 3758 | * Our fallback cfqq if cfq_find_alloc_queue() runs into OOM issues. |
| 3759 | * Grab a permanent reference to it, so that the normal code flow |
| 3760 | * will not attempt to free it. |
| 3761 | */ |
| 3762 | cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); |
| 3763 | atomic_inc(&cfqd->oom_cfqq.ref); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3764 | cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 3765 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3766 | INIT_LIST_HEAD(&cfqd->cic_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3767 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3768 | cfqd->queue = q; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3769 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3770 | init_timer(&cfqd->idle_slice_timer); |
| 3771 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; |
| 3772 | cfqd->idle_slice_timer.data = (unsigned long) cfqd; |
| 3773 | |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3774 | INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3775 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3776 | cfqd->cfq_quantum = cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3777 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |
| 3778 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3779 | cfqd->cfq_back_max = cfq_back_max; |
| 3780 | cfqd->cfq_back_penalty = cfq_back_penalty; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3781 | cfqd->cfq_slice[0] = cfq_slice_async; |
| 3782 | cfqd->cfq_slice[1] = cfq_slice_sync; |
| 3783 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; |
| 3784 | cfqd->cfq_slice_idle = cfq_slice_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3785 | cfqd->cfq_latency = 1; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3786 | cfqd->cfq_group_isolation = 0; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3787 | cfqd->hw_tag = -1; |
Corrado Zoccolo | edc7113 | 2009-12-09 20:56:04 +0100 | [diff] [blame] | 3788 | /* |
| 3789 | * we optimistically start assuming sync ops weren't delayed in last |
| 3790 | * second, in order to have larger depth for async operations. |
| 3791 | */ |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 3792 | cfqd->last_delayed_sync = jiffies - HZ; |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 3793 | return cfqd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3794 | } |
| 3795 | |
| 3796 | static void cfq_slab_kill(void) |
| 3797 | { |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 3798 | /* |
| 3799 | * Caller already ensured that pending RCU callbacks are completed, |
| 3800 | * so we should have no busy allocations at this point. |
| 3801 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3802 | if (cfq_pool) |
| 3803 | kmem_cache_destroy(cfq_pool); |
| 3804 | if (cfq_ioc_pool) |
| 3805 | kmem_cache_destroy(cfq_ioc_pool); |
| 3806 | } |
| 3807 | |
| 3808 | static int __init cfq_slab_setup(void) |
| 3809 | { |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame] | 3810 | cfq_pool = KMEM_CACHE(cfq_queue, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3811 | if (!cfq_pool) |
| 3812 | goto fail; |
| 3813 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 3814 | cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3815 | if (!cfq_ioc_pool) |
| 3816 | goto fail; |
| 3817 | |
| 3818 | return 0; |
| 3819 | fail: |
| 3820 | cfq_slab_kill(); |
| 3821 | return -ENOMEM; |
| 3822 | } |
| 3823 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3824 | /* |
| 3825 | * sysfs parts below --> |
| 3826 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3827 | static ssize_t |
| 3828 | cfq_var_show(unsigned int var, char *page) |
| 3829 | { |
| 3830 | return sprintf(page, "%d\n", var); |
| 3831 | } |
| 3832 | |
| 3833 | static ssize_t |
| 3834 | cfq_var_store(unsigned int *var, const char *page, size_t count) |
| 3835 | { |
| 3836 | char *p = (char *) page; |
| 3837 | |
| 3838 | *var = simple_strtoul(p, &p, 10); |
| 3839 | return count; |
| 3840 | } |
| 3841 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3842 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3843 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3844 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3845 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3846 | unsigned int __data = __VAR; \ |
| 3847 | if (__CONV) \ |
| 3848 | __data = jiffies_to_msecs(__data); \ |
| 3849 | return cfq_var_show(__data, (page)); \ |
| 3850 | } |
| 3851 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3852 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); |
| 3853 | 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] | 3854 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); |
| 3855 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3856 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); |
| 3857 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); |
| 3858 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); |
| 3859 | 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] | 3860 | SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3861 | SHOW_FUNCTION(cfq_group_isolation_show, cfqd->cfq_group_isolation, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3862 | #undef SHOW_FUNCTION |
| 3863 | |
| 3864 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3865 | 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] | 3866 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3867 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3868 | unsigned int __data; \ |
| 3869 | int ret = cfq_var_store(&__data, (page), count); \ |
| 3870 | if (__data < (MIN)) \ |
| 3871 | __data = (MIN); \ |
| 3872 | else if (__data > (MAX)) \ |
| 3873 | __data = (MAX); \ |
| 3874 | if (__CONV) \ |
| 3875 | *(__PTR) = msecs_to_jiffies(__data); \ |
| 3876 | else \ |
| 3877 | *(__PTR) = __data; \ |
| 3878 | return ret; \ |
| 3879 | } |
| 3880 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 3881 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, |
| 3882 | UINT_MAX, 1); |
| 3883 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, |
| 3884 | UINT_MAX, 1); |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3885 | 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] | 3886 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, |
| 3887 | UINT_MAX, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3888 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); |
| 3889 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); |
| 3890 | 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] | 3891 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, |
| 3892 | UINT_MAX, 0); |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3893 | STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3894 | 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] | 3895 | #undef STORE_FUNCTION |
| 3896 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3897 | #define CFQ_ATTR(name) \ |
| 3898 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3899 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3900 | static struct elv_fs_entry cfq_attrs[] = { |
| 3901 | CFQ_ATTR(quantum), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3902 | CFQ_ATTR(fifo_expire_sync), |
| 3903 | CFQ_ATTR(fifo_expire_async), |
| 3904 | CFQ_ATTR(back_seek_max), |
| 3905 | CFQ_ATTR(back_seek_penalty), |
| 3906 | CFQ_ATTR(slice_sync), |
| 3907 | CFQ_ATTR(slice_async), |
| 3908 | CFQ_ATTR(slice_async_rq), |
| 3909 | CFQ_ATTR(slice_idle), |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3910 | CFQ_ATTR(low_latency), |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3911 | CFQ_ATTR(group_isolation), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3912 | __ATTR_NULL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3913 | }; |
| 3914 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3915 | static struct elevator_type iosched_cfq = { |
| 3916 | .ops = { |
| 3917 | .elevator_merge_fn = cfq_merge, |
| 3918 | .elevator_merged_fn = cfq_merged_request, |
| 3919 | .elevator_merge_req_fn = cfq_merged_requests, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 3920 | .elevator_allow_merge_fn = cfq_allow_merge, |
Divyesh Shah | 812d402 | 2010-04-08 21:14:23 -0700 | [diff] [blame] | 3921 | .elevator_bio_merged_fn = cfq_bio_merged, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3922 | .elevator_dispatch_fn = cfq_dispatch_requests, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3923 | .elevator_add_req_fn = cfq_insert_request, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3924 | .elevator_activate_req_fn = cfq_activate_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3925 | .elevator_deactivate_req_fn = cfq_deactivate_request, |
| 3926 | .elevator_queue_empty_fn = cfq_queue_empty, |
| 3927 | .elevator_completed_req_fn = cfq_completed_request, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 3928 | .elevator_former_req_fn = elv_rb_former_request, |
| 3929 | .elevator_latter_req_fn = elv_rb_latter_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3930 | .elevator_set_req_fn = cfq_set_request, |
| 3931 | .elevator_put_req_fn = cfq_put_request, |
| 3932 | .elevator_may_queue_fn = cfq_may_queue, |
| 3933 | .elevator_init_fn = cfq_init_queue, |
| 3934 | .elevator_exit_fn = cfq_exit_queue, |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 3935 | .trim = cfq_free_io_context, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3936 | }, |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3937 | .elevator_attrs = cfq_attrs, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3938 | .elevator_name = "cfq", |
| 3939 | .elevator_owner = THIS_MODULE, |
| 3940 | }; |
| 3941 | |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3942 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 3943 | static struct blkio_policy_type blkio_policy_cfq = { |
| 3944 | .ops = { |
| 3945 | .blkio_unlink_group_fn = cfq_unlink_blkio_group, |
| 3946 | .blkio_update_group_weight_fn = cfq_update_blkio_group_weight, |
| 3947 | }, |
| 3948 | }; |
| 3949 | #else |
| 3950 | static struct blkio_policy_type blkio_policy_cfq; |
| 3951 | #endif |
| 3952 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3953 | static int __init cfq_init(void) |
| 3954 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3955 | /* |
| 3956 | * could be 0 on HZ < 1000 setups |
| 3957 | */ |
| 3958 | if (!cfq_slice_async) |
| 3959 | cfq_slice_async = 1; |
| 3960 | if (!cfq_slice_idle) |
| 3961 | cfq_slice_idle = 1; |
| 3962 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3963 | if (cfq_slab_setup()) |
| 3964 | return -ENOMEM; |
| 3965 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 3966 | elv_register(&iosched_cfq); |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3967 | blkio_policy_register(&blkio_policy_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3968 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 3969 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3970 | } |
| 3971 | |
| 3972 | static void __exit cfq_exit(void) |
| 3973 | { |
Peter Zijlstra | 6e9a473 | 2006-09-30 23:28:10 -0700 | [diff] [blame] | 3974 | DECLARE_COMPLETION_ONSTACK(all_gone); |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3975 | blkio_policy_unregister(&blkio_policy_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3976 | elv_unregister(&iosched_cfq); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 3977 | ioc_gone = &all_gone; |
OGAWA Hirofumi | fba8227 | 2006-04-18 09:44:06 +0200 | [diff] [blame] | 3978 | /* ioc_gone's update must be visible before reading ioc_count */ |
| 3979 | smp_wmb(); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 3980 | |
| 3981 | /* |
| 3982 | * this also protects us from entering cfq_slab_kill() with |
| 3983 | * pending RCU callbacks |
| 3984 | */ |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 3985 | if (elv_ioc_count_read(cfq_ioc_count)) |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 3986 | wait_for_completion(&all_gone); |
Christoph Hellwig | 83521d3 | 2005-10-30 15:01:39 -0800 | [diff] [blame] | 3987 | cfq_slab_kill(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3988 | } |
| 3989 | |
| 3990 | module_init(cfq_init); |
| 3991 | module_exit(cfq_exit); |
| 3992 | |
| 3993 | MODULE_AUTHOR("Jens Axboe"); |
| 3994 | MODULE_LICENSE("GPL"); |
| 3995 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |