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 | |
Jens Axboe | 4050cf1 | 2006-07-19 05:07:12 +0200 | [diff] [blame] | 51 | static DEFINE_PER_CPU(unsigned long, 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 | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 59 | #define ASYNC (0) |
| 60 | #define SYNC (1) |
| 61 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 62 | #define sample_valid(samples) ((samples) > 80) |
| 63 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 64 | /* |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 65 | * Most of our rbtree usage is for sorting with min extraction, so |
| 66 | * if we cache the leftmost node we don't have to walk down the tree |
| 67 | * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should |
| 68 | * move this into the elevator for the rq sorting as well. |
| 69 | */ |
| 70 | struct cfq_rb_root { |
| 71 | struct rb_root rb; |
| 72 | struct rb_node *left; |
| 73 | }; |
| 74 | #define CFQ_RB_ROOT (struct cfq_rb_root) { RB_ROOT, NULL, } |
| 75 | |
| 76 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 77 | * Per block device queue structure |
| 78 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | struct cfq_data { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 80 | struct request_queue *queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 81 | |
| 82 | /* |
| 83 | * rr list of queues with requests and the count of them |
| 84 | */ |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 85 | struct cfq_rb_root service_tree; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 86 | unsigned int busy_queues; |
| 87 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 88 | int rq_in_driver; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 89 | int sync_flight; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 90 | |
| 91 | /* |
| 92 | * queue-depth detection |
| 93 | */ |
| 94 | int rq_queued; |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 95 | int hw_tag; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 96 | int hw_tag_samples; |
| 97 | int rq_in_driver_peak; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 98 | |
| 99 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 100 | * idle window management |
| 101 | */ |
| 102 | struct timer_list idle_slice_timer; |
| 103 | struct work_struct unplug_work; |
| 104 | |
| 105 | struct cfq_queue *active_queue; |
| 106 | struct cfq_io_context *active_cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 107 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 108 | /* |
| 109 | * async queue for each priority case |
| 110 | */ |
| 111 | struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; |
| 112 | struct cfq_queue *async_idle_cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 113 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 114 | sector_t last_position; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 115 | unsigned long last_end_request; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | /* |
| 118 | * tunables, see top of file |
| 119 | */ |
| 120 | unsigned int cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 121 | unsigned int cfq_fifo_expire[2]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | unsigned int cfq_back_penalty; |
| 123 | unsigned int cfq_back_max; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 124 | unsigned int cfq_slice[2]; |
| 125 | unsigned int cfq_slice_async_rq; |
| 126 | unsigned int cfq_slice_idle; |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 127 | |
| 128 | struct list_head cic_list; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | }; |
| 130 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 131 | /* |
| 132 | * Per process-grouping structure |
| 133 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | struct cfq_queue { |
| 135 | /* reference count */ |
| 136 | atomic_t ref; |
Richard Kennedy | be754d2 | 2008-05-23 06:52:00 +0200 | [diff] [blame] | 137 | /* various state flags, see below */ |
| 138 | unsigned int flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | /* parent cfq_data */ |
| 140 | struct cfq_data *cfqd; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 141 | /* service_tree member */ |
| 142 | struct rb_node rb_node; |
| 143 | /* service_tree key */ |
| 144 | unsigned long rb_key; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | /* sorted list of pending requests */ |
| 146 | struct rb_root sort_list; |
| 147 | /* if fifo isn't expired, next request to serve */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 148 | struct request *next_rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | /* requests queued in sort_list */ |
| 150 | int queued[2]; |
| 151 | /* currently allocated requests */ |
| 152 | int allocated[2]; |
| 153 | /* fifo list of requests in sort_list */ |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 154 | struct list_head fifo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 156 | unsigned long slice_end; |
Jens Axboe | c5b680f | 2007-01-19 11:56:49 +1100 | [diff] [blame] | 157 | long slice_resid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | |
Richard Kennedy | be754d2 | 2008-05-23 06:52:00 +0200 | [diff] [blame] | 159 | /* pending metadata requests */ |
| 160 | int meta_pending; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 161 | /* number of requests that are on the dispatch list or inside driver */ |
| 162 | int dispatched; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 163 | |
| 164 | /* io prio of this group */ |
| 165 | unsigned short ioprio, org_ioprio; |
| 166 | unsigned short ioprio_class, org_ioprio_class; |
| 167 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 168 | pid_t pid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | }; |
| 170 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 171 | enum cfqq_state_flags { |
Jens Axboe | b0b8d74 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 172 | CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ |
| 173 | CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ |
| 174 | CFQ_CFQQ_FLAG_must_alloc, /* must be allowed rq alloc */ |
| 175 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ |
| 176 | CFQ_CFQQ_FLAG_must_dispatch, /* must dispatch, even if expired */ |
| 177 | CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ |
| 178 | CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ |
| 179 | CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ |
| 180 | CFQ_CFQQ_FLAG_queue_new, /* queue never been serviced */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 181 | CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 182 | CFQ_CFQQ_FLAG_sync, /* synchronous queue */ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 183 | }; |
| 184 | |
| 185 | #define CFQ_CFQQ_FNS(name) \ |
| 186 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ |
| 187 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 188 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 189 | } \ |
| 190 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ |
| 191 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 192 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 193 | } \ |
| 194 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ |
| 195 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 196 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 197 | } |
| 198 | |
| 199 | CFQ_CFQQ_FNS(on_rr); |
| 200 | CFQ_CFQQ_FNS(wait_request); |
| 201 | CFQ_CFQQ_FNS(must_alloc); |
| 202 | CFQ_CFQQ_FNS(must_alloc_slice); |
| 203 | CFQ_CFQQ_FNS(must_dispatch); |
| 204 | CFQ_CFQQ_FNS(fifo_expire); |
| 205 | CFQ_CFQQ_FNS(idle_window); |
| 206 | CFQ_CFQQ_FNS(prio_changed); |
Jens Axboe | 53b0374 | 2006-07-28 09:48:51 +0200 | [diff] [blame] | 207 | CFQ_CFQQ_FNS(queue_new); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 208 | CFQ_CFQQ_FNS(slice_new); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 209 | CFQ_CFQQ_FNS(sync); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 210 | #undef CFQ_CFQQ_FNS |
| 211 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 212 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 213 | blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args) |
| 214 | #define cfq_log(cfqd, fmt, args...) \ |
| 215 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) |
| 216 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 217 | static void cfq_dispatch_insert(struct request_queue *, struct request *); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 218 | static struct cfq_queue *cfq_get_queue(struct cfq_data *, int, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 219 | struct io_context *, gfp_t); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 220 | static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *, |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 221 | struct io_context *); |
| 222 | |
| 223 | static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic, |
| 224 | int is_sync) |
| 225 | { |
| 226 | return cic->cfqq[!!is_sync]; |
| 227 | } |
| 228 | |
| 229 | static inline void cic_set_cfqq(struct cfq_io_context *cic, |
| 230 | struct cfq_queue *cfqq, int is_sync) |
| 231 | { |
| 232 | cic->cfqq[!!is_sync] = cfqq; |
| 233 | } |
| 234 | |
| 235 | /* |
| 236 | * We regard a request as SYNC, if it's either a read or has the SYNC bit |
| 237 | * set (in which case it could also be direct WRITE). |
| 238 | */ |
| 239 | static inline int cfq_bio_sync(struct bio *bio) |
| 240 | { |
| 241 | if (bio_data_dir(bio) == READ || bio_sync(bio)) |
| 242 | return 1; |
| 243 | |
| 244 | return 0; |
| 245 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | /* |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 248 | * scheduler run of queue, if there are requests pending and no one in the |
| 249 | * driver that will restart queueing |
| 250 | */ |
| 251 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) |
| 252 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 253 | if (cfqd->busy_queues) { |
| 254 | cfq_log(cfqd, "schedule dispatch"); |
Jens Axboe | 18887ad | 2008-07-28 13:08:45 +0200 | [diff] [blame] | 255 | kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 256 | } |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 257 | } |
| 258 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 259 | static int cfq_queue_empty(struct request_queue *q) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 260 | { |
| 261 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 262 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 263 | return !cfqd->busy_queues; |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 264 | } |
| 265 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | /* |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 267 | * Scale schedule slice based on io priority. Use the sync time slice only |
| 268 | * if a queue is marked sync and has sync io queued. A sync queue with async |
| 269 | * io only, should not get full sync slice length. |
| 270 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 271 | static inline int cfq_prio_slice(struct cfq_data *cfqd, int sync, |
| 272 | unsigned short prio) |
| 273 | { |
| 274 | const int base_slice = cfqd->cfq_slice[sync]; |
| 275 | |
| 276 | WARN_ON(prio >= IOPRIO_BE_NR); |
| 277 | |
| 278 | return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); |
| 279 | } |
| 280 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 281 | static inline int |
| 282 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 283 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 284 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 285 | } |
| 286 | |
| 287 | static inline void |
| 288 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 289 | { |
| 290 | cfqq->slice_end = cfq_prio_to_slice(cfqd, cfqq) + jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 291 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 292 | } |
| 293 | |
| 294 | /* |
| 295 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end |
| 296 | * isn't valid until the first request from the dispatch is activated |
| 297 | * and the slice time set. |
| 298 | */ |
| 299 | static inline int cfq_slice_used(struct cfq_queue *cfqq) |
| 300 | { |
| 301 | if (cfq_cfqq_slice_new(cfqq)) |
| 302 | return 0; |
| 303 | if (time_before(jiffies, cfqq->slice_end)) |
| 304 | return 0; |
| 305 | |
| 306 | return 1; |
| 307 | } |
| 308 | |
| 309 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 310 | * 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] | 311 | * 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] | 312 | * behind the head is penalized and only allowed to a certain extent. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 314 | static struct request * |
| 315 | 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] | 316 | { |
| 317 | sector_t last, s1, s2, d1 = 0, d2 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | unsigned long back_max; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 319 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ |
| 320 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ |
| 321 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 323 | if (rq1 == NULL || rq1 == rq2) |
| 324 | return rq2; |
| 325 | if (rq2 == NULL) |
| 326 | return rq1; |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 327 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 328 | if (rq_is_sync(rq1) && !rq_is_sync(rq2)) |
| 329 | return rq1; |
| 330 | else if (rq_is_sync(rq2) && !rq_is_sync(rq1)) |
| 331 | return rq2; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 332 | if (rq_is_meta(rq1) && !rq_is_meta(rq2)) |
| 333 | return rq1; |
| 334 | else if (rq_is_meta(rq2) && !rq_is_meta(rq1)) |
| 335 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 337 | s1 = rq1->sector; |
| 338 | s2 = rq2->sector; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 340 | last = cfqd->last_position; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 342 | /* |
| 343 | * by definition, 1KiB is 2 sectors |
| 344 | */ |
| 345 | back_max = cfqd->cfq_back_max * 2; |
| 346 | |
| 347 | /* |
| 348 | * Strict one way elevator _except_ in the case where we allow |
| 349 | * short backward seeks which are biased as twice the cost of a |
| 350 | * similar forward seek. |
| 351 | */ |
| 352 | if (s1 >= last) |
| 353 | d1 = s1 - last; |
| 354 | else if (s1 + back_max >= last) |
| 355 | d1 = (last - s1) * cfqd->cfq_back_penalty; |
| 356 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 357 | wrap |= CFQ_RQ1_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | |
| 359 | if (s2 >= last) |
| 360 | d2 = s2 - last; |
| 361 | else if (s2 + back_max >= last) |
| 362 | d2 = (last - s2) * cfqd->cfq_back_penalty; |
| 363 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 364 | wrap |= CFQ_RQ2_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | |
| 366 | /* Found required data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 368 | /* |
| 369 | * By doing switch() on the bit mask "wrap" we avoid having to |
| 370 | * check two variables for all permutations: --> faster! |
| 371 | */ |
| 372 | switch (wrap) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 373 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 374 | if (d1 < d2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 375 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 376 | else if (d2 < d1) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 377 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 378 | else { |
| 379 | if (s1 >= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 380 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 381 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 382 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 383 | } |
| 384 | |
| 385 | case CFQ_RQ2_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 386 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 387 | case CFQ_RQ1_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 388 | return rq2; |
| 389 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 390 | default: |
| 391 | /* |
| 392 | * Since both rqs are wrapped, |
| 393 | * start with the one that's further behind head |
| 394 | * (--> only *one* back seek required), |
| 395 | * since back seek takes more time than forward. |
| 396 | */ |
| 397 | if (s1 <= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 398 | return rq1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 400 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | } |
| 402 | } |
| 403 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 404 | /* |
| 405 | * The below is leftmost cache rbtree addon |
| 406 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 407 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 408 | { |
| 409 | if (!root->left) |
| 410 | root->left = rb_first(&root->rb); |
| 411 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 412 | if (root->left) |
| 413 | return rb_entry(root->left, struct cfq_queue, rb_node); |
| 414 | |
| 415 | return NULL; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 416 | } |
| 417 | |
| 418 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) |
| 419 | { |
| 420 | if (root->left == n) |
| 421 | root->left = NULL; |
| 422 | |
| 423 | rb_erase(n, &root->rb); |
| 424 | RB_CLEAR_NODE(n); |
| 425 | } |
| 426 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | /* |
| 428 | * would be nice to take fifo expire time into account as well |
| 429 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 430 | static struct request * |
| 431 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 432 | struct request *last) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 434 | struct rb_node *rbnext = rb_next(&last->rb_node); |
| 435 | struct rb_node *rbprev = rb_prev(&last->rb_node); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 436 | struct request *next = NULL, *prev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 438 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | |
| 440 | if (rbprev) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 441 | prev = rb_entry_rq(rbprev); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 442 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | if (rbnext) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 444 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 445 | else { |
| 446 | rbnext = rb_first(&cfqq->sort_list); |
| 447 | if (rbnext && rbnext != &last->rb_node) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 448 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 449 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 451 | return cfq_choose_req(cfqd, next, prev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | } |
| 453 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 454 | static unsigned long cfq_slice_offset(struct cfq_data *cfqd, |
| 455 | struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 457 | /* |
| 458 | * just an approximation, should be ok. |
| 459 | */ |
Jens Axboe | 67e6b49 | 2007-04-20 14:18:00 +0200 | [diff] [blame] | 460 | return (cfqd->busy_queues - 1) * (cfq_prio_slice(cfqd, 1, 0) - |
| 461 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 462 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 464 | /* |
| 465 | * The cfqd->service_tree holds all pending cfq_queue's that have |
| 466 | * requests waiting to be processed. It is sorted in the order that |
| 467 | * we will service the queues. |
| 468 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 469 | static void cfq_service_tree_add(struct cfq_data *cfqd, |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 470 | struct cfq_queue *cfqq, int add_front) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 471 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 472 | struct rb_node **p, *parent; |
| 473 | struct cfq_queue *__cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 474 | unsigned long rb_key; |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 475 | int left; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 476 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 477 | if (cfq_class_idle(cfqq)) { |
| 478 | rb_key = CFQ_IDLE_DELAY; |
| 479 | parent = rb_last(&cfqd->service_tree.rb); |
| 480 | if (parent && parent != &cfqq->rb_node) { |
| 481 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 482 | rb_key += __cfqq->rb_key; |
| 483 | } else |
| 484 | rb_key += jiffies; |
| 485 | } else if (!add_front) { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 486 | rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; |
| 487 | rb_key += cfqq->slice_resid; |
| 488 | cfqq->slice_resid = 0; |
| 489 | } else |
| 490 | rb_key = 0; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 491 | |
| 492 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 493 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 494 | * same position, nothing more to do |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 495 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 496 | if (rb_key == cfqq->rb_key) |
| 497 | return; |
Jens Axboe | 53b0374 | 2006-07-28 09:48:51 +0200 | [diff] [blame] | 498 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 499 | cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 500 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 501 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 502 | left = 1; |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 503 | parent = NULL; |
| 504 | p = &cfqd->service_tree.rb.rb_node; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 505 | while (*p) { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 506 | struct rb_node **n; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 507 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 508 | parent = *p; |
| 509 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 510 | |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 511 | /* |
| 512 | * sort RT queues first, we always want to give |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 513 | * preference to them. IDLE queues goes to the back. |
| 514 | * after that, sort on the next service time. |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 515 | */ |
| 516 | if (cfq_class_rt(cfqq) > cfq_class_rt(__cfqq)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 517 | n = &(*p)->rb_left; |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 518 | else if (cfq_class_rt(cfqq) < cfq_class_rt(__cfqq)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 519 | n = &(*p)->rb_right; |
| 520 | else if (cfq_class_idle(cfqq) < cfq_class_idle(__cfqq)) |
| 521 | n = &(*p)->rb_left; |
| 522 | else if (cfq_class_idle(cfqq) > cfq_class_idle(__cfqq)) |
| 523 | n = &(*p)->rb_right; |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 524 | else if (rb_key < __cfqq->rb_key) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 525 | n = &(*p)->rb_left; |
| 526 | else |
| 527 | n = &(*p)->rb_right; |
| 528 | |
| 529 | if (n == &(*p)->rb_right) |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 530 | left = 0; |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 531 | |
| 532 | p = n; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 533 | } |
| 534 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 535 | if (left) |
| 536 | cfqd->service_tree.left = &cfqq->rb_node; |
| 537 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 538 | cfqq->rb_key = rb_key; |
| 539 | rb_link_node(&cfqq->rb_node, parent, p); |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 540 | rb_insert_color(&cfqq->rb_node, &cfqd->service_tree.rb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | } |
| 542 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 543 | /* |
| 544 | * Update cfqq's position in the service tree. |
| 545 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 546 | 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] | 547 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 548 | /* |
| 549 | * Resorting requires the cfqq to be on the RR list already. |
| 550 | */ |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 551 | if (cfq_cfqq_on_rr(cfqq)) |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 552 | cfq_service_tree_add(cfqd, cfqq, 0); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 553 | } |
| 554 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | /* |
| 556 | * 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] | 557 | * the pending list according to last request service |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 559 | 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] | 560 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 561 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 562 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
| 563 | cfq_mark_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | cfqd->busy_queues++; |
| 565 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 566 | cfq_resort_rr_list(cfqd, cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | } |
| 568 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 569 | /* |
| 570 | * Called when the cfqq no longer has requests pending, remove it from |
| 571 | * the service tree. |
| 572 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 573 | 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] | 574 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 575 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 576 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
| 577 | cfq_clear_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 579 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) |
| 580 | cfq_rb_erase(&cfqq->rb_node, &cfqd->service_tree); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 581 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | BUG_ON(!cfqd->busy_queues); |
| 583 | cfqd->busy_queues--; |
| 584 | } |
| 585 | |
| 586 | /* |
| 587 | * rb tree support functions |
| 588 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 589 | static void cfq_del_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 590 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 591 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 592 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 593 | const int sync = rq_is_sync(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 595 | BUG_ON(!cfqq->queued[sync]); |
| 596 | cfqq->queued[sync]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 598 | elv_rb_del(&cfqq->sort_list, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 600 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 601 | cfq_del_cfqq_rr(cfqd, cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | } |
| 603 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 604 | static void cfq_add_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 605 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 606 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 608 | struct request *__alias; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 609 | |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 610 | cfqq->queued[rq_is_sync(rq)]++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | |
| 612 | /* |
| 613 | * looks a little odd, but the first insert might return an alias. |
| 614 | * if that happens, put the alias on the dispatch list |
| 615 | */ |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 616 | while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 617 | cfq_dispatch_insert(cfqd->queue, __alias); |
Jens Axboe | 5fccbf6 | 2006-10-31 14:21:55 +0100 | [diff] [blame] | 618 | |
| 619 | if (!cfq_cfqq_on_rr(cfqq)) |
| 620 | cfq_add_cfqq_rr(cfqd, cfqq); |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 621 | |
| 622 | /* |
| 623 | * check if this request is a better next-serve candidate |
| 624 | */ |
| 625 | cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq); |
| 626 | BUG_ON(!cfqq->next_rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | } |
| 628 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 629 | 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] | 630 | { |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 631 | elv_rb_del(&cfqq->sort_list, rq); |
| 632 | cfqq->queued[rq_is_sync(rq)]--; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 633 | cfq_add_rq_rb(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 634 | } |
| 635 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 636 | static struct request * |
| 637 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | { |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 639 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 640 | struct cfq_io_context *cic; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 641 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 643 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 644 | if (!cic) |
| 645 | return NULL; |
| 646 | |
| 647 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 648 | if (cfqq) { |
| 649 | sector_t sector = bio->bi_sector + bio_sectors(bio); |
| 650 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 651 | return elv_rb_find(&cfqq->sort_list, sector); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 652 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 653 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 654 | return NULL; |
| 655 | } |
| 656 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 657 | static void cfq_activate_request(struct request_queue *q, struct request *rq) |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 658 | { |
| 659 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 660 | |
| 661 | cfqd->rq_in_driver++; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 662 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", |
| 663 | cfqd->rq_in_driver); |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 664 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 665 | cfqd->last_position = rq->hard_sector + rq->hard_nr_sectors; |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 666 | } |
| 667 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 668 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 670 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 671 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 672 | WARN_ON(!cfqd->rq_in_driver); |
| 673 | cfqd->rq_in_driver--; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 674 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", |
| 675 | cfqd->rq_in_driver); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 676 | } |
| 677 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 678 | static void cfq_remove_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 679 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 680 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 681 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 682 | if (cfqq->next_rq == rq) |
| 683 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 684 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 685 | list_del_init(&rq->queuelist); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 686 | cfq_del_rq_rb(rq); |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 687 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 688 | cfqq->cfqd->rq_queued--; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 689 | if (rq_is_meta(rq)) { |
| 690 | WARN_ON(!cfqq->meta_pending); |
| 691 | cfqq->meta_pending--; |
| 692 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | } |
| 694 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 695 | static int cfq_merge(struct request_queue *q, struct request **req, |
| 696 | struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | { |
| 698 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 699 | struct request *__rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 701 | __rq = cfq_find_rq_fmerge(cfqd, bio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 702 | if (__rq && elv_rq_merge_ok(__rq, bio)) { |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 703 | *req = __rq; |
| 704 | return ELEVATOR_FRONT_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | } |
| 706 | |
| 707 | return ELEVATOR_NO_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | } |
| 709 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 710 | static void cfq_merged_request(struct request_queue *q, struct request *req, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 711 | int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 713 | if (type == ELEVATOR_FRONT_MERGE) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 714 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 715 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 716 | cfq_reposition_rq_rb(cfqq, req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 718 | } |
| 719 | |
| 720 | static void |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 721 | cfq_merged_requests(struct request_queue *q, struct request *rq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 722 | struct request *next) |
| 723 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 724 | /* |
| 725 | * reposition in fifo if next is older than rq |
| 726 | */ |
| 727 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && |
| 728 | time_before(next->start_time, rq->start_time)) |
| 729 | list_move(&rq->queuelist, &next->queuelist); |
| 730 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 731 | cfq_remove_request(next); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 732 | } |
| 733 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 734 | static int cfq_allow_merge(struct request_queue *q, struct request *rq, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 735 | struct bio *bio) |
| 736 | { |
| 737 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 738 | struct cfq_io_context *cic; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 739 | struct cfq_queue *cfqq; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 740 | |
| 741 | /* |
Jens Axboe | ec8acb6 | 2007-01-02 18:32:11 +0100 | [diff] [blame] | 742 | * Disallow merge of a sync bio into an async request. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 743 | */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 744 | if (cfq_bio_sync(bio) && !rq_is_sync(rq)) |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 745 | return 0; |
| 746 | |
| 747 | /* |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 748 | * Lookup the cfqq that this bio will be queued with. Allow |
| 749 | * merge only if rq is queued there. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 750 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 751 | cic = cfq_cic_lookup(cfqd, current->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 752 | if (!cic) |
| 753 | return 0; |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 754 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 755 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 756 | if (cfqq == RQ_CFQQ(rq)) |
| 757 | return 1; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 758 | |
Jens Axboe | ec8acb6 | 2007-01-02 18:32:11 +0100 | [diff] [blame] | 759 | return 0; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 760 | } |
| 761 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 762 | static void __cfq_set_active_queue(struct cfq_data *cfqd, |
| 763 | struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 764 | { |
| 765 | if (cfqq) { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 766 | cfq_log_cfqq(cfqd, cfqq, "set_active"); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 767 | cfqq->slice_end = 0; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 768 | cfq_clear_cfqq_must_alloc_slice(cfqq); |
| 769 | cfq_clear_cfqq_fifo_expire(cfqq); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 770 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 1afba04 | 2007-04-17 12:47:55 +0200 | [diff] [blame] | 771 | cfq_clear_cfqq_queue_new(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 772 | } |
| 773 | |
| 774 | cfqd->active_queue = cfqq; |
| 775 | } |
| 776 | |
| 777 | /* |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 778 | * current cfqq expired its slice (or was too idle), select new one |
| 779 | */ |
| 780 | static void |
| 781 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 782 | int timed_out) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 783 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 784 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); |
| 785 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 786 | if (cfq_cfqq_wait_request(cfqq)) |
| 787 | del_timer(&cfqd->idle_slice_timer); |
| 788 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 789 | cfq_clear_cfqq_must_dispatch(cfqq); |
| 790 | cfq_clear_cfqq_wait_request(cfqq); |
| 791 | |
| 792 | /* |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 793 | * 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] | 794 | */ |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 795 | if (timed_out && !cfq_cfqq_slice_new(cfqq)) { |
Jens Axboe | c5b680f | 2007-01-19 11:56:49 +1100 | [diff] [blame] | 796 | cfqq->slice_resid = cfqq->slice_end - jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 797 | cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); |
| 798 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 799 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 800 | cfq_resort_rr_list(cfqd, cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 801 | |
| 802 | if (cfqq == cfqd->active_queue) |
| 803 | cfqd->active_queue = NULL; |
| 804 | |
| 805 | if (cfqd->active_cic) { |
| 806 | put_io_context(cfqd->active_cic->ioc); |
| 807 | cfqd->active_cic = NULL; |
| 808 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 809 | } |
| 810 | |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 811 | 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] | 812 | { |
| 813 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 814 | |
| 815 | if (cfqq) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 816 | __cfq_slice_expired(cfqd, cfqq, timed_out); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 817 | } |
| 818 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 819 | /* |
| 820 | * Get next queue for service. Unless we have a queue preemption, |
| 821 | * we'll simply select the first cfqq in the service tree. |
| 822 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 823 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 824 | { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 825 | if (RB_EMPTY_ROOT(&cfqd->service_tree.rb)) |
| 826 | return NULL; |
| 827 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 828 | return cfq_rb_first(&cfqd->service_tree); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 829 | } |
| 830 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 831 | /* |
| 832 | * Get and set a new active queue for service. |
| 833 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 834 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd) |
| 835 | { |
| 836 | struct cfq_queue *cfqq; |
| 837 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 838 | cfqq = cfq_get_next_queue(cfqd); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 839 | __cfq_set_active_queue(cfqd, cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 840 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 841 | } |
| 842 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 843 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, |
| 844 | struct request *rq) |
| 845 | { |
| 846 | if (rq->sector >= cfqd->last_position) |
| 847 | return rq->sector - cfqd->last_position; |
| 848 | else |
| 849 | return cfqd->last_position - rq->sector; |
| 850 | } |
| 851 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 852 | static inline int cfq_rq_close(struct cfq_data *cfqd, struct request *rq) |
| 853 | { |
| 854 | struct cfq_io_context *cic = cfqd->active_cic; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 855 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 856 | if (!sample_valid(cic->seek_samples)) |
| 857 | return 0; |
| 858 | |
| 859 | return cfq_dist_from_last(cfqd, rq) <= cic->seek_mean; |
| 860 | } |
| 861 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 862 | static int cfq_close_cooperator(struct cfq_data *cfq_data, |
| 863 | struct cfq_queue *cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 864 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 865 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 866 | * We should notice if some of the queues are cooperating, eg |
| 867 | * working closely on the same area of the disk. In that case, |
| 868 | * we can group them together and don't waste time idling. |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 869 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 870 | return 0; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 871 | } |
| 872 | |
| 873 | #define CIC_SEEKY(cic) ((cic)->seek_mean > (8 * 1024)) |
| 874 | |
| 875 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 876 | { |
Jens Axboe | 1792669 | 2007-01-19 11:59:30 +1100 | [diff] [blame] | 877 | struct cfq_queue *cfqq = cfqd->active_queue; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 878 | struct cfq_io_context *cic; |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 879 | unsigned long sl; |
| 880 | |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 881 | /* |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 882 | * SSD device without seek penalty, disable idling. But only do so |
| 883 | * for devices that support queuing, otherwise we still have a problem |
| 884 | * with sync vs async workloads. |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 885 | */ |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 886 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 887 | return; |
| 888 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 889 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 890 | WARN_ON(cfq_cfqq_slice_new(cfqq)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 891 | |
| 892 | /* |
| 893 | * idle is disabled, either manually or by past process history |
| 894 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 895 | if (!cfqd->cfq_slice_idle || !cfq_cfqq_idle_window(cfqq)) |
| 896 | return; |
| 897 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 898 | /* |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 899 | * still requests with the driver, don't idle |
| 900 | */ |
| 901 | if (cfqd->rq_in_driver) |
| 902 | return; |
| 903 | |
| 904 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 905 | * task has exited, don't wait |
| 906 | */ |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 907 | cic = cfqd->active_cic; |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 908 | if (!cic || !atomic_read(&cic->ioc->nr_tasks)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 909 | return; |
| 910 | |
| 911 | /* |
| 912 | * See if this prio level has a good candidate |
| 913 | */ |
Jens Axboe | 1afba04 | 2007-04-17 12:47:55 +0200 | [diff] [blame] | 914 | if (cfq_close_cooperator(cfqd, cfqq) && |
| 915 | (sample_valid(cic->ttime_samples) && cic->ttime_mean > 2)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 916 | return; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 917 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 918 | cfq_mark_cfqq_must_dispatch(cfqq); |
| 919 | cfq_mark_cfqq_wait_request(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 920 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 921 | /* |
| 922 | * we don't want to idle for seeks, but we do want to allow |
| 923 | * fair distribution of slice time for a process doing back-to-back |
| 924 | * seeks. so allow a little bit of time for him to submit a new rq |
| 925 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 926 | sl = cfqd->cfq_slice_idle; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 927 | if (sample_valid(cic->seek_samples) && CIC_SEEKY(cic)) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 928 | sl = min(sl, msecs_to_jiffies(CFQ_MIN_TT)); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 929 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 930 | mod_timer(&cfqd->idle_slice_timer, jiffies + sl); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 931 | cfq_log(cfqd, "arm_idle: %lu", sl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 932 | } |
| 933 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 934 | /* |
| 935 | * Move request from internal lists to the request queue dispatch list. |
| 936 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 937 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 938 | { |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 939 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 940 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 941 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 942 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); |
| 943 | |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 944 | cfq_remove_request(rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 945 | cfqq->dispatched++; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 946 | elv_dispatch_sort(q, rq); |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 947 | |
| 948 | if (cfq_cfqq_sync(cfqq)) |
| 949 | cfqd->sync_flight++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 950 | } |
| 951 | |
| 952 | /* |
| 953 | * return expired entry, or NULL to just start from scratch in rbtree |
| 954 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 955 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 956 | { |
| 957 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 958 | struct request *rq; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 959 | int fifo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 960 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 961 | if (cfq_cfqq_fifo_expire(cfqq)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 962 | return NULL; |
Jens Axboe | cb88741 | 2007-01-19 12:01:16 +1100 | [diff] [blame] | 963 | |
| 964 | cfq_mark_cfqq_fifo_expire(cfqq); |
| 965 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 966 | if (list_empty(&cfqq->fifo)) |
| 967 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 968 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 969 | fifo = cfq_cfqq_sync(cfqq); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 970 | rq = rq_entry_fifo(cfqq->fifo.next); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 972 | if (time_before(jiffies, rq->start_time + cfqd->cfq_fifo_expire[fifo])) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 973 | rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 975 | cfq_log_cfqq(cfqd, cfqq, "fifo=%p", rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 976 | return rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 977 | } |
| 978 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 979 | static inline int |
| 980 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 981 | { |
| 982 | const int base_rq = cfqd->cfq_slice_async_rq; |
| 983 | |
| 984 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); |
| 985 | |
| 986 | return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio)); |
| 987 | } |
| 988 | |
| 989 | /* |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 990 | * Select a queue for service. If we have a current active queue, |
| 991 | * 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] | 992 | */ |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 993 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 994 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 995 | struct cfq_queue *cfqq; |
| 996 | |
| 997 | cfqq = cfqd->active_queue; |
| 998 | if (!cfqq) |
| 999 | goto new_queue; |
| 1000 | |
| 1001 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1002 | * 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] | 1003 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1004 | if (cfq_slice_used(cfqq)) |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1005 | goto expire; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1006 | |
| 1007 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1008 | * The active queue has requests and isn't expired, allow it to |
| 1009 | * dispatch. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1010 | */ |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 1011 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1012 | goto keep_queue; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1013 | |
| 1014 | /* |
| 1015 | * No requests pending. If the active queue still has requests in |
| 1016 | * flight or is idling for a new request, allow either of these |
| 1017 | * conditions to happen (or time out) before selecting a new queue. |
| 1018 | */ |
Jens Axboe | cc19747 | 2007-04-20 20:45:39 +0200 | [diff] [blame] | 1019 | if (timer_pending(&cfqd->idle_slice_timer) || |
| 1020 | (cfqq->dispatched && cfq_cfqq_idle_window(cfqq))) { |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1021 | cfqq = NULL; |
| 1022 | goto keep_queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1023 | } |
| 1024 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1025 | expire: |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1026 | cfq_slice_expired(cfqd, 0); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1027 | new_queue: |
| 1028 | cfqq = cfq_set_active_queue(cfqd); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1029 | keep_queue: |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1030 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1031 | } |
| 1032 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1033 | /* |
| 1034 | * Dispatch some requests from cfqq, moving them to the request queue |
| 1035 | * dispatch list. |
| 1036 | */ |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1037 | static int |
| 1038 | __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 1039 | int max_dispatch) |
| 1040 | { |
| 1041 | int dispatched = 0; |
| 1042 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 1043 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1044 | |
| 1045 | do { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1046 | struct request *rq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1047 | |
| 1048 | /* |
| 1049 | * follow expired path, else get first next available |
| 1050 | */ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1051 | rq = cfq_check_fifo(cfqq); |
| 1052 | if (rq == NULL) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1053 | rq = cfqq->next_rq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1054 | |
| 1055 | /* |
| 1056 | * finally, insert request into driver dispatch list |
| 1057 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1058 | cfq_dispatch_insert(cfqd->queue, rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1059 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1060 | dispatched++; |
| 1061 | |
| 1062 | if (!cfqd->active_cic) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1063 | atomic_inc(&RQ_CIC(rq)->ioc->refcount); |
| 1064 | cfqd->active_cic = RQ_CIC(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1065 | } |
| 1066 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 1067 | if (RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1068 | break; |
| 1069 | |
| 1070 | } while (dispatched < max_dispatch); |
| 1071 | |
| 1072 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1073 | * expire an async queue immediately if it has used up its slice. idle |
| 1074 | * queue always expire after 1 dispatch round. |
| 1075 | */ |
Jens Axboe | a993800 | 2007-04-20 08:55:52 +0200 | [diff] [blame] | 1076 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && |
Jens Axboe | 20e493a | 2007-04-23 08:26:36 +0200 | [diff] [blame] | 1077 | dispatched >= cfq_prio_to_maxrq(cfqd, cfqq)) || |
Jens Axboe | a993800 | 2007-04-20 08:55:52 +0200 | [diff] [blame] | 1078 | cfq_class_idle(cfqq))) { |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 1079 | cfqq->slice_end = jiffies + 1; |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1080 | cfq_slice_expired(cfqd, 0); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 1081 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1082 | |
| 1083 | return dispatched; |
| 1084 | } |
| 1085 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1086 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1087 | { |
| 1088 | int dispatched = 0; |
| 1089 | |
| 1090 | while (cfqq->next_rq) { |
| 1091 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); |
| 1092 | dispatched++; |
| 1093 | } |
| 1094 | |
| 1095 | BUG_ON(!list_empty(&cfqq->fifo)); |
| 1096 | return dispatched; |
| 1097 | } |
| 1098 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1099 | /* |
| 1100 | * Drain our current requests. Used for barriers and when switching |
| 1101 | * io schedulers on-the-fly. |
| 1102 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1103 | static int cfq_forced_dispatch(struct cfq_data *cfqd) |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1104 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1105 | struct cfq_queue *cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1106 | int dispatched = 0; |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1107 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1108 | while ((cfqq = cfq_rb_first(&cfqd->service_tree)) != NULL) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1109 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1110 | |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1111 | cfq_slice_expired(cfqd, 0); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1112 | |
| 1113 | BUG_ON(cfqd->busy_queues); |
| 1114 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1115 | cfq_log(cfqd, "forced_dispatch=%d\n", dispatched); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1116 | return dispatched; |
| 1117 | } |
| 1118 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1119 | static int cfq_dispatch_requests(struct request_queue *q, int force) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1120 | { |
| 1121 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1122 | struct cfq_queue *cfqq; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1123 | int dispatched; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1124 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1125 | if (!cfqd->busy_queues) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | return 0; |
| 1127 | |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 1128 | if (unlikely(force)) |
| 1129 | return cfq_forced_dispatch(cfqd); |
| 1130 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1131 | dispatched = 0; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1132 | while ((cfqq = cfq_select_queue(cfqd)) != NULL) { |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1133 | int max_dispatch; |
| 1134 | |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1135 | max_dispatch = cfqd->cfq_quantum; |
| 1136 | if (cfq_class_idle(cfqq)) |
| 1137 | max_dispatch = 1; |
| 1138 | |
Jens Axboe | 30e0dc2 | 2008-10-20 15:44:28 +0200 | [diff] [blame^] | 1139 | if (cfqq->dispatched >= max_dispatch && cfqd->busy_queues > 1) |
| 1140 | break; |
Jens Axboe | 9ede209 | 2007-01-19 12:11:44 +1100 | [diff] [blame] | 1141 | |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1142 | if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq)) |
| 1143 | break; |
| 1144 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1145 | cfq_clear_cfqq_must_dispatch(cfqq); |
| 1146 | cfq_clear_cfqq_wait_request(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1147 | del_timer(&cfqd->idle_slice_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1148 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1149 | dispatched += __cfq_dispatch_requests(cfqd, cfqq, max_dispatch); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | } |
| 1151 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1152 | cfq_log(cfqd, "dispatched=%d", dispatched); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1153 | return dispatched; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1154 | } |
| 1155 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1156 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1157 | * task holds one reference to the queue, dropped when task exits. each rq |
| 1158 | * 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] | 1159 | * |
| 1160 | * queue lock must be held here. |
| 1161 | */ |
| 1162 | static void cfq_put_queue(struct cfq_queue *cfqq) |
| 1163 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1164 | struct cfq_data *cfqd = cfqq->cfqd; |
| 1165 | |
| 1166 | BUG_ON(atomic_read(&cfqq->ref) <= 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1167 | |
| 1168 | if (!atomic_dec_and_test(&cfqq->ref)) |
| 1169 | return; |
| 1170 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1171 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1172 | BUG_ON(rb_first(&cfqq->sort_list)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1173 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1174 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1175 | |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1176 | if (unlikely(cfqd->active_queue == cfqq)) { |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1177 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1178 | cfq_schedule_dispatch(cfqd); |
| 1179 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1180 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1181 | kmem_cache_free(cfq_pool, cfqq); |
| 1182 | } |
| 1183 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1184 | /* |
| 1185 | * Must always be called with the rcu_read_lock() held |
| 1186 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 1187 | static void |
| 1188 | __call_for_each_cic(struct io_context *ioc, |
| 1189 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 1190 | { |
| 1191 | struct cfq_io_context *cic; |
| 1192 | struct hlist_node *n; |
| 1193 | |
| 1194 | hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list) |
| 1195 | func(ioc, cic); |
| 1196 | } |
| 1197 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1198 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1199 | * Call func for each cic attached to this ioc. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1200 | */ |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1201 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1202 | call_for_each_cic(struct io_context *ioc, |
| 1203 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 1204 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1205 | rcu_read_lock(); |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 1206 | __call_for_each_cic(ioc, func); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1207 | rcu_read_unlock(); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1208 | } |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1209 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1210 | static void cfq_cic_free_rcu(struct rcu_head *head) |
| 1211 | { |
| 1212 | struct cfq_io_context *cic; |
| 1213 | |
| 1214 | cic = container_of(head, struct cfq_io_context, rcu_head); |
| 1215 | |
| 1216 | kmem_cache_free(cfq_ioc_pool, cic); |
| 1217 | elv_ioc_count_dec(ioc_count); |
| 1218 | |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 1219 | if (ioc_gone) { |
| 1220 | /* |
| 1221 | * CFQ scheduler is exiting, grab exit lock and check |
| 1222 | * the pending io context count. If it hits zero, |
| 1223 | * complete ioc_gone and set it back to NULL |
| 1224 | */ |
| 1225 | spin_lock(&ioc_gone_lock); |
| 1226 | if (ioc_gone && !elv_ioc_count_read(ioc_count)) { |
| 1227 | complete(ioc_gone); |
| 1228 | ioc_gone = NULL; |
| 1229 | } |
| 1230 | spin_unlock(&ioc_gone_lock); |
| 1231 | } |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1232 | } |
| 1233 | |
| 1234 | static void cfq_cic_free(struct cfq_io_context *cic) |
| 1235 | { |
| 1236 | call_rcu(&cic->rcu_head, cfq_cic_free_rcu); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1237 | } |
| 1238 | |
| 1239 | static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic) |
| 1240 | { |
| 1241 | unsigned long flags; |
| 1242 | |
| 1243 | BUG_ON(!cic->dead_key); |
| 1244 | |
| 1245 | spin_lock_irqsave(&ioc->lock, flags); |
| 1246 | radix_tree_delete(&ioc->radix_root, cic->dead_key); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1247 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1248 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 1249 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1250 | cfq_cic_free(cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1251 | } |
| 1252 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1253 | /* |
| 1254 | * Must be called with rcu_read_lock() held or preemption otherwise disabled. |
| 1255 | * Only two callers of this - ->dtor() which is called with the rcu_read_lock(), |
| 1256 | * and ->trim() which is called with the task lock held |
| 1257 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1258 | static void cfq_free_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1259 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1260 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 1261 | * ioc->refcount is zero here, or we are called from elv_unregister(), |
| 1262 | * so no more cic's are allowed to be linked into this ioc. So it |
| 1263 | * should be ok to iterate over the known list, we will see all cic's |
| 1264 | * since no new ones are added. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1265 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 1266 | __call_for_each_cic(ioc, cic_free_func); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1267 | } |
| 1268 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1269 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1270 | { |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1271 | if (unlikely(cfqq == cfqd->active_queue)) { |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1272 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 1273 | cfq_schedule_dispatch(cfqd); |
| 1274 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1275 | |
| 1276 | cfq_put_queue(cfqq); |
| 1277 | } |
| 1278 | |
| 1279 | static void __cfq_exit_single_io_context(struct cfq_data *cfqd, |
| 1280 | struct cfq_io_context *cic) |
| 1281 | { |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 1282 | struct io_context *ioc = cic->ioc; |
| 1283 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1284 | list_del_init(&cic->queue_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1285 | |
| 1286 | /* |
| 1287 | * Make sure key == NULL is seen for dead queues |
| 1288 | */ |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1289 | smp_wmb(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1290 | cic->dead_key = (unsigned long) cic->key; |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1291 | cic->key = NULL; |
| 1292 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 1293 | if (ioc->ioc_data == cic) |
| 1294 | rcu_assign_pointer(ioc->ioc_data, NULL); |
| 1295 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1296 | if (cic->cfqq[ASYNC]) { |
| 1297 | cfq_exit_cfqq(cfqd, cic->cfqq[ASYNC]); |
| 1298 | cic->cfqq[ASYNC] = NULL; |
| 1299 | } |
| 1300 | |
| 1301 | if (cic->cfqq[SYNC]) { |
| 1302 | cfq_exit_cfqq(cfqd, cic->cfqq[SYNC]); |
| 1303 | cic->cfqq[SYNC] = NULL; |
| 1304 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1305 | } |
| 1306 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1307 | static void cfq_exit_single_io_context(struct io_context *ioc, |
| 1308 | struct cfq_io_context *cic) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1309 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 1310 | struct cfq_data *cfqd = cic->key; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1311 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1312 | if (cfqd) { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1313 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1314 | unsigned long flags; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1315 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1316 | spin_lock_irqsave(q->queue_lock, flags); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1317 | __cfq_exit_single_io_context(cfqd, cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1318 | spin_unlock_irqrestore(q->queue_lock, flags); |
Al Viro | 12a0573 | 2006-03-18 13:38:01 -0500 | [diff] [blame] | 1319 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1320 | } |
| 1321 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1322 | /* |
| 1323 | * The process that ioc belongs to has exited, we need to clean up |
| 1324 | * and put the internal structures we have that belongs to that process. |
| 1325 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1326 | static void cfq_exit_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1327 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1328 | call_for_each_cic(ioc, cfq_exit_single_io_context); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1329 | } |
| 1330 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1331 | static struct cfq_io_context * |
Al Viro | 8267e26 | 2005-10-21 03:20:53 -0400 | [diff] [blame] | 1332 | cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1333 | { |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 1334 | struct cfq_io_context *cic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1335 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1336 | cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO, |
| 1337 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1338 | if (cic) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1339 | cic->last_end_request = jiffies; |
Jens Axboe | 553698f | 2006-06-14 19:11:57 +0200 | [diff] [blame] | 1340 | INIT_LIST_HEAD(&cic->queue_list); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1341 | INIT_HLIST_NODE(&cic->cic_list); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1342 | cic->dtor = cfq_free_io_context; |
| 1343 | cic->exit = cfq_exit_io_context; |
Jens Axboe | 4050cf1 | 2006-07-19 05:07:12 +0200 | [diff] [blame] | 1344 | elv_ioc_count_inc(ioc_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1345 | } |
| 1346 | |
| 1347 | return cic; |
| 1348 | } |
| 1349 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1350 | 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] | 1351 | { |
| 1352 | struct task_struct *tsk = current; |
| 1353 | int ioprio_class; |
| 1354 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1355 | if (!cfq_cfqq_prio_changed(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1356 | return; |
| 1357 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1358 | ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1359 | switch (ioprio_class) { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1360 | default: |
| 1361 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); |
| 1362 | case IOPRIO_CLASS_NONE: |
| 1363 | /* |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 1364 | * no prio set, inherit CPU scheduling settings |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1365 | */ |
| 1366 | cfqq->ioprio = task_nice_ioprio(tsk); |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 1367 | cfqq->ioprio_class = task_nice_ioclass(tsk); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1368 | break; |
| 1369 | case IOPRIO_CLASS_RT: |
| 1370 | cfqq->ioprio = task_ioprio(ioc); |
| 1371 | cfqq->ioprio_class = IOPRIO_CLASS_RT; |
| 1372 | break; |
| 1373 | case IOPRIO_CLASS_BE: |
| 1374 | cfqq->ioprio = task_ioprio(ioc); |
| 1375 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 1376 | break; |
| 1377 | case IOPRIO_CLASS_IDLE: |
| 1378 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; |
| 1379 | cfqq->ioprio = 7; |
| 1380 | cfq_clear_cfqq_idle_window(cfqq); |
| 1381 | break; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1382 | } |
| 1383 | |
| 1384 | /* |
| 1385 | * keep track of original prio settings in case we have to temporarily |
| 1386 | * elevate the priority of this queue |
| 1387 | */ |
| 1388 | cfqq->org_ioprio = cfqq->ioprio; |
| 1389 | cfqq->org_ioprio_class = cfqq->ioprio_class; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1390 | cfq_clear_cfqq_prio_changed(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1391 | } |
| 1392 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1393 | 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] | 1394 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 1395 | struct cfq_data *cfqd = cic->key; |
| 1396 | struct cfq_queue *cfqq; |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 1397 | unsigned long flags; |
Jens Axboe | 35e6077 | 2006-06-14 09:10:45 +0200 | [diff] [blame] | 1398 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1399 | if (unlikely(!cfqd)) |
| 1400 | return; |
| 1401 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 1402 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1403 | |
| 1404 | cfqq = cic->cfqq[ASYNC]; |
| 1405 | if (cfqq) { |
| 1406 | struct cfq_queue *new_cfqq; |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1407 | new_cfqq = cfq_get_queue(cfqd, ASYNC, cic->ioc, GFP_ATOMIC); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1408 | if (new_cfqq) { |
| 1409 | cic->cfqq[ASYNC] = new_cfqq; |
| 1410 | cfq_put_queue(cfqq); |
| 1411 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1412 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1413 | |
| 1414 | cfqq = cic->cfqq[SYNC]; |
| 1415 | if (cfqq) |
| 1416 | cfq_mark_cfqq_prio_changed(cfqq); |
| 1417 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 1418 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1419 | } |
| 1420 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1421 | static void cfq_ioc_set_ioprio(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1422 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1423 | call_for_each_cic(ioc, changed_ioprio); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1424 | ioc->ioprio_changed = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1425 | } |
| 1426 | |
| 1427 | static struct cfq_queue * |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1428 | cfq_find_alloc_queue(struct cfq_data *cfqd, int is_sync, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1429 | struct io_context *ioc, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1431 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1432 | struct cfq_io_context *cic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1433 | |
| 1434 | retry: |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1435 | cic = cfq_cic_lookup(cfqd, ioc); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1436 | /* cic always exists here */ |
| 1437 | cfqq = cic_to_cfqq(cic, is_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1438 | |
| 1439 | if (!cfqq) { |
| 1440 | if (new_cfqq) { |
| 1441 | cfqq = new_cfqq; |
| 1442 | new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1443 | } else if (gfp_mask & __GFP_WAIT) { |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1444 | /* |
| 1445 | * Inform the allocator of the fact that we will |
| 1446 | * just repeat this allocation if it fails, to allow |
| 1447 | * the allocator to do whatever it needs to attempt to |
| 1448 | * free memory. |
| 1449 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1450 | spin_unlock_irq(cfqd->queue->queue_lock); |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1451 | new_cfqq = kmem_cache_alloc_node(cfq_pool, |
| 1452 | gfp_mask | __GFP_NOFAIL | __GFP_ZERO, |
| 1453 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1454 | spin_lock_irq(cfqd->queue->queue_lock); |
| 1455 | goto retry; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1456 | } else { |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 1457 | cfqq = kmem_cache_alloc_node(cfq_pool, |
| 1458 | gfp_mask | __GFP_ZERO, |
| 1459 | cfqd->queue->node); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1460 | if (!cfqq) |
| 1461 | goto out; |
Kiyoshi Ueda | db3b584 | 2005-06-17 16:15:10 +0200 | [diff] [blame] | 1462 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1463 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1464 | RB_CLEAR_NODE(&cfqq->rb_node); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1465 | INIT_LIST_HEAD(&cfqq->fifo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1466 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1467 | atomic_set(&cfqq->ref, 0); |
| 1468 | cfqq->cfqd = cfqd; |
Jens Axboe | c5b680f | 2007-01-19 11:56:49 +1100 | [diff] [blame] | 1469 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1470 | cfq_mark_cfqq_prio_changed(cfqq); |
Jens Axboe | 53b0374 | 2006-07-28 09:48:51 +0200 | [diff] [blame] | 1471 | cfq_mark_cfqq_queue_new(cfqq); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1472 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1473 | cfq_init_prio_data(cfqq, ioc); |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1474 | |
| 1475 | if (is_sync) { |
| 1476 | if (!cfq_class_idle(cfqq)) |
| 1477 | cfq_mark_cfqq_idle_window(cfqq); |
| 1478 | cfq_mark_cfqq_sync(cfqq); |
| 1479 | } |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1480 | cfqq->pid = current->pid; |
| 1481 | cfq_log_cfqq(cfqd, cfqq, "alloced"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1482 | } |
| 1483 | |
| 1484 | if (new_cfqq) |
| 1485 | kmem_cache_free(cfq_pool, new_cfqq); |
| 1486 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1487 | out: |
| 1488 | WARN_ON((gfp_mask & __GFP_WAIT) && !cfqq); |
| 1489 | return cfqq; |
| 1490 | } |
| 1491 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1492 | static struct cfq_queue ** |
| 1493 | cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) |
| 1494 | { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 1495 | switch (ioprio_class) { |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1496 | case IOPRIO_CLASS_RT: |
| 1497 | return &cfqd->async_cfqq[0][ioprio]; |
| 1498 | case IOPRIO_CLASS_BE: |
| 1499 | return &cfqd->async_cfqq[1][ioprio]; |
| 1500 | case IOPRIO_CLASS_IDLE: |
| 1501 | return &cfqd->async_idle_cfqq; |
| 1502 | default: |
| 1503 | BUG(); |
| 1504 | } |
| 1505 | } |
| 1506 | |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1507 | static struct cfq_queue * |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1508 | 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] | 1509 | gfp_t gfp_mask) |
| 1510 | { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1511 | const int ioprio = task_ioprio(ioc); |
| 1512 | const int ioprio_class = task_ioprio_class(ioc); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1513 | struct cfq_queue **async_cfqq = NULL; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1514 | struct cfq_queue *cfqq = NULL; |
| 1515 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1516 | if (!is_sync) { |
| 1517 | async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); |
| 1518 | cfqq = *async_cfqq; |
| 1519 | } |
| 1520 | |
Oleg Nesterov | 0a0836a | 2007-10-23 15:08:21 +0200 | [diff] [blame] | 1521 | if (!cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1522 | cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask); |
Oleg Nesterov | 0a0836a | 2007-10-23 15:08:21 +0200 | [diff] [blame] | 1523 | if (!cfqq) |
| 1524 | return NULL; |
| 1525 | } |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1526 | |
| 1527 | /* |
| 1528 | * pin the queue now that it's allocated, scheduler exit will prune it |
| 1529 | */ |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1530 | if (!is_sync && !(*async_cfqq)) { |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1531 | atomic_inc(&cfqq->ref); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 1532 | *async_cfqq = cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 1533 | } |
| 1534 | |
| 1535 | atomic_inc(&cfqq->ref); |
| 1536 | return cfqq; |
| 1537 | } |
| 1538 | |
Jens Axboe | 498d3aa | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1539 | /* |
| 1540 | * We drop cfq io contexts lazily, so we may find a dead one. |
| 1541 | */ |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1542 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1543 | cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc, |
| 1544 | struct cfq_io_context *cic) |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1545 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1546 | unsigned long flags; |
| 1547 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1548 | WARN_ON(!list_empty(&cic->queue_list)); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1549 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1550 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1551 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 1552 | BUG_ON(ioc->ioc_data == cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1553 | |
| 1554 | radix_tree_delete(&ioc->radix_root, (unsigned long) cfqd); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1555 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1556 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 1557 | |
| 1558 | cfq_cic_free(cic); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1559 | } |
| 1560 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1561 | static struct cfq_io_context * |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1562 | cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1563 | { |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1564 | struct cfq_io_context *cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1565 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1566 | void *k; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1567 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1568 | if (unlikely(!ioc)) |
| 1569 | return NULL; |
| 1570 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1571 | rcu_read_lock(); |
| 1572 | |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1573 | /* |
| 1574 | * we maintain a last-hit cache, to avoid browsing over the tree |
| 1575 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1576 | cic = rcu_dereference(ioc->ioc_data); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1577 | if (cic && cic->key == cfqd) { |
| 1578 | rcu_read_unlock(); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1579 | return cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1580 | } |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 1581 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1582 | do { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1583 | cic = radix_tree_lookup(&ioc->radix_root, (unsigned long) cfqd); |
| 1584 | rcu_read_unlock(); |
| 1585 | if (!cic) |
| 1586 | break; |
OGAWA Hirofumi | be3b075 | 2006-04-18 19:18:31 +0200 | [diff] [blame] | 1587 | /* ->key must be copied to avoid race with cfq_exit_queue() */ |
| 1588 | k = cic->key; |
| 1589 | if (unlikely(!k)) { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1590 | cfq_drop_dead_cic(cfqd, ioc, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1591 | rcu_read_lock(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1592 | continue; |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1593 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1594 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1595 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1596 | rcu_assign_pointer(ioc->ioc_data, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 1597 | spin_unlock_irqrestore(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1598 | break; |
| 1599 | } while (1); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1600 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1601 | return cic; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1602 | } |
| 1603 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1604 | /* |
| 1605 | * Add cic into ioc, using cfqd as the search key. This enables us to lookup |
| 1606 | * the process specific cfq io context when entered from the block layer. |
| 1607 | * Also adds the cic to a per-cfqd list, used when this queue is removed. |
| 1608 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1609 | static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, |
| 1610 | struct cfq_io_context *cic, gfp_t gfp_mask) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1611 | { |
Jens Axboe | 0261d68 | 2006-10-30 19:07:48 +0100 | [diff] [blame] | 1612 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1613 | int ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1614 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1615 | ret = radix_tree_preload(gfp_mask); |
| 1616 | if (!ret) { |
| 1617 | cic->ioc = ioc; |
| 1618 | cic->key = cfqd; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1619 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1620 | spin_lock_irqsave(&ioc->lock, flags); |
| 1621 | ret = radix_tree_insert(&ioc->radix_root, |
| 1622 | (unsigned long) cfqd, cic); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 1623 | if (!ret) |
| 1624 | hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1625 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 1626 | |
| 1627 | radix_tree_preload_end(); |
| 1628 | |
| 1629 | if (!ret) { |
| 1630 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 1631 | list_add(&cic->queue_list, &cfqd->cic_list); |
| 1632 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 1633 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1634 | } |
| 1635 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1636 | if (ret) |
| 1637 | printk(KERN_ERR "cfq: cic link failed!\n"); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1638 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1639 | return ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1640 | } |
| 1641 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1642 | /* |
| 1643 | * Setup general io context and cfq io context. There can be several cfq |
| 1644 | * 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] | 1645 | * than one device managed by cfq. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1646 | */ |
| 1647 | static struct cfq_io_context * |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1648 | cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1649 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1650 | struct io_context *ioc = NULL; |
| 1651 | struct cfq_io_context *cic; |
| 1652 | |
| 1653 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 1654 | |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 1655 | ioc = get_io_context(gfp_mask, cfqd->queue->node); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1656 | if (!ioc) |
| 1657 | return NULL; |
| 1658 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1659 | cic = cfq_cic_lookup(cfqd, ioc); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1660 | if (cic) |
| 1661 | goto out; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1662 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 1663 | cic = cfq_alloc_io_context(cfqd, gfp_mask); |
| 1664 | if (cic == NULL) |
| 1665 | goto err; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1666 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1667 | if (cfq_cic_link(cfqd, ioc, cic, gfp_mask)) |
| 1668 | goto err_free; |
| 1669 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1670 | out: |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 1671 | smp_read_barrier_depends(); |
| 1672 | if (unlikely(ioc->ioprio_changed)) |
| 1673 | cfq_ioc_set_ioprio(ioc); |
| 1674 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1675 | return cic; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1676 | err_free: |
| 1677 | cfq_cic_free(cic); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1678 | err: |
| 1679 | put_io_context(ioc); |
| 1680 | return NULL; |
| 1681 | } |
| 1682 | |
| 1683 | static void |
| 1684 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic) |
| 1685 | { |
Jens Axboe | aaf1228 | 2007-01-19 11:30:16 +1100 | [diff] [blame] | 1686 | unsigned long elapsed = jiffies - cic->last_end_request; |
| 1687 | unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1688 | |
| 1689 | cic->ttime_samples = (7*cic->ttime_samples + 256) / 8; |
| 1690 | cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8; |
| 1691 | cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples; |
| 1692 | } |
| 1693 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1694 | static void |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1695 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_io_context *cic, |
| 1696 | struct request *rq) |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1697 | { |
| 1698 | sector_t sdist; |
| 1699 | u64 total; |
| 1700 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1701 | if (cic->last_request_pos < rq->sector) |
| 1702 | sdist = rq->sector - cic->last_request_pos; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1703 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1704 | sdist = cic->last_request_pos - rq->sector; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1705 | |
| 1706 | /* |
| 1707 | * Don't allow the seek distance to get too large from the |
| 1708 | * odd fragment, pagein, etc |
| 1709 | */ |
| 1710 | if (cic->seek_samples <= 60) /* second&third seek */ |
| 1711 | sdist = min(sdist, (cic->seek_mean * 4) + 2*1024*1024); |
| 1712 | else |
| 1713 | sdist = min(sdist, (cic->seek_mean * 4) + 2*1024*64); |
| 1714 | |
| 1715 | cic->seek_samples = (7*cic->seek_samples + 256) / 8; |
| 1716 | cic->seek_total = (7*cic->seek_total + (u64)256*sdist) / 8; |
| 1717 | total = cic->seek_total + (cic->seek_samples/2); |
| 1718 | do_div(total, cic->seek_samples); |
| 1719 | cic->seek_mean = (sector_t)total; |
| 1720 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1721 | |
| 1722 | /* |
| 1723 | * Disable idle window if the process thinks too long or seeks so much that |
| 1724 | * it doesn't matter |
| 1725 | */ |
| 1726 | static void |
| 1727 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 1728 | struct cfq_io_context *cic) |
| 1729 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1730 | int old_idle, enable_idle; |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 1731 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1732 | /* |
| 1733 | * Don't idle for async or idle io prio class |
| 1734 | */ |
| 1735 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 1736 | return; |
| 1737 | |
Jens Axboe | c265a7f | 2008-06-26 13:49:33 +0200 | [diff] [blame] | 1738 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1739 | |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 1740 | if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle || |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1741 | (cfqd->hw_tag && CIC_SEEKY(cic))) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1742 | enable_idle = 0; |
| 1743 | else if (sample_valid(cic->ttime_samples)) { |
| 1744 | if (cic->ttime_mean > cfqd->cfq_slice_idle) |
| 1745 | enable_idle = 0; |
| 1746 | else |
| 1747 | enable_idle = 1; |
| 1748 | } |
| 1749 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1750 | if (old_idle != enable_idle) { |
| 1751 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); |
| 1752 | if (enable_idle) |
| 1753 | cfq_mark_cfqq_idle_window(cfqq); |
| 1754 | else |
| 1755 | cfq_clear_cfqq_idle_window(cfqq); |
| 1756 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1757 | } |
| 1758 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1759 | /* |
| 1760 | * Check if new_cfqq should preempt the currently active queue. Return 0 for |
| 1761 | * no or if we aren't sure, a 1 will cause a preempt. |
| 1762 | */ |
| 1763 | static int |
| 1764 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1765 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1766 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1767 | struct cfq_queue *cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1768 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1769 | cfqq = cfqd->active_queue; |
| 1770 | if (!cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1771 | return 0; |
| 1772 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1773 | if (cfq_slice_used(cfqq)) |
| 1774 | return 1; |
| 1775 | |
| 1776 | if (cfq_class_idle(new_cfqq)) |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1777 | return 0; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1778 | |
| 1779 | if (cfq_class_idle(cfqq)) |
| 1780 | return 1; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 1781 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1782 | /* |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 1783 | * if the new request is sync, but the currently running queue is |
| 1784 | * not, let the sync request have priority. |
| 1785 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1786 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1787 | return 1; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 1788 | |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 1789 | /* |
| 1790 | * So both queues are sync. Let the new request get disk time if |
| 1791 | * it's a metadata request and the current queue is doing regular IO. |
| 1792 | */ |
| 1793 | if (rq_is_meta(rq) && !cfqq->meta_pending) |
| 1794 | return 1; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1795 | |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 1796 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) |
| 1797 | return 0; |
| 1798 | |
| 1799 | /* |
| 1800 | * if this request is as-good as one we would expect from the |
| 1801 | * current cfqq, let it preempt |
| 1802 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1803 | if (cfq_rq_close(cfqd, rq)) |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 1804 | return 1; |
| 1805 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1806 | return 0; |
| 1807 | } |
| 1808 | |
| 1809 | /* |
| 1810 | * cfqq preempts the active queue. if we allowed preempt with no slice left, |
| 1811 | * let it have half of its nominal slice. |
| 1812 | */ |
| 1813 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1814 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1815 | cfq_log_cfqq(cfqd, cfqq, "preempt"); |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1816 | cfq_slice_expired(cfqd, 1); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1817 | |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 1818 | /* |
| 1819 | * Put the new queue at the front of the of the current list, |
| 1820 | * so we know that it will be selected next. |
| 1821 | */ |
| 1822 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1823 | |
| 1824 | cfq_service_tree_add(cfqd, cfqq, 1); |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 1825 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 1826 | cfqq->slice_end = 0; |
| 1827 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1828 | } |
| 1829 | |
| 1830 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1831 | * 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] | 1832 | * something we should do about it |
| 1833 | */ |
| 1834 | static void |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1835 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 1836 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1837 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1838 | struct cfq_io_context *cic = RQ_CIC(rq); |
Jens Axboe | 12e9fdd | 2006-06-01 10:09:56 +0200 | [diff] [blame] | 1839 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 1840 | cfqd->rq_queued++; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 1841 | if (rq_is_meta(rq)) |
| 1842 | cfqq->meta_pending++; |
| 1843 | |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 1844 | cfq_update_io_thinktime(cfqd, cic); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1845 | cfq_update_io_seektime(cfqd, cic, rq); |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 1846 | cfq_update_idle_window(cfqd, cfqq, cic); |
| 1847 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1848 | cic->last_request_pos = rq->sector + rq->nr_sectors; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1849 | |
| 1850 | if (cfqq == cfqd->active_queue) { |
| 1851 | /* |
| 1852 | * if we are waiting for a request for this queue, let it rip |
| 1853 | * immediately and flag that we must not expire this queue |
| 1854 | * just now |
| 1855 | */ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1856 | if (cfq_cfqq_wait_request(cfqq)) { |
| 1857 | cfq_mark_cfqq_must_dispatch(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1858 | del_timer(&cfqd->idle_slice_timer); |
Jens Axboe | dc72ef4 | 2006-07-20 14:54:05 +0200 | [diff] [blame] | 1859 | blk_start_queueing(cfqd->queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1860 | } |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1861 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1862 | /* |
| 1863 | * not the active queue - expire current slice if it is |
| 1864 | * idle and has expired it's mean thinktime or this new queue |
| 1865 | * has some old slice time left and is of higher priority |
| 1866 | */ |
| 1867 | cfq_preempt_queue(cfqd, cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1868 | cfq_mark_cfqq_must_dispatch(cfqq); |
Jens Axboe | dc72ef4 | 2006-07-20 14:54:05 +0200 | [diff] [blame] | 1869 | blk_start_queueing(cfqd->queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1870 | } |
| 1871 | } |
| 1872 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1873 | static void cfq_insert_request(struct request_queue *q, struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1874 | { |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1875 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1876 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1877 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1878 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 1879 | cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1880 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1881 | cfq_add_rq_rb(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1882 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1883 | list_add_tail(&rq->queuelist, &cfqq->fifo); |
| 1884 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1885 | cfq_rq_enqueued(cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1886 | } |
| 1887 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 1888 | /* |
| 1889 | * Update hw_tag based on peak queue depth over 50 samples under |
| 1890 | * sufficient load. |
| 1891 | */ |
| 1892 | static void cfq_update_hw_tag(struct cfq_data *cfqd) |
| 1893 | { |
| 1894 | if (cfqd->rq_in_driver > cfqd->rq_in_driver_peak) |
| 1895 | cfqd->rq_in_driver_peak = cfqd->rq_in_driver; |
| 1896 | |
| 1897 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && |
| 1898 | cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN) |
| 1899 | return; |
| 1900 | |
| 1901 | if (cfqd->hw_tag_samples++ < 50) |
| 1902 | return; |
| 1903 | |
| 1904 | if (cfqd->rq_in_driver_peak >= CFQ_HW_QUEUE_MIN) |
| 1905 | cfqd->hw_tag = 1; |
| 1906 | else |
| 1907 | cfqd->hw_tag = 0; |
| 1908 | |
| 1909 | cfqd->hw_tag_samples = 0; |
| 1910 | cfqd->rq_in_driver_peak = 0; |
| 1911 | } |
| 1912 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1913 | static void cfq_completed_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1914 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1915 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1916 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1917 | const int sync = rq_is_sync(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1918 | unsigned long now; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1919 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1920 | now = jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1921 | cfq_log_cfqq(cfqd, cfqq, "complete"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1922 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 1923 | cfq_update_hw_tag(cfqd); |
| 1924 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1925 | WARN_ON(!cfqd->rq_in_driver); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1926 | WARN_ON(!cfqq->dispatched); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1927 | cfqd->rq_in_driver--; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1928 | cfqq->dispatched--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1929 | |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1930 | if (cfq_cfqq_sync(cfqq)) |
| 1931 | cfqd->sync_flight--; |
| 1932 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1933 | if (!cfq_class_idle(cfqq)) |
| 1934 | cfqd->last_end_request = now; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1935 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1936 | if (sync) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1937 | RQ_CIC(rq)->last_end_request = now; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1938 | |
| 1939 | /* |
| 1940 | * If this is the active queue, check if it needs to be expired, |
| 1941 | * or if we want to idle in case it has no pending requests. |
| 1942 | */ |
| 1943 | if (cfqd->active_queue == cfqq) { |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 1944 | if (cfq_cfqq_slice_new(cfqq)) { |
| 1945 | cfq_set_prio_slice(cfqd, cfqq); |
| 1946 | cfq_clear_cfqq_slice_new(cfqq); |
| 1947 | } |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1948 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1949 | cfq_slice_expired(cfqd, 1); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1950 | else if (sync && RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 1951 | cfq_arm_slice_timer(cfqd); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1952 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1953 | |
| 1954 | if (!cfqd->rq_in_driver) |
| 1955 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1956 | } |
| 1957 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1958 | /* |
| 1959 | * we temporarily boost lower priority queues if they are holding fs exclusive |
| 1960 | * resources. they are boosted to normal prio (CLASS_BE/4) |
| 1961 | */ |
| 1962 | static void cfq_prio_boost(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1963 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1964 | if (has_fs_excl()) { |
| 1965 | /* |
| 1966 | * boost idle prio on transactions that would lock out other |
| 1967 | * users of the filesystem |
| 1968 | */ |
| 1969 | if (cfq_class_idle(cfqq)) |
| 1970 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 1971 | if (cfqq->ioprio > IOPRIO_NORM) |
| 1972 | cfqq->ioprio = IOPRIO_NORM; |
| 1973 | } else { |
| 1974 | /* |
| 1975 | * check if we need to unboost the queue |
| 1976 | */ |
| 1977 | if (cfqq->ioprio_class != cfqq->org_ioprio_class) |
| 1978 | cfqq->ioprio_class = cfqq->org_ioprio_class; |
| 1979 | if (cfqq->ioprio != cfqq->org_ioprio) |
| 1980 | cfqq->ioprio = cfqq->org_ioprio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1981 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1982 | } |
| 1983 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1984 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1985 | { |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1986 | if ((cfq_cfqq_wait_request(cfqq) || cfq_cfqq_must_alloc(cfqq)) && |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 1987 | !cfq_cfqq_must_alloc_slice(cfqq)) { |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1988 | cfq_mark_cfqq_must_alloc_slice(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1989 | return ELV_MQUEUE_MUST; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1990 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1991 | |
| 1992 | return ELV_MQUEUE_MAY; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1993 | } |
| 1994 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1995 | static int cfq_may_queue(struct request_queue *q, int rw) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1996 | { |
| 1997 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1998 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1999 | struct cfq_io_context *cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2000 | struct cfq_queue *cfqq; |
| 2001 | |
| 2002 | /* |
| 2003 | * don't force setup of a queue from here, as a call to may_queue |
| 2004 | * does not necessarily imply that a request actually will be queued. |
| 2005 | * so just lookup a possibly existing queue, or return 'may queue' |
| 2006 | * if that fails |
| 2007 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2008 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2009 | if (!cic) |
| 2010 | return ELV_MQUEUE_MAY; |
| 2011 | |
| 2012 | cfqq = cic_to_cfqq(cic, rw & REQ_RW_SYNC); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2013 | if (cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2014 | cfq_init_prio_data(cfqq, cic->ioc); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2015 | cfq_prio_boost(cfqq); |
| 2016 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2017 | return __cfq_may_queue(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2018 | } |
| 2019 | |
| 2020 | return ELV_MQUEUE_MAY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2021 | } |
| 2022 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2023 | /* |
| 2024 | * queue lock held here |
| 2025 | */ |
Jens Axboe | bb37b94 | 2006-12-01 10:42:33 +0100 | [diff] [blame] | 2026 | static void cfq_put_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2027 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2028 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2029 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2030 | if (cfqq) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2031 | const int rw = rq_data_dir(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2032 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2033 | BUG_ON(!cfqq->allocated[rw]); |
| 2034 | cfqq->allocated[rw]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2035 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2036 | put_io_context(RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2037 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2038 | rq->elevator_private = NULL; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2039 | rq->elevator_private2 = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2040 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2041 | cfq_put_queue(cfqq); |
| 2042 | } |
| 2043 | } |
| 2044 | |
| 2045 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2046 | * Allocate cfq data structures associated with this request. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2047 | */ |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2048 | static int |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2049 | 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] | 2050 | { |
| 2051 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 2052 | struct cfq_io_context *cic; |
| 2053 | const int rw = rq_data_dir(rq); |
Jens Axboe | 7749a8d | 2006-12-13 13:02:26 +0100 | [diff] [blame] | 2054 | const int is_sync = rq_is_sync(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2055 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2056 | unsigned long flags; |
| 2057 | |
| 2058 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 2059 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2060 | cic = cfq_get_io_context(cfqd, gfp_mask); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2061 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2062 | spin_lock_irqsave(q->queue_lock, flags); |
| 2063 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2064 | if (!cic) |
| 2065 | goto queue_fail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2066 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2067 | cfqq = cic_to_cfqq(cic, is_sync); |
| 2068 | if (!cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2069 | cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2070 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2071 | if (!cfqq) |
| 2072 | goto queue_fail; |
| 2073 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2074 | cic_set_cfqq(cic, cfqq, is_sync); |
| 2075 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2076 | |
| 2077 | cfqq->allocated[rw]++; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2078 | cfq_clear_cfqq_must_alloc(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2079 | atomic_inc(&cfqq->ref); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2080 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2081 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2082 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2083 | rq->elevator_private = cic; |
| 2084 | rq->elevator_private2 = cfqq; |
| 2085 | return 0; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2086 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2087 | queue_fail: |
| 2088 | if (cic) |
| 2089 | put_io_context(cic->ioc); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2090 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2091 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2092 | spin_unlock_irqrestore(q->queue_lock, flags); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2093 | cfq_log(cfqd, "set_request fail"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2094 | return 1; |
| 2095 | } |
| 2096 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 2097 | static void cfq_kick_queue(struct work_struct *work) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2098 | { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 2099 | struct cfq_data *cfqd = |
| 2100 | container_of(work, struct cfq_data, unplug_work); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2101 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2102 | unsigned long flags; |
| 2103 | |
| 2104 | spin_lock_irqsave(q->queue_lock, flags); |
Jens Axboe | dc72ef4 | 2006-07-20 14:54:05 +0200 | [diff] [blame] | 2105 | blk_start_queueing(q); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2106 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2107 | } |
| 2108 | |
| 2109 | /* |
| 2110 | * Timer running if the active_queue is currently idling inside its time slice |
| 2111 | */ |
| 2112 | static void cfq_idle_slice_timer(unsigned long data) |
| 2113 | { |
| 2114 | struct cfq_data *cfqd = (struct cfq_data *) data; |
| 2115 | struct cfq_queue *cfqq; |
| 2116 | unsigned long flags; |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 2117 | int timed_out = 1; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2118 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2119 | cfq_log(cfqd, "idle timer fired"); |
| 2120 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2121 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 2122 | |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2123 | cfqq = cfqd->active_queue; |
| 2124 | if (cfqq) { |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 2125 | timed_out = 0; |
| 2126 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2127 | /* |
| 2128 | * expired |
| 2129 | */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 2130 | if (cfq_slice_used(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2131 | goto expire; |
| 2132 | |
| 2133 | /* |
| 2134 | * only expire and reinvoke request handler, if there are |
| 2135 | * other queues with pending requests |
| 2136 | */ |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2137 | if (!cfqd->busy_queues) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2138 | goto out_cont; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2139 | |
| 2140 | /* |
| 2141 | * not expired and it has a request pending, let it dispatch |
| 2142 | */ |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 2143 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) { |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2144 | cfq_mark_cfqq_must_dispatch(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2145 | goto out_kick; |
| 2146 | } |
| 2147 | } |
| 2148 | expire: |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2149 | cfq_slice_expired(cfqd, timed_out); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2150 | out_kick: |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2151 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2152 | out_cont: |
| 2153 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 2154 | } |
| 2155 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2156 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) |
| 2157 | { |
| 2158 | del_timer_sync(&cfqd->idle_slice_timer); |
Cheng Renquan | 64d01dc | 2008-12-03 12:41:39 +0100 | [diff] [blame] | 2159 | cancel_work_sync(&cfqd->unplug_work); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2160 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2161 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2162 | static void cfq_put_async_queues(struct cfq_data *cfqd) |
| 2163 | { |
| 2164 | int i; |
| 2165 | |
| 2166 | for (i = 0; i < IOPRIO_BE_NR; i++) { |
| 2167 | if (cfqd->async_cfqq[0][i]) |
| 2168 | cfq_put_queue(cfqd->async_cfqq[0][i]); |
| 2169 | if (cfqd->async_cfqq[1][i]) |
| 2170 | cfq_put_queue(cfqd->async_cfqq[1][i]); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2171 | } |
Oleg Nesterov | 2389d1e | 2007-11-05 08:58:05 +0100 | [diff] [blame] | 2172 | |
| 2173 | if (cfqd->async_idle_cfqq) |
| 2174 | cfq_put_queue(cfqd->async_idle_cfqq); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2175 | } |
| 2176 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 2177 | static void cfq_exit_queue(struct elevator_queue *e) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2178 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2179 | struct cfq_data *cfqd = e->elevator_data; |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2180 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2181 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2182 | cfq_shutdown_timer_wq(cfqd); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2183 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2184 | spin_lock_irq(q->queue_lock); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2185 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2186 | if (cfqd->active_queue) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2187 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2188 | |
| 2189 | while (!list_empty(&cfqd->cic_list)) { |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2190 | struct cfq_io_context *cic = list_entry(cfqd->cic_list.next, |
| 2191 | struct cfq_io_context, |
| 2192 | queue_list); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2193 | |
| 2194 | __cfq_exit_single_io_context(cfqd, cic); |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2195 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2196 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2197 | cfq_put_async_queues(cfqd); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2198 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2199 | spin_unlock_irq(q->queue_lock); |
Al Viro | a90d742 | 2006-03-18 12:05:37 -0500 | [diff] [blame] | 2200 | |
| 2201 | cfq_shutdown_timer_wq(cfqd); |
| 2202 | |
Al Viro | a90d742 | 2006-03-18 12:05:37 -0500 | [diff] [blame] | 2203 | kfree(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2204 | } |
| 2205 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2206 | static void *cfq_init_queue(struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2207 | { |
| 2208 | struct cfq_data *cfqd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2209 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2210 | cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2211 | if (!cfqd) |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 2212 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2213 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 2214 | cfqd->service_tree = CFQ_RB_ROOT; |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 2215 | INIT_LIST_HEAD(&cfqd->cic_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2216 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2217 | cfqd->queue = q; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2218 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2219 | init_timer(&cfqd->idle_slice_timer); |
| 2220 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; |
| 2221 | cfqd->idle_slice_timer.data = (unsigned long) cfqd; |
| 2222 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 2223 | INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2224 | |
Oleg Nesterov | b70c864 | 2007-11-07 09:46:13 +0100 | [diff] [blame] | 2225 | cfqd->last_end_request = jiffies; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2226 | cfqd->cfq_quantum = cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2227 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |
| 2228 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2229 | cfqd->cfq_back_max = cfq_back_max; |
| 2230 | cfqd->cfq_back_penalty = cfq_back_penalty; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2231 | cfqd->cfq_slice[0] = cfq_slice_async; |
| 2232 | cfqd->cfq_slice[1] = cfq_slice_sync; |
| 2233 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; |
| 2234 | cfqd->cfq_slice_idle = cfq_slice_idle; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 2235 | cfqd->hw_tag = 1; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2236 | |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 2237 | return cfqd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2238 | } |
| 2239 | |
| 2240 | static void cfq_slab_kill(void) |
| 2241 | { |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2242 | /* |
| 2243 | * Caller already ensured that pending RCU callbacks are completed, |
| 2244 | * so we should have no busy allocations at this point. |
| 2245 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2246 | if (cfq_pool) |
| 2247 | kmem_cache_destroy(cfq_pool); |
| 2248 | if (cfq_ioc_pool) |
| 2249 | kmem_cache_destroy(cfq_ioc_pool); |
| 2250 | } |
| 2251 | |
| 2252 | static int __init cfq_slab_setup(void) |
| 2253 | { |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame] | 2254 | cfq_pool = KMEM_CACHE(cfq_queue, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2255 | if (!cfq_pool) |
| 2256 | goto fail; |
| 2257 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2258 | cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2259 | if (!cfq_ioc_pool) |
| 2260 | goto fail; |
| 2261 | |
| 2262 | return 0; |
| 2263 | fail: |
| 2264 | cfq_slab_kill(); |
| 2265 | return -ENOMEM; |
| 2266 | } |
| 2267 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2268 | /* |
| 2269 | * sysfs parts below --> |
| 2270 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2271 | static ssize_t |
| 2272 | cfq_var_show(unsigned int var, char *page) |
| 2273 | { |
| 2274 | return sprintf(page, "%d\n", var); |
| 2275 | } |
| 2276 | |
| 2277 | static ssize_t |
| 2278 | cfq_var_store(unsigned int *var, const char *page, size_t count) |
| 2279 | { |
| 2280 | char *p = (char *) page; |
| 2281 | |
| 2282 | *var = simple_strtoul(p, &p, 10); |
| 2283 | return count; |
| 2284 | } |
| 2285 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2286 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 2287 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2288 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 2289 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2290 | unsigned int __data = __VAR; \ |
| 2291 | if (__CONV) \ |
| 2292 | __data = jiffies_to_msecs(__data); \ |
| 2293 | return cfq_var_show(__data, (page)); \ |
| 2294 | } |
| 2295 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2296 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); |
| 2297 | 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] | 2298 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); |
| 2299 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2300 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); |
| 2301 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); |
| 2302 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); |
| 2303 | SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2304 | #undef SHOW_FUNCTION |
| 2305 | |
| 2306 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 2307 | 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] | 2308 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 2309 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2310 | unsigned int __data; \ |
| 2311 | int ret = cfq_var_store(&__data, (page), count); \ |
| 2312 | if (__data < (MIN)) \ |
| 2313 | __data = (MIN); \ |
| 2314 | else if (__data > (MAX)) \ |
| 2315 | __data = (MAX); \ |
| 2316 | if (__CONV) \ |
| 2317 | *(__PTR) = msecs_to_jiffies(__data); \ |
| 2318 | else \ |
| 2319 | *(__PTR) = __data; \ |
| 2320 | return ret; \ |
| 2321 | } |
| 2322 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2323 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, |
| 2324 | UINT_MAX, 1); |
| 2325 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, |
| 2326 | UINT_MAX, 1); |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2327 | 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] | 2328 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, |
| 2329 | UINT_MAX, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2330 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); |
| 2331 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); |
| 2332 | 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] | 2333 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, |
| 2334 | UINT_MAX, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2335 | #undef STORE_FUNCTION |
| 2336 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2337 | #define CFQ_ATTR(name) \ |
| 2338 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2339 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2340 | static struct elv_fs_entry cfq_attrs[] = { |
| 2341 | CFQ_ATTR(quantum), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2342 | CFQ_ATTR(fifo_expire_sync), |
| 2343 | CFQ_ATTR(fifo_expire_async), |
| 2344 | CFQ_ATTR(back_seek_max), |
| 2345 | CFQ_ATTR(back_seek_penalty), |
| 2346 | CFQ_ATTR(slice_sync), |
| 2347 | CFQ_ATTR(slice_async), |
| 2348 | CFQ_ATTR(slice_async_rq), |
| 2349 | CFQ_ATTR(slice_idle), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 2350 | __ATTR_NULL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2351 | }; |
| 2352 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2353 | static struct elevator_type iosched_cfq = { |
| 2354 | .ops = { |
| 2355 | .elevator_merge_fn = cfq_merge, |
| 2356 | .elevator_merged_fn = cfq_merged_request, |
| 2357 | .elevator_merge_req_fn = cfq_merged_requests, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 2358 | .elevator_allow_merge_fn = cfq_allow_merge, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2359 | .elevator_dispatch_fn = cfq_dispatch_requests, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2360 | .elevator_add_req_fn = cfq_insert_request, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 2361 | .elevator_activate_req_fn = cfq_activate_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2362 | .elevator_deactivate_req_fn = cfq_deactivate_request, |
| 2363 | .elevator_queue_empty_fn = cfq_queue_empty, |
| 2364 | .elevator_completed_req_fn = cfq_completed_request, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 2365 | .elevator_former_req_fn = elv_rb_former_request, |
| 2366 | .elevator_latter_req_fn = elv_rb_latter_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2367 | .elevator_set_req_fn = cfq_set_request, |
| 2368 | .elevator_put_req_fn = cfq_put_request, |
| 2369 | .elevator_may_queue_fn = cfq_may_queue, |
| 2370 | .elevator_init_fn = cfq_init_queue, |
| 2371 | .elevator_exit_fn = cfq_exit_queue, |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2372 | .trim = cfq_free_io_context, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2373 | }, |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 2374 | .elevator_attrs = cfq_attrs, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2375 | .elevator_name = "cfq", |
| 2376 | .elevator_owner = THIS_MODULE, |
| 2377 | }; |
| 2378 | |
| 2379 | static int __init cfq_init(void) |
| 2380 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2381 | /* |
| 2382 | * could be 0 on HZ < 1000 setups |
| 2383 | */ |
| 2384 | if (!cfq_slice_async) |
| 2385 | cfq_slice_async = 1; |
| 2386 | if (!cfq_slice_idle) |
| 2387 | cfq_slice_idle = 1; |
| 2388 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2389 | if (cfq_slab_setup()) |
| 2390 | return -ENOMEM; |
| 2391 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 2392 | elv_register(&iosched_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2393 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 2394 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2395 | } |
| 2396 | |
| 2397 | static void __exit cfq_exit(void) |
| 2398 | { |
Peter Zijlstra | 6e9a473 | 2006-09-30 23:28:10 -0700 | [diff] [blame] | 2399 | DECLARE_COMPLETION_ONSTACK(all_gone); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2400 | elv_unregister(&iosched_cfq); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 2401 | ioc_gone = &all_gone; |
OGAWA Hirofumi | fba8227 | 2006-04-18 09:44:06 +0200 | [diff] [blame] | 2402 | /* ioc_gone's update must be visible before reading ioc_count */ |
| 2403 | smp_wmb(); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2404 | |
| 2405 | /* |
| 2406 | * this also protects us from entering cfq_slab_kill() with |
| 2407 | * pending RCU callbacks |
| 2408 | */ |
Jens Axboe | 4050cf1 | 2006-07-19 05:07:12 +0200 | [diff] [blame] | 2409 | if (elv_ioc_count_read(ioc_count)) |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 2410 | wait_for_completion(&all_gone); |
Christoph Hellwig | 83521d3 | 2005-10-30 15:01:39 -0800 | [diff] [blame] | 2411 | cfq_slab_kill(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2412 | } |
| 2413 | |
| 2414 | module_init(cfq_init); |
| 2415 | module_exit(cfq_exit); |
| 2416 | |
| 2417 | MODULE_AUTHOR("Jens Axboe"); |
| 2418 | MODULE_LICENSE("GPL"); |
| 2419 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |