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 | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 153 | struct delayed_work 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 | b0b8d749 | 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 | b0b8d749 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 192 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ |
Jens Axboe | b0b8d749 | 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 */ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 199 | }; |
| 200 | |
| 201 | #define CFQ_CFQQ_FNS(name) \ |
| 202 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ |
| 203 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 204 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 205 | } \ |
| 206 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ |
| 207 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 208 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 209 | } \ |
| 210 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ |
| 211 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 212 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 213 | } |
| 214 | |
| 215 | CFQ_CFQQ_FNS(on_rr); |
| 216 | CFQ_CFQQ_FNS(wait_request); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 217 | CFQ_CFQQ_FNS(must_dispatch); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 218 | CFQ_CFQQ_FNS(must_alloc_slice); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 219 | CFQ_CFQQ_FNS(fifo_expire); |
| 220 | CFQ_CFQQ_FNS(idle_window); |
| 221 | CFQ_CFQQ_FNS(prio_changed); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 222 | CFQ_CFQQ_FNS(slice_new); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 223 | CFQ_CFQQ_FNS(sync); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 224 | CFQ_CFQQ_FNS(coop); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 225 | #undef CFQ_CFQQ_FNS |
| 226 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 227 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 228 | blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args) |
| 229 | #define cfq_log(cfqd, fmt, args...) \ |
| 230 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) |
| 231 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 232 | static void cfq_dispatch_insert(struct request_queue *, struct request *); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 233 | static struct cfq_queue *cfq_get_queue(struct cfq_data *, int, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 234 | struct io_context *, gfp_t); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 235 | static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *, |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 236 | struct io_context *); |
| 237 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 238 | static inline int rq_in_driver(struct cfq_data *cfqd) |
| 239 | { |
| 240 | return cfqd->rq_in_driver[0] + cfqd->rq_in_driver[1]; |
| 241 | } |
| 242 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 243 | static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic, |
| 244 | int is_sync) |
| 245 | { |
| 246 | return cic->cfqq[!!is_sync]; |
| 247 | } |
| 248 | |
| 249 | static inline void cic_set_cfqq(struct cfq_io_context *cic, |
| 250 | struct cfq_queue *cfqq, int is_sync) |
| 251 | { |
| 252 | cic->cfqq[!!is_sync] = cfqq; |
| 253 | } |
| 254 | |
| 255 | /* |
| 256 | * We regard a request as SYNC, if it's either a read or has the SYNC bit |
| 257 | * set (in which case it could also be direct WRITE). |
| 258 | */ |
| 259 | static inline int cfq_bio_sync(struct bio *bio) |
| 260 | { |
Jens Axboe | 1f98a13 | 2009-09-11 14:32:04 +0200 | [diff] [blame] | 261 | if (bio_data_dir(bio) == READ || bio_rw_flagged(bio, BIO_RW_SYNCIO)) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 262 | return 1; |
| 263 | |
| 264 | return 0; |
| 265 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | /* |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 268 | * scheduler run of queue, if there are requests pending and no one in the |
| 269 | * driver that will restart queueing |
| 270 | */ |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 271 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd, |
| 272 | unsigned long delay) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 273 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 274 | if (cfqd->busy_queues) { |
| 275 | cfq_log(cfqd, "schedule dispatch"); |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 276 | kblockd_schedule_delayed_work(cfqd->queue, &cfqd->unplug_work, |
| 277 | delay); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 278 | } |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 279 | } |
| 280 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 281 | static int cfq_queue_empty(struct request_queue *q) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 282 | { |
| 283 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 284 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 285 | return !cfqd->busy_queues; |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 286 | } |
| 287 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | /* |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 289 | * Scale schedule slice based on io priority. Use the sync time slice only |
| 290 | * if a queue is marked sync and has sync io queued. A sync queue with async |
| 291 | * io only, should not get full sync slice length. |
| 292 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 293 | static inline int cfq_prio_slice(struct cfq_data *cfqd, int sync, |
| 294 | unsigned short prio) |
| 295 | { |
| 296 | const int base_slice = cfqd->cfq_slice[sync]; |
| 297 | |
| 298 | WARN_ON(prio >= IOPRIO_BE_NR); |
| 299 | |
| 300 | return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); |
| 301 | } |
| 302 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 303 | static inline int |
| 304 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 305 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 306 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 307 | } |
| 308 | |
| 309 | static inline void |
| 310 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 311 | { |
| 312 | cfqq->slice_end = cfq_prio_to_slice(cfqd, cfqq) + jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 313 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 314 | } |
| 315 | |
| 316 | /* |
| 317 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end |
| 318 | * isn't valid until the first request from the dispatch is activated |
| 319 | * and the slice time set. |
| 320 | */ |
| 321 | static inline int cfq_slice_used(struct cfq_queue *cfqq) |
| 322 | { |
| 323 | if (cfq_cfqq_slice_new(cfqq)) |
| 324 | return 0; |
| 325 | if (time_before(jiffies, cfqq->slice_end)) |
| 326 | return 0; |
| 327 | |
| 328 | return 1; |
| 329 | } |
| 330 | |
| 331 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 332 | * 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] | 333 | * 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] | 334 | * behind the head is penalized and only allowed to a certain extent. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 336 | static struct request * |
| 337 | 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] | 338 | { |
| 339 | sector_t last, s1, s2, d1 = 0, d2 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | unsigned long back_max; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 341 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ |
| 342 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ |
| 343 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 345 | if (rq1 == NULL || rq1 == rq2) |
| 346 | return rq2; |
| 347 | if (rq2 == NULL) |
| 348 | return rq1; |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 349 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 350 | if (rq_is_sync(rq1) && !rq_is_sync(rq2)) |
| 351 | return rq1; |
| 352 | else if (rq_is_sync(rq2) && !rq_is_sync(rq1)) |
| 353 | return rq2; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 354 | if (rq_is_meta(rq1) && !rq_is_meta(rq2)) |
| 355 | return rq1; |
| 356 | else if (rq_is_meta(rq2) && !rq_is_meta(rq1)) |
| 357 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 359 | s1 = blk_rq_pos(rq1); |
| 360 | s2 = blk_rq_pos(rq2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 362 | last = cfqd->last_position; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | /* |
| 365 | * by definition, 1KiB is 2 sectors |
| 366 | */ |
| 367 | back_max = cfqd->cfq_back_max * 2; |
| 368 | |
| 369 | /* |
| 370 | * Strict one way elevator _except_ in the case where we allow |
| 371 | * short backward seeks which are biased as twice the cost of a |
| 372 | * similar forward seek. |
| 373 | */ |
| 374 | if (s1 >= last) |
| 375 | d1 = s1 - last; |
| 376 | else if (s1 + back_max >= last) |
| 377 | d1 = (last - s1) * cfqd->cfq_back_penalty; |
| 378 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 379 | wrap |= CFQ_RQ1_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | |
| 381 | if (s2 >= last) |
| 382 | d2 = s2 - last; |
| 383 | else if (s2 + back_max >= last) |
| 384 | d2 = (last - s2) * cfqd->cfq_back_penalty; |
| 385 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 386 | wrap |= CFQ_RQ2_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | |
| 388 | /* Found required data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 390 | /* |
| 391 | * By doing switch() on the bit mask "wrap" we avoid having to |
| 392 | * check two variables for all permutations: --> faster! |
| 393 | */ |
| 394 | switch (wrap) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 395 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 396 | if (d1 < d2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 397 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 398 | else if (d2 < d1) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 399 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 400 | else { |
| 401 | if (s1 >= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 402 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 403 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 404 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 405 | } |
| 406 | |
| 407 | case CFQ_RQ2_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 408 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 409 | case CFQ_RQ1_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 410 | return rq2; |
| 411 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 412 | default: |
| 413 | /* |
| 414 | * Since both rqs are wrapped, |
| 415 | * start with the one that's further behind head |
| 416 | * (--> only *one* back seek required), |
| 417 | * since back seek takes more time than forward. |
| 418 | */ |
| 419 | if (s1 <= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 420 | return rq1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 422 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | } |
| 424 | } |
| 425 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 426 | /* |
| 427 | * The below is leftmost cache rbtree addon |
| 428 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 429 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 430 | { |
| 431 | if (!root->left) |
| 432 | root->left = rb_first(&root->rb); |
| 433 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 434 | if (root->left) |
| 435 | return rb_entry(root->left, struct cfq_queue, rb_node); |
| 436 | |
| 437 | return NULL; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 438 | } |
| 439 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 440 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
| 441 | { |
| 442 | rb_erase(n, root); |
| 443 | RB_CLEAR_NODE(n); |
| 444 | } |
| 445 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 446 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) |
| 447 | { |
| 448 | if (root->left == n) |
| 449 | root->left = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 450 | rb_erase_init(n, &root->rb); |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 451 | } |
| 452 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | /* |
| 454 | * would be nice to take fifo expire time into account as well |
| 455 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 456 | static struct request * |
| 457 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 458 | struct request *last) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 460 | struct rb_node *rbnext = rb_next(&last->rb_node); |
| 461 | struct rb_node *rbprev = rb_prev(&last->rb_node); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 462 | struct request *next = NULL, *prev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 464 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | |
| 466 | if (rbprev) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 467 | prev = rb_entry_rq(rbprev); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 468 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | if (rbnext) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 470 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 471 | else { |
| 472 | rbnext = rb_first(&cfqq->sort_list); |
| 473 | if (rbnext && rbnext != &last->rb_node) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 474 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 475 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 477 | return cfq_choose_req(cfqd, next, prev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | } |
| 479 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 480 | static unsigned long cfq_slice_offset(struct cfq_data *cfqd, |
| 481 | struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 483 | /* |
| 484 | * just an approximation, should be ok. |
| 485 | */ |
Jens Axboe | 67e6b49 | 2007-04-20 14:18:00 +0200 | [diff] [blame] | 486 | return (cfqd->busy_queues - 1) * (cfq_prio_slice(cfqd, 1, 0) - |
| 487 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 488 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 489 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 490 | /* |
| 491 | * The cfqd->service_tree holds all pending cfq_queue's that have |
| 492 | * requests waiting to be processed. It is sorted in the order that |
| 493 | * we will service the queues. |
| 494 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 495 | static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 496 | int add_front) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 497 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 498 | struct rb_node **p, *parent; |
| 499 | struct cfq_queue *__cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 500 | unsigned long rb_key; |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 501 | int left; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 502 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 503 | if (cfq_class_idle(cfqq)) { |
| 504 | rb_key = CFQ_IDLE_DELAY; |
| 505 | parent = rb_last(&cfqd->service_tree.rb); |
| 506 | if (parent && parent != &cfqq->rb_node) { |
| 507 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 508 | rb_key += __cfqq->rb_key; |
| 509 | } else |
| 510 | rb_key += jiffies; |
| 511 | } else if (!add_front) { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 512 | rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; |
| 513 | rb_key += cfqq->slice_resid; |
| 514 | cfqq->slice_resid = 0; |
| 515 | } else |
| 516 | rb_key = 0; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 517 | |
| 518 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 519 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 520 | * same position, nothing more to do |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 521 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 522 | if (rb_key == cfqq->rb_key) |
| 523 | return; |
Jens Axboe | 53b03744 | 2006-07-28 09:48:51 +0200 | [diff] [blame] | 524 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 525 | cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 526 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 527 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 528 | left = 1; |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 529 | parent = NULL; |
| 530 | p = &cfqd->service_tree.rb.rb_node; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 531 | while (*p) { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 532 | struct rb_node **n; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 533 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 534 | parent = *p; |
| 535 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 536 | |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 537 | /* |
| 538 | * sort RT queues first, we always want to give |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 539 | * preference to them. IDLE queues goes to the back. |
| 540 | * after that, sort on the next service time. |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 541 | */ |
| 542 | if (cfq_class_rt(cfqq) > cfq_class_rt(__cfqq)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 543 | n = &(*p)->rb_left; |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 544 | else if (cfq_class_rt(cfqq) < cfq_class_rt(__cfqq)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 545 | n = &(*p)->rb_right; |
| 546 | else if (cfq_class_idle(cfqq) < cfq_class_idle(__cfqq)) |
| 547 | n = &(*p)->rb_left; |
| 548 | else if (cfq_class_idle(cfqq) > cfq_class_idle(__cfqq)) |
| 549 | n = &(*p)->rb_right; |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 550 | else if (rb_key < __cfqq->rb_key) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 551 | n = &(*p)->rb_left; |
| 552 | else |
| 553 | n = &(*p)->rb_right; |
| 554 | |
| 555 | if (n == &(*p)->rb_right) |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 556 | left = 0; |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 557 | |
| 558 | p = n; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 559 | } |
| 560 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 561 | if (left) |
| 562 | cfqd->service_tree.left = &cfqq->rb_node; |
| 563 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 564 | cfqq->rb_key = rb_key; |
| 565 | rb_link_node(&cfqq->rb_node, parent, p); |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 566 | rb_insert_color(&cfqq->rb_node, &cfqd->service_tree.rb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | } |
| 568 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 569 | static struct cfq_queue * |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 570 | cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, |
| 571 | sector_t sector, struct rb_node **ret_parent, |
| 572 | struct rb_node ***rb_link) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 573 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 574 | struct rb_node **p, *parent; |
| 575 | struct cfq_queue *cfqq = NULL; |
| 576 | |
| 577 | parent = NULL; |
| 578 | p = &root->rb_node; |
| 579 | while (*p) { |
| 580 | struct rb_node **n; |
| 581 | |
| 582 | parent = *p; |
| 583 | cfqq = rb_entry(parent, struct cfq_queue, p_node); |
| 584 | |
| 585 | /* |
| 586 | * Sort strictly based on sector. Smallest to the left, |
| 587 | * largest to the right. |
| 588 | */ |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 589 | if (sector > blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 590 | n = &(*p)->rb_right; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 591 | else if (sector < blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 592 | n = &(*p)->rb_left; |
| 593 | else |
| 594 | break; |
| 595 | p = n; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 596 | cfqq = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 597 | } |
| 598 | |
| 599 | *ret_parent = parent; |
| 600 | if (rb_link) |
| 601 | *rb_link = p; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 602 | return cfqq; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 603 | } |
| 604 | |
| 605 | static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 606 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 607 | struct rb_node **p, *parent; |
| 608 | struct cfq_queue *__cfqq; |
| 609 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 610 | if (cfqq->p_root) { |
| 611 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 612 | cfqq->p_root = NULL; |
| 613 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 614 | |
| 615 | if (cfq_class_idle(cfqq)) |
| 616 | return; |
| 617 | if (!cfqq->next_rq) |
| 618 | return; |
| 619 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 620 | cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 621 | __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, |
| 622 | blk_rq_pos(cfqq->next_rq), &parent, &p); |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 623 | if (!__cfqq) { |
| 624 | rb_link_node(&cfqq->p_node, parent, p); |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 625 | rb_insert_color(&cfqq->p_node, cfqq->p_root); |
| 626 | } else |
| 627 | cfqq->p_root = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 628 | } |
| 629 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 630 | /* |
| 631 | * Update cfqq's position in the service tree. |
| 632 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 633 | 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] | 634 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 635 | /* |
| 636 | * Resorting requires the cfqq to be on the RR list already. |
| 637 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 638 | if (cfq_cfqq_on_rr(cfqq)) { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 639 | cfq_service_tree_add(cfqd, cfqq, 0); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 640 | cfq_prio_tree_add(cfqd, cfqq); |
| 641 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 642 | } |
| 643 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | /* |
| 645 | * 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] | 646 | * the pending list according to last request service |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 648 | 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] | 649 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 650 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 651 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
| 652 | cfq_mark_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | cfqd->busy_queues++; |
| 654 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 655 | cfq_resort_rr_list(cfqd, cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | } |
| 657 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 658 | /* |
| 659 | * Called when the cfqq no longer has requests pending, remove it from |
| 660 | * the service tree. |
| 661 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 662 | 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] | 663 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 664 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 665 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
| 666 | cfq_clear_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 668 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) |
| 669 | cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree); |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 670 | if (cfqq->p_root) { |
| 671 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 672 | cfqq->p_root = NULL; |
| 673 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 674 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 675 | BUG_ON(!cfqd->busy_queues); |
| 676 | cfqd->busy_queues--; |
| 677 | } |
| 678 | |
| 679 | /* |
| 680 | * rb tree support functions |
| 681 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 682 | static void cfq_del_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 683 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 684 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 685 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 686 | const int sync = rq_is_sync(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 688 | BUG_ON(!cfqq->queued[sync]); |
| 689 | cfqq->queued[sync]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 691 | elv_rb_del(&cfqq->sort_list, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 692 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 693 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 694 | cfq_del_cfqq_rr(cfqd, cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 695 | } |
| 696 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 697 | static void cfq_add_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 698 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 699 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 701 | struct request *__alias, *prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 702 | |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 703 | cfqq->queued[rq_is_sync(rq)]++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | |
| 705 | /* |
| 706 | * looks a little odd, but the first insert might return an alias. |
| 707 | * if that happens, put the alias on the dispatch list |
| 708 | */ |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 709 | while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 710 | cfq_dispatch_insert(cfqd->queue, __alias); |
Jens Axboe | 5fccbf6 | 2006-10-31 14:21:55 +0100 | [diff] [blame] | 711 | |
| 712 | if (!cfq_cfqq_on_rr(cfqq)) |
| 713 | cfq_add_cfqq_rr(cfqd, cfqq); |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 714 | |
| 715 | /* |
| 716 | * check if this request is a better next-serve candidate |
| 717 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 718 | prev = cfqq->next_rq; |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 719 | cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 720 | |
| 721 | /* |
| 722 | * adjust priority tree position, if ->next_rq changes |
| 723 | */ |
| 724 | if (prev != cfqq->next_rq) |
| 725 | cfq_prio_tree_add(cfqd, cfqq); |
| 726 | |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 727 | BUG_ON(!cfqq->next_rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | } |
| 729 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 730 | 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] | 731 | { |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 732 | elv_rb_del(&cfqq->sort_list, rq); |
| 733 | cfqq->queued[rq_is_sync(rq)]--; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 734 | cfq_add_rq_rb(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | } |
| 736 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 737 | static struct request * |
| 738 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 739 | { |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 740 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 741 | struct cfq_io_context *cic; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 742 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 744 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 745 | if (!cic) |
| 746 | return NULL; |
| 747 | |
| 748 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 749 | if (cfqq) { |
| 750 | sector_t sector = bio->bi_sector + bio_sectors(bio); |
| 751 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 752 | return elv_rb_find(&cfqq->sort_list, sector); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 753 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 754 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | return NULL; |
| 756 | } |
| 757 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 758 | static void cfq_activate_request(struct request_queue *q, struct request *rq) |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 759 | { |
| 760 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 761 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 762 | cfqd->rq_in_driver[rq_is_sync(rq)]++; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 763 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 764 | rq_in_driver(cfqd)); |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 765 | |
Tejun Heo | 5b93629 | 2009-05-07 22:24:38 +0900 | [diff] [blame] | 766 | cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 767 | } |
| 768 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 769 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 771 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 772 | const int sync = rq_is_sync(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 774 | WARN_ON(!cfqd->rq_in_driver[sync]); |
| 775 | cfqd->rq_in_driver[sync]--; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 776 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 777 | rq_in_driver(cfqd)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | } |
| 779 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 780 | static void cfq_remove_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 782 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 783 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 784 | if (cfqq->next_rq == rq) |
| 785 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 787 | list_del_init(&rq->queuelist); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 788 | cfq_del_rq_rb(rq); |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 789 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 790 | cfqq->cfqd->rq_queued--; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 791 | if (rq_is_meta(rq)) { |
| 792 | WARN_ON(!cfqq->meta_pending); |
| 793 | cfqq->meta_pending--; |
| 794 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | } |
| 796 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 797 | static int cfq_merge(struct request_queue *q, struct request **req, |
| 798 | struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | { |
| 800 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 801 | struct request *__rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 802 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 803 | __rq = cfq_find_rq_fmerge(cfqd, bio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 804 | if (__rq && elv_rq_merge_ok(__rq, bio)) { |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 805 | *req = __rq; |
| 806 | return ELEVATOR_FRONT_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | } |
| 808 | |
| 809 | return ELEVATOR_NO_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | } |
| 811 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 812 | static void cfq_merged_request(struct request_queue *q, struct request *req, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 813 | int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 814 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 815 | if (type == ELEVATOR_FRONT_MERGE) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 816 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 817 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 818 | cfq_reposition_rq_rb(cfqq, req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 820 | } |
| 821 | |
| 822 | static void |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 823 | cfq_merged_requests(struct request_queue *q, struct request *rq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 824 | struct request *next) |
| 825 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 826 | /* |
| 827 | * reposition in fifo if next is older than rq |
| 828 | */ |
| 829 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame^] | 830 | time_before(rq_fifo_time(next), rq_fifo_time(rq))) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 831 | list_move(&rq->queuelist, &next->queuelist); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame^] | 832 | rq_set_fifo_time(rq, rq_fifo_time(next)); |
| 833 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 834 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 835 | cfq_remove_request(next); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 836 | } |
| 837 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 838 | static int cfq_allow_merge(struct request_queue *q, struct request *rq, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 839 | struct bio *bio) |
| 840 | { |
| 841 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 842 | struct cfq_io_context *cic; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 843 | struct cfq_queue *cfqq; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 844 | |
| 845 | /* |
Jens Axboe | ec8acb6 | 2007-01-02 18:32:11 +0100 | [diff] [blame] | 846 | * Disallow merge of a sync bio into an async request. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 847 | */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 848 | if (cfq_bio_sync(bio) && !rq_is_sync(rq)) |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 849 | return 0; |
| 850 | |
| 851 | /* |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 852 | * Lookup the cfqq that this bio will be queued with. Allow |
| 853 | * merge only if rq is queued there. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 854 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 855 | cic = cfq_cic_lookup(cfqd, current->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 856 | if (!cic) |
| 857 | return 0; |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 858 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 859 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 860 | if (cfqq == RQ_CFQQ(rq)) |
| 861 | return 1; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 862 | |
Jens Axboe | ec8acb6 | 2007-01-02 18:32:11 +0100 | [diff] [blame] | 863 | return 0; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 864 | } |
| 865 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 866 | static void __cfq_set_active_queue(struct cfq_data *cfqd, |
| 867 | struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 868 | { |
| 869 | if (cfqq) { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 870 | cfq_log_cfqq(cfqd, cfqq, "set_active"); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 871 | cfqq->slice_end = 0; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 872 | cfqq->slice_dispatch = 0; |
| 873 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 874 | cfq_clear_cfqq_wait_request(cfqq); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 875 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 876 | cfq_clear_cfqq_must_alloc_slice(cfqq); |
| 877 | cfq_clear_cfqq_fifo_expire(cfqq); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 878 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 879 | |
| 880 | del_timer(&cfqd->idle_slice_timer); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 881 | } |
| 882 | |
| 883 | cfqd->active_queue = cfqq; |
| 884 | } |
| 885 | |
| 886 | /* |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 887 | * current cfqq expired its slice (or was too idle), select new one |
| 888 | */ |
| 889 | static void |
| 890 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 891 | int timed_out) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 892 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 893 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); |
| 894 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 895 | if (cfq_cfqq_wait_request(cfqq)) |
| 896 | del_timer(&cfqd->idle_slice_timer); |
| 897 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 898 | cfq_clear_cfqq_wait_request(cfqq); |
| 899 | |
| 900 | /* |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 901 | * 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] | 902 | */ |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 903 | if (timed_out && !cfq_cfqq_slice_new(cfqq)) { |
Jens Axboe | c5b680f | 2007-01-19 11:56:49 +1100 | [diff] [blame] | 904 | cfqq->slice_resid = cfqq->slice_end - jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 905 | cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); |
| 906 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 907 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 908 | cfq_resort_rr_list(cfqd, cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 909 | |
| 910 | if (cfqq == cfqd->active_queue) |
| 911 | cfqd->active_queue = NULL; |
| 912 | |
| 913 | if (cfqd->active_cic) { |
| 914 | put_io_context(cfqd->active_cic->ioc); |
| 915 | cfqd->active_cic = NULL; |
| 916 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 917 | } |
| 918 | |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 919 | static inline void cfq_slice_expired(struct cfq_data *cfqd, int timed_out) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 920 | { |
| 921 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 922 | |
| 923 | if (cfqq) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 924 | __cfq_slice_expired(cfqd, cfqq, timed_out); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 925 | } |
| 926 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 927 | /* |
| 928 | * Get next queue for service. Unless we have a queue preemption, |
| 929 | * we'll simply select the first cfqq in the service tree. |
| 930 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 931 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 932 | { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 933 | if (RB_EMPTY_ROOT(&cfqd->service_tree.rb)) |
| 934 | return NULL; |
| 935 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 936 | return cfq_rb_first(&cfqd->service_tree); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 937 | } |
| 938 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 939 | /* |
| 940 | * Get and set a new active queue for service. |
| 941 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 942 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, |
| 943 | struct cfq_queue *cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 944 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 945 | if (!cfqq) { |
| 946 | cfqq = cfq_get_next_queue(cfqd); |
| 947 | if (cfqq) |
| 948 | cfq_clear_cfqq_coop(cfqq); |
| 949 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 950 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 951 | __cfq_set_active_queue(cfqd, cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 952 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 953 | } |
| 954 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 955 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, |
| 956 | struct request *rq) |
| 957 | { |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 958 | if (blk_rq_pos(rq) >= cfqd->last_position) |
| 959 | return blk_rq_pos(rq) - cfqd->last_position; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 960 | else |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 961 | return cfqd->last_position - blk_rq_pos(rq); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 962 | } |
| 963 | |
Jeff Moyer | 04dc6e7 | 2009-04-21 07:31:56 +0200 | [diff] [blame] | 964 | #define CIC_SEEK_THR 8 * 1024 |
| 965 | #define CIC_SEEKY(cic) ((cic)->seek_mean > CIC_SEEK_THR) |
| 966 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 967 | static inline int cfq_rq_close(struct cfq_data *cfqd, struct request *rq) |
| 968 | { |
| 969 | struct cfq_io_context *cic = cfqd->active_cic; |
Jeff Moyer | 04dc6e7 | 2009-04-21 07:31:56 +0200 | [diff] [blame] | 970 | sector_t sdist = cic->seek_mean; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 971 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 972 | if (!sample_valid(cic->seek_samples)) |
Jeff Moyer | 04dc6e7 | 2009-04-21 07:31:56 +0200 | [diff] [blame] | 973 | sdist = CIC_SEEK_THR; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 974 | |
Jeff Moyer | 04dc6e7 | 2009-04-21 07:31:56 +0200 | [diff] [blame] | 975 | return cfq_dist_from_last(cfqd, rq) <= sdist; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 976 | } |
| 977 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 978 | static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, |
| 979 | struct cfq_queue *cur_cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 980 | { |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 981 | struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 982 | struct rb_node *parent, *node; |
| 983 | struct cfq_queue *__cfqq; |
| 984 | sector_t sector = cfqd->last_position; |
| 985 | |
| 986 | if (RB_EMPTY_ROOT(root)) |
| 987 | return NULL; |
| 988 | |
| 989 | /* |
| 990 | * First, if we find a request starting at the end of the last |
| 991 | * request, choose it. |
| 992 | */ |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 993 | __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 994 | if (__cfqq) |
| 995 | return __cfqq; |
| 996 | |
| 997 | /* |
| 998 | * If the exact sector wasn't found, the parent of the NULL leaf |
| 999 | * will contain the closest sector. |
| 1000 | */ |
| 1001 | __cfqq = rb_entry(parent, struct cfq_queue, p_node); |
| 1002 | if (cfq_rq_close(cfqd, __cfqq->next_rq)) |
| 1003 | return __cfqq; |
| 1004 | |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1005 | if (blk_rq_pos(__cfqq->next_rq) < sector) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1006 | node = rb_next(&__cfqq->p_node); |
| 1007 | else |
| 1008 | node = rb_prev(&__cfqq->p_node); |
| 1009 | if (!node) |
| 1010 | return NULL; |
| 1011 | |
| 1012 | __cfqq = rb_entry(node, struct cfq_queue, p_node); |
| 1013 | if (cfq_rq_close(cfqd, __cfqq->next_rq)) |
| 1014 | return __cfqq; |
| 1015 | |
| 1016 | return NULL; |
| 1017 | } |
| 1018 | |
| 1019 | /* |
| 1020 | * cfqd - obvious |
| 1021 | * cur_cfqq - passed in so that we don't decide that the current queue is |
| 1022 | * closely cooperating with itself. |
| 1023 | * |
| 1024 | * So, basically we're assuming that that cur_cfqq has dispatched at least |
| 1025 | * one request, and that cfqd->last_position reflects a position on the disk |
| 1026 | * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid |
| 1027 | * assumption. |
| 1028 | */ |
| 1029 | static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, |
| 1030 | struct cfq_queue *cur_cfqq, |
| 1031 | int probe) |
| 1032 | { |
| 1033 | struct cfq_queue *cfqq; |
| 1034 | |
| 1035 | /* |
| 1036 | * A valid cfq_io_context is necessary to compare requests against |
| 1037 | * the seek_mean of the current cfqq. |
| 1038 | */ |
| 1039 | if (!cfqd->active_cic) |
| 1040 | return NULL; |
| 1041 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1042 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1043 | * We should notice if some of the queues are cooperating, eg |
| 1044 | * working closely on the same area of the disk. In that case, |
| 1045 | * we can group them together and don't waste time idling. |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1046 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1047 | cfqq = cfqq_close(cfqd, cur_cfqq); |
| 1048 | if (!cfqq) |
| 1049 | return NULL; |
| 1050 | |
| 1051 | if (cfq_cfqq_coop(cfqq)) |
| 1052 | return NULL; |
| 1053 | |
| 1054 | if (!probe) |
| 1055 | cfq_mark_cfqq_coop(cfqq); |
| 1056 | return cfqq; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1057 | } |
| 1058 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1059 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1060 | { |
Jens Axboe | 1792669 | 2007-01-19 11:59:30 +1100 | [diff] [blame] | 1061 | struct cfq_queue *cfqq = cfqd->active_queue; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1062 | struct cfq_io_context *cic; |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1063 | unsigned long sl; |
| 1064 | |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1065 | /* |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 1066 | * SSD device without seek penalty, disable idling. But only do so |
| 1067 | * for devices that support queuing, otherwise we still have a problem |
| 1068 | * with sync vs async workloads. |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1069 | */ |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 1070 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1071 | return; |
| 1072 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 1073 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1074 | WARN_ON(cfq_cfqq_slice_new(cfqq)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1075 | |
| 1076 | /* |
| 1077 | * idle is disabled, either manually or by past process history |
| 1078 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1079 | if (!cfqd->cfq_slice_idle || !cfq_cfqq_idle_window(cfqq)) |
| 1080 | return; |
| 1081 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1082 | /* |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1083 | * still requests with the driver, don't idle |
| 1084 | */ |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 1085 | if (rq_in_driver(cfqd)) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1086 | return; |
| 1087 | |
| 1088 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1089 | * task has exited, don't wait |
| 1090 | */ |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1091 | cic = cfqd->active_cic; |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 1092 | if (!cic || !atomic_read(&cic->ioc->nr_tasks)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1093 | return; |
| 1094 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1095 | cfq_mark_cfqq_wait_request(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1096 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1097 | /* |
| 1098 | * we don't want to idle for seeks, but we do want to allow |
| 1099 | * fair distribution of slice time for a process doing back-to-back |
| 1100 | * seeks. so allow a little bit of time for him to submit a new rq |
| 1101 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1102 | sl = cfqd->cfq_slice_idle; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1103 | if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic)) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1104 | sl = min(sl, msecs_to_jiffies(CFQ_MIN_TT)); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1105 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1106 | mod_timer(&cfqd->idle_slice_timer, jiffies + sl); |
Jens Axboe | 9481ffd | 2009-04-15 12:14:13 +0200 | [diff] [blame] | 1107 | cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1108 | } |
| 1109 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1110 | /* |
| 1111 | * Move request from internal lists to the request queue dispatch list. |
| 1112 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1113 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1114 | { |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1115 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1116 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1117 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1118 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); |
| 1119 | |
Jeff Moyer | 06d2188 | 2009-09-11 17:08:59 +0200 | [diff] [blame] | 1120 | cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1121 | cfq_remove_request(rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1122 | cfqq->dispatched++; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1123 | elv_dispatch_sort(q, rq); |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1124 | |
| 1125 | if (cfq_cfqq_sync(cfqq)) |
| 1126 | cfqd->sync_flight++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1127 | } |
| 1128 | |
| 1129 | /* |
| 1130 | * return expired entry, or NULL to just start from scratch in rbtree |
| 1131 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1132 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1133 | { |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame^] | 1134 | struct request *rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1135 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1136 | if (cfq_cfqq_fifo_expire(cfqq)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1137 | return NULL; |
Jens Axboe | cb88741 | 2007-01-19 12:01:16 +1100 | [diff] [blame] | 1138 | |
| 1139 | cfq_mark_cfqq_fifo_expire(cfqq); |
| 1140 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1141 | if (list_empty(&cfqq->fifo)) |
| 1142 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1143 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1144 | rq = rq_entry_fifo(cfqq->fifo.next); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame^] | 1145 | if (time_before(jiffies, rq_fifo_time(rq))) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1146 | rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1147 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame^] | 1148 | cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1149 | return rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | } |
| 1151 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1152 | static inline int |
| 1153 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1154 | { |
| 1155 | const int base_rq = cfqd->cfq_slice_async_rq; |
| 1156 | |
| 1157 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); |
| 1158 | |
| 1159 | return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio)); |
| 1160 | } |
| 1161 | |
| 1162 | /* |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1163 | * Select a queue for service. If we have a current active queue, |
| 1164 | * 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] | 1165 | */ |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1166 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1167 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1168 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1169 | |
| 1170 | cfqq = cfqd->active_queue; |
| 1171 | if (!cfqq) |
| 1172 | goto new_queue; |
| 1173 | |
| 1174 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1175 | * 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] | 1176 | */ |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 1177 | if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1178 | goto expire; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1179 | |
| 1180 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1181 | * The active queue has requests and isn't expired, allow it to |
| 1182 | * dispatch. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1183 | */ |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 1184 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1185 | goto keep_queue; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1186 | |
| 1187 | /* |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1188 | * If another queue has a request waiting within our mean seek |
| 1189 | * distance, let it run. The expire code will check for close |
| 1190 | * cooperators and put the close queue at the front of the service |
| 1191 | * tree. |
| 1192 | */ |
| 1193 | new_cfqq = cfq_close_cooperator(cfqd, cfqq, 0); |
| 1194 | if (new_cfqq) |
| 1195 | goto expire; |
| 1196 | |
| 1197 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1198 | * No requests pending. If the active queue still has requests in |
| 1199 | * flight or is idling for a new request, allow either of these |
| 1200 | * conditions to happen (or time out) before selecting a new queue. |
| 1201 | */ |
Jens Axboe | cc19747 | 2007-04-20 20:45:39 +0200 | [diff] [blame] | 1202 | if (timer_pending(&cfqd->idle_slice_timer) || |
| 1203 | (cfqq->dispatched && cfq_cfqq_idle_window(cfqq))) { |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1204 | cfqq = NULL; |
| 1205 | goto keep_queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1206 | } |
| 1207 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1208 | expire: |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1209 | cfq_slice_expired(cfqd, 0); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1210 | new_queue: |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1211 | cfqq = cfq_set_active_queue(cfqd, new_cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1212 | keep_queue: |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1213 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1214 | } |
| 1215 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1216 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1217 | { |
| 1218 | int dispatched = 0; |
| 1219 | |
| 1220 | while (cfqq->next_rq) { |
| 1221 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); |
| 1222 | dispatched++; |
| 1223 | } |
| 1224 | |
| 1225 | BUG_ON(!list_empty(&cfqq->fifo)); |
| 1226 | return dispatched; |
| 1227 | } |
| 1228 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1229 | /* |
| 1230 | * Drain our current requests. Used for barriers and when switching |
| 1231 | * io schedulers on-the-fly. |
| 1232 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1233 | static int cfq_forced_dispatch(struct cfq_data *cfqd) |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1234 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1235 | struct cfq_queue *cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1236 | int dispatched = 0; |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1237 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1238 | while ((cfqq = cfq_rb_first(&cfqd->service_tree)) != NULL) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1239 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1240 | |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1241 | cfq_slice_expired(cfqd, 0); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1242 | |
| 1243 | BUG_ON(cfqd->busy_queues); |
| 1244 | |
Jeff Moyer | 6923715 | 2009-06-12 15:29:30 +0200 | [diff] [blame] | 1245 | cfq_log(cfqd, "forced_dispatch=%d", dispatched); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1246 | return dispatched; |
| 1247 | } |
| 1248 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1249 | /* |
| 1250 | * Dispatch a request from cfqq, moving them to the request queue |
| 1251 | * dispatch list. |
| 1252 | */ |
| 1253 | static void cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1254 | { |
| 1255 | struct request *rq; |
| 1256 | |
| 1257 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); |
| 1258 | |
| 1259 | /* |
| 1260 | * follow expired path, else get first next available |
| 1261 | */ |
| 1262 | rq = cfq_check_fifo(cfqq); |
| 1263 | if (!rq) |
| 1264 | rq = cfqq->next_rq; |
| 1265 | |
| 1266 | /* |
| 1267 | * insert request into driver dispatch list |
| 1268 | */ |
| 1269 | cfq_dispatch_insert(cfqd->queue, rq); |
| 1270 | |
| 1271 | if (!cfqd->active_cic) { |
| 1272 | struct cfq_io_context *cic = RQ_CIC(rq); |
| 1273 | |
Nikanth Karthikesan | d9c7d39 | 2009-06-10 12:57:06 -0700 | [diff] [blame] | 1274 | atomic_long_inc(&cic->ioc->refcount); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1275 | cfqd->active_cic = cic; |
| 1276 | } |
| 1277 | } |
| 1278 | |
| 1279 | /* |
| 1280 | * Find the cfqq that we need to service and move a request from that to the |
| 1281 | * dispatch list |
| 1282 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1283 | static int cfq_dispatch_requests(struct request_queue *q, int force) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1284 | { |
| 1285 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1286 | struct cfq_queue *cfqq; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1287 | unsigned int max_dispatch; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1288 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1289 | if (!cfqd->busy_queues) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1290 | return 0; |
| 1291 | |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1292 | if (unlikely(force)) |
| 1293 | return cfq_forced_dispatch(cfqd); |
| 1294 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1295 | cfqq = cfq_select_queue(cfqd); |
| 1296 | if (!cfqq) |
| 1297 | return 0; |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1298 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1299 | /* |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 1300 | * Drain async requests before we start sync IO |
| 1301 | */ |
| 1302 | if (cfq_cfqq_idle_window(cfqq) && cfqd->rq_in_driver[BLK_RW_ASYNC]) |
| 1303 | return 0; |
| 1304 | |
| 1305 | /* |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1306 | * If this is an async queue and we have sync IO in flight, let it wait |
| 1307 | */ |
| 1308 | if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq)) |
| 1309 | return 0; |
| 1310 | |
| 1311 | max_dispatch = cfqd->cfq_quantum; |
| 1312 | if (cfq_class_idle(cfqq)) |
| 1313 | max_dispatch = 1; |
| 1314 | |
| 1315 | /* |
| 1316 | * Does this cfqq already have too much IO in flight? |
| 1317 | */ |
| 1318 | if (cfqq->dispatched >= max_dispatch) { |
| 1319 | /* |
| 1320 | * idle queue must always only have a single IO in flight |
| 1321 | */ |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1322 | if (cfq_class_idle(cfqq)) |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1323 | return 0; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1324 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1325 | /* |
| 1326 | * We have other queues, don't allow more IO from this one |
| 1327 | */ |
| 1328 | if (cfqd->busy_queues > 1) |
| 1329 | return 0; |
Jens Axboe | 9ede209 | 2007-01-19 12:11:44 +1100 | [diff] [blame] | 1330 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1331 | /* |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1332 | * Sole queue user, allow bigger slice |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 1333 | */ |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1334 | max_dispatch *= 4; |
| 1335 | } |
| 1336 | |
| 1337 | /* |
| 1338 | * Async queues must wait a bit before being allowed dispatch. |
| 1339 | * We also ramp up the dispatch depth gradually for async IO, |
| 1340 | * based on the last sync IO we serviced |
| 1341 | */ |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 1342 | if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1343 | unsigned long last_sync = jiffies - cfqd->last_end_sync_rq; |
| 1344 | unsigned int depth; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 1345 | |
Jens Axboe | 61f0c1d | 2009-10-03 19:46:03 +0200 | [diff] [blame] | 1346 | depth = last_sync / cfqd->cfq_slice[1]; |
Jens Axboe | e00c54c | 2009-10-04 20:36:19 +0200 | [diff] [blame] | 1347 | if (!depth && !cfqq->dispatched) |
| 1348 | depth = 1; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1349 | if (depth < max_dispatch) |
| 1350 | max_dispatch = depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1351 | } |
| 1352 | |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1353 | if (cfqq->dispatched >= max_dispatch) |
| 1354 | return 0; |
| 1355 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1356 | /* |
| 1357 | * Dispatch a request from this cfqq |
| 1358 | */ |
| 1359 | cfq_dispatch_request(cfqd, cfqq); |
| 1360 | cfqq->slice_dispatch++; |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 1361 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1362 | |
| 1363 | /* |
| 1364 | * expire an async queue immediately if it has used up its slice. idle |
| 1365 | * queue always expire after 1 dispatch round. |
| 1366 | */ |
| 1367 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && |
| 1368 | cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || |
| 1369 | cfq_class_idle(cfqq))) { |
| 1370 | cfqq->slice_end = jiffies + 1; |
| 1371 | cfq_slice_expired(cfqd, 0); |
| 1372 | } |
| 1373 | |
Shan Wei | b217a90 | 2009-09-01 10:06:42 +0200 | [diff] [blame] | 1374 | cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1375 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1376 | } |
| 1377 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1378 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1379 | * task holds one reference to the queue, dropped when task exits. each rq |
| 1380 | * 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] | 1381 | * |
| 1382 | * queue lock must be held here. |
| 1383 | */ |
| 1384 | static void cfq_put_queue(struct cfq_queue *cfqq) |
| 1385 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1386 | struct cfq_data *cfqd = cfqq->cfqd; |
| 1387 | |
| 1388 | BUG_ON(atomic_read(&cfqq->ref) <= 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1389 | |
| 1390 | if (!atomic_dec_and_test(&cfqq->ref)) |
| 1391 | return; |
| 1392 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1393 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1394 | BUG_ON(rb_first(&cfqq->sort_list)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1395 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1396 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1397 | |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1398 | if (unlikely(cfqd->active_queue == cfqq)) { |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1399 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1400 | cfq_schedule_dispatch(cfqd, 0); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1401 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1402 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1403 | kmem_cache_free(cfq_pool, cfqq); |
| 1404 | } |
| 1405 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1406 | /* |
| 1407 | * Must always be called with the rcu_read_lock() held |
| 1408 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 1409 | static void |
| 1410 | __call_for_each_cic(struct io_context *ioc, |
| 1411 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 1412 | { |
| 1413 | struct cfq_io_context *cic; |
| 1414 | struct hlist_node *n; |
| 1415 | |
| 1416 | hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list) |
| 1417 | func(ioc, cic); |
| 1418 | } |
| 1419 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1420 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1421 | * Call func for each cic attached to this ioc. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1422 | */ |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1423 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1424 | call_for_each_cic(struct io_context *ioc, |
| 1425 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 1426 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1427 | rcu_read_lock(); |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 1428 | __call_for_each_cic(ioc, func); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1429 | rcu_read_unlock(); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1430 | } |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1431 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1432 | static void cfq_cic_free_rcu(struct rcu_head *head) |
| 1433 | { |
| 1434 | struct cfq_io_context *cic; |
| 1435 | |
| 1436 | cic = container_of(head, struct cfq_io_context, rcu_head); |
| 1437 | |
| 1438 | kmem_cache_free(cfq_ioc_pool, cic); |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 1439 | elv_ioc_count_dec(cfq_ioc_count); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1440 | |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 1441 | if (ioc_gone) { |
| 1442 | /* |
| 1443 | * CFQ scheduler is exiting, grab exit lock and check |
| 1444 | * the pending io context count. If it hits zero, |
| 1445 | * complete ioc_gone and set it back to NULL |
| 1446 | */ |
| 1447 | spin_lock(&ioc_gone_lock); |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 1448 | if (ioc_gone && !elv_ioc_count_read(cfq_ioc_count)) { |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 1449 | complete(ioc_gone); |
| 1450 | ioc_gone = NULL; |
| 1451 | } |
| 1452 | spin_unlock(&ioc_gone_lock); |
| 1453 | } |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1454 | } |
| 1455 | |
| 1456 | static void cfq_cic_free(struct cfq_io_context *cic) |
| 1457 | { |
| 1458 | call_rcu(&cic->rcu_head, cfq_cic_free_rcu); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1459 | } |
| 1460 | |
| 1461 | static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic) |
| 1462 | { |
| 1463 | unsigned long flags; |
| 1464 | |
| 1465 | BUG_ON(!cic->dead_key); |
| 1466 | |
| 1467 | spin_lock_irqsave(&ioc->lock, flags); |
| 1468 | radix_tree_delete(&ioc->radix_root, cic->dead_key); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1469 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1470 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 1471 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1472 | cfq_cic_free(cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1473 | } |
| 1474 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1475 | /* |
| 1476 | * Must be called with rcu_read_lock() held or preemption otherwise disabled. |
| 1477 | * Only two callers of this - ->dtor() which is called with the rcu_read_lock(), |
| 1478 | * and ->trim() which is called with the task lock held |
| 1479 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1480 | static void cfq_free_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1481 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1482 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1483 | * ioc->refcount is zero here, or we are called from elv_unregister(), |
| 1484 | * so no more cic's are allowed to be linked into this ioc. So it |
| 1485 | * should be ok to iterate over the known list, we will see all cic's |
| 1486 | * since no new ones are added. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1487 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 1488 | __call_for_each_cic(ioc, cic_free_func); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1489 | } |
| 1490 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1491 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1492 | { |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1493 | if (unlikely(cfqq == cfqd->active_queue)) { |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1494 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 1495 | cfq_schedule_dispatch(cfqd, 0); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1496 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1497 | |
| 1498 | cfq_put_queue(cfqq); |
| 1499 | } |
| 1500 | |
| 1501 | static void __cfq_exit_single_io_context(struct cfq_data *cfqd, |
| 1502 | struct cfq_io_context *cic) |
| 1503 | { |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 1504 | struct io_context *ioc = cic->ioc; |
| 1505 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1506 | list_del_init(&cic->queue_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1507 | |
| 1508 | /* |
| 1509 | * Make sure key == NULL is seen for dead queues |
| 1510 | */ |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1511 | smp_wmb(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1512 | cic->dead_key = (unsigned long) cic->key; |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1513 | cic->key = NULL; |
| 1514 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 1515 | if (ioc->ioc_data == cic) |
| 1516 | rcu_assign_pointer(ioc->ioc_data, NULL); |
| 1517 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1518 | if (cic->cfqq[BLK_RW_ASYNC]) { |
| 1519 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]); |
| 1520 | cic->cfqq[BLK_RW_ASYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1521 | } |
| 1522 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1523 | if (cic->cfqq[BLK_RW_SYNC]) { |
| 1524 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_SYNC]); |
| 1525 | cic->cfqq[BLK_RW_SYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1526 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1527 | } |
| 1528 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1529 | static void cfq_exit_single_io_context(struct io_context *ioc, |
| 1530 | struct cfq_io_context *cic) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1531 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 1532 | struct cfq_data *cfqd = cic->key; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1533 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1534 | if (cfqd) { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1535 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1536 | unsigned long flags; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1537 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1538 | spin_lock_irqsave(q->queue_lock, flags); |
Jens Axboe | 62c1fe9 | 2008-12-15 21:19:25 +0100 | [diff] [blame] | 1539 | |
| 1540 | /* |
| 1541 | * Ensure we get a fresh copy of the ->key to prevent |
| 1542 | * race between exiting task and queue |
| 1543 | */ |
| 1544 | smp_read_barrier_depends(); |
| 1545 | if (cic->key) |
| 1546 | __cfq_exit_single_io_context(cfqd, cic); |
| 1547 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1548 | spin_unlock_irqrestore(q->queue_lock, flags); |
Al Viro | 12a0573 | 2006-03-18 13:38:01 -0500 | [diff] [blame] | 1549 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1550 | } |
| 1551 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1552 | /* |
| 1553 | * The process that ioc belongs to has exited, we need to clean up |
| 1554 | * and put the internal structures we have that belongs to that process. |
| 1555 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1556 | static void cfq_exit_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1557 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1558 | call_for_each_cic(ioc, cfq_exit_single_io_context); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1559 | } |
| 1560 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1561 | static struct cfq_io_context * |
Al Viro | 8267e26 | 2005-10-21 03:20:53 -0400 | [diff] [blame] | 1562 | cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1563 | { |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 1564 | struct cfq_io_context *cic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1565 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1566 | cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO, |
| 1567 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1568 | if (cic) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1569 | cic->last_end_request = jiffies; |
Jens Axboe | 553698f | 2006-06-14 19:11:57 +0200 | [diff] [blame] | 1570 | INIT_LIST_HEAD(&cic->queue_list); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1571 | INIT_HLIST_NODE(&cic->cic_list); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1572 | cic->dtor = cfq_free_io_context; |
| 1573 | cic->exit = cfq_exit_io_context; |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 1574 | elv_ioc_count_inc(cfq_ioc_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1575 | } |
| 1576 | |
| 1577 | return cic; |
| 1578 | } |
| 1579 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1580 | 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] | 1581 | { |
| 1582 | struct task_struct *tsk = current; |
| 1583 | int ioprio_class; |
| 1584 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1585 | if (!cfq_cfqq_prio_changed(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1586 | return; |
| 1587 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1588 | ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1589 | switch (ioprio_class) { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1590 | default: |
| 1591 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); |
| 1592 | case IOPRIO_CLASS_NONE: |
| 1593 | /* |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 1594 | * no prio set, inherit CPU scheduling settings |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1595 | */ |
| 1596 | cfqq->ioprio = task_nice_ioprio(tsk); |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 1597 | cfqq->ioprio_class = task_nice_ioclass(tsk); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1598 | break; |
| 1599 | case IOPRIO_CLASS_RT: |
| 1600 | cfqq->ioprio = task_ioprio(ioc); |
| 1601 | cfqq->ioprio_class = IOPRIO_CLASS_RT; |
| 1602 | break; |
| 1603 | case IOPRIO_CLASS_BE: |
| 1604 | cfqq->ioprio = task_ioprio(ioc); |
| 1605 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 1606 | break; |
| 1607 | case IOPRIO_CLASS_IDLE: |
| 1608 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; |
| 1609 | cfqq->ioprio = 7; |
| 1610 | cfq_clear_cfqq_idle_window(cfqq); |
| 1611 | break; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1612 | } |
| 1613 | |
| 1614 | /* |
| 1615 | * keep track of original prio settings in case we have to temporarily |
| 1616 | * elevate the priority of this queue |
| 1617 | */ |
| 1618 | cfqq->org_ioprio = cfqq->ioprio; |
| 1619 | cfqq->org_ioprio_class = cfqq->ioprio_class; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1620 | cfq_clear_cfqq_prio_changed(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1621 | } |
| 1622 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1623 | 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] | 1624 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 1625 | struct cfq_data *cfqd = cic->key; |
| 1626 | struct cfq_queue *cfqq; |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 1627 | unsigned long flags; |
Jens Axboe | 35e6077 | 2006-06-14 09:10:45 +0200 | [diff] [blame] | 1628 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1629 | if (unlikely(!cfqd)) |
| 1630 | return; |
| 1631 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 1632 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1633 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1634 | cfqq = cic->cfqq[BLK_RW_ASYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1635 | if (cfqq) { |
| 1636 | struct cfq_queue *new_cfqq; |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1637 | new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->ioc, |
| 1638 | GFP_ATOMIC); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1639 | if (new_cfqq) { |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1640 | cic->cfqq[BLK_RW_ASYNC] = new_cfqq; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1641 | cfq_put_queue(cfqq); |
| 1642 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1643 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1644 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 1645 | cfqq = cic->cfqq[BLK_RW_SYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1646 | if (cfqq) |
| 1647 | cfq_mark_cfqq_prio_changed(cfqq); |
| 1648 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 1649 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1650 | } |
| 1651 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1652 | static void cfq_ioc_set_ioprio(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1653 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1654 | call_for_each_cic(ioc, changed_ioprio); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1655 | ioc->ioprio_changed = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1656 | } |
| 1657 | |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 1658 | static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 1659 | pid_t pid, int is_sync) |
| 1660 | { |
| 1661 | RB_CLEAR_NODE(&cfqq->rb_node); |
| 1662 | RB_CLEAR_NODE(&cfqq->p_node); |
| 1663 | INIT_LIST_HEAD(&cfqq->fifo); |
| 1664 | |
| 1665 | atomic_set(&cfqq->ref, 0); |
| 1666 | cfqq->cfqd = cfqd; |
| 1667 | |
| 1668 | cfq_mark_cfqq_prio_changed(cfqq); |
| 1669 | |
| 1670 | if (is_sync) { |
| 1671 | if (!cfq_class_idle(cfqq)) |
| 1672 | cfq_mark_cfqq_idle_window(cfqq); |
| 1673 | cfq_mark_cfqq_sync(cfqq); |
| 1674 | } |
| 1675 | cfqq->pid = pid; |
| 1676 | } |
| 1677 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1678 | static struct cfq_queue * |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1679 | cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1680 | struct io_context *ioc, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1681 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1682 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1683 | struct cfq_io_context *cic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1684 | |
| 1685 | retry: |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1686 | cic = cfq_cic_lookup(cfqd, ioc); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1687 | /* cic always exists here */ |
| 1688 | cfqq = cic_to_cfqq(cic, is_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1689 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 1690 | /* |
| 1691 | * Always try a new alloc if we fell back to the OOM cfqq |
| 1692 | * originally, since it should just be a temporary situation. |
| 1693 | */ |
| 1694 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
| 1695 | cfqq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1696 | if (new_cfqq) { |
| 1697 | cfqq = new_cfqq; |
| 1698 | new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1699 | } else if (gfp_mask & __GFP_WAIT) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1700 | spin_unlock_irq(cfqd->queue->queue_lock); |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1701 | new_cfqq = kmem_cache_alloc_node(cfq_pool, |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 1702 | gfp_mask | __GFP_ZERO, |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1703 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1704 | spin_lock_irq(cfqd->queue->queue_lock); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 1705 | if (new_cfqq) |
| 1706 | goto retry; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1707 | } else { |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1708 | cfqq = kmem_cache_alloc_node(cfq_pool, |
| 1709 | gfp_mask | __GFP_ZERO, |
| 1710 | cfqd->queue->node); |
Kiyoshi Ueda | db3b584 | 2005-06-17 16:15:10 +0200 | [diff] [blame] | 1711 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1712 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 1713 | if (cfqq) { |
| 1714 | cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); |
| 1715 | cfq_init_prio_data(cfqq, ioc); |
| 1716 | cfq_log_cfqq(cfqd, cfqq, "alloced"); |
| 1717 | } else |
| 1718 | cfqq = &cfqd->oom_cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1719 | } |
| 1720 | |
| 1721 | if (new_cfqq) |
| 1722 | kmem_cache_free(cfq_pool, new_cfqq); |
| 1723 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1724 | return cfqq; |
| 1725 | } |
| 1726 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1727 | static struct cfq_queue ** |
| 1728 | cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) |
| 1729 | { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1730 | switch (ioprio_class) { |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1731 | case IOPRIO_CLASS_RT: |
| 1732 | return &cfqd->async_cfqq[0][ioprio]; |
| 1733 | case IOPRIO_CLASS_BE: |
| 1734 | return &cfqd->async_cfqq[1][ioprio]; |
| 1735 | case IOPRIO_CLASS_IDLE: |
| 1736 | return &cfqd->async_idle_cfqq; |
| 1737 | default: |
| 1738 | BUG(); |
| 1739 | } |
| 1740 | } |
| 1741 | |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1742 | static struct cfq_queue * |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1743 | cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct io_context *ioc, |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1744 | gfp_t gfp_mask) |
| 1745 | { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1746 | const int ioprio = task_ioprio(ioc); |
| 1747 | const int ioprio_class = task_ioprio_class(ioc); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1748 | struct cfq_queue **async_cfqq = NULL; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1749 | struct cfq_queue *cfqq = NULL; |
| 1750 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1751 | if (!is_sync) { |
| 1752 | async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); |
| 1753 | cfqq = *async_cfqq; |
| 1754 | } |
| 1755 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 1756 | if (!cfqq) |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1757 | cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1758 | |
| 1759 | /* |
| 1760 | * pin the queue now that it's allocated, scheduler exit will prune it |
| 1761 | */ |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1762 | if (!is_sync && !(*async_cfqq)) { |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1763 | atomic_inc(&cfqq->ref); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1764 | *async_cfqq = cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1765 | } |
| 1766 | |
| 1767 | atomic_inc(&cfqq->ref); |
| 1768 | return cfqq; |
| 1769 | } |
| 1770 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1771 | /* |
| 1772 | * We drop cfq io contexts lazily, so we may find a dead one. |
| 1773 | */ |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1774 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1775 | cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc, |
| 1776 | struct cfq_io_context *cic) |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1777 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1778 | unsigned long flags; |
| 1779 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1780 | WARN_ON(!list_empty(&cic->queue_list)); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1781 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1782 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1783 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 1784 | BUG_ON(ioc->ioc_data == cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1785 | |
| 1786 | radix_tree_delete(&ioc->radix_root, (unsigned long) cfqd); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1787 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1788 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 1789 | |
| 1790 | cfq_cic_free(cic); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1791 | } |
| 1792 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1793 | static struct cfq_io_context * |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1794 | cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1795 | { |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1796 | struct cfq_io_context *cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1797 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1798 | void *k; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1799 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1800 | if (unlikely(!ioc)) |
| 1801 | return NULL; |
| 1802 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1803 | rcu_read_lock(); |
| 1804 | |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1805 | /* |
| 1806 | * we maintain a last-hit cache, to avoid browsing over the tree |
| 1807 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1808 | cic = rcu_dereference(ioc->ioc_data); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1809 | if (cic && cic->key == cfqd) { |
| 1810 | rcu_read_unlock(); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1811 | return cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1812 | } |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1813 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1814 | do { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1815 | cic = radix_tree_lookup(&ioc->radix_root, (unsigned long) cfqd); |
| 1816 | rcu_read_unlock(); |
| 1817 | if (!cic) |
| 1818 | break; |
OGAWA Hirofumi | be3b075 | 2006-04-18 19:18:31 +0200 | [diff] [blame] | 1819 | /* ->key must be copied to avoid race with cfq_exit_queue() */ |
| 1820 | k = cic->key; |
| 1821 | if (unlikely(!k)) { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1822 | cfq_drop_dead_cic(cfqd, ioc, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1823 | rcu_read_lock(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1824 | continue; |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1825 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1826 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1827 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1828 | rcu_assign_pointer(ioc->ioc_data, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1829 | spin_unlock_irqrestore(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1830 | break; |
| 1831 | } while (1); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1832 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1833 | return cic; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1834 | } |
| 1835 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1836 | /* |
| 1837 | * Add cic into ioc, using cfqd as the search key. This enables us to lookup |
| 1838 | * the process specific cfq io context when entered from the block layer. |
| 1839 | * Also adds the cic to a per-cfqd list, used when this queue is removed. |
| 1840 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1841 | static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, |
| 1842 | struct cfq_io_context *cic, gfp_t gfp_mask) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1843 | { |
Jens Axboe | 0261d68 | 2006-10-30 19:07:48 +0100 | [diff] [blame] | 1844 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1845 | int ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1846 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1847 | ret = radix_tree_preload(gfp_mask); |
| 1848 | if (!ret) { |
| 1849 | cic->ioc = ioc; |
| 1850 | cic->key = cfqd; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1851 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1852 | spin_lock_irqsave(&ioc->lock, flags); |
| 1853 | ret = radix_tree_insert(&ioc->radix_root, |
| 1854 | (unsigned long) cfqd, cic); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1855 | if (!ret) |
| 1856 | hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1857 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 1858 | |
| 1859 | radix_tree_preload_end(); |
| 1860 | |
| 1861 | if (!ret) { |
| 1862 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 1863 | list_add(&cic->queue_list, &cfqd->cic_list); |
| 1864 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1865 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1866 | } |
| 1867 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1868 | if (ret) |
| 1869 | printk(KERN_ERR "cfq: cic link failed!\n"); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1870 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1871 | return ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1872 | } |
| 1873 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1874 | /* |
| 1875 | * Setup general io context and cfq io context. There can be several cfq |
| 1876 | * 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] | 1877 | * than one device managed by cfq. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1878 | */ |
| 1879 | static struct cfq_io_context * |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1880 | cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1881 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1882 | struct io_context *ioc = NULL; |
| 1883 | struct cfq_io_context *cic; |
| 1884 | |
| 1885 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 1886 | |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 1887 | ioc = get_io_context(gfp_mask, cfqd->queue->node); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1888 | if (!ioc) |
| 1889 | return NULL; |
| 1890 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1891 | cic = cfq_cic_lookup(cfqd, ioc); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1892 | if (cic) |
| 1893 | goto out; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1894 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1895 | cic = cfq_alloc_io_context(cfqd, gfp_mask); |
| 1896 | if (cic == NULL) |
| 1897 | goto err; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1898 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1899 | if (cfq_cic_link(cfqd, ioc, cic, gfp_mask)) |
| 1900 | goto err_free; |
| 1901 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1902 | out: |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1903 | smp_read_barrier_depends(); |
| 1904 | if (unlikely(ioc->ioprio_changed)) |
| 1905 | cfq_ioc_set_ioprio(ioc); |
| 1906 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1907 | return cic; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1908 | err_free: |
| 1909 | cfq_cic_free(cic); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1910 | err: |
| 1911 | put_io_context(ioc); |
| 1912 | return NULL; |
| 1913 | } |
| 1914 | |
| 1915 | static void |
| 1916 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic) |
| 1917 | { |
Jens Axboe | aaf1228 | 2007-01-19 11:30:16 +1100 | [diff] [blame] | 1918 | unsigned long elapsed = jiffies - cic->last_end_request; |
| 1919 | unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1920 | |
| 1921 | cic->ttime_samples = (7*cic->ttime_samples + 256) / 8; |
| 1922 | cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8; |
| 1923 | cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples; |
| 1924 | } |
| 1925 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1926 | static void |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1927 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic, |
| 1928 | struct request *rq) |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1929 | { |
| 1930 | sector_t sdist; |
| 1931 | u64 total; |
| 1932 | |
Jeff Moyer | 4d00aa4 | 2009-04-21 07:25:04 +0200 | [diff] [blame] | 1933 | if (!cic->last_request_pos) |
| 1934 | sdist = 0; |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1935 | else if (cic->last_request_pos < blk_rq_pos(rq)) |
| 1936 | sdist = blk_rq_pos(rq) - cic->last_request_pos; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1937 | else |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1938 | sdist = cic->last_request_pos - blk_rq_pos(rq); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1939 | |
| 1940 | /* |
| 1941 | * Don't allow the seek distance to get too large from the |
| 1942 | * odd fragment, pagein, etc |
| 1943 | */ |
| 1944 | if (cic->seek_samples <= 60) /* second&third seek */ |
| 1945 | sdist = min(sdist, (cic->seek_mean * 4) + 2*1024*1024); |
| 1946 | else |
| 1947 | sdist = min(sdist, (cic->seek_mean * 4) + 2*1024*64); |
| 1948 | |
| 1949 | cic->seek_samples = (7*cic->seek_samples + 256) / 8; |
| 1950 | cic->seek_total = (7*cic->seek_total + (u64)256*sdist) / 8; |
| 1951 | total = cic->seek_total + (cic->seek_samples/2); |
| 1952 | do_div(total, cic->seek_samples); |
| 1953 | cic->seek_mean = (sector_t)total; |
| 1954 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1955 | |
| 1956 | /* |
| 1957 | * Disable idle window if the process thinks too long or seeks so much that |
| 1958 | * it doesn't matter |
| 1959 | */ |
| 1960 | static void |
| 1961 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 1962 | struct cfq_io_context *cic) |
| 1963 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1964 | int old_idle, enable_idle; |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 1965 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1966 | /* |
| 1967 | * Don't idle for async or idle io prio class |
| 1968 | */ |
| 1969 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 1970 | return; |
| 1971 | |
Jens Axboe | c265a7f | 2008-06-26 13:49:33 +0200 | [diff] [blame] | 1972 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1973 | |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 1974 | if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle || |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 1975 | (!cfqd->cfq_latency && cfqd->hw_tag && CIC_SEEKY(cic))) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1976 | enable_idle = 0; |
| 1977 | else if (sample_valid(cic->ttime_samples)) { |
| 1978 | if (cic->ttime_mean > cfqd->cfq_slice_idle) |
| 1979 | enable_idle = 0; |
| 1980 | else |
| 1981 | enable_idle = 1; |
| 1982 | } |
| 1983 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1984 | if (old_idle != enable_idle) { |
| 1985 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); |
| 1986 | if (enable_idle) |
| 1987 | cfq_mark_cfqq_idle_window(cfqq); |
| 1988 | else |
| 1989 | cfq_clear_cfqq_idle_window(cfqq); |
| 1990 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1991 | } |
| 1992 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1993 | /* |
| 1994 | * Check if new_cfqq should preempt the currently active queue. Return 0 for |
| 1995 | * no or if we aren't sure, a 1 will cause a preempt. |
| 1996 | */ |
| 1997 | static int |
| 1998 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1999 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2000 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2001 | struct cfq_queue *cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2002 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2003 | cfqq = cfqd->active_queue; |
| 2004 | if (!cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2005 | return 0; |
| 2006 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2007 | if (cfq_slice_used(cfqq)) |
| 2008 | return 1; |
| 2009 | |
| 2010 | if (cfq_class_idle(new_cfqq)) |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2011 | return 0; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2012 | |
| 2013 | if (cfq_class_idle(cfqq)) |
| 2014 | return 1; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 2015 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2016 | /* |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 2017 | * if the new request is sync, but the currently running queue is |
| 2018 | * not, let the sync request have priority. |
| 2019 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2020 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2021 | return 1; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 2022 | |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 2023 | /* |
| 2024 | * So both queues are sync. Let the new request get disk time if |
| 2025 | * it's a metadata request and the current queue is doing regular IO. |
| 2026 | */ |
| 2027 | if (rq_is_meta(rq) && !cfqq->meta_pending) |
| 2028 | return 1; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2029 | |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 2030 | /* |
| 2031 | * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. |
| 2032 | */ |
| 2033 | if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) |
| 2034 | return 1; |
| 2035 | |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 2036 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) |
| 2037 | return 0; |
| 2038 | |
| 2039 | /* |
| 2040 | * if this request is as-good as one we would expect from the |
| 2041 | * current cfqq, let it preempt |
| 2042 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2043 | if (cfq_rq_close(cfqd, rq)) |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 2044 | return 1; |
| 2045 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2046 | return 0; |
| 2047 | } |
| 2048 | |
| 2049 | /* |
| 2050 | * cfqq preempts the active queue. if we allowed preempt with no slice left, |
| 2051 | * let it have half of its nominal slice. |
| 2052 | */ |
| 2053 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2054 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2055 | cfq_log_cfqq(cfqd, cfqq, "preempt"); |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2056 | cfq_slice_expired(cfqd, 1); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2057 | |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 2058 | /* |
| 2059 | * Put the new queue at the front of the of the current list, |
| 2060 | * so we know that it will be selected next. |
| 2061 | */ |
| 2062 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 2063 | |
| 2064 | cfq_service_tree_add(cfqd, cfqq, 1); |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 2065 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 2066 | cfqq->slice_end = 0; |
| 2067 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2068 | } |
| 2069 | |
| 2070 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2071 | * 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] | 2072 | * something we should do about it |
| 2073 | */ |
| 2074 | static void |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2075 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 2076 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2077 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2078 | struct cfq_io_context *cic = RQ_CIC(rq); |
Jens Axboe | 12e9fdd | 2006-06-01 10:09:56 +0200 | [diff] [blame] | 2079 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2080 | cfqd->rq_queued++; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 2081 | if (rq_is_meta(rq)) |
| 2082 | cfqq->meta_pending++; |
| 2083 | |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 2084 | cfq_update_io_thinktime(cfqd, cic); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2085 | cfq_update_io_seektime(cfqd, cic, rq); |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 2086 | cfq_update_idle_window(cfqd, cfqq, cic); |
| 2087 | |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 2088 | cic->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2089 | |
| 2090 | if (cfqq == cfqd->active_queue) { |
| 2091 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 2092 | * Remember that we saw a request from this process, but |
| 2093 | * don't start queuing just yet. Otherwise we risk seeing lots |
| 2094 | * of tiny requests, because we disrupt the normal plugging |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 2095 | * and merging. If the request is already larger than a single |
| 2096 | * page, let it rip immediately. For that case we assume that |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 2097 | * merging is already done. Ditto for a busy system that |
| 2098 | * has other work pending, don't risk delaying until the |
| 2099 | * idle timer unplug to continue working. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2100 | */ |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 2101 | if (cfq_cfqq_wait_request(cfqq)) { |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 2102 | if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE || |
| 2103 | cfqd->busy_queues > 1) { |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 2104 | del_timer(&cfqd->idle_slice_timer); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 2105 | __blk_run_queue(cfqd->queue); |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 2106 | } |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 2107 | cfq_mark_cfqq_must_dispatch(cfqq); |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 2108 | } |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2109 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2110 | /* |
| 2111 | * not the active queue - expire current slice if it is |
| 2112 | * idle and has expired it's mean thinktime or this new queue |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 2113 | * has some old slice time left and is of higher priority or |
| 2114 | * this new queue is RT and the current one is BE |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2115 | */ |
| 2116 | cfq_preempt_queue(cfqd, cfqq); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 2117 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2118 | } |
| 2119 | } |
| 2120 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2121 | static void cfq_insert_request(struct request_queue *q, struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2122 | { |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2123 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2124 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2125 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2126 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2127 | cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2128 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2129 | cfq_add_rq_rb(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2130 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame^] | 2131 | 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] | 2132 | list_add_tail(&rq->queuelist, &cfqq->fifo); |
| 2133 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2134 | cfq_rq_enqueued(cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2135 | } |
| 2136 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2137 | /* |
| 2138 | * Update hw_tag based on peak queue depth over 50 samples under |
| 2139 | * sufficient load. |
| 2140 | */ |
| 2141 | static void cfq_update_hw_tag(struct cfq_data *cfqd) |
| 2142 | { |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2143 | if (rq_in_driver(cfqd) > cfqd->rq_in_driver_peak) |
| 2144 | cfqd->rq_in_driver_peak = rq_in_driver(cfqd); |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2145 | |
| 2146 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2147 | rq_in_driver(cfqd) <= CFQ_HW_QUEUE_MIN) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2148 | return; |
| 2149 | |
| 2150 | if (cfqd->hw_tag_samples++ < 50) |
| 2151 | return; |
| 2152 | |
| 2153 | if (cfqd->rq_in_driver_peak >= CFQ_HW_QUEUE_MIN) |
| 2154 | cfqd->hw_tag = 1; |
| 2155 | else |
| 2156 | cfqd->hw_tag = 0; |
| 2157 | |
| 2158 | cfqd->hw_tag_samples = 0; |
| 2159 | cfqd->rq_in_driver_peak = 0; |
| 2160 | } |
| 2161 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2162 | static void cfq_completed_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2163 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2164 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2165 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 2166 | const int sync = rq_is_sync(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2167 | unsigned long now; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2168 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2169 | now = jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2170 | cfq_log_cfqq(cfqd, cfqq, "complete"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2171 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2172 | cfq_update_hw_tag(cfqd); |
| 2173 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2174 | WARN_ON(!cfqd->rq_in_driver[sync]); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2175 | WARN_ON(!cfqq->dispatched); |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2176 | cfqd->rq_in_driver[sync]--; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2177 | cfqq->dispatched--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2178 | |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2179 | if (cfq_cfqq_sync(cfqq)) |
| 2180 | cfqd->sync_flight--; |
| 2181 | |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2182 | if (sync) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2183 | RQ_CIC(rq)->last_end_request = now; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2184 | cfqd->last_end_sync_rq = now; |
| 2185 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2186 | |
| 2187 | /* |
| 2188 | * If this is the active queue, check if it needs to be expired, |
| 2189 | * or if we want to idle in case it has no pending requests. |
| 2190 | */ |
| 2191 | if (cfqd->active_queue == cfqq) { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2192 | const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); |
| 2193 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 2194 | if (cfq_cfqq_slice_new(cfqq)) { |
| 2195 | cfq_set_prio_slice(cfqd, cfqq); |
| 2196 | cfq_clear_cfqq_slice_new(cfqq); |
| 2197 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2198 | /* |
| 2199 | * If there are no requests waiting in this queue, and |
| 2200 | * there are other queues ready to issue requests, AND |
| 2201 | * those other queues are issuing requests within our |
| 2202 | * mean seek distance, give them a chance to run instead |
| 2203 | * of idling. |
| 2204 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 2205 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2206 | cfq_slice_expired(cfqd, 1); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2207 | else if (cfqq_empty && !cfq_close_cooperator(cfqd, cfqq, 1) && |
| 2208 | sync && !rq_noidle(rq)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2209 | cfq_arm_slice_timer(cfqd); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2210 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2211 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2212 | if (!rq_in_driver(cfqd)) |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2213 | cfq_schedule_dispatch(cfqd, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2214 | } |
| 2215 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2216 | /* |
| 2217 | * we temporarily boost lower priority queues if they are holding fs exclusive |
| 2218 | * resources. they are boosted to normal prio (CLASS_BE/4) |
| 2219 | */ |
| 2220 | static void cfq_prio_boost(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2221 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2222 | if (has_fs_excl()) { |
| 2223 | /* |
| 2224 | * boost idle prio on transactions that would lock out other |
| 2225 | * users of the filesystem |
| 2226 | */ |
| 2227 | if (cfq_class_idle(cfqq)) |
| 2228 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 2229 | if (cfqq->ioprio > IOPRIO_NORM) |
| 2230 | cfqq->ioprio = IOPRIO_NORM; |
| 2231 | } else { |
| 2232 | /* |
| 2233 | * check if we need to unboost the queue |
| 2234 | */ |
| 2235 | if (cfqq->ioprio_class != cfqq->org_ioprio_class) |
| 2236 | cfqq->ioprio_class = cfqq->org_ioprio_class; |
| 2237 | if (cfqq->ioprio != cfqq->org_ioprio) |
| 2238 | cfqq->ioprio = cfqq->org_ioprio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2239 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2240 | } |
| 2241 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2242 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2243 | { |
Jens Axboe | 1b379d8 | 2009-08-11 08:26:11 +0200 | [diff] [blame] | 2244 | if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2245 | cfq_mark_cfqq_must_alloc_slice(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2246 | return ELV_MQUEUE_MUST; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2247 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2248 | |
| 2249 | return ELV_MQUEUE_MAY; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2250 | } |
| 2251 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2252 | static int cfq_may_queue(struct request_queue *q, int rw) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2253 | { |
| 2254 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 2255 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2256 | struct cfq_io_context *cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2257 | struct cfq_queue *cfqq; |
| 2258 | |
| 2259 | /* |
| 2260 | * don't force setup of a queue from here, as a call to may_queue |
| 2261 | * does not necessarily imply that a request actually will be queued. |
| 2262 | * so just lookup a possibly existing queue, or return 'may queue' |
| 2263 | * if that fails |
| 2264 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2265 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2266 | if (!cic) |
| 2267 | return ELV_MQUEUE_MAY; |
| 2268 | |
Jens Axboe | b0b78f8 | 2009-04-08 10:56:08 +0200 | [diff] [blame] | 2269 | cfqq = cic_to_cfqq(cic, rw_is_sync(rw)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2270 | if (cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2271 | cfq_init_prio_data(cfqq, cic->ioc); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2272 | cfq_prio_boost(cfqq); |
| 2273 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2274 | return __cfq_may_queue(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2275 | } |
| 2276 | |
| 2277 | return ELV_MQUEUE_MAY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2278 | } |
| 2279 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2280 | /* |
| 2281 | * queue lock held here |
| 2282 | */ |
Jens Axboe | bb37b94 | 2006-12-01 10:42:33 +0100 | [diff] [blame] | 2283 | static void cfq_put_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2284 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2285 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2286 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2287 | if (cfqq) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2288 | const int rw = rq_data_dir(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2289 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2290 | BUG_ON(!cfqq->allocated[rw]); |
| 2291 | cfqq->allocated[rw]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2292 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2293 | put_io_context(RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2294 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2295 | rq->elevator_private = NULL; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2296 | rq->elevator_private2 = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2297 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2298 | cfq_put_queue(cfqq); |
| 2299 | } |
| 2300 | } |
| 2301 | |
| 2302 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2303 | * Allocate cfq data structures associated with this request. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2304 | */ |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2305 | static int |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2306 | 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] | 2307 | { |
| 2308 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 2309 | struct cfq_io_context *cic; |
| 2310 | const int rw = rq_data_dir(rq); |
Jens Axboe | 7749a8d | 2006-12-13 13:02:26 +0100 | [diff] [blame] | 2311 | const int is_sync = rq_is_sync(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2312 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2313 | unsigned long flags; |
| 2314 | |
| 2315 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 2316 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2317 | cic = cfq_get_io_context(cfqd, gfp_mask); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2318 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2319 | spin_lock_irqsave(q->queue_lock, flags); |
| 2320 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2321 | if (!cic) |
| 2322 | goto queue_fail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2323 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2324 | cfqq = cic_to_cfqq(cic, is_sync); |
Vivek Goyal | 32f2e80 | 2009-07-09 22:13:16 +0200 | [diff] [blame] | 2325 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2326 | cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2327 | cic_set_cfqq(cic, cfqq, is_sync); |
| 2328 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2329 | |
| 2330 | cfqq->allocated[rw]++; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2331 | atomic_inc(&cfqq->ref); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2332 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2333 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2334 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2335 | rq->elevator_private = cic; |
| 2336 | rq->elevator_private2 = cfqq; |
| 2337 | return 0; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2338 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2339 | queue_fail: |
| 2340 | if (cic) |
| 2341 | put_io_context(cic->ioc); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2342 | |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2343 | cfq_schedule_dispatch(cfqd, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2344 | spin_unlock_irqrestore(q->queue_lock, flags); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2345 | cfq_log(cfqd, "set_request fail"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2346 | return 1; |
| 2347 | } |
| 2348 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 2349 | static void cfq_kick_queue(struct work_struct *work) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2350 | { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 2351 | struct cfq_data *cfqd = |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2352 | container_of(work, struct cfq_data, unplug_work.work); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2353 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2354 | |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 2355 | spin_lock_irq(q->queue_lock); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 2356 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 2357 | spin_unlock_irq(q->queue_lock); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2358 | } |
| 2359 | |
| 2360 | /* |
| 2361 | * Timer running if the active_queue is currently idling inside its time slice |
| 2362 | */ |
| 2363 | static void cfq_idle_slice_timer(unsigned long data) |
| 2364 | { |
| 2365 | struct cfq_data *cfqd = (struct cfq_data *) data; |
| 2366 | struct cfq_queue *cfqq; |
| 2367 | unsigned long flags; |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 2368 | int timed_out = 1; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2369 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2370 | cfq_log(cfqd, "idle timer fired"); |
| 2371 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2372 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 2373 | |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2374 | cfqq = cfqd->active_queue; |
| 2375 | if (cfqq) { |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 2376 | timed_out = 0; |
| 2377 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2378 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 2379 | * We saw a request before the queue expired, let it through |
| 2380 | */ |
| 2381 | if (cfq_cfqq_must_dispatch(cfqq)) |
| 2382 | goto out_kick; |
| 2383 | |
| 2384 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2385 | * expired |
| 2386 | */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 2387 | if (cfq_slice_used(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2388 | goto expire; |
| 2389 | |
| 2390 | /* |
| 2391 | * only expire and reinvoke request handler, if there are |
| 2392 | * other queues with pending requests |
| 2393 | */ |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2394 | if (!cfqd->busy_queues) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2395 | goto out_cont; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2396 | |
| 2397 | /* |
| 2398 | * not expired and it has a request pending, let it dispatch |
| 2399 | */ |
Jens Axboe | 75e5098 | 2009-04-07 08:56:14 +0200 | [diff] [blame] | 2400 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2401 | goto out_kick; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2402 | } |
| 2403 | expire: |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2404 | cfq_slice_expired(cfqd, timed_out); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2405 | out_kick: |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2406 | cfq_schedule_dispatch(cfqd, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2407 | out_cont: |
| 2408 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 2409 | } |
| 2410 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2411 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) |
| 2412 | { |
| 2413 | del_timer_sync(&cfqd->idle_slice_timer); |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2414 | cancel_delayed_work_sync(&cfqd->unplug_work); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2415 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2416 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2417 | static void cfq_put_async_queues(struct cfq_data *cfqd) |
| 2418 | { |
| 2419 | int i; |
| 2420 | |
| 2421 | for (i = 0; i < IOPRIO_BE_NR; i++) { |
| 2422 | if (cfqd->async_cfqq[0][i]) |
| 2423 | cfq_put_queue(cfqd->async_cfqq[0][i]); |
| 2424 | if (cfqd->async_cfqq[1][i]) |
| 2425 | cfq_put_queue(cfqd->async_cfqq[1][i]); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2426 | } |
Oleg Nesterov | 2389d1e | 2007-11-05 08:58:05 +0100 | [diff] [blame] | 2427 | |
| 2428 | if (cfqd->async_idle_cfqq) |
| 2429 | cfq_put_queue(cfqd->async_idle_cfqq); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2430 | } |
| 2431 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 2432 | static void cfq_exit_queue(struct elevator_queue *e) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2433 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2434 | struct cfq_data *cfqd = e->elevator_data; |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2435 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2436 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2437 | cfq_shutdown_timer_wq(cfqd); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2438 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2439 | spin_lock_irq(q->queue_lock); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2440 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2441 | if (cfqd->active_queue) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2442 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2443 | |
| 2444 | while (!list_empty(&cfqd->cic_list)) { |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2445 | struct cfq_io_context *cic = list_entry(cfqd->cic_list.next, |
| 2446 | struct cfq_io_context, |
| 2447 | queue_list); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2448 | |
| 2449 | __cfq_exit_single_io_context(cfqd, cic); |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2450 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2451 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2452 | cfq_put_async_queues(cfqd); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2453 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2454 | spin_unlock_irq(q->queue_lock); |
Al Viro | a90d742 | 2006-03-18 12:05:37 -0500 | [diff] [blame] | 2455 | |
| 2456 | cfq_shutdown_timer_wq(cfqd); |
| 2457 | |
Al Viro | a90d742 | 2006-03-18 12:05:37 -0500 | [diff] [blame] | 2458 | kfree(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2459 | } |
| 2460 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2461 | static void *cfq_init_queue(struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2462 | { |
| 2463 | struct cfq_data *cfqd; |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 2464 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2465 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2466 | cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2467 | if (!cfqd) |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 2468 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2469 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 2470 | cfqd->service_tree = CFQ_RB_ROOT; |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 2471 | |
| 2472 | /* |
| 2473 | * Not strictly needed (since RB_ROOT just clears the node and we |
| 2474 | * zeroed cfqd on alloc), but better be safe in case someone decides |
| 2475 | * to add magic to the rb code |
| 2476 | */ |
| 2477 | for (i = 0; i < CFQ_PRIO_LISTS; i++) |
| 2478 | cfqd->prio_trees[i] = RB_ROOT; |
| 2479 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2480 | /* |
| 2481 | * Our fallback cfqq if cfq_find_alloc_queue() runs into OOM issues. |
| 2482 | * Grab a permanent reference to it, so that the normal code flow |
| 2483 | * will not attempt to free it. |
| 2484 | */ |
| 2485 | cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); |
| 2486 | atomic_inc(&cfqd->oom_cfqq.ref); |
| 2487 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2488 | INIT_LIST_HEAD(&cfqd->cic_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2489 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2490 | cfqd->queue = q; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2491 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2492 | init_timer(&cfqd->idle_slice_timer); |
| 2493 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; |
| 2494 | cfqd->idle_slice_timer.data = (unsigned long) cfqd; |
| 2495 | |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2496 | INIT_DELAYED_WORK(&cfqd->unplug_work, cfq_kick_queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2497 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2498 | cfqd->cfq_quantum = cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2499 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |
| 2500 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2501 | cfqd->cfq_back_max = cfq_back_max; |
| 2502 | cfqd->cfq_back_penalty = cfq_back_penalty; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2503 | cfqd->cfq_slice[0] = cfq_slice_async; |
| 2504 | cfqd->cfq_slice[1] = cfq_slice_sync; |
| 2505 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; |
| 2506 | cfqd->cfq_slice_idle = cfq_slice_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2507 | cfqd->cfq_latency = 1; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2508 | cfqd->hw_tag = 1; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2509 | cfqd->last_end_sync_rq = jiffies; |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 2510 | return cfqd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2511 | } |
| 2512 | |
| 2513 | static void cfq_slab_kill(void) |
| 2514 | { |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2515 | /* |
| 2516 | * Caller already ensured that pending RCU callbacks are completed, |
| 2517 | * so we should have no busy allocations at this point. |
| 2518 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2519 | if (cfq_pool) |
| 2520 | kmem_cache_destroy(cfq_pool); |
| 2521 | if (cfq_ioc_pool) |
| 2522 | kmem_cache_destroy(cfq_ioc_pool); |
| 2523 | } |
| 2524 | |
| 2525 | static int __init cfq_slab_setup(void) |
| 2526 | { |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame] | 2527 | cfq_pool = KMEM_CACHE(cfq_queue, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2528 | if (!cfq_pool) |
| 2529 | goto fail; |
| 2530 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2531 | cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2532 | if (!cfq_ioc_pool) |
| 2533 | goto fail; |
| 2534 | |
| 2535 | return 0; |
| 2536 | fail: |
| 2537 | cfq_slab_kill(); |
| 2538 | return -ENOMEM; |
| 2539 | } |
| 2540 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2541 | /* |
| 2542 | * sysfs parts below --> |
| 2543 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2544 | static ssize_t |
| 2545 | cfq_var_show(unsigned int var, char *page) |
| 2546 | { |
| 2547 | return sprintf(page, "%d\n", var); |
| 2548 | } |
| 2549 | |
| 2550 | static ssize_t |
| 2551 | cfq_var_store(unsigned int *var, const char *page, size_t count) |
| 2552 | { |
| 2553 | char *p = (char *) page; |
| 2554 | |
| 2555 | *var = simple_strtoul(p, &p, 10); |
| 2556 | return count; |
| 2557 | } |
| 2558 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2559 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 2560 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2561 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 2562 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2563 | unsigned int __data = __VAR; \ |
| 2564 | if (__CONV) \ |
| 2565 | __data = jiffies_to_msecs(__data); \ |
| 2566 | return cfq_var_show(__data, (page)); \ |
| 2567 | } |
| 2568 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2569 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); |
| 2570 | 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] | 2571 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); |
| 2572 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2573 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); |
| 2574 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); |
| 2575 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); |
| 2576 | 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] | 2577 | SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2578 | #undef SHOW_FUNCTION |
| 2579 | |
| 2580 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 2581 | 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] | 2582 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 2583 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2584 | unsigned int __data; \ |
| 2585 | int ret = cfq_var_store(&__data, (page), count); \ |
| 2586 | if (__data < (MIN)) \ |
| 2587 | __data = (MIN); \ |
| 2588 | else if (__data > (MAX)) \ |
| 2589 | __data = (MAX); \ |
| 2590 | if (__CONV) \ |
| 2591 | *(__PTR) = msecs_to_jiffies(__data); \ |
| 2592 | else \ |
| 2593 | *(__PTR) = __data; \ |
| 2594 | return ret; \ |
| 2595 | } |
| 2596 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2597 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, |
| 2598 | UINT_MAX, 1); |
| 2599 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, |
| 2600 | UINT_MAX, 1); |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2601 | 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] | 2602 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, |
| 2603 | UINT_MAX, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2604 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); |
| 2605 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); |
| 2606 | 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] | 2607 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, |
| 2608 | UINT_MAX, 0); |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2609 | STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2610 | #undef STORE_FUNCTION |
| 2611 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2612 | #define CFQ_ATTR(name) \ |
| 2613 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2614 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2615 | static struct elv_fs_entry cfq_attrs[] = { |
| 2616 | CFQ_ATTR(quantum), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2617 | CFQ_ATTR(fifo_expire_sync), |
| 2618 | CFQ_ATTR(fifo_expire_async), |
| 2619 | CFQ_ATTR(back_seek_max), |
| 2620 | CFQ_ATTR(back_seek_penalty), |
| 2621 | CFQ_ATTR(slice_sync), |
| 2622 | CFQ_ATTR(slice_async), |
| 2623 | CFQ_ATTR(slice_async_rq), |
| 2624 | CFQ_ATTR(slice_idle), |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2625 | CFQ_ATTR(low_latency), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2626 | __ATTR_NULL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2627 | }; |
| 2628 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2629 | static struct elevator_type iosched_cfq = { |
| 2630 | .ops = { |
| 2631 | .elevator_merge_fn = cfq_merge, |
| 2632 | .elevator_merged_fn = cfq_merged_request, |
| 2633 | .elevator_merge_req_fn = cfq_merged_requests, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 2634 | .elevator_allow_merge_fn = cfq_allow_merge, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2635 | .elevator_dispatch_fn = cfq_dispatch_requests, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2636 | .elevator_add_req_fn = cfq_insert_request, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2637 | .elevator_activate_req_fn = cfq_activate_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2638 | .elevator_deactivate_req_fn = cfq_deactivate_request, |
| 2639 | .elevator_queue_empty_fn = cfq_queue_empty, |
| 2640 | .elevator_completed_req_fn = cfq_completed_request, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 2641 | .elevator_former_req_fn = elv_rb_former_request, |
| 2642 | .elevator_latter_req_fn = elv_rb_latter_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2643 | .elevator_set_req_fn = cfq_set_request, |
| 2644 | .elevator_put_req_fn = cfq_put_request, |
| 2645 | .elevator_may_queue_fn = cfq_may_queue, |
| 2646 | .elevator_init_fn = cfq_init_queue, |
| 2647 | .elevator_exit_fn = cfq_exit_queue, |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2648 | .trim = cfq_free_io_context, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2649 | }, |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 2650 | .elevator_attrs = cfq_attrs, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2651 | .elevator_name = "cfq", |
| 2652 | .elevator_owner = THIS_MODULE, |
| 2653 | }; |
| 2654 | |
| 2655 | static int __init cfq_init(void) |
| 2656 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2657 | /* |
| 2658 | * could be 0 on HZ < 1000 setups |
| 2659 | */ |
| 2660 | if (!cfq_slice_async) |
| 2661 | cfq_slice_async = 1; |
| 2662 | if (!cfq_slice_idle) |
| 2663 | cfq_slice_idle = 1; |
| 2664 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2665 | if (cfq_slab_setup()) |
| 2666 | return -ENOMEM; |
| 2667 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 2668 | elv_register(&iosched_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2669 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 2670 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2671 | } |
| 2672 | |
| 2673 | static void __exit cfq_exit(void) |
| 2674 | { |
Peter Zijlstra | 6e9a473 | 2006-09-30 23:28:10 -0700 | [diff] [blame] | 2675 | DECLARE_COMPLETION_ONSTACK(all_gone); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2676 | elv_unregister(&iosched_cfq); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 2677 | ioc_gone = &all_gone; |
OGAWA Hirofumi | fba8227 | 2006-04-18 09:44:06 +0200 | [diff] [blame] | 2678 | /* ioc_gone's update must be visible before reading ioc_count */ |
| 2679 | smp_wmb(); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2680 | |
| 2681 | /* |
| 2682 | * this also protects us from entering cfq_slab_kill() with |
| 2683 | * pending RCU callbacks |
| 2684 | */ |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2685 | if (elv_ioc_count_read(cfq_ioc_count)) |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 2686 | wait_for_completion(&all_gone); |
Christoph Hellwig | 83521d3 | 2005-10-30 15:01:39 -0800 | [diff] [blame] | 2687 | cfq_slab_kill(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2688 | } |
| 2689 | |
| 2690 | module_init(cfq_init); |
| 2691 | module_exit(cfq_exit); |
| 2692 | |
| 2693 | MODULE_AUTHOR("Jens Axboe"); |
| 2694 | MODULE_LICENSE("GPL"); |
| 2695 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |