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> |
Al Viro | 1cc9be6 | 2006-03-18 12:29:52 -0500 | [diff] [blame] | 10 | #include <linux/blkdev.h> |
| 11 | #include <linux/elevator.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <linux/rbtree.h> |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 13 | #include <linux/ioprio.h> |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 14 | #include <linux/blktrace_api.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | |
| 16 | /* |
| 17 | * tunables |
| 18 | */ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 19 | /* max queue in one round of service */ |
| 20 | static const int cfq_quantum = 4; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 21 | static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 22 | /* maximum backwards seek, in KiB */ |
| 23 | static const int cfq_back_max = 16 * 1024; |
| 24 | /* penalty of a backwards seek */ |
| 25 | static const int cfq_back_penalty = 2; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 26 | static const int cfq_slice_sync = HZ / 10; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 27 | static int cfq_slice_async = HZ / 25; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 28 | static const int cfq_slice_async_rq = 2; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 29 | static int cfq_slice_idle = HZ / 125; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 30 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 31 | /* |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 32 | * offset from end of service tree |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 33 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 34 | #define CFQ_IDLE_DELAY (HZ / 5) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 35 | |
| 36 | /* |
| 37 | * below this threshold, we consider thinktime immediate |
| 38 | */ |
| 39 | #define CFQ_MIN_TT (2) |
| 40 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 41 | #define CFQ_SLICE_SCALE (5) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 42 | #define CFQ_HW_QUEUE_MIN (5) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 43 | |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 44 | #define RQ_CIC(rq) \ |
| 45 | ((struct cfq_io_context *) (rq)->elevator_private) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 46 | #define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 48 | static struct kmem_cache *cfq_pool; |
| 49 | static struct kmem_cache *cfq_ioc_pool; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 51 | static DEFINE_PER_CPU(unsigned long, cfq_ioc_count); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 52 | static struct completion *ioc_gone; |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 53 | static DEFINE_SPINLOCK(ioc_gone_lock); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 54 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 55 | #define CFQ_PRIO_LISTS IOPRIO_BE_NR |
| 56 | #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 57 | #define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT) |
| 58 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 59 | #define sample_valid(samples) ((samples) > 80) |
| 60 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 61 | /* |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 62 | * Most of our rbtree usage is for sorting with min extraction, so |
| 63 | * if we cache the leftmost node we don't have to walk down the tree |
| 64 | * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should |
| 65 | * move this into the elevator for the rq sorting as well. |
| 66 | */ |
| 67 | struct cfq_rb_root { |
| 68 | struct rb_root rb; |
| 69 | struct rb_node *left; |
| 70 | }; |
| 71 | #define CFQ_RB_ROOT (struct cfq_rb_root) { RB_ROOT, NULL, } |
| 72 | |
| 73 | /* |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 74 | * Per process-grouping structure |
| 75 | */ |
| 76 | struct cfq_queue { |
| 77 | /* reference count */ |
| 78 | atomic_t ref; |
| 79 | /* various state flags, see below */ |
| 80 | unsigned int flags; |
| 81 | /* parent cfq_data */ |
| 82 | struct cfq_data *cfqd; |
| 83 | /* service_tree member */ |
| 84 | struct rb_node rb_node; |
| 85 | /* service_tree key */ |
| 86 | unsigned long rb_key; |
| 87 | /* prio tree member */ |
| 88 | struct rb_node p_node; |
| 89 | /* prio tree root we belong to, if any */ |
| 90 | struct rb_root *p_root; |
| 91 | /* sorted list of pending requests */ |
| 92 | struct rb_root sort_list; |
| 93 | /* if fifo isn't expired, next request to serve */ |
| 94 | struct request *next_rq; |
| 95 | /* requests queued in sort_list */ |
| 96 | int queued[2]; |
| 97 | /* currently allocated requests */ |
| 98 | int allocated[2]; |
| 99 | /* fifo list of requests in sort_list */ |
| 100 | struct list_head fifo; |
| 101 | |
| 102 | unsigned long slice_end; |
| 103 | long slice_resid; |
| 104 | unsigned int slice_dispatch; |
| 105 | |
| 106 | /* pending metadata requests */ |
| 107 | int meta_pending; |
| 108 | /* number of requests that are on the dispatch list or inside driver */ |
| 109 | int dispatched; |
| 110 | |
| 111 | /* io prio of this group */ |
| 112 | unsigned short ioprio, org_ioprio; |
| 113 | unsigned short ioprio_class, org_ioprio_class; |
| 114 | |
| 115 | pid_t pid; |
| 116 | }; |
| 117 | |
| 118 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 119 | * Per block device queue structure |
| 120 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | struct cfq_data { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 122 | struct request_queue *queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 123 | |
| 124 | /* |
| 125 | * rr list of queues with requests and the count of them |
| 126 | */ |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 127 | struct cfq_rb_root service_tree; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 128 | |
| 129 | /* |
| 130 | * Each priority tree is sorted by next_request position. These |
| 131 | * trees are used when determining if two or more queues are |
| 132 | * interleaving requests (see cfq_close_cooperator). |
| 133 | */ |
| 134 | struct rb_root prio_trees[CFQ_PRIO_LISTS]; |
| 135 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 136 | unsigned int busy_queues; |
| 137 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 138 | int rq_in_driver[2]; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 139 | int sync_flight; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 140 | |
| 141 | /* |
| 142 | * queue-depth detection |
| 143 | */ |
| 144 | int rq_queued; |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 145 | int hw_tag; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 146 | int hw_tag_samples; |
| 147 | int rq_in_driver_peak; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 148 | |
| 149 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 150 | * idle window management |
| 151 | */ |
| 152 | struct timer_list idle_slice_timer; |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 153 | struct work_struct unplug_work; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 154 | |
| 155 | struct cfq_queue *active_queue; |
| 156 | struct cfq_io_context *active_cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 157 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 158 | /* |
| 159 | * async queue for each priority case |
| 160 | */ |
| 161 | struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; |
| 162 | struct cfq_queue *async_idle_cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 163 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 164 | sector_t last_position; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | /* |
| 167 | * tunables, see top of file |
| 168 | */ |
| 169 | unsigned int cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 170 | unsigned int cfq_fifo_expire[2]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | unsigned int cfq_back_penalty; |
| 172 | unsigned int cfq_back_max; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 173 | unsigned int cfq_slice[2]; |
| 174 | unsigned int cfq_slice_async_rq; |
| 175 | unsigned int cfq_slice_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 176 | unsigned int cfq_latency; |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 177 | |
| 178 | struct list_head cic_list; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 180 | /* |
| 181 | * Fallback dummy cfqq for extreme OOM conditions |
| 182 | */ |
| 183 | struct cfq_queue oom_cfqq; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 184 | |
| 185 | unsigned long last_end_sync_rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | }; |
| 187 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 188 | enum cfqq_state_flags { |
Jens Axboe | b0b8d74 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 189 | CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ |
| 190 | CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 191 | CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ |
Jens Axboe | b0b8d74 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 192 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ |
Jens Axboe | b0b8d74 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 193 | CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ |
| 194 | CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ |
| 195 | CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 196 | CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 197 | CFQ_CFQQ_FLAG_sync, /* synchronous queue */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 198 | CFQ_CFQQ_FLAG_coop, /* has done a coop jump of the queue */ |
Shaohua Li | 4b27e1b | 2009-11-03 20:25:02 +0100 | [diff] [blame] | 199 | CFQ_CFQQ_FLAG_coop_preempt, /* coop preempt */ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 200 | }; |
| 201 | |
| 202 | #define CFQ_CFQQ_FNS(name) \ |
| 203 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ |
| 204 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 205 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 206 | } \ |
| 207 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ |
| 208 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 209 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 210 | } \ |
| 211 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ |
| 212 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 213 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 214 | } |
| 215 | |
| 216 | CFQ_CFQQ_FNS(on_rr); |
| 217 | CFQ_CFQQ_FNS(wait_request); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 218 | CFQ_CFQQ_FNS(must_dispatch); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 219 | CFQ_CFQQ_FNS(must_alloc_slice); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 220 | CFQ_CFQQ_FNS(fifo_expire); |
| 221 | CFQ_CFQQ_FNS(idle_window); |
| 222 | CFQ_CFQQ_FNS(prio_changed); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 223 | CFQ_CFQQ_FNS(slice_new); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 224 | CFQ_CFQQ_FNS(sync); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 225 | CFQ_CFQQ_FNS(coop); |
Shaohua Li | 4b27e1b | 2009-11-03 20:25:02 +0100 | [diff] [blame] | 226 | CFQ_CFQQ_FNS(coop_preempt); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 227 | #undef CFQ_CFQQ_FNS |
| 228 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 229 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 230 | blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args) |
| 231 | #define cfq_log(cfqd, fmt, args...) \ |
| 232 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) |
| 233 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 234 | static void cfq_dispatch_insert(struct request_queue *, struct request *); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 235 | static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 236 | struct io_context *, gfp_t); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 237 | static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *, |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 238 | struct io_context *); |
| 239 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 240 | static inline int rq_in_driver(struct cfq_data *cfqd) |
| 241 | { |
| 242 | return cfqd->rq_in_driver[0] + cfqd->rq_in_driver[1]; |
| 243 | } |
| 244 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 245 | 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] | 246 | bool is_sync) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 247 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 248 | return cic->cfqq[is_sync]; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 249 | } |
| 250 | |
| 251 | static inline void cic_set_cfqq(struct cfq_io_context *cic, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 252 | struct cfq_queue *cfqq, bool is_sync) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 253 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 254 | cic->cfqq[is_sync] = cfqq; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 255 | } |
| 256 | |
| 257 | /* |
| 258 | * We regard a request as SYNC, if it's either a read or has the SYNC bit |
| 259 | * set (in which case it could also be direct WRITE). |
| 260 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 261 | static inline bool cfq_bio_sync(struct bio *bio) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 262 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 263 | 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] | 264 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | /* |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 267 | * scheduler run of queue, if there are requests pending and no one in the |
| 268 | * driver that will restart queueing |
| 269 | */ |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 270 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 271 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 272 | if (cfqd->busy_queues) { |
| 273 | cfq_log(cfqd, "schedule dispatch"); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 274 | kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 275 | } |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 276 | } |
| 277 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 278 | static int cfq_queue_empty(struct request_queue *q) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 279 | { |
| 280 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 281 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 282 | return !cfqd->busy_queues; |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 283 | } |
| 284 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | /* |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 286 | * Scale schedule slice based on io priority. Use the sync time slice only |
| 287 | * if a queue is marked sync and has sync io queued. A sync queue with async |
| 288 | * io only, should not get full sync slice length. |
| 289 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 290 | static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync, |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 291 | unsigned short prio) |
| 292 | { |
| 293 | const int base_slice = cfqd->cfq_slice[sync]; |
| 294 | |
| 295 | WARN_ON(prio >= IOPRIO_BE_NR); |
| 296 | |
| 297 | return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); |
| 298 | } |
| 299 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 300 | static inline int |
| 301 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 302 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 303 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 304 | } |
| 305 | |
| 306 | static inline void |
| 307 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 308 | { |
| 309 | cfqq->slice_end = cfq_prio_to_slice(cfqd, cfqq) + jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 310 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 311 | } |
| 312 | |
| 313 | /* |
| 314 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end |
| 315 | * isn't valid until the first request from the dispatch is activated |
| 316 | * and the slice time set. |
| 317 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 318 | static inline bool cfq_slice_used(struct cfq_queue *cfqq) |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 319 | { |
| 320 | if (cfq_cfqq_slice_new(cfqq)) |
| 321 | return 0; |
| 322 | if (time_before(jiffies, cfqq->slice_end)) |
| 323 | return 0; |
| 324 | |
| 325 | return 1; |
| 326 | } |
| 327 | |
| 328 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 329 | * 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] | 330 | * 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] | 331 | * behind the head is penalized and only allowed to a certain extent. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 333 | static struct request * |
| 334 | cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | { |
| 336 | sector_t last, s1, s2, d1 = 0, d2 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | unsigned long back_max; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 338 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ |
| 339 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ |
| 340 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 342 | if (rq1 == NULL || rq1 == rq2) |
| 343 | return rq2; |
| 344 | if (rq2 == NULL) |
| 345 | return rq1; |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 346 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 347 | if (rq_is_sync(rq1) && !rq_is_sync(rq2)) |
| 348 | return rq1; |
| 349 | else if (rq_is_sync(rq2) && !rq_is_sync(rq1)) |
| 350 | return rq2; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 351 | if (rq_is_meta(rq1) && !rq_is_meta(rq2)) |
| 352 | return rq1; |
| 353 | else if (rq_is_meta(rq2) && !rq_is_meta(rq1)) |
| 354 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 356 | s1 = blk_rq_pos(rq1); |
| 357 | s2 = blk_rq_pos(rq2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 359 | last = cfqd->last_position; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | /* |
| 362 | * by definition, 1KiB is 2 sectors |
| 363 | */ |
| 364 | back_max = cfqd->cfq_back_max * 2; |
| 365 | |
| 366 | /* |
| 367 | * Strict one way elevator _except_ in the case where we allow |
| 368 | * short backward seeks which are biased as twice the cost of a |
| 369 | * similar forward seek. |
| 370 | */ |
| 371 | if (s1 >= last) |
| 372 | d1 = s1 - last; |
| 373 | else if (s1 + back_max >= last) |
| 374 | d1 = (last - s1) * cfqd->cfq_back_penalty; |
| 375 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 376 | wrap |= CFQ_RQ1_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | |
| 378 | if (s2 >= last) |
| 379 | d2 = s2 - last; |
| 380 | else if (s2 + back_max >= last) |
| 381 | d2 = (last - s2) * cfqd->cfq_back_penalty; |
| 382 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 383 | wrap |= CFQ_RQ2_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | |
| 385 | /* Found required data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 387 | /* |
| 388 | * By doing switch() on the bit mask "wrap" we avoid having to |
| 389 | * check two variables for all permutations: --> faster! |
| 390 | */ |
| 391 | switch (wrap) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 392 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 393 | if (d1 < d2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 394 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 395 | else if (d2 < d1) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 396 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 397 | else { |
| 398 | if (s1 >= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 399 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 400 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 401 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 402 | } |
| 403 | |
| 404 | case CFQ_RQ2_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 405 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 406 | case CFQ_RQ1_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 407 | return rq2; |
| 408 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 409 | default: |
| 410 | /* |
| 411 | * Since both rqs are wrapped, |
| 412 | * start with the one that's further behind head |
| 413 | * (--> only *one* back seek required), |
| 414 | * since back seek takes more time than forward. |
| 415 | */ |
| 416 | if (s1 <= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 417 | return rq1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 419 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | } |
| 421 | } |
| 422 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 423 | /* |
| 424 | * The below is leftmost cache rbtree addon |
| 425 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 426 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 427 | { |
| 428 | if (!root->left) |
| 429 | root->left = rb_first(&root->rb); |
| 430 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 431 | if (root->left) |
| 432 | return rb_entry(root->left, struct cfq_queue, rb_node); |
| 433 | |
| 434 | return NULL; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 435 | } |
| 436 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 437 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
| 438 | { |
| 439 | rb_erase(n, root); |
| 440 | RB_CLEAR_NODE(n); |
| 441 | } |
| 442 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 443 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) |
| 444 | { |
| 445 | if (root->left == n) |
| 446 | root->left = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 447 | rb_erase_init(n, &root->rb); |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 448 | } |
| 449 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | /* |
| 451 | * would be nice to take fifo expire time into account as well |
| 452 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 453 | static struct request * |
| 454 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 455 | struct request *last) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 457 | struct rb_node *rbnext = rb_next(&last->rb_node); |
| 458 | struct rb_node *rbprev = rb_prev(&last->rb_node); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 459 | struct request *next = NULL, *prev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 461 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | |
| 463 | if (rbprev) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 464 | prev = rb_entry_rq(rbprev); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 465 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | if (rbnext) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 467 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 468 | else { |
| 469 | rbnext = rb_first(&cfqq->sort_list); |
| 470 | if (rbnext && rbnext != &last->rb_node) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 471 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 472 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 474 | return cfq_choose_req(cfqd, next, prev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | } |
| 476 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 477 | static unsigned long cfq_slice_offset(struct cfq_data *cfqd, |
| 478 | struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 480 | /* |
| 481 | * just an approximation, should be ok. |
| 482 | */ |
Jens Axboe | 67e6b49 | 2007-04-20 14:18:00 +0200 | [diff] [blame] | 483 | return (cfqd->busy_queues - 1) * (cfq_prio_slice(cfqd, 1, 0) - |
| 484 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 485 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 487 | /* |
| 488 | * The cfqd->service_tree holds all pending cfq_queue's that have |
| 489 | * requests waiting to be processed. It is sorted in the order that |
| 490 | * we will service the queues. |
| 491 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 492 | 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] | 493 | bool add_front) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 494 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 495 | struct rb_node **p, *parent; |
| 496 | struct cfq_queue *__cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 497 | unsigned long rb_key; |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 498 | int left; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 499 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 500 | if (cfq_class_idle(cfqq)) { |
| 501 | rb_key = CFQ_IDLE_DELAY; |
| 502 | parent = rb_last(&cfqd->service_tree.rb); |
| 503 | if (parent && parent != &cfqq->rb_node) { |
| 504 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 505 | rb_key += __cfqq->rb_key; |
| 506 | } else |
| 507 | rb_key += jiffies; |
| 508 | } else if (!add_front) { |
Jens Axboe | b9c8946 | 2009-10-06 20:53:44 +0200 | [diff] [blame] | 509 | /* |
| 510 | * Get our rb key offset. Subtract any residual slice |
| 511 | * value carried from last service. A negative resid |
| 512 | * count indicates slice overrun, and this should position |
| 513 | * the next service time further away in the tree. |
| 514 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 515 | rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; |
Jens Axboe | b9c8946 | 2009-10-06 20:53:44 +0200 | [diff] [blame] | 516 | rb_key -= cfqq->slice_resid; |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 517 | cfqq->slice_resid = 0; |
Corrado Zoccolo | 48e025e | 2009-10-05 08:49:23 +0200 | [diff] [blame] | 518 | } else { |
| 519 | rb_key = -HZ; |
| 520 | __cfqq = cfq_rb_first(&cfqd->service_tree); |
| 521 | rb_key += __cfqq ? __cfqq->rb_key : jiffies; |
| 522 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 523 | |
| 524 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 525 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 526 | * same position, nothing more to do |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 527 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 528 | if (rb_key == cfqq->rb_key) |
| 529 | return; |
Jens Axboe | 53b0374 | 2006-07-28 09:48:51 +0200 | [diff] [blame] | 530 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 531 | cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 532 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 533 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 534 | left = 1; |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 535 | parent = NULL; |
| 536 | p = &cfqd->service_tree.rb.rb_node; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 537 | while (*p) { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 538 | struct rb_node **n; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 539 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 540 | parent = *p; |
| 541 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 542 | |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 543 | /* |
| 544 | * sort RT queues first, we always want to give |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 545 | * preference to them. IDLE queues goes to the back. |
| 546 | * after that, sort on the next service time. |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 547 | */ |
| 548 | if (cfq_class_rt(cfqq) > cfq_class_rt(__cfqq)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 549 | n = &(*p)->rb_left; |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 550 | else if (cfq_class_rt(cfqq) < cfq_class_rt(__cfqq)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 551 | n = &(*p)->rb_right; |
| 552 | else if (cfq_class_idle(cfqq) < cfq_class_idle(__cfqq)) |
| 553 | n = &(*p)->rb_left; |
| 554 | else if (cfq_class_idle(cfqq) > cfq_class_idle(__cfqq)) |
| 555 | n = &(*p)->rb_right; |
Corrado Zoccolo | 48e025e | 2009-10-05 08:49:23 +0200 | [diff] [blame] | 556 | else if (time_before(rb_key, __cfqq->rb_key)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 557 | n = &(*p)->rb_left; |
| 558 | else |
| 559 | n = &(*p)->rb_right; |
| 560 | |
| 561 | if (n == &(*p)->rb_right) |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 562 | left = 0; |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 563 | |
| 564 | p = n; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 565 | } |
| 566 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 567 | if (left) |
| 568 | cfqd->service_tree.left = &cfqq->rb_node; |
| 569 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 570 | cfqq->rb_key = rb_key; |
| 571 | rb_link_node(&cfqq->rb_node, parent, p); |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 572 | rb_insert_color(&cfqq->rb_node, &cfqd->service_tree.rb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | } |
| 574 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 575 | static struct cfq_queue * |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 576 | cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, |
| 577 | sector_t sector, struct rb_node **ret_parent, |
| 578 | struct rb_node ***rb_link) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 579 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 580 | struct rb_node **p, *parent; |
| 581 | struct cfq_queue *cfqq = NULL; |
| 582 | |
| 583 | parent = NULL; |
| 584 | p = &root->rb_node; |
| 585 | while (*p) { |
| 586 | struct rb_node **n; |
| 587 | |
| 588 | parent = *p; |
| 589 | cfqq = rb_entry(parent, struct cfq_queue, p_node); |
| 590 | |
| 591 | /* |
| 592 | * Sort strictly based on sector. Smallest to the left, |
| 593 | * largest to the right. |
| 594 | */ |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 595 | if (sector > blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 596 | n = &(*p)->rb_right; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 597 | else if (sector < blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 598 | n = &(*p)->rb_left; |
| 599 | else |
| 600 | break; |
| 601 | p = n; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 602 | cfqq = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 603 | } |
| 604 | |
| 605 | *ret_parent = parent; |
| 606 | if (rb_link) |
| 607 | *rb_link = p; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 608 | return cfqq; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 609 | } |
| 610 | |
| 611 | static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 612 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 613 | struct rb_node **p, *parent; |
| 614 | struct cfq_queue *__cfqq; |
| 615 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 616 | if (cfqq->p_root) { |
| 617 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 618 | cfqq->p_root = NULL; |
| 619 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 620 | |
| 621 | if (cfq_class_idle(cfqq)) |
| 622 | return; |
| 623 | if (!cfqq->next_rq) |
| 624 | return; |
| 625 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 626 | cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 627 | __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, |
| 628 | blk_rq_pos(cfqq->next_rq), &parent, &p); |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 629 | if (!__cfqq) { |
| 630 | rb_link_node(&cfqq->p_node, parent, p); |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 631 | rb_insert_color(&cfqq->p_node, cfqq->p_root); |
| 632 | } else |
| 633 | cfqq->p_root = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 634 | } |
| 635 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 636 | /* |
| 637 | * Update cfqq's position in the service tree. |
| 638 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 639 | 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] | 640 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 641 | /* |
| 642 | * Resorting requires the cfqq to be on the RR list already. |
| 643 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 644 | if (cfq_cfqq_on_rr(cfqq)) { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 645 | cfq_service_tree_add(cfqd, cfqq, 0); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 646 | cfq_prio_tree_add(cfqd, cfqq); |
| 647 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 648 | } |
| 649 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | /* |
| 651 | * 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] | 652 | * the pending list according to last request service |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 654 | 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] | 655 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 656 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 657 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
| 658 | cfq_mark_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 659 | cfqd->busy_queues++; |
| 660 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 661 | cfq_resort_rr_list(cfqd, cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 662 | } |
| 663 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 664 | /* |
| 665 | * Called when the cfqq no longer has requests pending, remove it from |
| 666 | * the service tree. |
| 667 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 668 | 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] | 669 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 670 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 671 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
| 672 | cfq_clear_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 674 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) |
| 675 | cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree); |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 676 | if (cfqq->p_root) { |
| 677 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 678 | cfqq->p_root = NULL; |
| 679 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 680 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 681 | BUG_ON(!cfqd->busy_queues); |
| 682 | cfqd->busy_queues--; |
| 683 | } |
| 684 | |
| 685 | /* |
| 686 | * rb tree support functions |
| 687 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 688 | static void cfq_del_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 690 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 691 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 692 | const int sync = rq_is_sync(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 694 | BUG_ON(!cfqq->queued[sync]); |
| 695 | cfqq->queued[sync]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 697 | elv_rb_del(&cfqq->sort_list, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 699 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 700 | cfq_del_cfqq_rr(cfqd, cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | } |
| 702 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 703 | static void cfq_add_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 705 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 707 | struct request *__alias, *prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 709 | cfqq->queued[rq_is_sync(rq)]++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | |
| 711 | /* |
| 712 | * looks a little odd, but the first insert might return an alias. |
| 713 | * if that happens, put the alias on the dispatch list |
| 714 | */ |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 715 | while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 716 | cfq_dispatch_insert(cfqd->queue, __alias); |
Jens Axboe | 5fccbf6 | 2006-10-31 14:21:55 +0100 | [diff] [blame] | 717 | |
| 718 | if (!cfq_cfqq_on_rr(cfqq)) |
| 719 | cfq_add_cfqq_rr(cfqd, cfqq); |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 720 | |
| 721 | /* |
| 722 | * check if this request is a better next-serve candidate |
| 723 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 724 | prev = cfqq->next_rq; |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 725 | cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 726 | |
| 727 | /* |
| 728 | * adjust priority tree position, if ->next_rq changes |
| 729 | */ |
| 730 | if (prev != cfqq->next_rq) |
| 731 | cfq_prio_tree_add(cfqd, cfqq); |
| 732 | |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 733 | BUG_ON(!cfqq->next_rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | } |
| 735 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 736 | 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] | 737 | { |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 738 | elv_rb_del(&cfqq->sort_list, rq); |
| 739 | cfqq->queued[rq_is_sync(rq)]--; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 740 | cfq_add_rq_rb(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 741 | } |
| 742 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 743 | static struct request * |
| 744 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 745 | { |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 746 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 747 | struct cfq_io_context *cic; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 748 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 749 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 750 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 751 | if (!cic) |
| 752 | return NULL; |
| 753 | |
| 754 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 755 | if (cfqq) { |
| 756 | sector_t sector = bio->bi_sector + bio_sectors(bio); |
| 757 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 758 | return elv_rb_find(&cfqq->sort_list, sector); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 759 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | return NULL; |
| 762 | } |
| 763 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 764 | static void cfq_activate_request(struct request_queue *q, struct request *rq) |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 765 | { |
| 766 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 767 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 768 | cfqd->rq_in_driver[rq_is_sync(rq)]++; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 769 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 770 | rq_in_driver(cfqd)); |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 771 | |
Tejun Heo | 5b93629 | 2009-05-07 22:24:38 +0900 | [diff] [blame] | 772 | cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 773 | } |
| 774 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 775 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 777 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 778 | const int sync = rq_is_sync(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 779 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 780 | WARN_ON(!cfqd->rq_in_driver[sync]); |
| 781 | cfqd->rq_in_driver[sync]--; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 782 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 783 | rq_in_driver(cfqd)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 784 | } |
| 785 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 786 | static void cfq_remove_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 788 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 789 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 790 | if (cfqq->next_rq == rq) |
| 791 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 792 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 793 | list_del_init(&rq->queuelist); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 794 | cfq_del_rq_rb(rq); |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 795 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 796 | cfqq->cfqd->rq_queued--; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 797 | if (rq_is_meta(rq)) { |
| 798 | WARN_ON(!cfqq->meta_pending); |
| 799 | cfqq->meta_pending--; |
| 800 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | } |
| 802 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 803 | static int cfq_merge(struct request_queue *q, struct request **req, |
| 804 | struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | { |
| 806 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 807 | struct request *__rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 809 | __rq = cfq_find_rq_fmerge(cfqd, bio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 810 | if (__rq && elv_rq_merge_ok(__rq, bio)) { |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 811 | *req = __rq; |
| 812 | return ELEVATOR_FRONT_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | } |
| 814 | |
| 815 | return ELEVATOR_NO_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 816 | } |
| 817 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 818 | static void cfq_merged_request(struct request_queue *q, struct request *req, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 819 | int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 820 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 821 | if (type == ELEVATOR_FRONT_MERGE) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 822 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 823 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 824 | cfq_reposition_rq_rb(cfqq, req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 826 | } |
| 827 | |
| 828 | static void |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 829 | cfq_merged_requests(struct request_queue *q, struct request *rq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | struct request *next) |
| 831 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 832 | /* |
| 833 | * reposition in fifo if next is older than rq |
| 834 | */ |
| 835 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 836 | time_before(rq_fifo_time(next), rq_fifo_time(rq))) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 837 | list_move(&rq->queuelist, &next->queuelist); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 838 | rq_set_fifo_time(rq, rq_fifo_time(next)); |
| 839 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 840 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 841 | cfq_remove_request(next); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 842 | } |
| 843 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 844 | static int cfq_allow_merge(struct request_queue *q, struct request *rq, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 845 | struct bio *bio) |
| 846 | { |
| 847 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 848 | struct cfq_io_context *cic; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 849 | struct cfq_queue *cfqq; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 850 | |
| 851 | /* |
Jens Axboe | ec8acb6 | 2007-01-02 18:32:11 +0100 | [diff] [blame] | 852 | * Disallow merge of a sync bio into an async request. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 853 | */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 854 | if (cfq_bio_sync(bio) && !rq_is_sync(rq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 855 | return false; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 856 | |
| 857 | /* |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 858 | * Lookup the cfqq that this bio will be queued with. Allow |
| 859 | * merge only if rq is queued there. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 860 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 861 | cic = cfq_cic_lookup(cfqd, current->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 862 | if (!cic) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 863 | return false; |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 864 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 865 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 866 | return cfqq == RQ_CFQQ(rq); |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 867 | } |
| 868 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 869 | static void __cfq_set_active_queue(struct cfq_data *cfqd, |
| 870 | struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 871 | { |
| 872 | if (cfqq) { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 873 | cfq_log_cfqq(cfqd, cfqq, "set_active"); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 874 | cfqq->slice_end = 0; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 875 | cfqq->slice_dispatch = 0; |
| 876 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 877 | cfq_clear_cfqq_wait_request(cfqq); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 878 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 879 | cfq_clear_cfqq_must_alloc_slice(cfqq); |
| 880 | cfq_clear_cfqq_fifo_expire(cfqq); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 881 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 882 | |
| 883 | del_timer(&cfqd->idle_slice_timer); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 884 | } |
| 885 | |
| 886 | cfqd->active_queue = cfqq; |
| 887 | } |
| 888 | |
| 889 | /* |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 890 | * current cfqq expired its slice (or was too idle), select new one |
| 891 | */ |
| 892 | static void |
| 893 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 894 | bool timed_out) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 895 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 896 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); |
| 897 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 898 | if (cfq_cfqq_wait_request(cfqq)) |
| 899 | del_timer(&cfqd->idle_slice_timer); |
| 900 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 901 | cfq_clear_cfqq_wait_request(cfqq); |
| 902 | |
| 903 | /* |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 904 | * 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] | 905 | */ |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 906 | if (timed_out && !cfq_cfqq_slice_new(cfqq)) { |
Jens Axboe | c5b680f | 2007-01-19 11:56:49 +1100 | [diff] [blame] | 907 | cfqq->slice_resid = cfqq->slice_end - jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 908 | cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); |
| 909 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 910 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 911 | cfq_resort_rr_list(cfqd, cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 912 | |
| 913 | if (cfqq == cfqd->active_queue) |
| 914 | cfqd->active_queue = NULL; |
| 915 | |
| 916 | if (cfqd->active_cic) { |
| 917 | put_io_context(cfqd->active_cic->ioc); |
| 918 | cfqd->active_cic = NULL; |
| 919 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 920 | } |
| 921 | |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 922 | 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] | 923 | { |
| 924 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 925 | |
| 926 | if (cfqq) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 927 | __cfq_slice_expired(cfqd, cfqq, timed_out); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 928 | } |
| 929 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 930 | /* |
| 931 | * Get next queue for service. Unless we have a queue preemption, |
| 932 | * we'll simply select the first cfqq in the service tree. |
| 933 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 934 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 935 | { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 936 | if (RB_EMPTY_ROOT(&cfqd->service_tree.rb)) |
| 937 | return NULL; |
| 938 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 939 | return cfq_rb_first(&cfqd->service_tree); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 940 | } |
| 941 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 942 | /* |
| 943 | * Get and set a new active queue for service. |
| 944 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 945 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, |
| 946 | struct cfq_queue *cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 947 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 948 | if (!cfqq) { |
| 949 | cfqq = cfq_get_next_queue(cfqd); |
Shaohua Li | 4b27e1b | 2009-11-03 20:25:02 +0100 | [diff] [blame] | 950 | if (cfqq && !cfq_cfqq_coop_preempt(cfqq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 951 | cfq_clear_cfqq_coop(cfqq); |
| 952 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 953 | |
Shaohua Li | 4b27e1b | 2009-11-03 20:25:02 +0100 | [diff] [blame] | 954 | if (cfqq) |
| 955 | cfq_clear_cfqq_coop_preempt(cfqq); |
| 956 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 957 | __cfq_set_active_queue(cfqd, cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 958 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 959 | } |
| 960 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 961 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, |
| 962 | struct request *rq) |
| 963 | { |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 964 | if (blk_rq_pos(rq) >= cfqd->last_position) |
| 965 | return blk_rq_pos(rq) - cfqd->last_position; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 966 | else |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 967 | return cfqd->last_position - blk_rq_pos(rq); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 968 | } |
| 969 | |
Jeff Moyer | 04dc6e7 | 2009-04-21 07:31:56 +0200 | [diff] [blame] | 970 | #define CIC_SEEK_THR 8 * 1024 |
| 971 | #define CIC_SEEKY(cic) ((cic)->seek_mean > CIC_SEEK_THR) |
| 972 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 973 | static inline int cfq_rq_close(struct cfq_data *cfqd, struct request *rq) |
| 974 | { |
| 975 | struct cfq_io_context *cic = cfqd->active_cic; |
Jeff Moyer | 04dc6e7 | 2009-04-21 07:31:56 +0200 | [diff] [blame] | 976 | sector_t sdist = cic->seek_mean; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 977 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 978 | if (!sample_valid(cic->seek_samples)) |
Jeff Moyer | 04dc6e7 | 2009-04-21 07:31:56 +0200 | [diff] [blame] | 979 | sdist = CIC_SEEK_THR; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 980 | |
Jeff Moyer | 04dc6e7 | 2009-04-21 07:31:56 +0200 | [diff] [blame] | 981 | return cfq_dist_from_last(cfqd, rq) <= sdist; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 982 | } |
| 983 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 984 | static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, |
| 985 | struct cfq_queue *cur_cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 986 | { |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 987 | struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 988 | struct rb_node *parent, *node; |
| 989 | struct cfq_queue *__cfqq; |
| 990 | sector_t sector = cfqd->last_position; |
| 991 | |
| 992 | if (RB_EMPTY_ROOT(root)) |
| 993 | return NULL; |
| 994 | |
| 995 | /* |
| 996 | * First, if we find a request starting at the end of the last |
| 997 | * request, choose it. |
| 998 | */ |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 999 | __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1000 | if (__cfqq) |
| 1001 | return __cfqq; |
| 1002 | |
| 1003 | /* |
| 1004 | * If the exact sector wasn't found, the parent of the NULL leaf |
| 1005 | * will contain the closest sector. |
| 1006 | */ |
| 1007 | __cfqq = rb_entry(parent, struct cfq_queue, p_node); |
| 1008 | if (cfq_rq_close(cfqd, __cfqq->next_rq)) |
| 1009 | return __cfqq; |
| 1010 | |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1011 | if (blk_rq_pos(__cfqq->next_rq) < sector) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1012 | node = rb_next(&__cfqq->p_node); |
| 1013 | else |
| 1014 | node = rb_prev(&__cfqq->p_node); |
| 1015 | if (!node) |
| 1016 | return NULL; |
| 1017 | |
| 1018 | __cfqq = rb_entry(node, struct cfq_queue, p_node); |
| 1019 | if (cfq_rq_close(cfqd, __cfqq->next_rq)) |
| 1020 | return __cfqq; |
| 1021 | |
| 1022 | return NULL; |
| 1023 | } |
| 1024 | |
| 1025 | /* |
| 1026 | * cfqd - obvious |
| 1027 | * cur_cfqq - passed in so that we don't decide that the current queue is |
| 1028 | * closely cooperating with itself. |
| 1029 | * |
| 1030 | * So, basically we're assuming that that cur_cfqq has dispatched at least |
| 1031 | * one request, and that cfqd->last_position reflects a position on the disk |
| 1032 | * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid |
| 1033 | * assumption. |
| 1034 | */ |
| 1035 | static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, |
| 1036 | struct cfq_queue *cur_cfqq, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1037 | bool probe) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1038 | { |
| 1039 | struct cfq_queue *cfqq; |
| 1040 | |
| 1041 | /* |
| 1042 | * A valid cfq_io_context is necessary to compare requests against |
| 1043 | * the seek_mean of the current cfqq. |
| 1044 | */ |
| 1045 | if (!cfqd->active_cic) |
| 1046 | return NULL; |
| 1047 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1048 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1049 | * We should notice if some of the queues are cooperating, eg |
| 1050 | * working closely on the same area of the disk. In that case, |
| 1051 | * we can group them together and don't waste time idling. |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1052 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1053 | cfqq = cfqq_close(cfqd, cur_cfqq); |
| 1054 | if (!cfqq) |
| 1055 | return NULL; |
| 1056 | |
| 1057 | if (cfq_cfqq_coop(cfqq)) |
| 1058 | return NULL; |
| 1059 | |
| 1060 | if (!probe) |
| 1061 | cfq_mark_cfqq_coop(cfqq); |
| 1062 | return cfqq; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1063 | } |
| 1064 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1065 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1066 | { |
Jens Axboe | 1792669 | 2007-01-19 11:59:30 +1100 | [diff] [blame] | 1067 | struct cfq_queue *cfqq = cfqd->active_queue; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1068 | struct cfq_io_context *cic; |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1069 | unsigned long sl; |
| 1070 | |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1071 | /* |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 1072 | * SSD device without seek penalty, disable idling. But only do so |
| 1073 | * for devices that support queuing, otherwise we still have a problem |
| 1074 | * with sync vs async workloads. |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1075 | */ |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 1076 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1077 | return; |
| 1078 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 1079 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1080 | WARN_ON(cfq_cfqq_slice_new(cfqq)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1081 | |
| 1082 | /* |
| 1083 | * idle is disabled, either manually or by past process history |
| 1084 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1085 | if (!cfqd->cfq_slice_idle || !cfq_cfqq_idle_window(cfqq)) |
| 1086 | return; |
| 1087 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1088 | /* |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1089 | * still requests with the driver, don't idle |
| 1090 | */ |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 1091 | if (rq_in_driver(cfqd)) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1092 | return; |
| 1093 | |
| 1094 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1095 | * task has exited, don't wait |
| 1096 | */ |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1097 | cic = cfqd->active_cic; |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 1098 | if (!cic || !atomic_read(&cic->ioc->nr_tasks)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1099 | return; |
| 1100 | |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 1101 | /* |
| 1102 | * If our average think time is larger than the remaining time |
| 1103 | * slice, then don't idle. This avoids overrunning the allotted |
| 1104 | * time slice. |
| 1105 | */ |
| 1106 | if (sample_valid(cic->ttime_samples) && |
| 1107 | (cfqq->slice_end - jiffies < cic->ttime_mean)) |
| 1108 | return; |
| 1109 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1110 | cfq_mark_cfqq_wait_request(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1111 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1112 | /* |
| 1113 | * we don't want to idle for seeks, but we do want to allow |
| 1114 | * fair distribution of slice time for a process doing back-to-back |
| 1115 | * seeks. so allow a little bit of time for him to submit a new rq |
| 1116 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1117 | sl = cfqd->cfq_slice_idle; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1118 | if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic)) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1119 | sl = min(sl, msecs_to_jiffies(CFQ_MIN_TT)); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1120 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1121 | mod_timer(&cfqd->idle_slice_timer, jiffies + sl); |
Jens Axboe | 9481ffd | 2009-04-15 12:14:13 +0200 | [diff] [blame] | 1122 | cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | } |
| 1124 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1125 | /* |
| 1126 | * Move request from internal lists to the request queue dispatch list. |
| 1127 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1128 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1129 | { |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1130 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1131 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1132 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1133 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); |
| 1134 | |
Jeff Moyer | 06d2188 | 2009-09-11 17:08:59 +0200 | [diff] [blame] | 1135 | cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1136 | cfq_remove_request(rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1137 | cfqq->dispatched++; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1138 | elv_dispatch_sort(q, rq); |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1139 | |
| 1140 | if (cfq_cfqq_sync(cfqq)) |
| 1141 | cfqd->sync_flight++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1142 | } |
| 1143 | |
| 1144 | /* |
| 1145 | * return expired entry, or NULL to just start from scratch in rbtree |
| 1146 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1147 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1148 | { |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1149 | struct request *rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1151 | if (cfq_cfqq_fifo_expire(cfqq)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1152 | return NULL; |
Jens Axboe | cb88741 | 2007-01-19 12:01:16 +1100 | [diff] [blame] | 1153 | |
| 1154 | cfq_mark_cfqq_fifo_expire(cfqq); |
| 1155 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1156 | if (list_empty(&cfqq->fifo)) |
| 1157 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1158 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1159 | rq = rq_entry_fifo(cfqq->fifo.next); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1160 | if (time_before(jiffies, rq_fifo_time(rq))) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1161 | rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1162 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1163 | cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1164 | return rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1165 | } |
| 1166 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1167 | static inline int |
| 1168 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1169 | { |
| 1170 | const int base_rq = cfqd->cfq_slice_async_rq; |
| 1171 | |
| 1172 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); |
| 1173 | |
| 1174 | return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio)); |
| 1175 | } |
| 1176 | |
| 1177 | /* |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1178 | * Select a queue for service. If we have a current active queue, |
| 1179 | * 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] | 1180 | */ |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1181 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1182 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1183 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1184 | |
| 1185 | cfqq = cfqd->active_queue; |
| 1186 | if (!cfqq) |
| 1187 | goto new_queue; |
| 1188 | |
| 1189 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1190 | * 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] | 1191 | */ |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 1192 | if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1193 | goto expire; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1194 | |
| 1195 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1196 | * The active queue has requests and isn't expired, allow it to |
| 1197 | * dispatch. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1198 | */ |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 1199 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1200 | goto keep_queue; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1201 | |
| 1202 | /* |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1203 | * If another queue has a request waiting within our mean seek |
| 1204 | * distance, let it run. The expire code will check for close |
| 1205 | * cooperators and put the close queue at the front of the service |
| 1206 | * tree. |
| 1207 | */ |
| 1208 | new_cfqq = cfq_close_cooperator(cfqd, cfqq, 0); |
| 1209 | if (new_cfqq) |
| 1210 | goto expire; |
| 1211 | |
| 1212 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1213 | * No requests pending. If the active queue still has requests in |
| 1214 | * flight or is idling for a new request, allow either of these |
| 1215 | * conditions to happen (or time out) before selecting a new queue. |
| 1216 | */ |
Jens Axboe | cc19747 | 2007-04-20 20:45:39 +0200 | [diff] [blame] | 1217 | if (timer_pending(&cfqd->idle_slice_timer) || |
| 1218 | (cfqq->dispatched && cfq_cfqq_idle_window(cfqq))) { |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1219 | cfqq = NULL; |
| 1220 | goto keep_queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1221 | } |
| 1222 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1223 | expire: |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1224 | cfq_slice_expired(cfqd, 0); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1225 | new_queue: |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1226 | cfqq = cfq_set_active_queue(cfqd, new_cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1227 | keep_queue: |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1228 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1229 | } |
| 1230 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1231 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1232 | { |
| 1233 | int dispatched = 0; |
| 1234 | |
| 1235 | while (cfqq->next_rq) { |
| 1236 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); |
| 1237 | dispatched++; |
| 1238 | } |
| 1239 | |
| 1240 | BUG_ON(!list_empty(&cfqq->fifo)); |
| 1241 | return dispatched; |
| 1242 | } |
| 1243 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1244 | /* |
| 1245 | * Drain our current requests. Used for barriers and when switching |
| 1246 | * io schedulers on-the-fly. |
| 1247 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1248 | static int cfq_forced_dispatch(struct cfq_data *cfqd) |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1249 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1250 | struct cfq_queue *cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1251 | int dispatched = 0; |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1252 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1253 | while ((cfqq = cfq_rb_first(&cfqd->service_tree)) != NULL) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1254 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1255 | |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1256 | cfq_slice_expired(cfqd, 0); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1257 | |
| 1258 | BUG_ON(cfqd->busy_queues); |
| 1259 | |
Jeff Moyer | 6923715 | 2009-06-12 15:29:30 +0200 | [diff] [blame] | 1260 | cfq_log(cfqd, "forced_dispatch=%d", dispatched); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1261 | return dispatched; |
| 1262 | } |
| 1263 | |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 1264 | 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] | 1265 | { |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1266 | unsigned int max_dispatch; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1267 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1268 | /* |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 1269 | * Drain async requests before we start sync IO |
| 1270 | */ |
| 1271 | if (cfq_cfqq_idle_window(cfqq) && cfqd->rq_in_driver[BLK_RW_ASYNC]) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 1272 | return false; |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 1273 | |
| 1274 | /* |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1275 | * If this is an async queue and we have sync IO in flight, let it wait |
| 1276 | */ |
| 1277 | if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 1278 | return false; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1279 | |
| 1280 | max_dispatch = cfqd->cfq_quantum; |
| 1281 | if (cfq_class_idle(cfqq)) |
| 1282 | max_dispatch = 1; |
| 1283 | |
| 1284 | /* |
| 1285 | * Does this cfqq already have too much IO in flight? |
| 1286 | */ |
| 1287 | if (cfqq->dispatched >= max_dispatch) { |
| 1288 | /* |
| 1289 | * idle queue must always only have a single IO in flight |
| 1290 | */ |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1291 | if (cfq_class_idle(cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 1292 | return false; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1293 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1294 | /* |
| 1295 | * We have other queues, don't allow more IO from this one |
| 1296 | */ |
| 1297 | if (cfqd->busy_queues > 1) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 1298 | return false; |
Jens Axboe | 9ede209 | 2007-01-19 12:11:44 +1100 | [diff] [blame] | 1299 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1300 | /* |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1301 | * Sole queue user, allow bigger slice |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 1302 | */ |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1303 | max_dispatch *= 4; |
| 1304 | } |
| 1305 | |
| 1306 | /* |
| 1307 | * Async queues must wait a bit before being allowed dispatch. |
| 1308 | * We also ramp up the dispatch depth gradually for async IO, |
| 1309 | * based on the last sync IO we serviced |
| 1310 | */ |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 1311 | if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1312 | unsigned long last_sync = jiffies - cfqd->last_end_sync_rq; |
| 1313 | unsigned int depth; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 1314 | |
Jens Axboe | 61f0c1d | 2009-10-03 19:46:03 +0200 | [diff] [blame] | 1315 | depth = last_sync / cfqd->cfq_slice[1]; |
Jens Axboe | e00c54c | 2009-10-04 20:36:19 +0200 | [diff] [blame] | 1316 | if (!depth && !cfqq->dispatched) |
| 1317 | depth = 1; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1318 | if (depth < max_dispatch) |
| 1319 | max_dispatch = depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1320 | } |
| 1321 | |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 1322 | /* |
| 1323 | * If we're below the current max, allow a dispatch |
| 1324 | */ |
| 1325 | return cfqq->dispatched < max_dispatch; |
| 1326 | } |
| 1327 | |
| 1328 | /* |
| 1329 | * Dispatch a request from cfqq, moving them to the request queue |
| 1330 | * dispatch list. |
| 1331 | */ |
| 1332 | static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1333 | { |
| 1334 | struct request *rq; |
| 1335 | |
| 1336 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); |
| 1337 | |
| 1338 | if (!cfq_may_dispatch(cfqd, cfqq)) |
| 1339 | return false; |
| 1340 | |
| 1341 | /* |
| 1342 | * follow expired path, else get first next available |
| 1343 | */ |
| 1344 | rq = cfq_check_fifo(cfqq); |
| 1345 | if (!rq) |
| 1346 | rq = cfqq->next_rq; |
| 1347 | |
| 1348 | /* |
| 1349 | * insert request into driver dispatch list |
| 1350 | */ |
| 1351 | cfq_dispatch_insert(cfqd->queue, rq); |
| 1352 | |
| 1353 | if (!cfqd->active_cic) { |
| 1354 | struct cfq_io_context *cic = RQ_CIC(rq); |
| 1355 | |
| 1356 | atomic_long_inc(&cic->ioc->refcount); |
| 1357 | cfqd->active_cic = cic; |
| 1358 | } |
| 1359 | |
| 1360 | return true; |
| 1361 | } |
| 1362 | |
| 1363 | /* |
| 1364 | * Find the cfqq that we need to service and move a request from that to the |
| 1365 | * dispatch list |
| 1366 | */ |
| 1367 | static int cfq_dispatch_requests(struct request_queue *q, int force) |
| 1368 | { |
| 1369 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1370 | struct cfq_queue *cfqq; |
| 1371 | |
| 1372 | if (!cfqd->busy_queues) |
| 1373 | return 0; |
| 1374 | |
| 1375 | if (unlikely(force)) |
| 1376 | return cfq_forced_dispatch(cfqd); |
| 1377 | |
| 1378 | cfqq = cfq_select_queue(cfqd); |
| 1379 | if (!cfqq) |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1380 | return 0; |
| 1381 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1382 | /* |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 1383 | * Dispatch a request from this cfqq, if it is allowed |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1384 | */ |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 1385 | if (!cfq_dispatch_request(cfqd, cfqq)) |
| 1386 | return 0; |
| 1387 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1388 | cfqq->slice_dispatch++; |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 1389 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1390 | |
| 1391 | /* |
| 1392 | * expire an async queue immediately if it has used up its slice. idle |
| 1393 | * queue always expire after 1 dispatch round. |
| 1394 | */ |
| 1395 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && |
| 1396 | cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || |
| 1397 | cfq_class_idle(cfqq))) { |
| 1398 | cfqq->slice_end = jiffies + 1; |
| 1399 | cfq_slice_expired(cfqd, 0); |
| 1400 | } |
| 1401 | |
Shan Wei | b217a90 | 2009-09-01 10:06:42 +0200 | [diff] [blame] | 1402 | cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1403 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1404 | } |
| 1405 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1406 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1407 | * task holds one reference to the queue, dropped when task exits. each rq |
| 1408 | * 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] | 1409 | * |
| 1410 | * queue lock must be held here. |
| 1411 | */ |
| 1412 | static void cfq_put_queue(struct cfq_queue *cfqq) |
| 1413 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1414 | struct cfq_data *cfqd = cfqq->cfqd; |
| 1415 | |
| 1416 | BUG_ON(atomic_read(&cfqq->ref) <= 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1417 | |
| 1418 | if (!atomic_dec_and_test(&cfqq->ref)) |
| 1419 | return; |
| 1420 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1421 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1422 | BUG_ON(rb_first(&cfqq->sort_list)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1423 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1424 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1425 | |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1426 | if (unlikely(cfqd->active_queue == cfqq)) { |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1427 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 1428 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1429 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1430 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1431 | kmem_cache_free(cfq_pool, cfqq); |
| 1432 | } |
| 1433 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1434 | /* |
| 1435 | * Must always be called with the rcu_read_lock() held |
| 1436 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 1437 | static void |
| 1438 | __call_for_each_cic(struct io_context *ioc, |
| 1439 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 1440 | { |
| 1441 | struct cfq_io_context *cic; |
| 1442 | struct hlist_node *n; |
| 1443 | |
| 1444 | hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list) |
| 1445 | func(ioc, cic); |
| 1446 | } |
| 1447 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1448 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1449 | * Call func for each cic attached to this ioc. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1450 | */ |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1451 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1452 | call_for_each_cic(struct io_context *ioc, |
| 1453 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 1454 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1455 | rcu_read_lock(); |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 1456 | __call_for_each_cic(ioc, func); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1457 | rcu_read_unlock(); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1458 | } |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1459 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1460 | static void cfq_cic_free_rcu(struct rcu_head *head) |
| 1461 | { |
| 1462 | struct cfq_io_context *cic; |
| 1463 | |
| 1464 | cic = container_of(head, struct cfq_io_context, rcu_head); |
| 1465 | |
| 1466 | kmem_cache_free(cfq_ioc_pool, cic); |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 1467 | elv_ioc_count_dec(cfq_ioc_count); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1468 | |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 1469 | if (ioc_gone) { |
| 1470 | /* |
| 1471 | * CFQ scheduler is exiting, grab exit lock and check |
| 1472 | * the pending io context count. If it hits zero, |
| 1473 | * complete ioc_gone and set it back to NULL |
| 1474 | */ |
| 1475 | spin_lock(&ioc_gone_lock); |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 1476 | if (ioc_gone && !elv_ioc_count_read(cfq_ioc_count)) { |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 1477 | complete(ioc_gone); |
| 1478 | ioc_gone = NULL; |
| 1479 | } |
| 1480 | spin_unlock(&ioc_gone_lock); |
| 1481 | } |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1482 | } |
| 1483 | |
| 1484 | static void cfq_cic_free(struct cfq_io_context *cic) |
| 1485 | { |
| 1486 | call_rcu(&cic->rcu_head, cfq_cic_free_rcu); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1487 | } |
| 1488 | |
| 1489 | static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic) |
| 1490 | { |
| 1491 | unsigned long flags; |
| 1492 | |
| 1493 | BUG_ON(!cic->dead_key); |
| 1494 | |
| 1495 | spin_lock_irqsave(&ioc->lock, flags); |
| 1496 | radix_tree_delete(&ioc->radix_root, cic->dead_key); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1497 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1498 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 1499 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1500 | cfq_cic_free(cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1501 | } |
| 1502 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1503 | /* |
| 1504 | * Must be called with rcu_read_lock() held or preemption otherwise disabled. |
| 1505 | * Only two callers of this - ->dtor() which is called with the rcu_read_lock(), |
| 1506 | * and ->trim() which is called with the task lock held |
| 1507 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1508 | static void cfq_free_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1509 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1510 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1511 | * ioc->refcount is zero here, or we are called from elv_unregister(), |
| 1512 | * so no more cic's are allowed to be linked into this ioc. So it |
| 1513 | * should be ok to iterate over the known list, we will see all cic's |
| 1514 | * since no new ones are added. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1515 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 1516 | __call_for_each_cic(ioc, cic_free_func); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1517 | } |
| 1518 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1519 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1520 | { |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1521 | if (unlikely(cfqq == cfqd->active_queue)) { |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1522 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 1523 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1524 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1525 | |
| 1526 | cfq_put_queue(cfqq); |
| 1527 | } |
| 1528 | |
| 1529 | static void __cfq_exit_single_io_context(struct cfq_data *cfqd, |
| 1530 | struct cfq_io_context *cic) |
| 1531 | { |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 1532 | struct io_context *ioc = cic->ioc; |
| 1533 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1534 | list_del_init(&cic->queue_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1535 | |
| 1536 | /* |
| 1537 | * Make sure key == NULL is seen for dead queues |
| 1538 | */ |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1539 | smp_wmb(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1540 | cic->dead_key = (unsigned long) cic->key; |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1541 | cic->key = NULL; |
| 1542 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 1543 | if (ioc->ioc_data == cic) |
| 1544 | rcu_assign_pointer(ioc->ioc_data, NULL); |
| 1545 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1546 | if (cic->cfqq[BLK_RW_ASYNC]) { |
| 1547 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]); |
| 1548 | cic->cfqq[BLK_RW_ASYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1549 | } |
| 1550 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1551 | if (cic->cfqq[BLK_RW_SYNC]) { |
| 1552 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_SYNC]); |
| 1553 | cic->cfqq[BLK_RW_SYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1554 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1555 | } |
| 1556 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1557 | static void cfq_exit_single_io_context(struct io_context *ioc, |
| 1558 | struct cfq_io_context *cic) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1559 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 1560 | struct cfq_data *cfqd = cic->key; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1561 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1562 | if (cfqd) { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1563 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1564 | unsigned long flags; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1565 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1566 | spin_lock_irqsave(q->queue_lock, flags); |
Jens Axboe | 62c1fe9 | 2008-12-15 21:19:25 +0100 | [diff] [blame] | 1567 | |
| 1568 | /* |
| 1569 | * Ensure we get a fresh copy of the ->key to prevent |
| 1570 | * race between exiting task and queue |
| 1571 | */ |
| 1572 | smp_read_barrier_depends(); |
| 1573 | if (cic->key) |
| 1574 | __cfq_exit_single_io_context(cfqd, cic); |
| 1575 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1576 | spin_unlock_irqrestore(q->queue_lock, flags); |
Al Viro | 12a0573 | 2006-03-18 13:38:01 -0500 | [diff] [blame] | 1577 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1578 | } |
| 1579 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1580 | /* |
| 1581 | * The process that ioc belongs to has exited, we need to clean up |
| 1582 | * and put the internal structures we have that belongs to that process. |
| 1583 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1584 | static void cfq_exit_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1585 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1586 | call_for_each_cic(ioc, cfq_exit_single_io_context); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1587 | } |
| 1588 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1589 | static struct cfq_io_context * |
Al Viro | 8267e26 | 2005-10-21 03:20:53 -0400 | [diff] [blame] | 1590 | cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1591 | { |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 1592 | struct cfq_io_context *cic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1593 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1594 | cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO, |
| 1595 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1596 | if (cic) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1597 | cic->last_end_request = jiffies; |
Jens Axboe | 553698f | 2006-06-14 19:11:57 +0200 | [diff] [blame] | 1598 | INIT_LIST_HEAD(&cic->queue_list); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1599 | INIT_HLIST_NODE(&cic->cic_list); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1600 | cic->dtor = cfq_free_io_context; |
| 1601 | cic->exit = cfq_exit_io_context; |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 1602 | elv_ioc_count_inc(cfq_ioc_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1603 | } |
| 1604 | |
| 1605 | return cic; |
| 1606 | } |
| 1607 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1608 | 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] | 1609 | { |
| 1610 | struct task_struct *tsk = current; |
| 1611 | int ioprio_class; |
| 1612 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1613 | if (!cfq_cfqq_prio_changed(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1614 | return; |
| 1615 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1616 | ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1617 | switch (ioprio_class) { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1618 | default: |
| 1619 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); |
| 1620 | case IOPRIO_CLASS_NONE: |
| 1621 | /* |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 1622 | * no prio set, inherit CPU scheduling settings |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1623 | */ |
| 1624 | cfqq->ioprio = task_nice_ioprio(tsk); |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 1625 | cfqq->ioprio_class = task_nice_ioclass(tsk); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1626 | break; |
| 1627 | case IOPRIO_CLASS_RT: |
| 1628 | cfqq->ioprio = task_ioprio(ioc); |
| 1629 | cfqq->ioprio_class = IOPRIO_CLASS_RT; |
| 1630 | break; |
| 1631 | case IOPRIO_CLASS_BE: |
| 1632 | cfqq->ioprio = task_ioprio(ioc); |
| 1633 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 1634 | break; |
| 1635 | case IOPRIO_CLASS_IDLE: |
| 1636 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; |
| 1637 | cfqq->ioprio = 7; |
| 1638 | cfq_clear_cfqq_idle_window(cfqq); |
| 1639 | break; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1640 | } |
| 1641 | |
| 1642 | /* |
| 1643 | * keep track of original prio settings in case we have to temporarily |
| 1644 | * elevate the priority of this queue |
| 1645 | */ |
| 1646 | cfqq->org_ioprio = cfqq->ioprio; |
| 1647 | cfqq->org_ioprio_class = cfqq->ioprio_class; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1648 | cfq_clear_cfqq_prio_changed(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1649 | } |
| 1650 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1651 | 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] | 1652 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 1653 | struct cfq_data *cfqd = cic->key; |
| 1654 | struct cfq_queue *cfqq; |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 1655 | unsigned long flags; |
Jens Axboe | 35e6077 | 2006-06-14 09:10:45 +0200 | [diff] [blame] | 1656 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1657 | if (unlikely(!cfqd)) |
| 1658 | return; |
| 1659 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 1660 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1661 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1662 | cfqq = cic->cfqq[BLK_RW_ASYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1663 | if (cfqq) { |
| 1664 | struct cfq_queue *new_cfqq; |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1665 | new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->ioc, |
| 1666 | GFP_ATOMIC); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1667 | if (new_cfqq) { |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1668 | cic->cfqq[BLK_RW_ASYNC] = new_cfqq; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1669 | cfq_put_queue(cfqq); |
| 1670 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1671 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1672 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1673 | cfqq = cic->cfqq[BLK_RW_SYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1674 | if (cfqq) |
| 1675 | cfq_mark_cfqq_prio_changed(cfqq); |
| 1676 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 1677 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1678 | } |
| 1679 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1680 | static void cfq_ioc_set_ioprio(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1681 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1682 | call_for_each_cic(ioc, changed_ioprio); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1683 | ioc->ioprio_changed = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1684 | } |
| 1685 | |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 1686 | 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] | 1687 | pid_t pid, bool is_sync) |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 1688 | { |
| 1689 | RB_CLEAR_NODE(&cfqq->rb_node); |
| 1690 | RB_CLEAR_NODE(&cfqq->p_node); |
| 1691 | INIT_LIST_HEAD(&cfqq->fifo); |
| 1692 | |
| 1693 | atomic_set(&cfqq->ref, 0); |
| 1694 | cfqq->cfqd = cfqd; |
| 1695 | |
| 1696 | cfq_mark_cfqq_prio_changed(cfqq); |
| 1697 | |
| 1698 | if (is_sync) { |
| 1699 | if (!cfq_class_idle(cfqq)) |
| 1700 | cfq_mark_cfqq_idle_window(cfqq); |
| 1701 | cfq_mark_cfqq_sync(cfqq); |
| 1702 | } |
| 1703 | cfqq->pid = pid; |
| 1704 | } |
| 1705 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1706 | static struct cfq_queue * |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1707 | cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1708 | struct io_context *ioc, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1709 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1710 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1711 | struct cfq_io_context *cic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1712 | |
| 1713 | retry: |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1714 | cic = cfq_cic_lookup(cfqd, ioc); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1715 | /* cic always exists here */ |
| 1716 | cfqq = cic_to_cfqq(cic, is_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1717 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 1718 | /* |
| 1719 | * Always try a new alloc if we fell back to the OOM cfqq |
| 1720 | * originally, since it should just be a temporary situation. |
| 1721 | */ |
| 1722 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
| 1723 | cfqq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1724 | if (new_cfqq) { |
| 1725 | cfqq = new_cfqq; |
| 1726 | new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1727 | } else if (gfp_mask & __GFP_WAIT) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1728 | spin_unlock_irq(cfqd->queue->queue_lock); |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1729 | new_cfqq = kmem_cache_alloc_node(cfq_pool, |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 1730 | gfp_mask | __GFP_ZERO, |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1731 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1732 | spin_lock_irq(cfqd->queue->queue_lock); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 1733 | if (new_cfqq) |
| 1734 | goto retry; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1735 | } else { |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1736 | cfqq = kmem_cache_alloc_node(cfq_pool, |
| 1737 | gfp_mask | __GFP_ZERO, |
| 1738 | cfqd->queue->node); |
Kiyoshi Ueda | db3b584 | 2005-06-17 16:15:10 +0200 | [diff] [blame] | 1739 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1740 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 1741 | if (cfqq) { |
| 1742 | cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); |
| 1743 | cfq_init_prio_data(cfqq, ioc); |
| 1744 | cfq_log_cfqq(cfqd, cfqq, "alloced"); |
| 1745 | } else |
| 1746 | cfqq = &cfqd->oom_cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1747 | } |
| 1748 | |
| 1749 | if (new_cfqq) |
| 1750 | kmem_cache_free(cfq_pool, new_cfqq); |
| 1751 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1752 | return cfqq; |
| 1753 | } |
| 1754 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1755 | static struct cfq_queue ** |
| 1756 | cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) |
| 1757 | { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1758 | switch (ioprio_class) { |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1759 | case IOPRIO_CLASS_RT: |
| 1760 | return &cfqd->async_cfqq[0][ioprio]; |
| 1761 | case IOPRIO_CLASS_BE: |
| 1762 | return &cfqd->async_cfqq[1][ioprio]; |
| 1763 | case IOPRIO_CLASS_IDLE: |
| 1764 | return &cfqd->async_idle_cfqq; |
| 1765 | default: |
| 1766 | BUG(); |
| 1767 | } |
| 1768 | } |
| 1769 | |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1770 | static struct cfq_queue * |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1771 | 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] | 1772 | gfp_t gfp_mask) |
| 1773 | { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1774 | const int ioprio = task_ioprio(ioc); |
| 1775 | const int ioprio_class = task_ioprio_class(ioc); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1776 | struct cfq_queue **async_cfqq = NULL; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1777 | struct cfq_queue *cfqq = NULL; |
| 1778 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1779 | if (!is_sync) { |
| 1780 | async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); |
| 1781 | cfqq = *async_cfqq; |
| 1782 | } |
| 1783 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 1784 | if (!cfqq) |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1785 | cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1786 | |
| 1787 | /* |
| 1788 | * pin the queue now that it's allocated, scheduler exit will prune it |
| 1789 | */ |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1790 | if (!is_sync && !(*async_cfqq)) { |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1791 | atomic_inc(&cfqq->ref); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1792 | *async_cfqq = cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1793 | } |
| 1794 | |
| 1795 | atomic_inc(&cfqq->ref); |
| 1796 | return cfqq; |
| 1797 | } |
| 1798 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1799 | /* |
| 1800 | * We drop cfq io contexts lazily, so we may find a dead one. |
| 1801 | */ |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1802 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1803 | cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc, |
| 1804 | struct cfq_io_context *cic) |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1805 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1806 | unsigned long flags; |
| 1807 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1808 | WARN_ON(!list_empty(&cic->queue_list)); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1809 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1810 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1811 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 1812 | BUG_ON(ioc->ioc_data == cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1813 | |
| 1814 | radix_tree_delete(&ioc->radix_root, (unsigned long) cfqd); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1815 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1816 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 1817 | |
| 1818 | cfq_cic_free(cic); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1819 | } |
| 1820 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1821 | static struct cfq_io_context * |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1822 | cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1823 | { |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1824 | struct cfq_io_context *cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1825 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1826 | void *k; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1827 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1828 | if (unlikely(!ioc)) |
| 1829 | return NULL; |
| 1830 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1831 | rcu_read_lock(); |
| 1832 | |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1833 | /* |
| 1834 | * we maintain a last-hit cache, to avoid browsing over the tree |
| 1835 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1836 | cic = rcu_dereference(ioc->ioc_data); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1837 | if (cic && cic->key == cfqd) { |
| 1838 | rcu_read_unlock(); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1839 | return cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1840 | } |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1841 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1842 | do { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1843 | cic = radix_tree_lookup(&ioc->radix_root, (unsigned long) cfqd); |
| 1844 | rcu_read_unlock(); |
| 1845 | if (!cic) |
| 1846 | break; |
OGAWA Hirofumi | be3b075 | 2006-04-18 19:18:31 +0200 | [diff] [blame] | 1847 | /* ->key must be copied to avoid race with cfq_exit_queue() */ |
| 1848 | k = cic->key; |
| 1849 | if (unlikely(!k)) { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1850 | cfq_drop_dead_cic(cfqd, ioc, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1851 | rcu_read_lock(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1852 | continue; |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1853 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1854 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1855 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1856 | rcu_assign_pointer(ioc->ioc_data, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1857 | spin_unlock_irqrestore(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1858 | break; |
| 1859 | } while (1); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1860 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1861 | return cic; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1862 | } |
| 1863 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1864 | /* |
| 1865 | * Add cic into ioc, using cfqd as the search key. This enables us to lookup |
| 1866 | * the process specific cfq io context when entered from the block layer. |
| 1867 | * Also adds the cic to a per-cfqd list, used when this queue is removed. |
| 1868 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1869 | static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, |
| 1870 | struct cfq_io_context *cic, gfp_t gfp_mask) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1871 | { |
Jens Axboe | 0261d68 | 2006-10-30 19:07:48 +0100 | [diff] [blame] | 1872 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1873 | int ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1874 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1875 | ret = radix_tree_preload(gfp_mask); |
| 1876 | if (!ret) { |
| 1877 | cic->ioc = ioc; |
| 1878 | cic->key = cfqd; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1879 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1880 | spin_lock_irqsave(&ioc->lock, flags); |
| 1881 | ret = radix_tree_insert(&ioc->radix_root, |
| 1882 | (unsigned long) cfqd, cic); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1883 | if (!ret) |
| 1884 | hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1885 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 1886 | |
| 1887 | radix_tree_preload_end(); |
| 1888 | |
| 1889 | if (!ret) { |
| 1890 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 1891 | list_add(&cic->queue_list, &cfqd->cic_list); |
| 1892 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1893 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1894 | } |
| 1895 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1896 | if (ret) |
| 1897 | printk(KERN_ERR "cfq: cic link failed!\n"); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1898 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1899 | return ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1900 | } |
| 1901 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1902 | /* |
| 1903 | * Setup general io context and cfq io context. There can be several cfq |
| 1904 | * 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] | 1905 | * than one device managed by cfq. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1906 | */ |
| 1907 | static struct cfq_io_context * |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1908 | cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1909 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1910 | struct io_context *ioc = NULL; |
| 1911 | struct cfq_io_context *cic; |
| 1912 | |
| 1913 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 1914 | |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 1915 | ioc = get_io_context(gfp_mask, cfqd->queue->node); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1916 | if (!ioc) |
| 1917 | return NULL; |
| 1918 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1919 | cic = cfq_cic_lookup(cfqd, ioc); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1920 | if (cic) |
| 1921 | goto out; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1922 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1923 | cic = cfq_alloc_io_context(cfqd, gfp_mask); |
| 1924 | if (cic == NULL) |
| 1925 | goto err; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1926 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1927 | if (cfq_cic_link(cfqd, ioc, cic, gfp_mask)) |
| 1928 | goto err_free; |
| 1929 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1930 | out: |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1931 | smp_read_barrier_depends(); |
| 1932 | if (unlikely(ioc->ioprio_changed)) |
| 1933 | cfq_ioc_set_ioprio(ioc); |
| 1934 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1935 | return cic; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1936 | err_free: |
| 1937 | cfq_cic_free(cic); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1938 | err: |
| 1939 | put_io_context(ioc); |
| 1940 | return NULL; |
| 1941 | } |
| 1942 | |
| 1943 | static void |
| 1944 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic) |
| 1945 | { |
Jens Axboe | aaf1228 | 2007-01-19 11:30:16 +1100 | [diff] [blame] | 1946 | unsigned long elapsed = jiffies - cic->last_end_request; |
| 1947 | unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1948 | |
| 1949 | cic->ttime_samples = (7*cic->ttime_samples + 256) / 8; |
| 1950 | cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8; |
| 1951 | cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples; |
| 1952 | } |
| 1953 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1954 | static void |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1955 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic, |
| 1956 | struct request *rq) |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1957 | { |
| 1958 | sector_t sdist; |
| 1959 | u64 total; |
| 1960 | |
Jeff Moyer | 4d00aa4 | 2009-04-21 07:25:04 +0200 | [diff] [blame] | 1961 | if (!cic->last_request_pos) |
| 1962 | sdist = 0; |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1963 | else if (cic->last_request_pos < blk_rq_pos(rq)) |
| 1964 | sdist = blk_rq_pos(rq) - cic->last_request_pos; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1965 | else |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1966 | sdist = cic->last_request_pos - blk_rq_pos(rq); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1967 | |
| 1968 | /* |
| 1969 | * Don't allow the seek distance to get too large from the |
| 1970 | * odd fragment, pagein, etc |
| 1971 | */ |
| 1972 | if (cic->seek_samples <= 60) /* second&third seek */ |
| 1973 | sdist = min(sdist, (cic->seek_mean * 4) + 2*1024*1024); |
| 1974 | else |
| 1975 | sdist = min(sdist, (cic->seek_mean * 4) + 2*1024*64); |
| 1976 | |
| 1977 | cic->seek_samples = (7*cic->seek_samples + 256) / 8; |
| 1978 | cic->seek_total = (7*cic->seek_total + (u64)256*sdist) / 8; |
| 1979 | total = cic->seek_total + (cic->seek_samples/2); |
| 1980 | do_div(total, cic->seek_samples); |
| 1981 | cic->seek_mean = (sector_t)total; |
| 1982 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1983 | |
| 1984 | /* |
| 1985 | * Disable idle window if the process thinks too long or seeks so much that |
| 1986 | * it doesn't matter |
| 1987 | */ |
| 1988 | static void |
| 1989 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 1990 | struct cfq_io_context *cic) |
| 1991 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1992 | int old_idle, enable_idle; |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 1993 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1994 | /* |
| 1995 | * Don't idle for async or idle io prio class |
| 1996 | */ |
| 1997 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 1998 | return; |
| 1999 | |
Jens Axboe | c265a7f | 2008-06-26 13:49:33 +0200 | [diff] [blame] | 2000 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2001 | |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 2002 | if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle || |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2003 | (!cfqd->cfq_latency && cfqd->hw_tag && CIC_SEEKY(cic))) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2004 | enable_idle = 0; |
| 2005 | else if (sample_valid(cic->ttime_samples)) { |
Corrado Zoccolo | ec60e4f | 2009-10-07 19:51:54 +0200 | [diff] [blame] | 2006 | unsigned int slice_idle = cfqd->cfq_slice_idle; |
| 2007 | if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic)) |
| 2008 | slice_idle = msecs_to_jiffies(CFQ_MIN_TT); |
| 2009 | if (cic->ttime_mean > slice_idle) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2010 | enable_idle = 0; |
| 2011 | else |
| 2012 | enable_idle = 1; |
| 2013 | } |
| 2014 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2015 | if (old_idle != enable_idle) { |
| 2016 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); |
| 2017 | if (enable_idle) |
| 2018 | cfq_mark_cfqq_idle_window(cfqq); |
| 2019 | else |
| 2020 | cfq_clear_cfqq_idle_window(cfqq); |
| 2021 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2022 | } |
| 2023 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2024 | /* |
| 2025 | * Check if new_cfqq should preempt the currently active queue. Return 0 for |
| 2026 | * no or if we aren't sure, a 1 will cause a preempt. |
| 2027 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2028 | static bool |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2029 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2030 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2031 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2032 | struct cfq_queue *cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2033 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2034 | cfqq = cfqd->active_queue; |
| 2035 | if (!cfqq) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2036 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2037 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2038 | if (cfq_slice_used(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2039 | return true; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2040 | |
| 2041 | if (cfq_class_idle(new_cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2042 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2043 | |
| 2044 | if (cfq_class_idle(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2045 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 2046 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2047 | /* |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 2048 | * if the new request is sync, but the currently running queue is |
| 2049 | * not, let the sync request have priority. |
| 2050 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2051 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2052 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 2053 | |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 2054 | /* |
| 2055 | * So both queues are sync. Let the new request get disk time if |
| 2056 | * it's a metadata request and the current queue is doing regular IO. |
| 2057 | */ |
| 2058 | if (rq_is_meta(rq) && !cfqq->meta_pending) |
Jens Axboe | e6ec4fe | 2009-11-03 20:21:35 +0100 | [diff] [blame] | 2059 | return true; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2060 | |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 2061 | /* |
| 2062 | * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. |
| 2063 | */ |
| 2064 | if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2065 | return true; |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 2066 | |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 2067 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2068 | return false; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 2069 | |
| 2070 | /* |
| 2071 | * if this request is as-good as one we would expect from the |
| 2072 | * current cfqq, let it preempt |
| 2073 | */ |
Shaohua Li | 4b27e1b | 2009-11-03 20:25:02 +0100 | [diff] [blame] | 2074 | if (cfq_rq_close(cfqd, rq) && (!cfq_cfqq_coop(new_cfqq) || |
| 2075 | cfqd->busy_queues == 1)) { |
| 2076 | /* |
| 2077 | * Mark new queue coop_preempt, so its coop flag will not be |
| 2078 | * cleared when new queue gets scheduled at the very first time |
| 2079 | */ |
| 2080 | cfq_mark_cfqq_coop_preempt(new_cfqq); |
| 2081 | cfq_mark_cfqq_coop(new_cfqq); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2082 | return true; |
Shaohua Li | 4b27e1b | 2009-11-03 20:25:02 +0100 | [diff] [blame] | 2083 | } |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 2084 | |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2085 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2086 | } |
| 2087 | |
| 2088 | /* |
| 2089 | * cfqq preempts the active queue. if we allowed preempt with no slice left, |
| 2090 | * let it have half of its nominal slice. |
| 2091 | */ |
| 2092 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2093 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2094 | cfq_log_cfqq(cfqd, cfqq, "preempt"); |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2095 | cfq_slice_expired(cfqd, 1); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2096 | |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 2097 | /* |
| 2098 | * Put the new queue at the front of the of the current list, |
| 2099 | * so we know that it will be selected next. |
| 2100 | */ |
| 2101 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 2102 | |
| 2103 | cfq_service_tree_add(cfqd, cfqq, 1); |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 2104 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 2105 | cfqq->slice_end = 0; |
| 2106 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2107 | } |
| 2108 | |
| 2109 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2110 | * 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] | 2111 | * something we should do about it |
| 2112 | */ |
| 2113 | static void |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2114 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 2115 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2116 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2117 | struct cfq_io_context *cic = RQ_CIC(rq); |
Jens Axboe | 12e9fdd | 2006-06-01 10:09:56 +0200 | [diff] [blame] | 2118 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2119 | cfqd->rq_queued++; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 2120 | if (rq_is_meta(rq)) |
| 2121 | cfqq->meta_pending++; |
| 2122 | |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 2123 | cfq_update_io_thinktime(cfqd, cic); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2124 | cfq_update_io_seektime(cfqd, cic, rq); |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 2125 | cfq_update_idle_window(cfqd, cfqq, cic); |
| 2126 | |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 2127 | cic->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2128 | |
| 2129 | if (cfqq == cfqd->active_queue) { |
| 2130 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 2131 | * Remember that we saw a request from this process, but |
| 2132 | * don't start queuing just yet. Otherwise we risk seeing lots |
| 2133 | * of tiny requests, because we disrupt the normal plugging |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 2134 | * and merging. If the request is already larger than a single |
| 2135 | * page, let it rip immediately. For that case we assume that |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 2136 | * merging is already done. Ditto for a busy system that |
| 2137 | * has other work pending, don't risk delaying until the |
| 2138 | * idle timer unplug to continue working. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2139 | */ |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 2140 | if (cfq_cfqq_wait_request(cfqq)) { |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 2141 | if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE || |
| 2142 | cfqd->busy_queues > 1) { |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 2143 | del_timer(&cfqd->idle_slice_timer); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 2144 | __blk_run_queue(cfqd->queue); |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 2145 | } |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 2146 | cfq_mark_cfqq_must_dispatch(cfqq); |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 2147 | } |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2148 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2149 | /* |
| 2150 | * not the active queue - expire current slice if it is |
| 2151 | * idle and has expired it's mean thinktime or this new queue |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 2152 | * has some old slice time left and is of higher priority or |
| 2153 | * this new queue is RT and the current one is BE |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2154 | */ |
| 2155 | cfq_preempt_queue(cfqd, cfqq); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 2156 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2157 | } |
| 2158 | } |
| 2159 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2160 | static void cfq_insert_request(struct request_queue *q, struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2161 | { |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2162 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2163 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2164 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2165 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2166 | cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2167 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2168 | cfq_add_rq_rb(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2169 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 2170 | 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] | 2171 | list_add_tail(&rq->queuelist, &cfqq->fifo); |
| 2172 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2173 | cfq_rq_enqueued(cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2174 | } |
| 2175 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2176 | /* |
| 2177 | * Update hw_tag based on peak queue depth over 50 samples under |
| 2178 | * sufficient load. |
| 2179 | */ |
| 2180 | static void cfq_update_hw_tag(struct cfq_data *cfqd) |
| 2181 | { |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2182 | if (rq_in_driver(cfqd) > cfqd->rq_in_driver_peak) |
| 2183 | cfqd->rq_in_driver_peak = rq_in_driver(cfqd); |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2184 | |
| 2185 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2186 | rq_in_driver(cfqd) <= CFQ_HW_QUEUE_MIN) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2187 | return; |
| 2188 | |
| 2189 | if (cfqd->hw_tag_samples++ < 50) |
| 2190 | return; |
| 2191 | |
| 2192 | if (cfqd->rq_in_driver_peak >= CFQ_HW_QUEUE_MIN) |
| 2193 | cfqd->hw_tag = 1; |
| 2194 | else |
| 2195 | cfqd->hw_tag = 0; |
| 2196 | |
| 2197 | cfqd->hw_tag_samples = 0; |
| 2198 | cfqd->rq_in_driver_peak = 0; |
| 2199 | } |
| 2200 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2201 | static void cfq_completed_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2202 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2203 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2204 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 2205 | const int sync = rq_is_sync(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2206 | unsigned long now; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2207 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2208 | now = jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2209 | cfq_log_cfqq(cfqd, cfqq, "complete"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2210 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2211 | cfq_update_hw_tag(cfqd); |
| 2212 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2213 | WARN_ON(!cfqd->rq_in_driver[sync]); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2214 | WARN_ON(!cfqq->dispatched); |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2215 | cfqd->rq_in_driver[sync]--; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2216 | cfqq->dispatched--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2217 | |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2218 | if (cfq_cfqq_sync(cfqq)) |
| 2219 | cfqd->sync_flight--; |
| 2220 | |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2221 | if (sync) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2222 | RQ_CIC(rq)->last_end_request = now; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2223 | cfqd->last_end_sync_rq = now; |
| 2224 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2225 | |
| 2226 | /* |
| 2227 | * If this is the active queue, check if it needs to be expired, |
| 2228 | * or if we want to idle in case it has no pending requests. |
| 2229 | */ |
| 2230 | if (cfqd->active_queue == cfqq) { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2231 | const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); |
| 2232 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 2233 | if (cfq_cfqq_slice_new(cfqq)) { |
| 2234 | cfq_set_prio_slice(cfqd, cfqq); |
| 2235 | cfq_clear_cfqq_slice_new(cfqq); |
| 2236 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2237 | /* |
| 2238 | * If there are no requests waiting in this queue, and |
| 2239 | * there are other queues ready to issue requests, AND |
| 2240 | * those other queues are issuing requests within our |
| 2241 | * mean seek distance, give them a chance to run instead |
| 2242 | * of idling. |
| 2243 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 2244 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2245 | cfq_slice_expired(cfqd, 1); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2246 | else if (cfqq_empty && !cfq_close_cooperator(cfqd, cfqq, 1) && |
| 2247 | sync && !rq_noidle(rq)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2248 | cfq_arm_slice_timer(cfqd); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2249 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2250 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2251 | if (!rq_in_driver(cfqd)) |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2252 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2253 | } |
| 2254 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2255 | /* |
| 2256 | * we temporarily boost lower priority queues if they are holding fs exclusive |
| 2257 | * resources. they are boosted to normal prio (CLASS_BE/4) |
| 2258 | */ |
| 2259 | static void cfq_prio_boost(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2260 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2261 | if (has_fs_excl()) { |
| 2262 | /* |
| 2263 | * boost idle prio on transactions that would lock out other |
| 2264 | * users of the filesystem |
| 2265 | */ |
| 2266 | if (cfq_class_idle(cfqq)) |
| 2267 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 2268 | if (cfqq->ioprio > IOPRIO_NORM) |
| 2269 | cfqq->ioprio = IOPRIO_NORM; |
| 2270 | } else { |
| 2271 | /* |
| 2272 | * check if we need to unboost the queue |
| 2273 | */ |
| 2274 | if (cfqq->ioprio_class != cfqq->org_ioprio_class) |
| 2275 | cfqq->ioprio_class = cfqq->org_ioprio_class; |
| 2276 | if (cfqq->ioprio != cfqq->org_ioprio) |
| 2277 | cfqq->ioprio = cfqq->org_ioprio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2278 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2279 | } |
| 2280 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2281 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2282 | { |
Jens Axboe | 1b379d8 | 2009-08-11 08:26:11 +0200 | [diff] [blame] | 2283 | if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2284 | cfq_mark_cfqq_must_alloc_slice(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2285 | return ELV_MQUEUE_MUST; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2286 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2287 | |
| 2288 | return ELV_MQUEUE_MAY; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2289 | } |
| 2290 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2291 | static int cfq_may_queue(struct request_queue *q, int rw) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2292 | { |
| 2293 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 2294 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2295 | struct cfq_io_context *cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2296 | struct cfq_queue *cfqq; |
| 2297 | |
| 2298 | /* |
| 2299 | * don't force setup of a queue from here, as a call to may_queue |
| 2300 | * does not necessarily imply that a request actually will be queued. |
| 2301 | * so just lookup a possibly existing queue, or return 'may queue' |
| 2302 | * if that fails |
| 2303 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2304 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2305 | if (!cic) |
| 2306 | return ELV_MQUEUE_MAY; |
| 2307 | |
Jens Axboe | b0b78f8 | 2009-04-08 10:56:08 +0200 | [diff] [blame] | 2308 | cfqq = cic_to_cfqq(cic, rw_is_sync(rw)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2309 | if (cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2310 | cfq_init_prio_data(cfqq, cic->ioc); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2311 | cfq_prio_boost(cfqq); |
| 2312 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2313 | return __cfq_may_queue(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2314 | } |
| 2315 | |
| 2316 | return ELV_MQUEUE_MAY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2317 | } |
| 2318 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2319 | /* |
| 2320 | * queue lock held here |
| 2321 | */ |
Jens Axboe | bb37b94 | 2006-12-01 10:42:33 +0100 | [diff] [blame] | 2322 | static void cfq_put_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2323 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2324 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2325 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2326 | if (cfqq) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2327 | const int rw = rq_data_dir(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2328 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2329 | BUG_ON(!cfqq->allocated[rw]); |
| 2330 | cfqq->allocated[rw]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2331 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2332 | put_io_context(RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2333 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2334 | rq->elevator_private = NULL; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2335 | rq->elevator_private2 = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2336 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2337 | cfq_put_queue(cfqq); |
| 2338 | } |
| 2339 | } |
| 2340 | |
| 2341 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2342 | * Allocate cfq data structures associated with this request. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2343 | */ |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2344 | static int |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2345 | 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] | 2346 | { |
| 2347 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 2348 | struct cfq_io_context *cic; |
| 2349 | const int rw = rq_data_dir(rq); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2350 | const bool is_sync = rq_is_sync(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2351 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2352 | unsigned long flags; |
| 2353 | |
| 2354 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 2355 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2356 | cic = cfq_get_io_context(cfqd, gfp_mask); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2357 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2358 | spin_lock_irqsave(q->queue_lock, flags); |
| 2359 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2360 | if (!cic) |
| 2361 | goto queue_fail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2362 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2363 | cfqq = cic_to_cfqq(cic, is_sync); |
Vivek Goyal | 32f2e80 | 2009-07-09 22:13:16 +0200 | [diff] [blame] | 2364 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2365 | cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2366 | cic_set_cfqq(cic, cfqq, is_sync); |
| 2367 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2368 | |
| 2369 | cfqq->allocated[rw]++; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2370 | atomic_inc(&cfqq->ref); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2371 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2372 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2373 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2374 | rq->elevator_private = cic; |
| 2375 | rq->elevator_private2 = cfqq; |
| 2376 | return 0; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2377 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2378 | queue_fail: |
| 2379 | if (cic) |
| 2380 | put_io_context(cic->ioc); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2381 | |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2382 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2383 | spin_unlock_irqrestore(q->queue_lock, flags); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2384 | cfq_log(cfqd, "set_request fail"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2385 | return 1; |
| 2386 | } |
| 2387 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 2388 | static void cfq_kick_queue(struct work_struct *work) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2389 | { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 2390 | struct cfq_data *cfqd = |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2391 | container_of(work, struct cfq_data, unplug_work); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2392 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2393 | |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 2394 | spin_lock_irq(q->queue_lock); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 2395 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 2396 | spin_unlock_irq(q->queue_lock); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2397 | } |
| 2398 | |
| 2399 | /* |
| 2400 | * Timer running if the active_queue is currently idling inside its time slice |
| 2401 | */ |
| 2402 | static void cfq_idle_slice_timer(unsigned long data) |
| 2403 | { |
| 2404 | struct cfq_data *cfqd = (struct cfq_data *) data; |
| 2405 | struct cfq_queue *cfqq; |
| 2406 | unsigned long flags; |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 2407 | int timed_out = 1; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2408 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2409 | cfq_log(cfqd, "idle timer fired"); |
| 2410 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2411 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 2412 | |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2413 | cfqq = cfqd->active_queue; |
| 2414 | if (cfqq) { |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 2415 | timed_out = 0; |
| 2416 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2417 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 2418 | * We saw a request before the queue expired, let it through |
| 2419 | */ |
| 2420 | if (cfq_cfqq_must_dispatch(cfqq)) |
| 2421 | goto out_kick; |
| 2422 | |
| 2423 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2424 | * expired |
| 2425 | */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 2426 | if (cfq_slice_used(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2427 | goto expire; |
| 2428 | |
| 2429 | /* |
| 2430 | * only expire and reinvoke request handler, if there are |
| 2431 | * other queues with pending requests |
| 2432 | */ |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2433 | if (!cfqd->busy_queues) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2434 | goto out_cont; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2435 | |
| 2436 | /* |
| 2437 | * not expired and it has a request pending, let it dispatch |
| 2438 | */ |
Jens Axboe | 75e5098 | 2009-04-07 08:56:14 +0200 | [diff] [blame] | 2439 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2440 | goto out_kick; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2441 | } |
| 2442 | expire: |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2443 | cfq_slice_expired(cfqd, timed_out); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2444 | out_kick: |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2445 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2446 | out_cont: |
| 2447 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 2448 | } |
| 2449 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2450 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) |
| 2451 | { |
| 2452 | del_timer_sync(&cfqd->idle_slice_timer); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2453 | cancel_work_sync(&cfqd->unplug_work); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2454 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2455 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2456 | static void cfq_put_async_queues(struct cfq_data *cfqd) |
| 2457 | { |
| 2458 | int i; |
| 2459 | |
| 2460 | for (i = 0; i < IOPRIO_BE_NR; i++) { |
| 2461 | if (cfqd->async_cfqq[0][i]) |
| 2462 | cfq_put_queue(cfqd->async_cfqq[0][i]); |
| 2463 | if (cfqd->async_cfqq[1][i]) |
| 2464 | cfq_put_queue(cfqd->async_cfqq[1][i]); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2465 | } |
Oleg Nesterov | 2389d1e | 2007-11-05 08:58:05 +0100 | [diff] [blame] | 2466 | |
| 2467 | if (cfqd->async_idle_cfqq) |
| 2468 | cfq_put_queue(cfqd->async_idle_cfqq); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2469 | } |
| 2470 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 2471 | static void cfq_exit_queue(struct elevator_queue *e) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2472 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2473 | struct cfq_data *cfqd = e->elevator_data; |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2474 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2475 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2476 | cfq_shutdown_timer_wq(cfqd); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2477 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2478 | spin_lock_irq(q->queue_lock); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2479 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2480 | if (cfqd->active_queue) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2481 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2482 | |
| 2483 | while (!list_empty(&cfqd->cic_list)) { |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2484 | struct cfq_io_context *cic = list_entry(cfqd->cic_list.next, |
| 2485 | struct cfq_io_context, |
| 2486 | queue_list); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2487 | |
| 2488 | __cfq_exit_single_io_context(cfqd, cic); |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2489 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2490 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2491 | cfq_put_async_queues(cfqd); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2492 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2493 | spin_unlock_irq(q->queue_lock); |
Al Viro | a90d742 | 2006-03-18 12:05:37 -0500 | [diff] [blame] | 2494 | |
| 2495 | cfq_shutdown_timer_wq(cfqd); |
| 2496 | |
Al Viro | a90d742 | 2006-03-18 12:05:37 -0500 | [diff] [blame] | 2497 | kfree(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2498 | } |
| 2499 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2500 | static void *cfq_init_queue(struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2501 | { |
| 2502 | struct cfq_data *cfqd; |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 2503 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2504 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2505 | cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2506 | if (!cfqd) |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 2507 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2508 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 2509 | cfqd->service_tree = CFQ_RB_ROOT; |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 2510 | |
| 2511 | /* |
| 2512 | * Not strictly needed (since RB_ROOT just clears the node and we |
| 2513 | * zeroed cfqd on alloc), but better be safe in case someone decides |
| 2514 | * to add magic to the rb code |
| 2515 | */ |
| 2516 | for (i = 0; i < CFQ_PRIO_LISTS; i++) |
| 2517 | cfqd->prio_trees[i] = RB_ROOT; |
| 2518 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2519 | /* |
| 2520 | * Our fallback cfqq if cfq_find_alloc_queue() runs into OOM issues. |
| 2521 | * Grab a permanent reference to it, so that the normal code flow |
| 2522 | * will not attempt to free it. |
| 2523 | */ |
| 2524 | cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); |
| 2525 | atomic_inc(&cfqd->oom_cfqq.ref); |
| 2526 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2527 | INIT_LIST_HEAD(&cfqd->cic_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2528 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2529 | cfqd->queue = q; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2530 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2531 | init_timer(&cfqd->idle_slice_timer); |
| 2532 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; |
| 2533 | cfqd->idle_slice_timer.data = (unsigned long) cfqd; |
| 2534 | |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2535 | INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2536 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2537 | cfqd->cfq_quantum = cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2538 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |
| 2539 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2540 | cfqd->cfq_back_max = cfq_back_max; |
| 2541 | cfqd->cfq_back_penalty = cfq_back_penalty; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2542 | cfqd->cfq_slice[0] = cfq_slice_async; |
| 2543 | cfqd->cfq_slice[1] = cfq_slice_sync; |
| 2544 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; |
| 2545 | cfqd->cfq_slice_idle = cfq_slice_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2546 | cfqd->cfq_latency = 1; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2547 | cfqd->hw_tag = 1; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2548 | cfqd->last_end_sync_rq = jiffies; |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 2549 | return cfqd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2550 | } |
| 2551 | |
| 2552 | static void cfq_slab_kill(void) |
| 2553 | { |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2554 | /* |
| 2555 | * Caller already ensured that pending RCU callbacks are completed, |
| 2556 | * so we should have no busy allocations at this point. |
| 2557 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2558 | if (cfq_pool) |
| 2559 | kmem_cache_destroy(cfq_pool); |
| 2560 | if (cfq_ioc_pool) |
| 2561 | kmem_cache_destroy(cfq_ioc_pool); |
| 2562 | } |
| 2563 | |
| 2564 | static int __init cfq_slab_setup(void) |
| 2565 | { |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame] | 2566 | cfq_pool = KMEM_CACHE(cfq_queue, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2567 | if (!cfq_pool) |
| 2568 | goto fail; |
| 2569 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2570 | cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2571 | if (!cfq_ioc_pool) |
| 2572 | goto fail; |
| 2573 | |
| 2574 | return 0; |
| 2575 | fail: |
| 2576 | cfq_slab_kill(); |
| 2577 | return -ENOMEM; |
| 2578 | } |
| 2579 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2580 | /* |
| 2581 | * sysfs parts below --> |
| 2582 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2583 | static ssize_t |
| 2584 | cfq_var_show(unsigned int var, char *page) |
| 2585 | { |
| 2586 | return sprintf(page, "%d\n", var); |
| 2587 | } |
| 2588 | |
| 2589 | static ssize_t |
| 2590 | cfq_var_store(unsigned int *var, const char *page, size_t count) |
| 2591 | { |
| 2592 | char *p = (char *) page; |
| 2593 | |
| 2594 | *var = simple_strtoul(p, &p, 10); |
| 2595 | return count; |
| 2596 | } |
| 2597 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2598 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 2599 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2600 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 2601 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2602 | unsigned int __data = __VAR; \ |
| 2603 | if (__CONV) \ |
| 2604 | __data = jiffies_to_msecs(__data); \ |
| 2605 | return cfq_var_show(__data, (page)); \ |
| 2606 | } |
| 2607 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2608 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); |
| 2609 | 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] | 2610 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); |
| 2611 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2612 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); |
| 2613 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); |
| 2614 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); |
| 2615 | 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] | 2616 | SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2617 | #undef SHOW_FUNCTION |
| 2618 | |
| 2619 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 2620 | 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] | 2621 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 2622 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2623 | unsigned int __data; \ |
| 2624 | int ret = cfq_var_store(&__data, (page), count); \ |
| 2625 | if (__data < (MIN)) \ |
| 2626 | __data = (MIN); \ |
| 2627 | else if (__data > (MAX)) \ |
| 2628 | __data = (MAX); \ |
| 2629 | if (__CONV) \ |
| 2630 | *(__PTR) = msecs_to_jiffies(__data); \ |
| 2631 | else \ |
| 2632 | *(__PTR) = __data; \ |
| 2633 | return ret; \ |
| 2634 | } |
| 2635 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2636 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, |
| 2637 | UINT_MAX, 1); |
| 2638 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, |
| 2639 | UINT_MAX, 1); |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2640 | 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] | 2641 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, |
| 2642 | UINT_MAX, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2643 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); |
| 2644 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); |
| 2645 | 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] | 2646 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, |
| 2647 | UINT_MAX, 0); |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2648 | STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2649 | #undef STORE_FUNCTION |
| 2650 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2651 | #define CFQ_ATTR(name) \ |
| 2652 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2653 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2654 | static struct elv_fs_entry cfq_attrs[] = { |
| 2655 | CFQ_ATTR(quantum), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2656 | CFQ_ATTR(fifo_expire_sync), |
| 2657 | CFQ_ATTR(fifo_expire_async), |
| 2658 | CFQ_ATTR(back_seek_max), |
| 2659 | CFQ_ATTR(back_seek_penalty), |
| 2660 | CFQ_ATTR(slice_sync), |
| 2661 | CFQ_ATTR(slice_async), |
| 2662 | CFQ_ATTR(slice_async_rq), |
| 2663 | CFQ_ATTR(slice_idle), |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2664 | CFQ_ATTR(low_latency), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2665 | __ATTR_NULL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2666 | }; |
| 2667 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2668 | static struct elevator_type iosched_cfq = { |
| 2669 | .ops = { |
| 2670 | .elevator_merge_fn = cfq_merge, |
| 2671 | .elevator_merged_fn = cfq_merged_request, |
| 2672 | .elevator_merge_req_fn = cfq_merged_requests, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 2673 | .elevator_allow_merge_fn = cfq_allow_merge, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2674 | .elevator_dispatch_fn = cfq_dispatch_requests, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2675 | .elevator_add_req_fn = cfq_insert_request, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2676 | .elevator_activate_req_fn = cfq_activate_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2677 | .elevator_deactivate_req_fn = cfq_deactivate_request, |
| 2678 | .elevator_queue_empty_fn = cfq_queue_empty, |
| 2679 | .elevator_completed_req_fn = cfq_completed_request, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 2680 | .elevator_former_req_fn = elv_rb_former_request, |
| 2681 | .elevator_latter_req_fn = elv_rb_latter_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2682 | .elevator_set_req_fn = cfq_set_request, |
| 2683 | .elevator_put_req_fn = cfq_put_request, |
| 2684 | .elevator_may_queue_fn = cfq_may_queue, |
| 2685 | .elevator_init_fn = cfq_init_queue, |
| 2686 | .elevator_exit_fn = cfq_exit_queue, |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2687 | .trim = cfq_free_io_context, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2688 | }, |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 2689 | .elevator_attrs = cfq_attrs, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2690 | .elevator_name = "cfq", |
| 2691 | .elevator_owner = THIS_MODULE, |
| 2692 | }; |
| 2693 | |
| 2694 | static int __init cfq_init(void) |
| 2695 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2696 | /* |
| 2697 | * could be 0 on HZ < 1000 setups |
| 2698 | */ |
| 2699 | if (!cfq_slice_async) |
| 2700 | cfq_slice_async = 1; |
| 2701 | if (!cfq_slice_idle) |
| 2702 | cfq_slice_idle = 1; |
| 2703 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2704 | if (cfq_slab_setup()) |
| 2705 | return -ENOMEM; |
| 2706 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 2707 | elv_register(&iosched_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2708 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 2709 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2710 | } |
| 2711 | |
| 2712 | static void __exit cfq_exit(void) |
| 2713 | { |
Peter Zijlstra | 6e9a473 | 2006-09-30 23:28:10 -0700 | [diff] [blame] | 2714 | DECLARE_COMPLETION_ONSTACK(all_gone); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2715 | elv_unregister(&iosched_cfq); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 2716 | ioc_gone = &all_gone; |
OGAWA Hirofumi | fba8227 | 2006-04-18 09:44:06 +0200 | [diff] [blame] | 2717 | /* ioc_gone's update must be visible before reading ioc_count */ |
| 2718 | smp_wmb(); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2719 | |
| 2720 | /* |
| 2721 | * this also protects us from entering cfq_slab_kill() with |
| 2722 | * pending RCU callbacks |
| 2723 | */ |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2724 | if (elv_ioc_count_read(cfq_ioc_count)) |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 2725 | wait_for_completion(&all_gone); |
Christoph Hellwig | 83521d3 | 2005-10-30 15:01:39 -0800 | [diff] [blame] | 2726 | cfq_slab_kill(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2727 | } |
| 2728 | |
| 2729 | module_init(cfq_init); |
| 2730 | module_exit(cfq_exit); |
| 2731 | |
| 2732 | MODULE_AUTHOR("Jens Axboe"); |
| 2733 | MODULE_LICENSE("GPL"); |
| 2734 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |