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> |
Randy Dunlap | ad5ebd2 | 2009-11-11 13:47:45 +0100 | [diff] [blame] | 12 | #include <linux/jiffies.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/rbtree.h> |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 14 | #include <linux/ioprio.h> |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 15 | #include <linux/blktrace_api.h> |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 16 | #include "blk-cgroup.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | |
| 18 | /* |
| 19 | * tunables |
| 20 | */ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 21 | /* max queue in one round of service */ |
| 22 | static const int cfq_quantum = 4; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 23 | static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 24 | /* maximum backwards seek, in KiB */ |
| 25 | static const int cfq_back_max = 16 * 1024; |
| 26 | /* penalty of a backwards seek */ |
| 27 | static const int cfq_back_penalty = 2; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 28 | static const int cfq_slice_sync = HZ / 10; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 29 | static int cfq_slice_async = HZ / 25; |
Arjan van de Ven | 6410009 | 2006-01-06 09:46:02 +0100 | [diff] [blame] | 30 | static const int cfq_slice_async_rq = 2; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 31 | static int cfq_slice_idle = HZ / 125; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 32 | static const int cfq_target_latency = HZ * 3/10; /* 300 ms */ |
| 33 | static const int cfq_hist_divisor = 4; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 34 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 35 | /* |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 36 | * offset from end of service tree |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 37 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 38 | #define CFQ_IDLE_DELAY (HZ / 5) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 39 | |
| 40 | /* |
| 41 | * below this threshold, we consider thinktime immediate |
| 42 | */ |
| 43 | #define CFQ_MIN_TT (2) |
| 44 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 45 | /* |
| 46 | * Allow merged cfqqs to perform this amount of seeky I/O before |
| 47 | * deciding to break the queues up again. |
| 48 | */ |
| 49 | #define CFQQ_COOP_TOUT (HZ) |
| 50 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 51 | #define CFQ_SLICE_SCALE (5) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 52 | #define CFQ_HW_QUEUE_MIN (5) |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 53 | #define CFQ_SERVICE_SHIFT 12 |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 54 | |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 55 | #define RQ_CIC(rq) \ |
| 56 | ((struct cfq_io_context *) (rq)->elevator_private) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 57 | #define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elevator_private2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 59 | static struct kmem_cache *cfq_pool; |
| 60 | static struct kmem_cache *cfq_ioc_pool; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 62 | static DEFINE_PER_CPU(unsigned long, cfq_ioc_count); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 63 | static struct completion *ioc_gone; |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 64 | static DEFINE_SPINLOCK(ioc_gone_lock); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 65 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 66 | #define CFQ_PRIO_LISTS IOPRIO_BE_NR |
| 67 | #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 68 | #define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT) |
| 69 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 70 | #define sample_valid(samples) ((samples) > 80) |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 71 | #define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node) |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 72 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 73 | /* |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 74 | * Most of our rbtree usage is for sorting with min extraction, so |
| 75 | * if we cache the leftmost node we don't have to walk down the tree |
| 76 | * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should |
| 77 | * move this into the elevator for the rq sorting as well. |
| 78 | */ |
| 79 | struct cfq_rb_root { |
| 80 | struct rb_root rb; |
| 81 | struct rb_node *left; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 82 | unsigned count; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 83 | u64 min_vdisktime; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 84 | struct rb_node *active; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 85 | unsigned total_weight; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 86 | }; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 87 | #define CFQ_RB_ROOT (struct cfq_rb_root) { RB_ROOT, NULL, 0, 0, } |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 88 | |
| 89 | /* |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 90 | * Per process-grouping structure |
| 91 | */ |
| 92 | struct cfq_queue { |
| 93 | /* reference count */ |
| 94 | atomic_t ref; |
| 95 | /* various state flags, see below */ |
| 96 | unsigned int flags; |
| 97 | /* parent cfq_data */ |
| 98 | struct cfq_data *cfqd; |
| 99 | /* service_tree member */ |
| 100 | struct rb_node rb_node; |
| 101 | /* service_tree key */ |
| 102 | unsigned long rb_key; |
| 103 | /* prio tree member */ |
| 104 | struct rb_node p_node; |
| 105 | /* prio tree root we belong to, if any */ |
| 106 | struct rb_root *p_root; |
| 107 | /* sorted list of pending requests */ |
| 108 | struct rb_root sort_list; |
| 109 | /* if fifo isn't expired, next request to serve */ |
| 110 | struct request *next_rq; |
| 111 | /* requests queued in sort_list */ |
| 112 | int queued[2]; |
| 113 | /* currently allocated requests */ |
| 114 | int allocated[2]; |
| 115 | /* fifo list of requests in sort_list */ |
| 116 | struct list_head fifo; |
| 117 | |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 118 | /* time when queue got scheduled in to dispatch first request. */ |
| 119 | unsigned long dispatch_start; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 120 | unsigned int allocated_slice; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 121 | /* time when first request from queue completed and slice started. */ |
| 122 | unsigned long slice_start; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 123 | unsigned long slice_end; |
| 124 | long slice_resid; |
| 125 | unsigned int slice_dispatch; |
| 126 | |
| 127 | /* pending metadata requests */ |
| 128 | int meta_pending; |
| 129 | /* number of requests that are on the dispatch list or inside driver */ |
| 130 | int dispatched; |
| 131 | |
| 132 | /* io prio of this group */ |
| 133 | unsigned short ioprio, org_ioprio; |
| 134 | unsigned short ioprio_class, org_ioprio_class; |
| 135 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 136 | unsigned int seek_samples; |
| 137 | u64 seek_total; |
| 138 | sector_t seek_mean; |
| 139 | sector_t last_request_pos; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 140 | unsigned long seeky_start; |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 141 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 142 | pid_t pid; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 143 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 144 | struct cfq_rb_root *service_tree; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 145 | struct cfq_queue *new_cfqq; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 146 | struct cfq_group *cfqg; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 147 | struct cfq_group *orig_cfqg; |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 148 | /* Sectors dispatched in current dispatch round */ |
| 149 | unsigned long nr_sectors; |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 150 | }; |
| 151 | |
| 152 | /* |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 153 | * First index in the service_trees. |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 154 | * IDLE is handled separately, so it has negative index |
| 155 | */ |
| 156 | enum wl_prio_t { |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 157 | BE_WORKLOAD = 0, |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 158 | RT_WORKLOAD = 1, |
| 159 | IDLE_WORKLOAD = 2, |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 160 | }; |
| 161 | |
| 162 | /* |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 163 | * Second index in the service_trees. |
| 164 | */ |
| 165 | enum wl_type_t { |
| 166 | ASYNC_WORKLOAD = 0, |
| 167 | SYNC_NOIDLE_WORKLOAD = 1, |
| 168 | SYNC_WORKLOAD = 2 |
| 169 | }; |
| 170 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 171 | /* This is per cgroup per device grouping structure */ |
| 172 | struct cfq_group { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 173 | /* group service_tree member */ |
| 174 | struct rb_node rb_node; |
| 175 | |
| 176 | /* group service_tree key */ |
| 177 | u64 vdisktime; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 178 | unsigned int weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 179 | bool on_st; |
| 180 | |
| 181 | /* number of cfqq currently on this group */ |
| 182 | int nr_cfqq; |
| 183 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 184 | /* Per group busy queus average. Useful for workload slice calc. */ |
| 185 | unsigned int busy_queues_avg[2]; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 186 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 187 | * rr lists of queues with requests, onle rr for each priority class. |
| 188 | * Counts are embedded in the cfq_rb_root |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 189 | */ |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 190 | struct cfq_rb_root service_trees[2][3]; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 191 | struct cfq_rb_root service_tree_idle; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 192 | |
| 193 | unsigned long saved_workload_slice; |
| 194 | enum wl_type_t saved_workload; |
| 195 | enum wl_prio_t saved_serving_prio; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 196 | struct blkio_group blkg; |
| 197 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 198 | struct hlist_node cfqd_node; |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 199 | atomic_t ref; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 200 | #endif |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 201 | }; |
| 202 | |
| 203 | /* |
| 204 | * Per block device queue structure |
| 205 | */ |
| 206 | struct cfq_data { |
| 207 | struct request_queue *queue; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 208 | /* Root service tree for cfq_groups */ |
| 209 | struct cfq_rb_root grp_service_tree; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 210 | struct cfq_group root_group; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 211 | /* Number of active cfq groups on group service tree */ |
| 212 | int nr_groups; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 213 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 214 | /* |
| 215 | * The priority currently being served |
| 216 | */ |
| 217 | enum wl_prio_t serving_prio; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 218 | enum wl_type_t serving_type; |
| 219 | unsigned long workload_expires; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 220 | struct cfq_group *serving_group; |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 221 | bool noidle_tree_requires_idle; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 222 | |
| 223 | /* |
| 224 | * Each priority tree is sorted by next_request position. These |
| 225 | * trees are used when determining if two or more queues are |
| 226 | * interleaving requests (see cfq_close_cooperator). |
| 227 | */ |
| 228 | struct rb_root prio_trees[CFQ_PRIO_LISTS]; |
| 229 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 230 | unsigned int busy_queues; |
| 231 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 232 | int rq_in_driver[2]; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 233 | int sync_flight; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 234 | |
| 235 | /* |
| 236 | * queue-depth detection |
| 237 | */ |
| 238 | int rq_queued; |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 239 | int hw_tag; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 240 | /* |
| 241 | * hw_tag can be |
| 242 | * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection) |
| 243 | * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth) |
| 244 | * 0 => no NCQ |
| 245 | */ |
| 246 | int hw_tag_est_depth; |
| 247 | unsigned int hw_tag_samples; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 248 | |
| 249 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 250 | * idle window management |
| 251 | */ |
| 252 | struct timer_list idle_slice_timer; |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 253 | struct work_struct unplug_work; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 254 | |
| 255 | struct cfq_queue *active_queue; |
| 256 | struct cfq_io_context *active_cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 257 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 258 | /* |
| 259 | * async queue for each priority case |
| 260 | */ |
| 261 | struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; |
| 262 | struct cfq_queue *async_idle_cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 263 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 264 | sector_t last_position; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | /* |
| 267 | * tunables, see top of file |
| 268 | */ |
| 269 | unsigned int cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 270 | unsigned int cfq_fifo_expire[2]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | unsigned int cfq_back_penalty; |
| 272 | unsigned int cfq_back_max; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 273 | unsigned int cfq_slice[2]; |
| 274 | unsigned int cfq_slice_async_rq; |
| 275 | unsigned int cfq_slice_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 276 | unsigned int cfq_latency; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 277 | unsigned int cfq_group_isolation; |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 278 | |
| 279 | struct list_head cic_list; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 281 | /* |
| 282 | * Fallback dummy cfqq for extreme OOM conditions |
| 283 | */ |
| 284 | struct cfq_queue oom_cfqq; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 285 | |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 286 | unsigned long last_delayed_sync; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 287 | |
| 288 | /* List of cfq groups being managed on this device*/ |
| 289 | struct hlist_head cfqg_list; |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 290 | struct rcu_head rcu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | }; |
| 292 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 293 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd); |
| 294 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 295 | static struct cfq_rb_root *service_tree_for(struct cfq_group *cfqg, |
| 296 | enum wl_prio_t prio, |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 297 | enum wl_type_t type, |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 298 | struct cfq_data *cfqd) |
| 299 | { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 300 | if (!cfqg) |
| 301 | return NULL; |
| 302 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 303 | if (prio == IDLE_WORKLOAD) |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 304 | return &cfqg->service_tree_idle; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 305 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 306 | return &cfqg->service_trees[prio][type]; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 307 | } |
| 308 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 309 | enum cfqq_state_flags { |
Jens Axboe | b0b8d749 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 310 | CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ |
| 311 | CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 312 | CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ |
Jens Axboe | b0b8d749 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 313 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ |
Jens Axboe | b0b8d749 | 2007-01-19 11:35:30 +1100 | [diff] [blame] | 314 | CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ |
| 315 | CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ |
| 316 | CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 317 | CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 318 | CFQ_CFQQ_FLAG_sync, /* synchronous queue */ |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 319 | CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 320 | CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 321 | CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 322 | }; |
| 323 | |
| 324 | #define CFQ_CFQQ_FNS(name) \ |
| 325 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ |
| 326 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 327 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 328 | } \ |
| 329 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ |
| 330 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 331 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 332 | } \ |
| 333 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ |
| 334 | { \ |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 335 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 336 | } |
| 337 | |
| 338 | CFQ_CFQQ_FNS(on_rr); |
| 339 | CFQ_CFQQ_FNS(wait_request); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 340 | CFQ_CFQQ_FNS(must_dispatch); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 341 | CFQ_CFQQ_FNS(must_alloc_slice); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 342 | CFQ_CFQQ_FNS(fifo_expire); |
| 343 | CFQ_CFQQ_FNS(idle_window); |
| 344 | CFQ_CFQQ_FNS(prio_changed); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 345 | CFQ_CFQQ_FNS(slice_new); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 346 | CFQ_CFQQ_FNS(sync); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 347 | CFQ_CFQQ_FNS(coop); |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 348 | CFQ_CFQQ_FNS(deep); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 349 | CFQ_CFQQ_FNS(wait_busy); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 350 | #undef CFQ_CFQQ_FNS |
| 351 | |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 352 | #ifdef CONFIG_DEBUG_CFQ_IOSCHED |
| 353 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 354 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c %s " fmt, (cfqq)->pid, \ |
| 355 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ |
| 356 | blkg_path(&(cfqq)->cfqg->blkg), ##args); |
| 357 | |
| 358 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) \ |
| 359 | blk_add_trace_msg((cfqd)->queue, "%s " fmt, \ |
| 360 | blkg_path(&(cfqg)->blkg), ##args); \ |
| 361 | |
| 362 | #else |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 363 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
| 364 | blk_add_trace_msg((cfqd)->queue, "cfq%d " fmt, (cfqq)->pid, ##args) |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 365 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0); |
| 366 | #endif |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 367 | #define cfq_log(cfqd, fmt, args...) \ |
| 368 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) |
| 369 | |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 370 | /* Traverses through cfq group service trees */ |
| 371 | #define for_each_cfqg_st(cfqg, i, j, st) \ |
| 372 | for (i = 0; i <= IDLE_WORKLOAD; i++) \ |
| 373 | for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\ |
| 374 | : &cfqg->service_tree_idle; \ |
| 375 | (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \ |
| 376 | (i == IDLE_WORKLOAD && j == 0); \ |
| 377 | j++, st = i < IDLE_WORKLOAD ? \ |
| 378 | &cfqg->service_trees[i][j]: NULL) \ |
| 379 | |
| 380 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 381 | static inline enum wl_prio_t cfqq_prio(struct cfq_queue *cfqq) |
| 382 | { |
| 383 | if (cfq_class_idle(cfqq)) |
| 384 | return IDLE_WORKLOAD; |
| 385 | if (cfq_class_rt(cfqq)) |
| 386 | return RT_WORKLOAD; |
| 387 | return BE_WORKLOAD; |
| 388 | } |
| 389 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 390 | |
| 391 | static enum wl_type_t cfqq_type(struct cfq_queue *cfqq) |
| 392 | { |
| 393 | if (!cfq_cfqq_sync(cfqq)) |
| 394 | return ASYNC_WORKLOAD; |
| 395 | if (!cfq_cfqq_idle_window(cfqq)) |
| 396 | return SYNC_NOIDLE_WORKLOAD; |
| 397 | return SYNC_WORKLOAD; |
| 398 | } |
| 399 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 400 | static inline int cfq_group_busy_queues_wl(enum wl_prio_t wl, |
| 401 | struct cfq_data *cfqd, |
| 402 | struct cfq_group *cfqg) |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 403 | { |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 404 | if (wl == IDLE_WORKLOAD) |
| 405 | return cfqg->service_tree_idle.count; |
| 406 | |
| 407 | return cfqg->service_trees[wl][ASYNC_WORKLOAD].count |
| 408 | + cfqg->service_trees[wl][SYNC_NOIDLE_WORKLOAD].count |
| 409 | + cfqg->service_trees[wl][SYNC_WORKLOAD].count; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 410 | } |
| 411 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 412 | static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, |
| 413 | struct cfq_group *cfqg) |
| 414 | { |
| 415 | return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count |
| 416 | + cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count; |
| 417 | } |
| 418 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 419 | static void cfq_dispatch_insert(struct request_queue *, struct request *); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 420 | static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 421 | struct io_context *, gfp_t); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 422 | static struct cfq_io_context *cfq_cic_lookup(struct cfq_data *, |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 423 | struct io_context *); |
| 424 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 425 | static inline int rq_in_driver(struct cfq_data *cfqd) |
| 426 | { |
| 427 | return cfqd->rq_in_driver[0] + cfqd->rq_in_driver[1]; |
| 428 | } |
| 429 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 430 | static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_context *cic, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 431 | bool is_sync) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 432 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 433 | return cic->cfqq[is_sync]; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 434 | } |
| 435 | |
| 436 | static inline void cic_set_cfqq(struct cfq_io_context *cic, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 437 | struct cfq_queue *cfqq, bool is_sync) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 438 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 439 | cic->cfqq[is_sync] = cfqq; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 440 | } |
| 441 | |
| 442 | /* |
| 443 | * We regard a request as SYNC, if it's either a read or has the SYNC bit |
| 444 | * set (in which case it could also be direct WRITE). |
| 445 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 446 | static inline bool cfq_bio_sync(struct bio *bio) |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 447 | { |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 448 | return bio_data_dir(bio) == READ || bio_rw_flagged(bio, BIO_RW_SYNCIO); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 449 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | /* |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 452 | * scheduler run of queue, if there are requests pending and no one in the |
| 453 | * driver that will restart queueing |
| 454 | */ |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 455 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 456 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 457 | if (cfqd->busy_queues) { |
| 458 | cfq_log(cfqd, "schedule dispatch"); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 459 | kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 460 | } |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 461 | } |
| 462 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 463 | static int cfq_queue_empty(struct request_queue *q) |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 464 | { |
| 465 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 466 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 467 | return !cfqd->rq_queued; |
Andrew Morton | 99f95e5 | 2005-06-27 20:14:05 -0700 | [diff] [blame] | 468 | } |
| 469 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | /* |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 471 | * Scale schedule slice based on io priority. Use the sync time slice only |
| 472 | * if a queue is marked sync and has sync io queued. A sync queue with async |
| 473 | * io only, should not get full sync slice length. |
| 474 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 475 | static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync, |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 476 | unsigned short prio) |
| 477 | { |
| 478 | const int base_slice = cfqd->cfq_slice[sync]; |
| 479 | |
| 480 | WARN_ON(prio >= IOPRIO_BE_NR); |
| 481 | |
| 482 | return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); |
| 483 | } |
| 484 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 485 | static inline int |
| 486 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 487 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 488 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 489 | } |
| 490 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 491 | static inline u64 cfq_scale_slice(unsigned long delta, struct cfq_group *cfqg) |
| 492 | { |
| 493 | u64 d = delta << CFQ_SERVICE_SHIFT; |
| 494 | |
| 495 | d = d * BLKIO_WEIGHT_DEFAULT; |
| 496 | do_div(d, cfqg->weight); |
| 497 | return d; |
| 498 | } |
| 499 | |
| 500 | static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime) |
| 501 | { |
| 502 | s64 delta = (s64)(vdisktime - min_vdisktime); |
| 503 | if (delta > 0) |
| 504 | min_vdisktime = vdisktime; |
| 505 | |
| 506 | return min_vdisktime; |
| 507 | } |
| 508 | |
| 509 | static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime) |
| 510 | { |
| 511 | s64 delta = (s64)(vdisktime - min_vdisktime); |
| 512 | if (delta < 0) |
| 513 | min_vdisktime = vdisktime; |
| 514 | |
| 515 | return min_vdisktime; |
| 516 | } |
| 517 | |
| 518 | static void update_min_vdisktime(struct cfq_rb_root *st) |
| 519 | { |
| 520 | u64 vdisktime = st->min_vdisktime; |
| 521 | struct cfq_group *cfqg; |
| 522 | |
| 523 | if (st->active) { |
| 524 | cfqg = rb_entry_cfqg(st->active); |
| 525 | vdisktime = cfqg->vdisktime; |
| 526 | } |
| 527 | |
| 528 | if (st->left) { |
| 529 | cfqg = rb_entry_cfqg(st->left); |
| 530 | vdisktime = min_vdisktime(vdisktime, cfqg->vdisktime); |
| 531 | } |
| 532 | |
| 533 | st->min_vdisktime = max_vdisktime(st->min_vdisktime, vdisktime); |
| 534 | } |
| 535 | |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 536 | /* |
| 537 | * get averaged number of queues of RT/BE priority. |
| 538 | * average is updated, with a formula that gives more weight to higher numbers, |
| 539 | * to quickly follows sudden increases and decrease slowly |
| 540 | */ |
| 541 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 542 | static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd, |
| 543 | struct cfq_group *cfqg, bool rt) |
Jens Axboe | 5869619c | 2009-10-28 09:27:07 +0100 | [diff] [blame] | 544 | { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 545 | unsigned min_q, max_q; |
| 546 | unsigned mult = cfq_hist_divisor - 1; |
| 547 | unsigned round = cfq_hist_divisor / 2; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 548 | unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg); |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 549 | |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 550 | min_q = min(cfqg->busy_queues_avg[rt], busy); |
| 551 | max_q = max(cfqg->busy_queues_avg[rt], busy); |
| 552 | cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) / |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 553 | cfq_hist_divisor; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 554 | return cfqg->busy_queues_avg[rt]; |
| 555 | } |
| 556 | |
| 557 | static inline unsigned |
| 558 | cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 559 | { |
| 560 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 561 | |
| 562 | return cfq_target_latency * cfqg->weight / st->total_weight; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 563 | } |
| 564 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 565 | static inline void |
| 566 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 567 | { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 568 | unsigned slice = cfq_prio_to_slice(cfqd, cfqq); |
| 569 | if (cfqd->cfq_latency) { |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 570 | /* |
| 571 | * interested queues (we consider only the ones with the same |
| 572 | * priority class in the cfq group) |
| 573 | */ |
| 574 | unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg, |
| 575 | cfq_class_rt(cfqq)); |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 576 | unsigned sync_slice = cfqd->cfq_slice[1]; |
| 577 | unsigned expect_latency = sync_slice * iq; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 578 | unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg); |
| 579 | |
| 580 | if (expect_latency > group_slice) { |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 581 | unsigned base_low_slice = 2 * cfqd->cfq_slice_idle; |
| 582 | /* scale low_slice according to IO priority |
| 583 | * and sync vs async */ |
| 584 | unsigned low_slice = |
| 585 | min(slice, base_low_slice * slice / sync_slice); |
| 586 | /* the adapted slice value is scaled to fit all iqs |
| 587 | * into the target latency */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 588 | slice = max(slice * group_slice / expect_latency, |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 589 | low_slice); |
| 590 | } |
| 591 | } |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 592 | cfqq->slice_start = jiffies; |
Corrado Zoccolo | 5db5d64 | 2009-10-26 22:44:04 +0100 | [diff] [blame] | 593 | cfqq->slice_end = jiffies + slice; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 594 | cfqq->allocated_slice = slice; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 595 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 596 | } |
| 597 | |
| 598 | /* |
| 599 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end |
| 600 | * isn't valid until the first request from the dispatch is activated |
| 601 | * and the slice time set. |
| 602 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 603 | static inline bool cfq_slice_used(struct cfq_queue *cfqq) |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 604 | { |
| 605 | if (cfq_cfqq_slice_new(cfqq)) |
| 606 | return 0; |
| 607 | if (time_before(jiffies, cfqq->slice_end)) |
| 608 | return 0; |
| 609 | |
| 610 | return 1; |
| 611 | } |
| 612 | |
| 613 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 614 | * 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] | 615 | * 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] | 616 | * behind the head is penalized and only allowed to a certain extent. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 617 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 618 | static struct request * |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 619 | cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, sector_t last) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | { |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 621 | sector_t s1, s2, d1 = 0, d2 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | unsigned long back_max; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 623 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ |
| 624 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ |
| 625 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 627 | if (rq1 == NULL || rq1 == rq2) |
| 628 | return rq2; |
| 629 | if (rq2 == NULL) |
| 630 | return rq1; |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 631 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 632 | if (rq_is_sync(rq1) && !rq_is_sync(rq2)) |
| 633 | return rq1; |
| 634 | else if (rq_is_sync(rq2) && !rq_is_sync(rq1)) |
| 635 | return rq2; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 636 | if (rq_is_meta(rq1) && !rq_is_meta(rq2)) |
| 637 | return rq1; |
| 638 | else if (rq_is_meta(rq2) && !rq_is_meta(rq1)) |
| 639 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 641 | s1 = blk_rq_pos(rq1); |
| 642 | s2 = blk_rq_pos(rq2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 643 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | /* |
| 645 | * by definition, 1KiB is 2 sectors |
| 646 | */ |
| 647 | back_max = cfqd->cfq_back_max * 2; |
| 648 | |
| 649 | /* |
| 650 | * Strict one way elevator _except_ in the case where we allow |
| 651 | * short backward seeks which are biased as twice the cost of a |
| 652 | * similar forward seek. |
| 653 | */ |
| 654 | if (s1 >= last) |
| 655 | d1 = s1 - last; |
| 656 | else if (s1 + back_max >= last) |
| 657 | d1 = (last - s1) * cfqd->cfq_back_penalty; |
| 658 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 659 | wrap |= CFQ_RQ1_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | |
| 661 | if (s2 >= last) |
| 662 | d2 = s2 - last; |
| 663 | else if (s2 + back_max >= last) |
| 664 | d2 = (last - s2) * cfqd->cfq_back_penalty; |
| 665 | else |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 666 | wrap |= CFQ_RQ2_WRAP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | |
| 668 | /* Found required data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 670 | /* |
| 671 | * By doing switch() on the bit mask "wrap" we avoid having to |
| 672 | * check two variables for all permutations: --> faster! |
| 673 | */ |
| 674 | switch (wrap) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 675 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 676 | if (d1 < d2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 677 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 678 | else if (d2 < d1) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 679 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 680 | else { |
| 681 | if (s1 >= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 682 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 683 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 684 | return rq2; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 685 | } |
| 686 | |
| 687 | case CFQ_RQ2_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 688 | return rq1; |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 689 | case CFQ_RQ1_WRAP: |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 690 | return rq2; |
| 691 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ |
Andreas Mohr | e8a9905 | 2006-03-28 08:59:49 +0200 | [diff] [blame] | 692 | default: |
| 693 | /* |
| 694 | * Since both rqs are wrapped, |
| 695 | * start with the one that's further behind head |
| 696 | * (--> only *one* back seek required), |
| 697 | * since back seek takes more time than forward. |
| 698 | */ |
| 699 | if (s1 <= s2) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 700 | return rq1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | else |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 702 | return rq2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | } |
| 704 | } |
| 705 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 706 | /* |
| 707 | * The below is leftmost cache rbtree addon |
| 708 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 709 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 710 | { |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 711 | /* Service tree is empty */ |
| 712 | if (!root->count) |
| 713 | return NULL; |
| 714 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 715 | if (!root->left) |
| 716 | root->left = rb_first(&root->rb); |
| 717 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 718 | if (root->left) |
| 719 | return rb_entry(root->left, struct cfq_queue, rb_node); |
| 720 | |
| 721 | return NULL; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 722 | } |
| 723 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 724 | static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root) |
| 725 | { |
| 726 | if (!root->left) |
| 727 | root->left = rb_first(&root->rb); |
| 728 | |
| 729 | if (root->left) |
| 730 | return rb_entry_cfqg(root->left); |
| 731 | |
| 732 | return NULL; |
| 733 | } |
| 734 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 735 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
| 736 | { |
| 737 | rb_erase(n, root); |
| 738 | RB_CLEAR_NODE(n); |
| 739 | } |
| 740 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 741 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) |
| 742 | { |
| 743 | if (root->left == n) |
| 744 | root->left = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 745 | rb_erase_init(n, &root->rb); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 746 | --root->count; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 747 | } |
| 748 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 749 | /* |
| 750 | * would be nice to take fifo expire time into account as well |
| 751 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 752 | static struct request * |
| 753 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 754 | struct request *last) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 755 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 756 | struct rb_node *rbnext = rb_next(&last->rb_node); |
| 757 | struct rb_node *rbprev = rb_prev(&last->rb_node); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 758 | struct request *next = NULL, *prev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 760 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | |
| 762 | if (rbprev) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 763 | prev = rb_entry_rq(rbprev); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 764 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 765 | if (rbnext) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 766 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 767 | else { |
| 768 | rbnext = rb_first(&cfqq->sort_list); |
| 769 | if (rbnext && rbnext != &last->rb_node) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 770 | next = rb_entry_rq(rbnext); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 771 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 772 | |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 773 | return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 774 | } |
| 775 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 776 | static unsigned long cfq_slice_offset(struct cfq_data *cfqd, |
| 777 | struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | { |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 779 | /* |
| 780 | * just an approximation, should be ok. |
| 781 | */ |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 782 | return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - |
Jens Axboe | 464191c | 2009-11-30 09:38:13 +0100 | [diff] [blame] | 783 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 784 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 785 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 786 | static inline s64 |
| 787 | cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg) |
| 788 | { |
| 789 | return cfqg->vdisktime - st->min_vdisktime; |
| 790 | } |
| 791 | |
| 792 | static void |
| 793 | __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) |
| 794 | { |
| 795 | struct rb_node **node = &st->rb.rb_node; |
| 796 | struct rb_node *parent = NULL; |
| 797 | struct cfq_group *__cfqg; |
| 798 | s64 key = cfqg_key(st, cfqg); |
| 799 | int left = 1; |
| 800 | |
| 801 | while (*node != NULL) { |
| 802 | parent = *node; |
| 803 | __cfqg = rb_entry_cfqg(parent); |
| 804 | |
| 805 | if (key < cfqg_key(st, __cfqg)) |
| 806 | node = &parent->rb_left; |
| 807 | else { |
| 808 | node = &parent->rb_right; |
| 809 | left = 0; |
| 810 | } |
| 811 | } |
| 812 | |
| 813 | if (left) |
| 814 | st->left = &cfqg->rb_node; |
| 815 | |
| 816 | rb_link_node(&cfqg->rb_node, parent, node); |
| 817 | rb_insert_color(&cfqg->rb_node, &st->rb); |
| 818 | } |
| 819 | |
| 820 | static void |
| 821 | cfq_group_service_tree_add(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 822 | { |
| 823 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 824 | struct cfq_group *__cfqg; |
| 825 | struct rb_node *n; |
| 826 | |
| 827 | cfqg->nr_cfqq++; |
| 828 | if (cfqg->on_st) |
| 829 | return; |
| 830 | |
| 831 | /* |
| 832 | * Currently put the group at the end. Later implement something |
| 833 | * so that groups get lesser vtime based on their weights, so that |
| 834 | * if group does not loose all if it was not continously backlogged. |
| 835 | */ |
| 836 | n = rb_last(&st->rb); |
| 837 | if (n) { |
| 838 | __cfqg = rb_entry_cfqg(n); |
| 839 | cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY; |
| 840 | } else |
| 841 | cfqg->vdisktime = st->min_vdisktime; |
| 842 | |
| 843 | __cfq_group_service_tree_add(st, cfqg); |
| 844 | cfqg->on_st = true; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 845 | cfqd->nr_groups++; |
| 846 | st->total_weight += cfqg->weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 847 | } |
| 848 | |
| 849 | static void |
| 850 | cfq_group_service_tree_del(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 851 | { |
| 852 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
| 853 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 854 | if (st->active == &cfqg->rb_node) |
| 855 | st->active = NULL; |
| 856 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 857 | BUG_ON(cfqg->nr_cfqq < 1); |
| 858 | cfqg->nr_cfqq--; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 859 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 860 | /* If there are other cfq queues under this group, don't delete it */ |
| 861 | if (cfqg->nr_cfqq) |
| 862 | return; |
| 863 | |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 864 | cfq_log_cfqg(cfqd, cfqg, "del_from_rr group"); |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 865 | cfqg->on_st = false; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 866 | cfqd->nr_groups--; |
| 867 | st->total_weight -= cfqg->weight; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 868 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
| 869 | cfq_rb_erase(&cfqg->rb_node, st); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 870 | cfqg->saved_workload_slice = 0; |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 871 | blkiocg_update_blkio_group_dequeue_stats(&cfqg->blkg, 1); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 872 | } |
| 873 | |
| 874 | static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq) |
| 875 | { |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 876 | unsigned int slice_used; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 877 | |
| 878 | /* |
| 879 | * Queue got expired before even a single request completed or |
| 880 | * got expired immediately after first request completion. |
| 881 | */ |
| 882 | if (!cfqq->slice_start || cfqq->slice_start == jiffies) { |
| 883 | /* |
| 884 | * Also charge the seek time incurred to the group, otherwise |
| 885 | * if there are mutiple queues in the group, each can dispatch |
| 886 | * a single request on seeky media and cause lots of seek time |
| 887 | * and group will never know it. |
| 888 | */ |
| 889 | slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start), |
| 890 | 1); |
| 891 | } else { |
| 892 | slice_used = jiffies - cfqq->slice_start; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 893 | if (slice_used > cfqq->allocated_slice) |
| 894 | slice_used = cfqq->allocated_slice; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 895 | } |
| 896 | |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 897 | cfq_log_cfqq(cfqq->cfqd, cfqq, "sl_used=%u sect=%lu", slice_used, |
| 898 | cfqq->nr_sectors); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 899 | return slice_used; |
| 900 | } |
| 901 | |
| 902 | static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, |
| 903 | struct cfq_queue *cfqq) |
| 904 | { |
| 905 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 906 | unsigned int used_sl, charge_sl; |
| 907 | int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) |
| 908 | - cfqg->service_tree_idle.count; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 909 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 910 | BUG_ON(nr_sync < 0); |
| 911 | used_sl = charge_sl = cfq_cfqq_slice_usage(cfqq); |
| 912 | |
| 913 | if (!cfq_cfqq_sync(cfqq) && !nr_sync) |
| 914 | charge_sl = cfqq->allocated_slice; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 915 | |
| 916 | /* Can't update vdisktime while group is on service tree */ |
| 917 | cfq_rb_erase(&cfqg->rb_node, st); |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 918 | cfqg->vdisktime += cfq_scale_slice(charge_sl, cfqg); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 919 | __cfq_group_service_tree_add(st, cfqg); |
| 920 | |
| 921 | /* This group is being expired. Save the context */ |
| 922 | if (time_after(cfqd->workload_expires, jiffies)) { |
| 923 | cfqg->saved_workload_slice = cfqd->workload_expires |
| 924 | - jiffies; |
| 925 | cfqg->saved_workload = cfqd->serving_type; |
| 926 | cfqg->saved_serving_prio = cfqd->serving_prio; |
| 927 | } else |
| 928 | cfqg->saved_workload_slice = 0; |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 929 | |
| 930 | cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime, |
| 931 | st->min_vdisktime); |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 932 | blkiocg_update_blkio_group_stats(&cfqg->blkg, used_sl, |
| 933 | cfqq->nr_sectors); |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 934 | } |
| 935 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 936 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 937 | static inline struct cfq_group *cfqg_of_blkg(struct blkio_group *blkg) |
| 938 | { |
| 939 | if (blkg) |
| 940 | return container_of(blkg, struct cfq_group, blkg); |
| 941 | return NULL; |
| 942 | } |
| 943 | |
Vivek Goyal | f8d461d | 2009-12-03 12:59:52 -0500 | [diff] [blame] | 944 | void |
| 945 | cfq_update_blkio_group_weight(struct blkio_group *blkg, unsigned int weight) |
| 946 | { |
| 947 | cfqg_of_blkg(blkg)->weight = weight; |
| 948 | } |
| 949 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 950 | static struct cfq_group * |
| 951 | cfq_find_alloc_cfqg(struct cfq_data *cfqd, struct cgroup *cgroup, int create) |
| 952 | { |
| 953 | struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); |
| 954 | struct cfq_group *cfqg = NULL; |
| 955 | void *key = cfqd; |
| 956 | int i, j; |
| 957 | struct cfq_rb_root *st; |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 958 | struct backing_dev_info *bdi = &cfqd->queue->backing_dev_info; |
| 959 | unsigned int major, minor; |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 960 | |
| 961 | /* Do we need to take this reference */ |
Vivek Goyal | 9d6a986 | 2009-12-04 10:36:41 -0500 | [diff] [blame] | 962 | if (!blkiocg_css_tryget(blkcg)) |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 963 | return NULL;; |
| 964 | |
| 965 | cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key)); |
| 966 | if (cfqg || !create) |
| 967 | goto done; |
| 968 | |
| 969 | cfqg = kzalloc_node(sizeof(*cfqg), GFP_ATOMIC, cfqd->queue->node); |
| 970 | if (!cfqg) |
| 971 | goto done; |
| 972 | |
| 973 | cfqg->weight = blkcg->weight; |
| 974 | for_each_cfqg_st(cfqg, i, j, st) |
| 975 | *st = CFQ_RB_ROOT; |
| 976 | RB_CLEAR_NODE(&cfqg->rb_node); |
| 977 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 978 | /* |
| 979 | * Take the initial reference that will be released on destroy |
| 980 | * This can be thought of a joint reference by cgroup and |
| 981 | * elevator which will be dropped by either elevator exit |
| 982 | * or cgroup deletion path depending on who is exiting first. |
| 983 | */ |
| 984 | atomic_set(&cfqg->ref, 1); |
| 985 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 986 | /* Add group onto cgroup list */ |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 987 | sscanf(dev_name(bdi->dev), "%u:%u", &major, &minor); |
| 988 | blkiocg_add_blkio_group(blkcg, &cfqg->blkg, (void *)cfqd, |
| 989 | MKDEV(major, minor)); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 990 | |
| 991 | /* Add group on cfqd list */ |
| 992 | hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list); |
| 993 | |
| 994 | done: |
Vivek Goyal | 9d6a986 | 2009-12-04 10:36:41 -0500 | [diff] [blame] | 995 | blkiocg_css_put(blkcg); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 996 | return cfqg; |
| 997 | } |
| 998 | |
| 999 | /* |
| 1000 | * Search for the cfq group current task belongs to. If create = 1, then also |
| 1001 | * create the cfq group if it does not exist. request_queue lock must be held. |
| 1002 | */ |
| 1003 | static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create) |
| 1004 | { |
| 1005 | struct cgroup *cgroup; |
| 1006 | struct cfq_group *cfqg = NULL; |
| 1007 | |
| 1008 | rcu_read_lock(); |
| 1009 | cgroup = task_cgroup(current, blkio_subsys_id); |
| 1010 | cfqg = cfq_find_alloc_cfqg(cfqd, cgroup, create); |
| 1011 | if (!cfqg && create) |
| 1012 | cfqg = &cfqd->root_group; |
| 1013 | rcu_read_unlock(); |
| 1014 | return cfqg; |
| 1015 | } |
| 1016 | |
| 1017 | static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) |
| 1018 | { |
| 1019 | /* Currently, all async queues are mapped to root group */ |
| 1020 | if (!cfq_cfqq_sync(cfqq)) |
| 1021 | cfqg = &cfqq->cfqd->root_group; |
| 1022 | |
| 1023 | cfqq->cfqg = cfqg; |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1024 | /* cfqq reference on cfqg */ |
| 1025 | atomic_inc(&cfqq->cfqg->ref); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1026 | } |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1027 | |
| 1028 | static void cfq_put_cfqg(struct cfq_group *cfqg) |
| 1029 | { |
| 1030 | struct cfq_rb_root *st; |
| 1031 | int i, j; |
| 1032 | |
| 1033 | BUG_ON(atomic_read(&cfqg->ref) <= 0); |
| 1034 | if (!atomic_dec_and_test(&cfqg->ref)) |
| 1035 | return; |
| 1036 | for_each_cfqg_st(cfqg, i, j, st) |
| 1037 | BUG_ON(!RB_EMPTY_ROOT(&st->rb) || st->active != NULL); |
| 1038 | kfree(cfqg); |
| 1039 | } |
| 1040 | |
| 1041 | static void cfq_destroy_cfqg(struct cfq_data *cfqd, struct cfq_group *cfqg) |
| 1042 | { |
| 1043 | /* Something wrong if we are trying to remove same group twice */ |
| 1044 | BUG_ON(hlist_unhashed(&cfqg->cfqd_node)); |
| 1045 | |
| 1046 | hlist_del_init(&cfqg->cfqd_node); |
| 1047 | |
| 1048 | /* |
| 1049 | * Put the reference taken at the time of creation so that when all |
| 1050 | * queues are gone, group can be destroyed. |
| 1051 | */ |
| 1052 | cfq_put_cfqg(cfqg); |
| 1053 | } |
| 1054 | |
| 1055 | static void cfq_release_cfq_groups(struct cfq_data *cfqd) |
| 1056 | { |
| 1057 | struct hlist_node *pos, *n; |
| 1058 | struct cfq_group *cfqg; |
| 1059 | |
| 1060 | hlist_for_each_entry_safe(cfqg, pos, n, &cfqd->cfqg_list, cfqd_node) { |
| 1061 | /* |
| 1062 | * If cgroup removal path got to blk_group first and removed |
| 1063 | * it from cgroup list, then it will take care of destroying |
| 1064 | * cfqg also. |
| 1065 | */ |
| 1066 | if (!blkiocg_del_blkio_group(&cfqg->blkg)) |
| 1067 | cfq_destroy_cfqg(cfqd, cfqg); |
| 1068 | } |
| 1069 | } |
| 1070 | |
| 1071 | /* |
| 1072 | * Blk cgroup controller notification saying that blkio_group object is being |
| 1073 | * delinked as associated cgroup object is going away. That also means that |
| 1074 | * no new IO will come in this group. So get rid of this group as soon as |
| 1075 | * any pending IO in the group is finished. |
| 1076 | * |
| 1077 | * This function is called under rcu_read_lock(). key is the rcu protected |
| 1078 | * pointer. That means "key" is a valid cfq_data pointer as long as we are rcu |
| 1079 | * read lock. |
| 1080 | * |
| 1081 | * "key" was fetched from blkio_group under blkio_cgroup->lock. That means |
| 1082 | * it should not be NULL as even if elevator was exiting, cgroup deltion |
| 1083 | * path got to it first. |
| 1084 | */ |
| 1085 | void cfq_unlink_blkio_group(void *key, struct blkio_group *blkg) |
| 1086 | { |
| 1087 | unsigned long flags; |
| 1088 | struct cfq_data *cfqd = key; |
| 1089 | |
| 1090 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 1091 | cfq_destroy_cfqg(cfqd, cfqg_of_blkg(blkg)); |
| 1092 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 1093 | } |
| 1094 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1095 | #else /* GROUP_IOSCHED */ |
| 1096 | static struct cfq_group *cfq_get_cfqg(struct cfq_data *cfqd, int create) |
| 1097 | { |
| 1098 | return &cfqd->root_group; |
| 1099 | } |
| 1100 | static inline void |
| 1101 | cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { |
| 1102 | cfqq->cfqg = cfqg; |
| 1103 | } |
| 1104 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 1105 | static void cfq_release_cfq_groups(struct cfq_data *cfqd) {} |
| 1106 | static inline void cfq_put_cfqg(struct cfq_group *cfqg) {} |
| 1107 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1108 | #endif /* GROUP_IOSCHED */ |
| 1109 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1110 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1111 | * The cfqd->service_trees holds all pending cfq_queue's that have |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1112 | * requests waiting to be processed. It is sorted in the order that |
| 1113 | * we will service the queues. |
| 1114 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1115 | static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1116 | bool add_front) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1117 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1118 | struct rb_node **p, *parent; |
| 1119 | struct cfq_queue *__cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1120 | unsigned long rb_key; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1121 | struct cfq_rb_root *service_tree; |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1122 | int left; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1123 | int new_cfqq = 1; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 1124 | int group_changed = 0; |
| 1125 | |
| 1126 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 1127 | if (!cfqd->cfq_group_isolation |
| 1128 | && cfqq_type(cfqq) == SYNC_NOIDLE_WORKLOAD |
| 1129 | && cfqq->cfqg && cfqq->cfqg != &cfqd->root_group) { |
| 1130 | /* Move this cfq to root group */ |
| 1131 | cfq_log_cfqq(cfqd, cfqq, "moving to root group"); |
| 1132 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) |
| 1133 | cfq_group_service_tree_del(cfqd, cfqq->cfqg); |
| 1134 | cfqq->orig_cfqg = cfqq->cfqg; |
| 1135 | cfqq->cfqg = &cfqd->root_group; |
| 1136 | atomic_inc(&cfqd->root_group.ref); |
| 1137 | group_changed = 1; |
| 1138 | } else if (!cfqd->cfq_group_isolation |
| 1139 | && cfqq_type(cfqq) == SYNC_WORKLOAD && cfqq->orig_cfqg) { |
| 1140 | /* cfqq is sequential now needs to go to its original group */ |
| 1141 | BUG_ON(cfqq->cfqg != &cfqd->root_group); |
| 1142 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) |
| 1143 | cfq_group_service_tree_del(cfqd, cfqq->cfqg); |
| 1144 | cfq_put_cfqg(cfqq->cfqg); |
| 1145 | cfqq->cfqg = cfqq->orig_cfqg; |
| 1146 | cfqq->orig_cfqg = NULL; |
| 1147 | group_changed = 1; |
| 1148 | cfq_log_cfqq(cfqd, cfqq, "moved to origin group"); |
| 1149 | } |
| 1150 | #endif |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1151 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1152 | service_tree = service_tree_for(cfqq->cfqg, cfqq_prio(cfqq), |
| 1153 | cfqq_type(cfqq), cfqd); |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1154 | if (cfq_class_idle(cfqq)) { |
| 1155 | rb_key = CFQ_IDLE_DELAY; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1156 | parent = rb_last(&service_tree->rb); |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1157 | if (parent && parent != &cfqq->rb_node) { |
| 1158 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 1159 | rb_key += __cfqq->rb_key; |
| 1160 | } else |
| 1161 | rb_key += jiffies; |
| 1162 | } else if (!add_front) { |
Jens Axboe | b9c8946 | 2009-10-06 20:53:44 +0200 | [diff] [blame] | 1163 | /* |
| 1164 | * Get our rb key offset. Subtract any residual slice |
| 1165 | * value carried from last service. A negative resid |
| 1166 | * count indicates slice overrun, and this should position |
| 1167 | * the next service time further away in the tree. |
| 1168 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1169 | rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; |
Jens Axboe | b9c8946 | 2009-10-06 20:53:44 +0200 | [diff] [blame] | 1170 | rb_key -= cfqq->slice_resid; |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1171 | cfqq->slice_resid = 0; |
Corrado Zoccolo | 48e025e | 2009-10-05 08:49:23 +0200 | [diff] [blame] | 1172 | } else { |
| 1173 | rb_key = -HZ; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1174 | __cfqq = cfq_rb_first(service_tree); |
Corrado Zoccolo | 48e025e | 2009-10-05 08:49:23 +0200 | [diff] [blame] | 1175 | rb_key += __cfqq ? __cfqq->rb_key : jiffies; |
| 1176 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1177 | |
| 1178 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1179 | new_cfqq = 0; |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 1180 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1181 | * same position, nothing more to do |
Jens Axboe | 99f9628 | 2007-02-05 11:56:25 +0100 | [diff] [blame] | 1182 | */ |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1183 | if (rb_key == cfqq->rb_key && |
| 1184 | cfqq->service_tree == service_tree) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1185 | return; |
Jens Axboe | 53b03744 | 2006-07-28 09:48:51 +0200 | [diff] [blame] | 1186 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1187 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
| 1188 | cfqq->service_tree = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1189 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1190 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1191 | left = 1; |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 1192 | parent = NULL; |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1193 | cfqq->service_tree = service_tree; |
| 1194 | p = &service_tree->rb.rb_node; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1195 | while (*p) { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1196 | struct rb_node **n; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1197 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1198 | parent = *p; |
| 1199 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); |
| 1200 | |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 1201 | /* |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1202 | * sort by key, that represents service time. |
Jens Axboe | 0c534e0 | 2007-04-18 20:01:57 +0200 | [diff] [blame] | 1203 | */ |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1204 | if (time_before(rb_key, __cfqq->rb_key)) |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1205 | n = &(*p)->rb_left; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1206 | else { |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1207 | n = &(*p)->rb_right; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1208 | left = 0; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1209 | } |
Jens Axboe | 67060e3 | 2007-04-18 20:13:32 +0200 | [diff] [blame] | 1210 | |
| 1211 | p = n; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1212 | } |
| 1213 | |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1214 | if (left) |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1215 | service_tree->left = &cfqq->rb_node; |
Jens Axboe | cc09e29 | 2007-04-26 12:53:50 +0200 | [diff] [blame] | 1216 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1217 | cfqq->rb_key = rb_key; |
| 1218 | rb_link_node(&cfqq->rb_node, parent, p); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1219 | rb_insert_color(&cfqq->rb_node, &service_tree->rb); |
| 1220 | service_tree->count++; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 1221 | if ((add_front || !new_cfqq) && !group_changed) |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1222 | return; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1223 | cfq_group_service_tree_add(cfqd, cfqq->cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1224 | } |
| 1225 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1226 | static struct cfq_queue * |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1227 | cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, |
| 1228 | sector_t sector, struct rb_node **ret_parent, |
| 1229 | struct rb_node ***rb_link) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1230 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1231 | struct rb_node **p, *parent; |
| 1232 | struct cfq_queue *cfqq = NULL; |
| 1233 | |
| 1234 | parent = NULL; |
| 1235 | p = &root->rb_node; |
| 1236 | while (*p) { |
| 1237 | struct rb_node **n; |
| 1238 | |
| 1239 | parent = *p; |
| 1240 | cfqq = rb_entry(parent, struct cfq_queue, p_node); |
| 1241 | |
| 1242 | /* |
| 1243 | * Sort strictly based on sector. Smallest to the left, |
| 1244 | * largest to the right. |
| 1245 | */ |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1246 | if (sector > blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1247 | n = &(*p)->rb_right; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1248 | else if (sector < blk_rq_pos(cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1249 | n = &(*p)->rb_left; |
| 1250 | else |
| 1251 | break; |
| 1252 | p = n; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1253 | cfqq = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1254 | } |
| 1255 | |
| 1256 | *ret_parent = parent; |
| 1257 | if (rb_link) |
| 1258 | *rb_link = p; |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1259 | return cfqq; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1260 | } |
| 1261 | |
| 1262 | static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1263 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1264 | struct rb_node **p, *parent; |
| 1265 | struct cfq_queue *__cfqq; |
| 1266 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1267 | if (cfqq->p_root) { |
| 1268 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1269 | cfqq->p_root = NULL; |
| 1270 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1271 | |
| 1272 | if (cfq_class_idle(cfqq)) |
| 1273 | return; |
| 1274 | if (!cfqq->next_rq) |
| 1275 | return; |
| 1276 | |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1277 | cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1278 | __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, |
| 1279 | blk_rq_pos(cfqq->next_rq), &parent, &p); |
Jens Axboe | 3ac6c9f | 2009-04-23 12:14:56 +0200 | [diff] [blame] | 1280 | if (!__cfqq) { |
| 1281 | rb_link_node(&cfqq->p_node, parent, p); |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1282 | rb_insert_color(&cfqq->p_node, cfqq->p_root); |
| 1283 | } else |
| 1284 | cfqq->p_root = NULL; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1285 | } |
| 1286 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1287 | /* |
| 1288 | * Update cfqq's position in the service tree. |
| 1289 | */ |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1290 | static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1291 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1292 | /* |
| 1293 | * Resorting requires the cfqq to be on the RR list already. |
| 1294 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1295 | if (cfq_cfqq_on_rr(cfqq)) { |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1296 | cfq_service_tree_add(cfqd, cfqq, 0); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1297 | cfq_prio_tree_add(cfqd, cfqq); |
| 1298 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1299 | } |
| 1300 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | /* |
| 1302 | * add to busy list of queues for service, trying to be fair in ordering |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1303 | * the pending list according to last request service |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1304 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1305 | static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1306 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1307 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1308 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
| 1309 | cfq_mark_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1310 | cfqd->busy_queues++; |
| 1311 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1312 | cfq_resort_rr_list(cfqd, cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1313 | } |
| 1314 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1315 | /* |
| 1316 | * Called when the cfqq no longer has requests pending, remove it from |
| 1317 | * the service tree. |
| 1318 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1319 | static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1320 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1321 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1322 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
| 1323 | cfq_clear_cfqq_on_rr(cfqq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1324 | |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 1325 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
| 1326 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
| 1327 | cfqq->service_tree = NULL; |
| 1328 | } |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1329 | if (cfqq->p_root) { |
| 1330 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1331 | cfqq->p_root = NULL; |
| 1332 | } |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1333 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1334 | cfq_group_service_tree_del(cfqd, cfqq->cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1335 | BUG_ON(!cfqd->busy_queues); |
| 1336 | cfqd->busy_queues--; |
| 1337 | } |
| 1338 | |
| 1339 | /* |
| 1340 | * rb tree support functions |
| 1341 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1342 | static void cfq_del_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1344 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1345 | const int sync = rq_is_sync(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1346 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1347 | BUG_ON(!cfqq->queued[sync]); |
| 1348 | cfqq->queued[sync]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1349 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1350 | elv_rb_del(&cfqq->sort_list, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1351 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1352 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) { |
| 1353 | /* |
| 1354 | * Queue will be deleted from service tree when we actually |
| 1355 | * expire it later. Right now just remove it from prio tree |
| 1356 | * as it is empty. |
| 1357 | */ |
| 1358 | if (cfqq->p_root) { |
| 1359 | rb_erase(&cfqq->p_node, cfqq->p_root); |
| 1360 | cfqq->p_root = NULL; |
| 1361 | } |
| 1362 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1363 | } |
| 1364 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1365 | static void cfq_add_rq_rb(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1366 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1367 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1368 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1369 | struct request *__alias, *prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1370 | |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1371 | cfqq->queued[rq_is_sync(rq)]++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1372 | |
| 1373 | /* |
| 1374 | * looks a little odd, but the first insert might return an alias. |
| 1375 | * if that happens, put the alias on the dispatch list |
| 1376 | */ |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1377 | while ((__alias = elv_rb_add(&cfqq->sort_list, rq)) != NULL) |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1378 | cfq_dispatch_insert(cfqd->queue, __alias); |
Jens Axboe | 5fccbf6 | 2006-10-31 14:21:55 +0100 | [diff] [blame] | 1379 | |
| 1380 | if (!cfq_cfqq_on_rr(cfqq)) |
| 1381 | cfq_add_cfqq_rr(cfqd, cfqq); |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 1382 | |
| 1383 | /* |
| 1384 | * check if this request is a better next-serve candidate |
| 1385 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1386 | prev = cfqq->next_rq; |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1387 | cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq, cfqd->last_position); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1388 | |
| 1389 | /* |
| 1390 | * adjust priority tree position, if ->next_rq changes |
| 1391 | */ |
| 1392 | if (prev != cfqq->next_rq) |
| 1393 | cfq_prio_tree_add(cfqd, cfqq); |
| 1394 | |
Jens Axboe | 5044eed | 2007-04-25 11:53:48 +0200 | [diff] [blame] | 1395 | BUG_ON(!cfqq->next_rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | } |
| 1397 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1398 | static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1399 | { |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1400 | elv_rb_del(&cfqq->sort_list, rq); |
| 1401 | cfqq->queued[rq_is_sync(rq)]--; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1402 | cfq_add_rq_rb(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1403 | } |
| 1404 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1405 | static struct request * |
| 1406 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1407 | { |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1408 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1409 | struct cfq_io_context *cic; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1410 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1411 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1412 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1413 | if (!cic) |
| 1414 | return NULL; |
| 1415 | |
| 1416 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1417 | if (cfqq) { |
| 1418 | sector_t sector = bio->bi_sector + bio_sectors(bio); |
| 1419 | |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1420 | return elv_rb_find(&cfqq->sort_list, sector); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1421 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1422 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1423 | return NULL; |
| 1424 | } |
| 1425 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1426 | static void cfq_activate_request(struct request_queue *q, struct request *rq) |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1427 | { |
| 1428 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1429 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 1430 | cfqd->rq_in_driver[rq_is_sync(rq)]++; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1431 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 1432 | rq_in_driver(cfqd)); |
Jens Axboe | 25776e3 | 2006-06-01 10:12:26 +0200 | [diff] [blame] | 1433 | |
Tejun Heo | 5b93629 | 2009-05-07 22:24:38 +0900 | [diff] [blame] | 1434 | cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1435 | } |
| 1436 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1437 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1438 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1439 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 1440 | const int sync = rq_is_sync(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1441 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 1442 | WARN_ON(!cfqd->rq_in_driver[sync]); |
| 1443 | cfqd->rq_in_driver[sync]--; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1444 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 1445 | rq_in_driver(cfqd)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1446 | } |
| 1447 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1448 | static void cfq_remove_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1449 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1450 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1451 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1452 | if (cfqq->next_rq == rq) |
| 1453 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1454 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1455 | list_del_init(&rq->queuelist); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1456 | cfq_del_rq_rb(rq); |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 1457 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 1458 | cfqq->cfqd->rq_queued--; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 1459 | if (rq_is_meta(rq)) { |
| 1460 | WARN_ON(!cfqq->meta_pending); |
| 1461 | cfqq->meta_pending--; |
| 1462 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1463 | } |
| 1464 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1465 | static int cfq_merge(struct request_queue *q, struct request **req, |
| 1466 | struct bio *bio) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1467 | { |
| 1468 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 1469 | struct request *__rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1470 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1471 | __rq = cfq_find_rq_fmerge(cfqd, bio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1472 | if (__rq && elv_rq_merge_ok(__rq, bio)) { |
Jens Axboe | 9817064 | 2006-07-28 09:23:08 +0200 | [diff] [blame] | 1473 | *req = __rq; |
| 1474 | return ELEVATOR_FRONT_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1475 | } |
| 1476 | |
| 1477 | return ELEVATOR_NO_MERGE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1478 | } |
| 1479 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1480 | static void cfq_merged_request(struct request_queue *q, struct request *req, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1481 | int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1482 | { |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 1483 | if (type == ELEVATOR_FRONT_MERGE) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1484 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1485 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1486 | cfq_reposition_rq_rb(cfqq, req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1487 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1488 | } |
| 1489 | |
| 1490 | static void |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1491 | cfq_merged_requests(struct request_queue *q, struct request *rq, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1492 | struct request *next) |
| 1493 | { |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1494 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1495 | /* |
| 1496 | * reposition in fifo if next is older than rq |
| 1497 | */ |
| 1498 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1499 | time_before(rq_fifo_time(next), rq_fifo_time(rq))) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1500 | list_move(&rq->queuelist, &next->queuelist); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1501 | rq_set_fifo_time(rq, rq_fifo_time(next)); |
| 1502 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1503 | |
Corrado Zoccolo | cf7c25c | 2009-11-08 17:16:46 +0100 | [diff] [blame] | 1504 | if (cfqq->next_rq == next) |
| 1505 | cfqq->next_rq = rq; |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 1506 | cfq_remove_request(next); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1507 | } |
| 1508 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1509 | static int cfq_allow_merge(struct request_queue *q, struct request *rq, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1510 | struct bio *bio) |
| 1511 | { |
| 1512 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1513 | struct cfq_io_context *cic; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1514 | struct cfq_queue *cfqq; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1515 | |
Vivek Goyal | 8682e1f | 2009-12-03 12:59:50 -0500 | [diff] [blame] | 1516 | /* Deny merge if bio and rq don't belong to same cfq group */ |
| 1517 | if ((RQ_CFQQ(rq))->cfqg != cfq_get_cfqg(cfqd, 0)) |
| 1518 | return false; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1519 | /* |
Jens Axboe | ec8acb6 | 2007-01-02 18:32:11 +0100 | [diff] [blame] | 1520 | * Disallow merge of a sync bio into an async request. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1521 | */ |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1522 | if (cfq_bio_sync(bio) && !rq_is_sync(rq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1523 | return false; |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1524 | |
| 1525 | /* |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 1526 | * Lookup the cfqq that this bio will be queued with. Allow |
| 1527 | * merge only if rq is queued there. |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1528 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 1529 | cic = cfq_cic_lookup(cfqd, current->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1530 | if (!cic) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1531 | return false; |
Jens Axboe | 719d340 | 2006-12-22 09:38:53 +0100 | [diff] [blame] | 1532 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 1533 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1534 | return cfqq == RQ_CFQQ(rq); |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 1535 | } |
| 1536 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1537 | static void __cfq_set_active_queue(struct cfq_data *cfqd, |
| 1538 | struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1539 | { |
| 1540 | if (cfqq) { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1541 | cfq_log_cfqq(cfqd, cfqq, "set_active"); |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1542 | cfqq->slice_start = 0; |
| 1543 | cfqq->dispatch_start = jiffies; |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 1544 | cfqq->allocated_slice = 0; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1545 | cfqq->slice_end = 0; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1546 | cfqq->slice_dispatch = 0; |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 1547 | cfqq->nr_sectors = 0; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1548 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1549 | cfq_clear_cfqq_wait_request(cfqq); |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 1550 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1551 | cfq_clear_cfqq_must_alloc_slice(cfqq); |
| 1552 | cfq_clear_cfqq_fifo_expire(cfqq); |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 1553 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 1554 | |
| 1555 | del_timer(&cfqd->idle_slice_timer); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1556 | } |
| 1557 | |
| 1558 | cfqd->active_queue = cfqq; |
| 1559 | } |
| 1560 | |
| 1561 | /* |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1562 | * current cfqq expired its slice (or was too idle), select new one |
| 1563 | */ |
| 1564 | static void |
| 1565 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1566 | bool timed_out) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1567 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1568 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); |
| 1569 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1570 | if (cfq_cfqq_wait_request(cfqq)) |
| 1571 | del_timer(&cfqd->idle_slice_timer); |
| 1572 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1573 | cfq_clear_cfqq_wait_request(cfqq); |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 1574 | cfq_clear_cfqq_wait_busy(cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1575 | |
| 1576 | /* |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1577 | * 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] | 1578 | */ |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1579 | if (timed_out && !cfq_cfqq_slice_new(cfqq)) { |
Jens Axboe | c5b680f | 2007-01-19 11:56:49 +1100 | [diff] [blame] | 1580 | cfqq->slice_resid = cfqq->slice_end - jiffies; |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1581 | cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); |
| 1582 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1583 | |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1584 | cfq_group_served(cfqd, cfqq->cfqg, cfqq); |
| 1585 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1586 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 1587 | cfq_del_cfqq_rr(cfqd, cfqq); |
| 1588 | |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1589 | cfq_resort_rr_list(cfqd, cfqq); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1590 | |
| 1591 | if (cfqq == cfqd->active_queue) |
| 1592 | cfqd->active_queue = NULL; |
| 1593 | |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 1594 | if (&cfqq->cfqg->rb_node == cfqd->grp_service_tree.active) |
| 1595 | cfqd->grp_service_tree.active = NULL; |
| 1596 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1597 | if (cfqd->active_cic) { |
| 1598 | put_io_context(cfqd->active_cic->ioc); |
| 1599 | cfqd->active_cic = NULL; |
| 1600 | } |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1601 | } |
| 1602 | |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 1603 | static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out) |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1604 | { |
| 1605 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 1606 | |
| 1607 | if (cfqq) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 1608 | __cfq_slice_expired(cfqd, cfqq, timed_out); |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1609 | } |
| 1610 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1611 | /* |
| 1612 | * Get next queue for service. Unless we have a queue preemption, |
| 1613 | * we'll simply select the first cfqq in the service tree. |
| 1614 | */ |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1615 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1616 | { |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1617 | struct cfq_rb_root *service_tree = |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1618 | service_tree_for(cfqd->serving_group, cfqd->serving_prio, |
| 1619 | cfqd->serving_type, cfqd); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 1620 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1621 | if (!cfqd->rq_queued) |
| 1622 | return NULL; |
| 1623 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 1624 | /* There is nothing to dispatch */ |
| 1625 | if (!service_tree) |
| 1626 | return NULL; |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1627 | if (RB_EMPTY_ROOT(&service_tree->rb)) |
| 1628 | return NULL; |
| 1629 | return cfq_rb_first(service_tree); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1630 | } |
| 1631 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1632 | static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd) |
| 1633 | { |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1634 | struct cfq_group *cfqg; |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1635 | struct cfq_queue *cfqq; |
| 1636 | int i, j; |
| 1637 | struct cfq_rb_root *st; |
| 1638 | |
| 1639 | if (!cfqd->rq_queued) |
| 1640 | return NULL; |
| 1641 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 1642 | cfqg = cfq_get_next_cfqg(cfqd); |
| 1643 | if (!cfqg) |
| 1644 | return NULL; |
| 1645 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1646 | for_each_cfqg_st(cfqg, i, j, st) |
| 1647 | if ((cfqq = cfq_rb_first(st)) != NULL) |
| 1648 | return cfqq; |
| 1649 | return NULL; |
| 1650 | } |
| 1651 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1652 | /* |
| 1653 | * Get and set a new active queue for service. |
| 1654 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1655 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, |
| 1656 | struct cfq_queue *cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1657 | { |
Jens Axboe | e00ef79 | 2009-11-04 08:54:55 +0100 | [diff] [blame] | 1658 | if (!cfqq) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1659 | cfqq = cfq_get_next_queue(cfqd); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1660 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1661 | __cfq_set_active_queue(cfqd, cfqq); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1662 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1663 | } |
| 1664 | |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1665 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, |
| 1666 | struct request *rq) |
| 1667 | { |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1668 | if (blk_rq_pos(rq) >= cfqd->last_position) |
| 1669 | return blk_rq_pos(rq) - cfqd->last_position; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1670 | else |
Tejun Heo | 83096eb | 2009-05-07 22:24:39 +0900 | [diff] [blame] | 1671 | return cfqd->last_position - blk_rq_pos(rq); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1672 | } |
| 1673 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 1674 | #define CFQQ_SEEK_THR 8 * 1024 |
| 1675 | #define CFQQ_SEEKY(cfqq) ((cfqq)->seek_mean > CFQQ_SEEK_THR) |
Jeff Moyer | 04dc6e7 | 2009-04-21 07:31:56 +0200 | [diff] [blame] | 1676 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 1677 | static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 1678 | struct request *rq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1679 | { |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 1680 | sector_t sdist = cfqq->seek_mean; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 1681 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 1682 | if (!sample_valid(cfqq->seek_samples)) |
| 1683 | sdist = CFQQ_SEEK_THR; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1684 | |
Jeff Moyer | 04dc6e7 | 2009-04-21 07:31:56 +0200 | [diff] [blame] | 1685 | return cfq_dist_from_last(cfqd, rq) <= sdist; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1686 | } |
| 1687 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1688 | static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, |
| 1689 | struct cfq_queue *cur_cfqq) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1690 | { |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1691 | struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1692 | struct rb_node *parent, *node; |
| 1693 | struct cfq_queue *__cfqq; |
| 1694 | sector_t sector = cfqd->last_position; |
| 1695 | |
| 1696 | if (RB_EMPTY_ROOT(root)) |
| 1697 | return NULL; |
| 1698 | |
| 1699 | /* |
| 1700 | * First, if we find a request starting at the end of the last |
| 1701 | * request, choose it. |
| 1702 | */ |
Jens Axboe | f2d1f0a | 2009-04-23 12:19:38 +0200 | [diff] [blame] | 1703 | __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1704 | if (__cfqq) |
| 1705 | return __cfqq; |
| 1706 | |
| 1707 | /* |
| 1708 | * If the exact sector wasn't found, the parent of the NULL leaf |
| 1709 | * will contain the closest sector. |
| 1710 | */ |
| 1711 | __cfqq = rb_entry(parent, struct cfq_queue, p_node); |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 1712 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1713 | return __cfqq; |
| 1714 | |
Tejun Heo | 2e46e8b | 2009-05-07 22:24:41 +0900 | [diff] [blame] | 1715 | if (blk_rq_pos(__cfqq->next_rq) < sector) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1716 | node = rb_next(&__cfqq->p_node); |
| 1717 | else |
| 1718 | node = rb_prev(&__cfqq->p_node); |
| 1719 | if (!node) |
| 1720 | return NULL; |
| 1721 | |
| 1722 | __cfqq = rb_entry(node, struct cfq_queue, p_node); |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 1723 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1724 | return __cfqq; |
| 1725 | |
| 1726 | return NULL; |
| 1727 | } |
| 1728 | |
| 1729 | /* |
| 1730 | * cfqd - obvious |
| 1731 | * cur_cfqq - passed in so that we don't decide that the current queue is |
| 1732 | * closely cooperating with itself. |
| 1733 | * |
| 1734 | * So, basically we're assuming that that cur_cfqq has dispatched at least |
| 1735 | * one request, and that cfqd->last_position reflects a position on the disk |
| 1736 | * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid |
| 1737 | * assumption. |
| 1738 | */ |
| 1739 | static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 1740 | struct cfq_queue *cur_cfqq) |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1741 | { |
| 1742 | struct cfq_queue *cfqq; |
| 1743 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1744 | if (!cfq_cfqq_sync(cur_cfqq)) |
| 1745 | return NULL; |
| 1746 | if (CFQQ_SEEKY(cur_cfqq)) |
| 1747 | return NULL; |
| 1748 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1749 | /* |
Gui Jianfeng | b9d8f4c | 2009-12-08 08:54:17 +0100 | [diff] [blame] | 1750 | * Don't search priority tree if it's the only queue in the group. |
| 1751 | */ |
| 1752 | if (cur_cfqq->cfqg->nr_cfqq == 1) |
| 1753 | return NULL; |
| 1754 | |
| 1755 | /* |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 1756 | * We should notice if some of the queues are cooperating, eg |
| 1757 | * working closely on the same area of the disk. In that case, |
| 1758 | * we can group them together and don't waste time idling. |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1759 | */ |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1760 | cfqq = cfqq_close(cfqd, cur_cfqq); |
| 1761 | if (!cfqq) |
| 1762 | return NULL; |
| 1763 | |
Vivek Goyal | 8682e1f | 2009-12-03 12:59:50 -0500 | [diff] [blame] | 1764 | /* If new queue belongs to different cfq_group, don't choose it */ |
| 1765 | if (cur_cfqq->cfqg != cfqq->cfqg) |
| 1766 | return NULL; |
| 1767 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1768 | /* |
| 1769 | * It only makes sense to merge sync queues. |
| 1770 | */ |
| 1771 | if (!cfq_cfqq_sync(cfqq)) |
| 1772 | return NULL; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1773 | if (CFQQ_SEEKY(cfqq)) |
| 1774 | return NULL; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1775 | |
Corrado Zoccolo | c0324a0 | 2009-10-27 19:16:03 +0100 | [diff] [blame] | 1776 | /* |
| 1777 | * Do not merge queues of different priority classes |
| 1778 | */ |
| 1779 | if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq)) |
| 1780 | return NULL; |
| 1781 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 1782 | return cfqq; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1783 | } |
| 1784 | |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1785 | /* |
| 1786 | * Determine whether we should enforce idle window for this queue. |
| 1787 | */ |
| 1788 | |
| 1789 | static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1790 | { |
| 1791 | enum wl_prio_t prio = cfqq_prio(cfqq); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1792 | struct cfq_rb_root *service_tree = cfqq->service_tree; |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1793 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1794 | BUG_ON(!service_tree); |
| 1795 | BUG_ON(!service_tree->count); |
| 1796 | |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1797 | /* We never do for idle class queues. */ |
| 1798 | if (prio == IDLE_WORKLOAD) |
| 1799 | return false; |
| 1800 | |
| 1801 | /* We do for queues that were marked with idle window flag. */ |
Shaohua Li | 3c764b7 | 2009-12-04 13:12:06 +0100 | [diff] [blame] | 1802 | if (cfq_cfqq_idle_window(cfqq) && |
| 1803 | !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)) |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1804 | return true; |
| 1805 | |
| 1806 | /* |
| 1807 | * Otherwise, we do only if they are the last ones |
| 1808 | * in their service tree. |
| 1809 | */ |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 1810 | return service_tree->count == 1; |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1811 | } |
| 1812 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1813 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1814 | { |
Jens Axboe | 1792669 | 2007-01-19 11:59:30 +1100 | [diff] [blame] | 1815 | struct cfq_queue *cfqq = cfqd->active_queue; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1816 | struct cfq_io_context *cic; |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1817 | unsigned long sl; |
| 1818 | |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1819 | /* |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 1820 | * SSD device without seek penalty, disable idling. But only do so |
| 1821 | * for devices that support queuing, otherwise we still have a problem |
| 1822 | * with sync vs async workloads. |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1823 | */ |
Jens Axboe | f7d7b7a | 2008-09-25 11:37:50 +0200 | [diff] [blame] | 1824 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) |
Jens Axboe | a68bbdd | 2008-09-24 13:03:33 +0200 | [diff] [blame] | 1825 | return; |
| 1826 | |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 1827 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1828 | WARN_ON(cfq_cfqq_slice_new(cfqq)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1829 | |
| 1830 | /* |
| 1831 | * idle is disabled, either manually or by past process history |
| 1832 | */ |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 1833 | if (!cfqd->cfq_slice_idle || !cfq_should_idle(cfqd, cfqq)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1834 | return; |
| 1835 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1836 | /* |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 1837 | * still active requests from this queue, don't idle |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1838 | */ |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 1839 | if (cfqq->dispatched) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1840 | return; |
| 1841 | |
| 1842 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1843 | * task has exited, don't wait |
| 1844 | */ |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1845 | cic = cfqd->active_cic; |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 1846 | if (!cic || !atomic_read(&cic->ioc->nr_tasks)) |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1847 | return; |
| 1848 | |
Corrado Zoccolo | 355b659 | 2009-10-08 08:43:32 +0200 | [diff] [blame] | 1849 | /* |
| 1850 | * If our average think time is larger than the remaining time |
| 1851 | * slice, then don't idle. This avoids overrunning the allotted |
| 1852 | * time slice. |
| 1853 | */ |
| 1854 | if (sample_valid(cic->ttime_samples) && |
| 1855 | (cfqq->slice_end - jiffies < cic->ttime_mean)) |
| 1856 | return; |
| 1857 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1858 | cfq_mark_cfqq_wait_request(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1859 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1860 | sl = cfqd->cfq_slice_idle; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 1861 | |
Jens Axboe | 7b14e3b | 2006-02-28 09:35:11 +0100 | [diff] [blame] | 1862 | mod_timer(&cfqd->idle_slice_timer, jiffies + sl); |
Jens Axboe | 9481ffd | 2009-04-15 12:14:13 +0200 | [diff] [blame] | 1863 | cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu", sl); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1864 | } |
| 1865 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 1866 | /* |
| 1867 | * Move request from internal lists to the request queue dispatch list. |
| 1868 | */ |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 1869 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1870 | { |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1871 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 1872 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1873 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1874 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); |
| 1875 | |
Jeff Moyer | 06d2188 | 2009-09-11 17:08:59 +0200 | [diff] [blame] | 1876 | cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1877 | cfq_remove_request(rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1878 | cfqq->dispatched++; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 1879 | elv_dispatch_sort(q, rq); |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 1880 | |
| 1881 | if (cfq_cfqq_sync(cfqq)) |
| 1882 | cfqd->sync_flight++; |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 1883 | cfqq->nr_sectors += blk_rq_sectors(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1884 | } |
| 1885 | |
| 1886 | /* |
| 1887 | * return expired entry, or NULL to just start from scratch in rbtree |
| 1888 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 1889 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1890 | { |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1891 | struct request *rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1892 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 1893 | if (cfq_cfqq_fifo_expire(cfqq)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1894 | return NULL; |
Jens Axboe | cb88741 | 2007-01-19 12:01:16 +1100 | [diff] [blame] | 1895 | |
| 1896 | cfq_mark_cfqq_fifo_expire(cfqq); |
| 1897 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1898 | if (list_empty(&cfqq->fifo)) |
| 1899 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1900 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 1901 | rq = rq_entry_fifo(cfqq->fifo.next); |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1902 | if (time_before(jiffies, rq_fifo_time(rq))) |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 1903 | rq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1904 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 1905 | cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 1906 | return rq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1907 | } |
| 1908 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 1909 | static inline int |
| 1910 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 1911 | { |
| 1912 | const int base_rq = cfqd->cfq_slice_async_rq; |
| 1913 | |
| 1914 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); |
| 1915 | |
| 1916 | return 2 * (base_rq + base_rq * (CFQ_PRIO_LISTS - 1 - cfqq->ioprio)); |
| 1917 | } |
| 1918 | |
| 1919 | /* |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1920 | * Must be called with the queue_lock held. |
| 1921 | */ |
| 1922 | static int cfqq_process_refs(struct cfq_queue *cfqq) |
| 1923 | { |
| 1924 | int process_refs, io_refs; |
| 1925 | |
| 1926 | io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE]; |
| 1927 | process_refs = atomic_read(&cfqq->ref) - io_refs; |
| 1928 | BUG_ON(process_refs < 0); |
| 1929 | return process_refs; |
| 1930 | } |
| 1931 | |
| 1932 | static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) |
| 1933 | { |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1934 | int process_refs, new_process_refs; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1935 | struct cfq_queue *__cfqq; |
| 1936 | |
| 1937 | /* Avoid a circular list and skip interim queue merges */ |
| 1938 | while ((__cfqq = new_cfqq->new_cfqq)) { |
| 1939 | if (__cfqq == cfqq) |
| 1940 | return; |
| 1941 | new_cfqq = __cfqq; |
| 1942 | } |
| 1943 | |
| 1944 | process_refs = cfqq_process_refs(cfqq); |
| 1945 | /* |
| 1946 | * If the process for the cfqq has gone away, there is no |
| 1947 | * sense in merging the queues. |
| 1948 | */ |
| 1949 | if (process_refs == 0) |
| 1950 | return; |
| 1951 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 1952 | /* |
| 1953 | * Merge in the direction of the lesser amount of work. |
| 1954 | */ |
| 1955 | new_process_refs = cfqq_process_refs(new_cfqq); |
| 1956 | if (new_process_refs >= process_refs) { |
| 1957 | cfqq->new_cfqq = new_cfqq; |
| 1958 | atomic_add(process_refs, &new_cfqq->ref); |
| 1959 | } else { |
| 1960 | new_cfqq->new_cfqq = cfqq; |
| 1961 | atomic_add(new_process_refs, &cfqq->ref); |
| 1962 | } |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 1963 | } |
| 1964 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1965 | static enum wl_type_t cfq_choose_wl(struct cfq_data *cfqd, |
| 1966 | struct cfq_group *cfqg, enum wl_prio_t prio, |
| 1967 | bool prio_changed) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1968 | { |
| 1969 | struct cfq_queue *queue; |
| 1970 | int i; |
| 1971 | bool key_valid = false; |
| 1972 | unsigned long lowest_key = 0; |
| 1973 | enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; |
| 1974 | |
| 1975 | if (prio_changed) { |
| 1976 | /* |
| 1977 | * When priorities switched, we prefer starting |
| 1978 | * from SYNC_NOIDLE (first choice), or just SYNC |
| 1979 | * over ASYNC |
| 1980 | */ |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1981 | if (service_tree_for(cfqg, prio, cur_best, cfqd)->count) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1982 | return cur_best; |
| 1983 | cur_best = SYNC_WORKLOAD; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1984 | if (service_tree_for(cfqg, prio, cur_best, cfqd)->count) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1985 | return cur_best; |
| 1986 | |
| 1987 | return ASYNC_WORKLOAD; |
| 1988 | } |
| 1989 | |
| 1990 | for (i = 0; i < 3; ++i) { |
| 1991 | /* otherwise, select the one with lowest rb_key */ |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 1992 | queue = cfq_rb_first(service_tree_for(cfqg, prio, i, cfqd)); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 1993 | if (queue && |
| 1994 | (!key_valid || time_before(queue->rb_key, lowest_key))) { |
| 1995 | lowest_key = queue->rb_key; |
| 1996 | cur_best = i; |
| 1997 | key_valid = true; |
| 1998 | } |
| 1999 | } |
| 2000 | |
| 2001 | return cur_best; |
| 2002 | } |
| 2003 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2004 | static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2005 | { |
| 2006 | enum wl_prio_t previous_prio = cfqd->serving_prio; |
| 2007 | bool prio_changed; |
| 2008 | unsigned slice; |
| 2009 | unsigned count; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2010 | struct cfq_rb_root *st; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2011 | unsigned group_slice; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2012 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2013 | if (!cfqg) { |
| 2014 | cfqd->serving_prio = IDLE_WORKLOAD; |
| 2015 | cfqd->workload_expires = jiffies + 1; |
| 2016 | return; |
| 2017 | } |
| 2018 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2019 | /* Choose next priority. RT > BE > IDLE */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2020 | if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2021 | cfqd->serving_prio = RT_WORKLOAD; |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2022 | else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg)) |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2023 | cfqd->serving_prio = BE_WORKLOAD; |
| 2024 | else { |
| 2025 | cfqd->serving_prio = IDLE_WORKLOAD; |
| 2026 | cfqd->workload_expires = jiffies + 1; |
| 2027 | return; |
| 2028 | } |
| 2029 | |
| 2030 | /* |
| 2031 | * For RT and BE, we have to choose also the type |
| 2032 | * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload |
| 2033 | * expiration time |
| 2034 | */ |
| 2035 | prio_changed = (cfqd->serving_prio != previous_prio); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2036 | st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type, |
| 2037 | cfqd); |
| 2038 | count = st->count; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2039 | |
| 2040 | /* |
| 2041 | * If priority didn't change, check workload expiration, |
| 2042 | * and that we still have other queues ready |
| 2043 | */ |
| 2044 | if (!prio_changed && count && |
| 2045 | !time_after(jiffies, cfqd->workload_expires)) |
| 2046 | return; |
| 2047 | |
| 2048 | /* otherwise select new workload type */ |
| 2049 | cfqd->serving_type = |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2050 | cfq_choose_wl(cfqd, cfqg, cfqd->serving_prio, prio_changed); |
| 2051 | st = service_tree_for(cfqg, cfqd->serving_prio, cfqd->serving_type, |
| 2052 | cfqd); |
| 2053 | count = st->count; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2054 | |
| 2055 | /* |
| 2056 | * the workload slice is computed as a fraction of target latency |
| 2057 | * proportional to the number of queues in that workload, over |
| 2058 | * all the queues in the same priority class |
| 2059 | */ |
Vivek Goyal | 58ff82f | 2009-12-03 12:59:44 -0500 | [diff] [blame] | 2060 | group_slice = cfq_group_slice(cfqd, cfqg); |
| 2061 | |
| 2062 | slice = group_slice * count / |
| 2063 | max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_prio], |
| 2064 | cfq_group_busy_queues_wl(cfqd->serving_prio, cfqd, cfqg)); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2065 | |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 2066 | if (cfqd->serving_type == ASYNC_WORKLOAD) { |
| 2067 | unsigned int tmp; |
| 2068 | |
| 2069 | /* |
| 2070 | * Async queues are currently system wide. Just taking |
| 2071 | * proportion of queues with-in same group will lead to higher |
| 2072 | * async ratio system wide as generally root group is going |
| 2073 | * to have higher weight. A more accurate thing would be to |
| 2074 | * calculate system wide asnc/sync ratio. |
| 2075 | */ |
| 2076 | tmp = cfq_target_latency * cfqg_busy_async_queues(cfqd, cfqg); |
| 2077 | tmp = tmp/cfqd->busy_queues; |
| 2078 | slice = min_t(unsigned, slice, tmp); |
| 2079 | |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2080 | /* async workload slice is scaled down according to |
| 2081 | * the sync/async slice ratio. */ |
| 2082 | slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1]; |
Vivek Goyal | f26bd1f | 2009-12-03 12:59:54 -0500 | [diff] [blame] | 2083 | } else |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2084 | /* sync workload slice is at least 2 * cfq_slice_idle */ |
| 2085 | slice = max(slice, 2 * cfqd->cfq_slice_idle); |
| 2086 | |
| 2087 | slice = max_t(unsigned, slice, CFQ_MIN_TT); |
| 2088 | cfqd->workload_expires = jiffies + slice; |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 2089 | cfqd->noidle_tree_requires_idle = false; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2090 | } |
| 2091 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2092 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) |
| 2093 | { |
| 2094 | struct cfq_rb_root *st = &cfqd->grp_service_tree; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 2095 | struct cfq_group *cfqg; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2096 | |
| 2097 | if (RB_EMPTY_ROOT(&st->rb)) |
| 2098 | return NULL; |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 2099 | cfqg = cfq_rb_first_group(st); |
| 2100 | st->active = &cfqg->rb_node; |
| 2101 | update_min_vdisktime(st); |
| 2102 | return cfqg; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2103 | } |
| 2104 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2105 | static void cfq_choose_cfqg(struct cfq_data *cfqd) |
| 2106 | { |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2107 | struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); |
| 2108 | |
| 2109 | cfqd->serving_group = cfqg; |
Vivek Goyal | dae739e | 2009-12-03 12:59:45 -0500 | [diff] [blame] | 2110 | |
| 2111 | /* Restore the workload type data */ |
| 2112 | if (cfqg->saved_workload_slice) { |
| 2113 | cfqd->workload_expires = jiffies + cfqg->saved_workload_slice; |
| 2114 | cfqd->serving_type = cfqg->saved_workload; |
| 2115 | cfqd->serving_prio = cfqg->saved_serving_prio; |
Gui Jianfeng | 66ae291 | 2009-12-15 10:08:45 +0100 | [diff] [blame] | 2116 | } else |
| 2117 | cfqd->workload_expires = jiffies - 1; |
| 2118 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 2119 | choose_service_tree(cfqd, cfqg); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2120 | } |
| 2121 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2122 | /* |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2123 | * Select a queue for service. If we have a current active queue, |
| 2124 | * 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] | 2125 | */ |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2126 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2127 | { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2128 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2129 | |
| 2130 | cfqq = cfqd->active_queue; |
| 2131 | if (!cfqq) |
| 2132 | goto new_queue; |
| 2133 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2134 | if (!cfqd->rq_queued) |
| 2135 | return NULL; |
Vivek Goyal | c244bb5 | 2009-12-08 17:52:57 -0500 | [diff] [blame] | 2136 | |
| 2137 | /* |
| 2138 | * We were waiting for group to get backlogged. Expire the queue |
| 2139 | */ |
| 2140 | if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 2141 | goto expire; |
| 2142 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2143 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2144 | * 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] | 2145 | */ |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2146 | if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) { |
| 2147 | /* |
| 2148 | * If slice had not expired at the completion of last request |
| 2149 | * we might not have turned on wait_busy flag. Don't expire |
| 2150 | * the queue yet. Allow the group to get backlogged. |
| 2151 | * |
| 2152 | * The very fact that we have used the slice, that means we |
| 2153 | * have been idling all along on this queue and it should be |
| 2154 | * ok to wait for this request to complete. |
| 2155 | */ |
Vivek Goyal | 82bbbf2 | 2009-12-10 19:25:41 +0100 | [diff] [blame] | 2156 | if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list) |
| 2157 | && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { |
| 2158 | cfqq = NULL; |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2159 | goto keep_queue; |
Vivek Goyal | 82bbbf2 | 2009-12-10 19:25:41 +0100 | [diff] [blame] | 2160 | } else |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 2161 | goto expire; |
| 2162 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2163 | |
| 2164 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2165 | * The active queue has requests and isn't expired, allow it to |
| 2166 | * dispatch. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2167 | */ |
Jens Axboe | dd67d05 | 2006-06-21 09:36:18 +0200 | [diff] [blame] | 2168 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2169 | goto keep_queue; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2170 | |
| 2171 | /* |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2172 | * If another queue has a request waiting within our mean seek |
| 2173 | * distance, let it run. The expire code will check for close |
| 2174 | * cooperators and put the close queue at the front of the service |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2175 | * tree. If possible, merge the expiring queue with the new cfqq. |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2176 | */ |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 2177 | new_cfqq = cfq_close_cooperator(cfqd, cfqq); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2178 | if (new_cfqq) { |
| 2179 | if (!cfqq->new_cfqq) |
| 2180 | cfq_setup_merge(cfqq, new_cfqq); |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2181 | goto expire; |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2182 | } |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2183 | |
| 2184 | /* |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 2185 | * No requests pending. If the active queue still has requests in |
| 2186 | * flight or is idling for a new request, allow either of these |
| 2187 | * conditions to happen (or time out) before selecting a new queue. |
| 2188 | */ |
Jens Axboe | cc19747 | 2007-04-20 20:45:39 +0200 | [diff] [blame] | 2189 | if (timer_pending(&cfqd->idle_slice_timer) || |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 2190 | (cfqq->dispatched && cfq_should_idle(cfqd, cfqq))) { |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2191 | cfqq = NULL; |
| 2192 | goto keep_queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2193 | } |
| 2194 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2195 | expire: |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2196 | cfq_slice_expired(cfqd, 0); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2197 | new_queue: |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2198 | /* |
| 2199 | * Current queue expired. Check if we have to switch to a new |
| 2200 | * service tree |
| 2201 | */ |
| 2202 | if (!new_cfqq) |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2203 | cfq_choose_cfqg(cfqd); |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 2204 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 2205 | cfqq = cfq_set_active_queue(cfqd, new_cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2206 | keep_queue: |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2207 | return cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2208 | } |
| 2209 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2210 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2211 | { |
| 2212 | int dispatched = 0; |
| 2213 | |
| 2214 | while (cfqq->next_rq) { |
| 2215 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); |
| 2216 | dispatched++; |
| 2217 | } |
| 2218 | |
| 2219 | BUG_ON(!list_empty(&cfqq->fifo)); |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2220 | |
| 2221 | /* By default cfqq is not expired if it is empty. Do it explicitly */ |
| 2222 | __cfq_slice_expired(cfqq->cfqd, cfqq, 0); |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2223 | return dispatched; |
| 2224 | } |
| 2225 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2226 | /* |
| 2227 | * Drain our current requests. Used for barriers and when switching |
| 2228 | * io schedulers on-the-fly. |
| 2229 | */ |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2230 | static int cfq_forced_dispatch(struct cfq_data *cfqd) |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2231 | { |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 2232 | struct cfq_queue *cfqq; |
Jens Axboe | d9e7620 | 2007-04-20 14:27:50 +0200 | [diff] [blame] | 2233 | int dispatched = 0; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2234 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2235 | while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) |
| 2236 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2237 | |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2238 | cfq_slice_expired(cfqd, 0); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2239 | BUG_ON(cfqd->busy_queues); |
| 2240 | |
Jeff Moyer | 6923715 | 2009-06-12 15:29:30 +0200 | [diff] [blame] | 2241 | cfq_log(cfqd, "forced_dispatch=%d", dispatched); |
Tejun Heo | 1b5ed5e1 | 2005-11-10 08:49:19 +0100 | [diff] [blame] | 2242 | return dispatched; |
| 2243 | } |
| 2244 | |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2245 | static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2246 | { |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2247 | unsigned int max_dispatch; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2248 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2249 | /* |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2250 | * Drain async requests before we start sync IO |
| 2251 | */ |
Corrado Zoccolo | a6d44e9 | 2009-10-26 22:45:11 +0100 | [diff] [blame] | 2252 | if (cfq_should_idle(cfqd, cfqq) && cfqd->rq_in_driver[BLK_RW_ASYNC]) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2253 | return false; |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 2254 | |
| 2255 | /* |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2256 | * If this is an async queue and we have sync IO in flight, let it wait |
| 2257 | */ |
| 2258 | if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2259 | return false; |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2260 | |
| 2261 | max_dispatch = cfqd->cfq_quantum; |
| 2262 | if (cfq_class_idle(cfqq)) |
| 2263 | max_dispatch = 1; |
| 2264 | |
| 2265 | /* |
| 2266 | * Does this cfqq already have too much IO in flight? |
| 2267 | */ |
| 2268 | if (cfqq->dispatched >= max_dispatch) { |
| 2269 | /* |
| 2270 | * idle queue must always only have a single IO in flight |
| 2271 | */ |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2272 | if (cfq_class_idle(cfqq)) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2273 | return false; |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 2274 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2275 | /* |
| 2276 | * We have other queues, don't allow more IO from this one |
| 2277 | */ |
| 2278 | if (cfqd->busy_queues > 1) |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2279 | return false; |
Jens Axboe | 9ede209 | 2007-01-19 12:11:44 +1100 | [diff] [blame] | 2280 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2281 | /* |
Shaohua Li | 474b18c | 2009-12-03 12:58:05 +0100 | [diff] [blame] | 2282 | * Sole queue user, no limit |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2283 | */ |
Shaohua Li | 474b18c | 2009-12-03 12:58:05 +0100 | [diff] [blame] | 2284 | max_dispatch = -1; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2285 | } |
| 2286 | |
| 2287 | /* |
| 2288 | * Async queues must wait a bit before being allowed dispatch. |
| 2289 | * We also ramp up the dispatch depth gradually for async IO, |
| 2290 | * based on the last sync IO we serviced |
| 2291 | */ |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 2292 | if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 2293 | unsigned long last_sync = jiffies - cfqd->last_delayed_sync; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2294 | unsigned int depth; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 2295 | |
Jens Axboe | 61f0c1d | 2009-10-03 19:46:03 +0200 | [diff] [blame] | 2296 | depth = last_sync / cfqd->cfq_slice[1]; |
Jens Axboe | e00c54c | 2009-10-04 20:36:19 +0200 | [diff] [blame] | 2297 | if (!depth && !cfqq->dispatched) |
| 2298 | depth = 1; |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2299 | if (depth < max_dispatch) |
| 2300 | max_dispatch = depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2301 | } |
| 2302 | |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2303 | /* |
| 2304 | * If we're below the current max, allow a dispatch |
| 2305 | */ |
| 2306 | return cfqq->dispatched < max_dispatch; |
| 2307 | } |
| 2308 | |
| 2309 | /* |
| 2310 | * Dispatch a request from cfqq, moving them to the request queue |
| 2311 | * dispatch list. |
| 2312 | */ |
| 2313 | static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2314 | { |
| 2315 | struct request *rq; |
| 2316 | |
| 2317 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); |
| 2318 | |
| 2319 | if (!cfq_may_dispatch(cfqd, cfqq)) |
| 2320 | return false; |
| 2321 | |
| 2322 | /* |
| 2323 | * follow expired path, else get first next available |
| 2324 | */ |
| 2325 | rq = cfq_check_fifo(cfqq); |
| 2326 | if (!rq) |
| 2327 | rq = cfqq->next_rq; |
| 2328 | |
| 2329 | /* |
| 2330 | * insert request into driver dispatch list |
| 2331 | */ |
| 2332 | cfq_dispatch_insert(cfqd->queue, rq); |
| 2333 | |
| 2334 | if (!cfqd->active_cic) { |
| 2335 | struct cfq_io_context *cic = RQ_CIC(rq); |
| 2336 | |
| 2337 | atomic_long_inc(&cic->ioc->refcount); |
| 2338 | cfqd->active_cic = cic; |
| 2339 | } |
| 2340 | |
| 2341 | return true; |
| 2342 | } |
| 2343 | |
| 2344 | /* |
| 2345 | * Find the cfqq that we need to service and move a request from that to the |
| 2346 | * dispatch list |
| 2347 | */ |
| 2348 | static int cfq_dispatch_requests(struct request_queue *q, int force) |
| 2349 | { |
| 2350 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 2351 | struct cfq_queue *cfqq; |
| 2352 | |
| 2353 | if (!cfqd->busy_queues) |
| 2354 | return 0; |
| 2355 | |
| 2356 | if (unlikely(force)) |
| 2357 | return cfq_forced_dispatch(cfqd); |
| 2358 | |
| 2359 | cfqq = cfq_select_queue(cfqd); |
| 2360 | if (!cfqq) |
Jens Axboe | 8e29675 | 2009-10-03 16:26:03 +0200 | [diff] [blame] | 2361 | return 0; |
| 2362 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2363 | /* |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2364 | * Dispatch a request from this cfqq, if it is allowed |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2365 | */ |
Jens Axboe | 0b182d6 | 2009-10-06 20:49:37 +0200 | [diff] [blame] | 2366 | if (!cfq_dispatch_request(cfqd, cfqq)) |
| 2367 | return 0; |
| 2368 | |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2369 | cfqq->slice_dispatch++; |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 2370 | cfq_clear_cfqq_must_dispatch(cfqq); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2371 | |
| 2372 | /* |
| 2373 | * expire an async queue immediately if it has used up its slice. idle |
| 2374 | * queue always expire after 1 dispatch round. |
| 2375 | */ |
| 2376 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && |
| 2377 | cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || |
| 2378 | cfq_class_idle(cfqq))) { |
| 2379 | cfqq->slice_end = jiffies + 1; |
| 2380 | cfq_slice_expired(cfqd, 0); |
| 2381 | } |
| 2382 | |
Shan Wei | b217a90 | 2009-09-01 10:06:42 +0200 | [diff] [blame] | 2383 | cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); |
Jens Axboe | 2f5cb73 | 2009-04-07 08:51:19 +0200 | [diff] [blame] | 2384 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2385 | } |
| 2386 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2387 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 2388 | * task holds one reference to the queue, dropped when task exits. each rq |
| 2389 | * 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] | 2390 | * |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2391 | * Each cfq queue took a reference on the parent group. Drop it now. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2392 | * queue lock must be held here. |
| 2393 | */ |
| 2394 | static void cfq_put_queue(struct cfq_queue *cfqq) |
| 2395 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2396 | struct cfq_data *cfqd = cfqq->cfqd; |
Vivek Goyal | 878eadd | 2009-12-07 19:37:15 +0100 | [diff] [blame] | 2397 | struct cfq_group *cfqg, *orig_cfqg; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2398 | |
| 2399 | BUG_ON(atomic_read(&cfqq->ref) <= 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2400 | |
| 2401 | if (!atomic_dec_and_test(&cfqq->ref)) |
| 2402 | return; |
| 2403 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 2404 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2405 | BUG_ON(rb_first(&cfqq->sort_list)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2406 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2407 | cfqg = cfqq->cfqg; |
Vivek Goyal | 878eadd | 2009-12-07 19:37:15 +0100 | [diff] [blame] | 2408 | orig_cfqg = cfqq->orig_cfqg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2409 | |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2410 | if (unlikely(cfqd->active_queue == cfqq)) { |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2411 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2412 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2413 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2414 | |
Vivek Goyal | f04a642 | 2009-12-03 12:59:40 -0500 | [diff] [blame] | 2415 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2416 | kmem_cache_free(cfq_pool, cfqq); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 2417 | cfq_put_cfqg(cfqg); |
Vivek Goyal | 878eadd | 2009-12-07 19:37:15 +0100 | [diff] [blame] | 2418 | if (orig_cfqg) |
| 2419 | cfq_put_cfqg(orig_cfqg); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2420 | } |
| 2421 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2422 | /* |
| 2423 | * Must always be called with the rcu_read_lock() held |
| 2424 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 2425 | static void |
| 2426 | __call_for_each_cic(struct io_context *ioc, |
| 2427 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 2428 | { |
| 2429 | struct cfq_io_context *cic; |
| 2430 | struct hlist_node *n; |
| 2431 | |
| 2432 | hlist_for_each_entry_rcu(cic, n, &ioc->cic_list, cic_list) |
| 2433 | func(ioc, cic); |
| 2434 | } |
| 2435 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2436 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2437 | * Call func for each cic attached to this ioc. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2438 | */ |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2439 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2440 | call_for_each_cic(struct io_context *ioc, |
| 2441 | void (*func)(struct io_context *, struct cfq_io_context *)) |
| 2442 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2443 | rcu_read_lock(); |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 2444 | __call_for_each_cic(ioc, func); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2445 | rcu_read_unlock(); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2446 | } |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2447 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2448 | static void cfq_cic_free_rcu(struct rcu_head *head) |
| 2449 | { |
| 2450 | struct cfq_io_context *cic; |
| 2451 | |
| 2452 | cic = container_of(head, struct cfq_io_context, rcu_head); |
| 2453 | |
| 2454 | kmem_cache_free(cfq_ioc_pool, cic); |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2455 | elv_ioc_count_dec(cfq_ioc_count); |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2456 | |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 2457 | if (ioc_gone) { |
| 2458 | /* |
| 2459 | * CFQ scheduler is exiting, grab exit lock and check |
| 2460 | * the pending io context count. If it hits zero, |
| 2461 | * complete ioc_gone and set it back to NULL |
| 2462 | */ |
| 2463 | spin_lock(&ioc_gone_lock); |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2464 | if (ioc_gone && !elv_ioc_count_read(cfq_ioc_count)) { |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 2465 | complete(ioc_gone); |
| 2466 | ioc_gone = NULL; |
| 2467 | } |
| 2468 | spin_unlock(&ioc_gone_lock); |
| 2469 | } |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2470 | } |
| 2471 | |
| 2472 | static void cfq_cic_free(struct cfq_io_context *cic) |
| 2473 | { |
| 2474 | call_rcu(&cic->rcu_head, cfq_cic_free_rcu); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2475 | } |
| 2476 | |
| 2477 | static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic) |
| 2478 | { |
| 2479 | unsigned long flags; |
| 2480 | |
| 2481 | BUG_ON(!cic->dead_key); |
| 2482 | |
| 2483 | spin_lock_irqsave(&ioc->lock, flags); |
| 2484 | radix_tree_delete(&ioc->radix_root, cic->dead_key); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2485 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2486 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 2487 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2488 | cfq_cic_free(cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2489 | } |
| 2490 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2491 | /* |
| 2492 | * Must be called with rcu_read_lock() held or preemption otherwise disabled. |
| 2493 | * Only two callers of this - ->dtor() which is called with the rcu_read_lock(), |
| 2494 | * and ->trim() which is called with the task lock held |
| 2495 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2496 | static void cfq_free_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2497 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2498 | /* |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 2499 | * ioc->refcount is zero here, or we are called from elv_unregister(), |
| 2500 | * so no more cic's are allowed to be linked into this ioc. So it |
| 2501 | * should be ok to iterate over the known list, we will see all cic's |
| 2502 | * since no new ones are added. |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2503 | */ |
Jens Axboe | 07416d2 | 2008-05-07 09:17:12 +0200 | [diff] [blame] | 2504 | __call_for_each_cic(ioc, cic_free_func); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2505 | } |
| 2506 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2507 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 2508 | { |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2509 | struct cfq_queue *__cfqq, *next; |
| 2510 | |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2511 | if (unlikely(cfqq == cfqd->active_queue)) { |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 2512 | __cfq_slice_expired(cfqd, cfqq, 0); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 2513 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 28f95cbc | 2007-01-19 12:09:53 +1100 | [diff] [blame] | 2514 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2515 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 2516 | /* |
| 2517 | * If this queue was scheduled to merge with another queue, be |
| 2518 | * sure to drop the reference taken on that queue (and others in |
| 2519 | * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. |
| 2520 | */ |
| 2521 | __cfqq = cfqq->new_cfqq; |
| 2522 | while (__cfqq) { |
| 2523 | if (__cfqq == cfqq) { |
| 2524 | WARN(1, "cfqq->new_cfqq loop detected\n"); |
| 2525 | break; |
| 2526 | } |
| 2527 | next = __cfqq->new_cfqq; |
| 2528 | cfq_put_queue(__cfqq); |
| 2529 | __cfqq = next; |
| 2530 | } |
| 2531 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2532 | cfq_put_queue(cfqq); |
| 2533 | } |
| 2534 | |
| 2535 | static void __cfq_exit_single_io_context(struct cfq_data *cfqd, |
| 2536 | struct cfq_io_context *cic) |
| 2537 | { |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 2538 | struct io_context *ioc = cic->ioc; |
| 2539 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2540 | list_del_init(&cic->queue_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2541 | |
| 2542 | /* |
| 2543 | * Make sure key == NULL is seen for dead queues |
| 2544 | */ |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2545 | smp_wmb(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2546 | cic->dead_key = (unsigned long) cic->key; |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2547 | cic->key = NULL; |
| 2548 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 2549 | if (ioc->ioc_data == cic) |
| 2550 | rcu_assign_pointer(ioc->ioc_data, NULL); |
| 2551 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2552 | if (cic->cfqq[BLK_RW_ASYNC]) { |
| 2553 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]); |
| 2554 | cic->cfqq[BLK_RW_ASYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2555 | } |
| 2556 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2557 | if (cic->cfqq[BLK_RW_SYNC]) { |
| 2558 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_SYNC]); |
| 2559 | cic->cfqq[BLK_RW_SYNC] = NULL; |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2560 | } |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2561 | } |
| 2562 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2563 | static void cfq_exit_single_io_context(struct io_context *ioc, |
| 2564 | struct cfq_io_context *cic) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2565 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 2566 | struct cfq_data *cfqd = cic->key; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2567 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 2568 | if (cfqd) { |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 2569 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2570 | unsigned long flags; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2571 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2572 | spin_lock_irqsave(q->queue_lock, flags); |
Jens Axboe | 62c1fe9 | 2008-12-15 21:19:25 +0100 | [diff] [blame] | 2573 | |
| 2574 | /* |
| 2575 | * Ensure we get a fresh copy of the ->key to prevent |
| 2576 | * race between exiting task and queue |
| 2577 | */ |
| 2578 | smp_read_barrier_depends(); |
| 2579 | if (cic->key) |
| 2580 | __cfq_exit_single_io_context(cfqd, cic); |
| 2581 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2582 | spin_unlock_irqrestore(q->queue_lock, flags); |
Al Viro | 12a0573 | 2006-03-18 13:38:01 -0500 | [diff] [blame] | 2583 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2584 | } |
| 2585 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2586 | /* |
| 2587 | * The process that ioc belongs to has exited, we need to clean up |
| 2588 | * and put the internal structures we have that belongs to that process. |
| 2589 | */ |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2590 | static void cfq_exit_io_context(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2591 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2592 | call_for_each_cic(ioc, cfq_exit_single_io_context); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2593 | } |
| 2594 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2595 | static struct cfq_io_context * |
Al Viro | 8267e26 | 2005-10-21 03:20:53 -0400 | [diff] [blame] | 2596 | cfq_alloc_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2597 | { |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 2598 | struct cfq_io_context *cic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2599 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2600 | cic = kmem_cache_alloc_node(cfq_ioc_pool, gfp_mask | __GFP_ZERO, |
| 2601 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2602 | if (cic) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2603 | cic->last_end_request = jiffies; |
Jens Axboe | 553698f | 2006-06-14 19:11:57 +0200 | [diff] [blame] | 2604 | INIT_LIST_HEAD(&cic->queue_list); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2605 | INIT_HLIST_NODE(&cic->cic_list); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2606 | cic->dtor = cfq_free_io_context; |
| 2607 | cic->exit = cfq_exit_io_context; |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 2608 | elv_ioc_count_inc(cfq_ioc_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2609 | } |
| 2610 | |
| 2611 | return cic; |
| 2612 | } |
| 2613 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2614 | 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] | 2615 | { |
| 2616 | struct task_struct *tsk = current; |
| 2617 | int ioprio_class; |
| 2618 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2619 | if (!cfq_cfqq_prio_changed(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2620 | return; |
| 2621 | |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2622 | ioprio_class = IOPRIO_PRIO_CLASS(ioc->ioprio); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2623 | switch (ioprio_class) { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2624 | default: |
| 2625 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); |
| 2626 | case IOPRIO_CLASS_NONE: |
| 2627 | /* |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 2628 | * no prio set, inherit CPU scheduling settings |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2629 | */ |
| 2630 | cfqq->ioprio = task_nice_ioprio(tsk); |
Jens Axboe | 6d63c27 | 2008-05-07 09:51:23 +0200 | [diff] [blame] | 2631 | cfqq->ioprio_class = task_nice_ioclass(tsk); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2632 | break; |
| 2633 | case IOPRIO_CLASS_RT: |
| 2634 | cfqq->ioprio = task_ioprio(ioc); |
| 2635 | cfqq->ioprio_class = IOPRIO_CLASS_RT; |
| 2636 | break; |
| 2637 | case IOPRIO_CLASS_BE: |
| 2638 | cfqq->ioprio = task_ioprio(ioc); |
| 2639 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 2640 | break; |
| 2641 | case IOPRIO_CLASS_IDLE: |
| 2642 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; |
| 2643 | cfqq->ioprio = 7; |
| 2644 | cfq_clear_cfqq_idle_window(cfqq); |
| 2645 | break; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2646 | } |
| 2647 | |
| 2648 | /* |
| 2649 | * keep track of original prio settings in case we have to temporarily |
| 2650 | * elevate the priority of this queue |
| 2651 | */ |
| 2652 | cfqq->org_ioprio = cfqq->ioprio; |
| 2653 | cfqq->org_ioprio_class = cfqq->ioprio_class; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 2654 | cfq_clear_cfqq_prio_changed(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2655 | } |
| 2656 | |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2657 | 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] | 2658 | { |
Al Viro | 478a82b | 2006-03-18 13:25:24 -0500 | [diff] [blame] | 2659 | struct cfq_data *cfqd = cic->key; |
| 2660 | struct cfq_queue *cfqq; |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 2661 | unsigned long flags; |
Jens Axboe | 35e6077 | 2006-06-14 09:10:45 +0200 | [diff] [blame] | 2662 | |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2663 | if (unlikely(!cfqd)) |
| 2664 | return; |
| 2665 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 2666 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2667 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2668 | cfqq = cic->cfqq[BLK_RW_ASYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2669 | if (cfqq) { |
| 2670 | struct cfq_queue *new_cfqq; |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2671 | new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic->ioc, |
| 2672 | GFP_ATOMIC); |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2673 | if (new_cfqq) { |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2674 | cic->cfqq[BLK_RW_ASYNC] = new_cfqq; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2675 | cfq_put_queue(cfqq); |
| 2676 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2677 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2678 | |
Jens Axboe | ff6657c | 2009-04-08 10:58:57 +0200 | [diff] [blame] | 2679 | cfqq = cic->cfqq[BLK_RW_SYNC]; |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 2680 | if (cfqq) |
| 2681 | cfq_mark_cfqq_prio_changed(cfqq); |
| 2682 | |
Jens Axboe | c1b707d | 2006-10-30 19:54:23 +0100 | [diff] [blame] | 2683 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2684 | } |
| 2685 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2686 | static void cfq_ioc_set_ioprio(struct io_context *ioc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2687 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2688 | call_for_each_cic(ioc, changed_ioprio); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2689 | ioc->ioprio_changed = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2690 | } |
| 2691 | |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 2692 | static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2693 | pid_t pid, bool is_sync) |
Jens Axboe | d5036d7 | 2009-06-26 10:44:34 +0200 | [diff] [blame] | 2694 | { |
| 2695 | RB_CLEAR_NODE(&cfqq->rb_node); |
| 2696 | RB_CLEAR_NODE(&cfqq->p_node); |
| 2697 | INIT_LIST_HEAD(&cfqq->fifo); |
| 2698 | |
| 2699 | atomic_set(&cfqq->ref, 0); |
| 2700 | cfqq->cfqd = cfqd; |
| 2701 | |
| 2702 | cfq_mark_cfqq_prio_changed(cfqq); |
| 2703 | |
| 2704 | if (is_sync) { |
| 2705 | if (!cfq_class_idle(cfqq)) |
| 2706 | cfq_mark_cfqq_idle_window(cfqq); |
| 2707 | cfq_mark_cfqq_sync(cfqq); |
| 2708 | } |
| 2709 | cfqq->pid = pid; |
| 2710 | } |
| 2711 | |
Vivek Goyal | 24610333 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 2712 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 2713 | static void changed_cgroup(struct io_context *ioc, struct cfq_io_context *cic) |
| 2714 | { |
| 2715 | struct cfq_queue *sync_cfqq = cic_to_cfqq(cic, 1); |
| 2716 | struct cfq_data *cfqd = cic->key; |
| 2717 | unsigned long flags; |
| 2718 | struct request_queue *q; |
| 2719 | |
| 2720 | if (unlikely(!cfqd)) |
| 2721 | return; |
| 2722 | |
| 2723 | q = cfqd->queue; |
| 2724 | |
| 2725 | spin_lock_irqsave(q->queue_lock, flags); |
| 2726 | |
| 2727 | if (sync_cfqq) { |
| 2728 | /* |
| 2729 | * Drop reference to sync queue. A new sync queue will be |
| 2730 | * assigned in new group upon arrival of a fresh request. |
| 2731 | */ |
| 2732 | cfq_log_cfqq(cfqd, sync_cfqq, "changed cgroup"); |
| 2733 | cic_set_cfqq(cic, NULL, 1); |
| 2734 | cfq_put_queue(sync_cfqq); |
| 2735 | } |
| 2736 | |
| 2737 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 2738 | } |
| 2739 | |
| 2740 | static void cfq_ioc_set_cgroup(struct io_context *ioc) |
| 2741 | { |
| 2742 | call_for_each_cic(ioc, changed_cgroup); |
| 2743 | ioc->cgroup_changed = 0; |
| 2744 | } |
| 2745 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ |
| 2746 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2747 | static struct cfq_queue * |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2748 | cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2749 | struct io_context *ioc, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2750 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2751 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2752 | struct cfq_io_context *cic; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2753 | struct cfq_group *cfqg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2754 | |
| 2755 | retry: |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2756 | cfqg = cfq_get_cfqg(cfqd, 1); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2757 | cic = cfq_cic_lookup(cfqd, ioc); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2758 | /* cic always exists here */ |
| 2759 | cfqq = cic_to_cfqq(cic, is_sync); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2760 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2761 | /* |
| 2762 | * Always try a new alloc if we fell back to the OOM cfqq |
| 2763 | * originally, since it should just be a temporary situation. |
| 2764 | */ |
| 2765 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
| 2766 | cfqq = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2767 | if (new_cfqq) { |
| 2768 | cfqq = new_cfqq; |
| 2769 | new_cfqq = NULL; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2770 | } else if (gfp_mask & __GFP_WAIT) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2771 | spin_unlock_irq(cfqd->queue->queue_lock); |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2772 | new_cfqq = kmem_cache_alloc_node(cfq_pool, |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2773 | gfp_mask | __GFP_ZERO, |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2774 | cfqd->queue->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2775 | spin_lock_irq(cfqd->queue->queue_lock); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2776 | if (new_cfqq) |
| 2777 | goto retry; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2778 | } else { |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 2779 | cfqq = kmem_cache_alloc_node(cfq_pool, |
| 2780 | gfp_mask | __GFP_ZERO, |
| 2781 | cfqd->queue->node); |
Kiyoshi Ueda | db3b584 | 2005-06-17 16:15:10 +0200 | [diff] [blame] | 2782 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2783 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2784 | if (cfqq) { |
| 2785 | cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); |
| 2786 | cfq_init_prio_data(cfqq, ioc); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 2787 | cfq_link_cfqq_cfqg(cfqq, cfqg); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2788 | cfq_log_cfqq(cfqd, cfqq, "alloced"); |
| 2789 | } else |
| 2790 | cfqq = &cfqd->oom_cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2791 | } |
| 2792 | |
| 2793 | if (new_cfqq) |
| 2794 | kmem_cache_free(cfq_pool, new_cfqq); |
| 2795 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2796 | return cfqq; |
| 2797 | } |
| 2798 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2799 | static struct cfq_queue ** |
| 2800 | cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) |
| 2801 | { |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 2802 | switch (ioprio_class) { |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2803 | case IOPRIO_CLASS_RT: |
| 2804 | return &cfqd->async_cfqq[0][ioprio]; |
| 2805 | case IOPRIO_CLASS_BE: |
| 2806 | return &cfqd->async_cfqq[1][ioprio]; |
| 2807 | case IOPRIO_CLASS_IDLE: |
| 2808 | return &cfqd->async_idle_cfqq; |
| 2809 | default: |
| 2810 | BUG(); |
| 2811 | } |
| 2812 | } |
| 2813 | |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2814 | static struct cfq_queue * |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 2815 | cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct io_context *ioc, |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2816 | gfp_t gfp_mask) |
| 2817 | { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2818 | const int ioprio = task_ioprio(ioc); |
| 2819 | const int ioprio_class = task_ioprio_class(ioc); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2820 | struct cfq_queue **async_cfqq = NULL; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2821 | struct cfq_queue *cfqq = NULL; |
| 2822 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2823 | if (!is_sync) { |
| 2824 | async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); |
| 2825 | cfqq = *async_cfqq; |
| 2826 | } |
| 2827 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 2828 | if (!cfqq) |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 2829 | cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2830 | |
| 2831 | /* |
| 2832 | * pin the queue now that it's allocated, scheduler exit will prune it |
| 2833 | */ |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2834 | if (!is_sync && !(*async_cfqq)) { |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2835 | atomic_inc(&cfqq->ref); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 2836 | *async_cfqq = cfqq; |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 2837 | } |
| 2838 | |
| 2839 | atomic_inc(&cfqq->ref); |
| 2840 | return cfqq; |
| 2841 | } |
| 2842 | |
Jens Axboe | 498d3aa2 | 2007-04-26 12:54:48 +0200 | [diff] [blame] | 2843 | /* |
| 2844 | * We drop cfq io contexts lazily, so we may find a dead one. |
| 2845 | */ |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2846 | static void |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2847 | cfq_drop_dead_cic(struct cfq_data *cfqd, struct io_context *ioc, |
| 2848 | struct cfq_io_context *cic) |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2849 | { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2850 | unsigned long flags; |
| 2851 | |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2852 | WARN_ON(!list_empty(&cic->queue_list)); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2853 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2854 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2855 | |
Fabio Checconi | 4faa3c8 | 2008-04-10 08:28:01 +0200 | [diff] [blame] | 2856 | BUG_ON(ioc->ioc_data == cic); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2857 | |
| 2858 | radix_tree_delete(&ioc->radix_root, (unsigned long) cfqd); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2859 | hlist_del_rcu(&cic->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2860 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 2861 | |
| 2862 | cfq_cic_free(cic); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2863 | } |
| 2864 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2865 | static struct cfq_io_context * |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2866 | cfq_cic_lookup(struct cfq_data *cfqd, struct io_context *ioc) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2867 | { |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2868 | struct cfq_io_context *cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2869 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2870 | void *k; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2871 | |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 2872 | if (unlikely(!ioc)) |
| 2873 | return NULL; |
| 2874 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2875 | rcu_read_lock(); |
| 2876 | |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2877 | /* |
| 2878 | * we maintain a last-hit cache, to avoid browsing over the tree |
| 2879 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2880 | cic = rcu_dereference(ioc->ioc_data); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2881 | if (cic && cic->key == cfqd) { |
| 2882 | rcu_read_unlock(); |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2883 | return cic; |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2884 | } |
Jens Axboe | 597bc48 | 2007-04-24 21:23:53 +0200 | [diff] [blame] | 2885 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2886 | do { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2887 | cic = radix_tree_lookup(&ioc->radix_root, (unsigned long) cfqd); |
| 2888 | rcu_read_unlock(); |
| 2889 | if (!cic) |
| 2890 | break; |
OGAWA Hirofumi | be3b075 | 2006-04-18 19:18:31 +0200 | [diff] [blame] | 2891 | /* ->key must be copied to avoid race with cfq_exit_queue() */ |
| 2892 | k = cic->key; |
| 2893 | if (unlikely(!k)) { |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2894 | cfq_drop_dead_cic(cfqd, ioc, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2895 | rcu_read_lock(); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2896 | continue; |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2897 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2898 | |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2899 | spin_lock_irqsave(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2900 | rcu_assign_pointer(ioc->ioc_data, cic); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 2901 | spin_unlock_irqrestore(&ioc->lock, flags); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2902 | break; |
| 2903 | } while (1); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2904 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2905 | return cic; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2906 | } |
| 2907 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2908 | /* |
| 2909 | * Add cic into ioc, using cfqd as the search key. This enables us to lookup |
| 2910 | * the process specific cfq io context when entered from the block layer. |
| 2911 | * Also adds the cic to a per-cfqd list, used when this queue is removed. |
| 2912 | */ |
Jens Axboe | febffd6 | 2008-01-28 13:19:43 +0100 | [diff] [blame] | 2913 | static int cfq_cic_link(struct cfq_data *cfqd, struct io_context *ioc, |
| 2914 | struct cfq_io_context *cic, gfp_t gfp_mask) |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2915 | { |
Jens Axboe | 0261d68 | 2006-10-30 19:07:48 +0100 | [diff] [blame] | 2916 | unsigned long flags; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2917 | int ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2918 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2919 | ret = radix_tree_preload(gfp_mask); |
| 2920 | if (!ret) { |
| 2921 | cic->ioc = ioc; |
| 2922 | cic->key = cfqd; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2923 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2924 | spin_lock_irqsave(&ioc->lock, flags); |
| 2925 | ret = radix_tree_insert(&ioc->radix_root, |
| 2926 | (unsigned long) cfqd, cic); |
Jens Axboe | ffc4e75 | 2008-02-19 10:02:29 +0100 | [diff] [blame] | 2927 | if (!ret) |
| 2928 | hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list); |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2929 | spin_unlock_irqrestore(&ioc->lock, flags); |
| 2930 | |
| 2931 | radix_tree_preload_end(); |
| 2932 | |
| 2933 | if (!ret) { |
| 2934 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 2935 | list_add(&cic->queue_list, &cfqd->cic_list); |
| 2936 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
OGAWA Hirofumi | dbecf3a | 2006-04-18 09:45:18 +0200 | [diff] [blame] | 2937 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2938 | } |
| 2939 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2940 | if (ret) |
| 2941 | printk(KERN_ERR "cfq: cic link failed!\n"); |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2942 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2943 | return ret; |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2944 | } |
| 2945 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2946 | /* |
| 2947 | * Setup general io context and cfq io context. There can be several cfq |
| 2948 | * 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] | 2949 | * than one device managed by cfq. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2950 | */ |
| 2951 | static struct cfq_io_context * |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2952 | cfq_get_io_context(struct cfq_data *cfqd, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2953 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2954 | struct io_context *ioc = NULL; |
| 2955 | struct cfq_io_context *cic; |
| 2956 | |
| 2957 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 2958 | |
Jens Axboe | b5deef9 | 2006-07-19 23:39:40 +0200 | [diff] [blame] | 2959 | ioc = get_io_context(gfp_mask, cfqd->queue->node); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2960 | if (!ioc) |
| 2961 | return NULL; |
| 2962 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2963 | cic = cfq_cic_lookup(cfqd, ioc); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2964 | if (cic) |
| 2965 | goto out; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2966 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 2967 | cic = cfq_alloc_io_context(cfqd, gfp_mask); |
| 2968 | if (cic == NULL) |
| 2969 | goto err; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2970 | |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2971 | if (cfq_cic_link(cfqd, ioc, cic, gfp_mask)) |
| 2972 | goto err_free; |
| 2973 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2974 | out: |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 2975 | smp_read_barrier_depends(); |
| 2976 | if (unlikely(ioc->ioprio_changed)) |
| 2977 | cfq_ioc_set_ioprio(ioc); |
| 2978 | |
Vivek Goyal | 24610333 | 2009-12-03 12:59:51 -0500 | [diff] [blame] | 2979 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 2980 | if (unlikely(ioc->cgroup_changed)) |
| 2981 | cfq_ioc_set_cgroup(ioc); |
| 2982 | #endif |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2983 | return cic; |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 2984 | err_free: |
| 2985 | cfq_cic_free(cic); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2986 | err: |
| 2987 | put_io_context(ioc); |
| 2988 | return NULL; |
| 2989 | } |
| 2990 | |
| 2991 | static void |
| 2992 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic) |
| 2993 | { |
Jens Axboe | aaf1228 | 2007-01-19 11:30:16 +1100 | [diff] [blame] | 2994 | unsigned long elapsed = jiffies - cic->last_end_request; |
| 2995 | unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 2996 | |
| 2997 | cic->ttime_samples = (7*cic->ttime_samples + 256) / 8; |
| 2998 | cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8; |
| 2999 | cic->ttime_mean = (cic->ttime_total + 128) / cic->ttime_samples; |
| 3000 | } |
| 3001 | |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3002 | static void |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3003 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3004 | struct request *rq) |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3005 | { |
| 3006 | sector_t sdist; |
| 3007 | u64 total; |
| 3008 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3009 | if (!cfqq->last_request_pos) |
Jeff Moyer | 4d00aa4 | 2009-04-21 07:25:04 +0200 | [diff] [blame] | 3010 | sdist = 0; |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3011 | else if (cfqq->last_request_pos < blk_rq_pos(rq)) |
| 3012 | sdist = blk_rq_pos(rq) - cfqq->last_request_pos; |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3013 | else |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3014 | sdist = cfqq->last_request_pos - blk_rq_pos(rq); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3015 | |
| 3016 | /* |
| 3017 | * Don't allow the seek distance to get too large from the |
| 3018 | * odd fragment, pagein, etc |
| 3019 | */ |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3020 | if (cfqq->seek_samples <= 60) /* second&third seek */ |
| 3021 | sdist = min(sdist, (cfqq->seek_mean * 4) + 2*1024*1024); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3022 | else |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3023 | sdist = min(sdist, (cfqq->seek_mean * 4) + 2*1024*64); |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3024 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3025 | cfqq->seek_samples = (7*cfqq->seek_samples + 256) / 8; |
| 3026 | cfqq->seek_total = (7*cfqq->seek_total + (u64)256*sdist) / 8; |
| 3027 | total = cfqq->seek_total + (cfqq->seek_samples/2); |
| 3028 | do_div(total, cfqq->seek_samples); |
| 3029 | cfqq->seek_mean = (sector_t)total; |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3030 | |
| 3031 | /* |
| 3032 | * If this cfqq is shared between multiple processes, check to |
| 3033 | * make sure that those processes are still issuing I/Os within |
| 3034 | * the mean seek distance. If not, it may be time to break the |
| 3035 | * queues apart again. |
| 3036 | */ |
| 3037 | if (cfq_cfqq_coop(cfqq)) { |
| 3038 | if (CFQQ_SEEKY(cfqq) && !cfqq->seeky_start) |
| 3039 | cfqq->seeky_start = jiffies; |
| 3040 | else if (!CFQQ_SEEKY(cfqq)) |
| 3041 | cfqq->seeky_start = 0; |
| 3042 | } |
Jens Axboe | 206dc69 | 2006-03-28 13:03:44 +0200 | [diff] [blame] | 3043 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3044 | |
| 3045 | /* |
| 3046 | * Disable idle window if the process thinks too long or seeks so much that |
| 3047 | * it doesn't matter |
| 3048 | */ |
| 3049 | static void |
| 3050 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 3051 | struct cfq_io_context *cic) |
| 3052 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3053 | int old_idle, enable_idle; |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 3054 | |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 3055 | /* |
| 3056 | * Don't idle for async or idle io prio class |
| 3057 | */ |
| 3058 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 1be92f2 | 2007-04-19 14:32:26 +0200 | [diff] [blame] | 3059 | return; |
| 3060 | |
Jens Axboe | c265a7f | 2008-06-26 13:49:33 +0200 | [diff] [blame] | 3061 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3062 | |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3063 | if (cfqq->queued[0] + cfqq->queued[1] >= 4) |
| 3064 | cfq_mark_cfqq_deep(cfqq); |
| 3065 | |
Nikanth Karthikesan | 66dac98 | 2007-11-27 12:47:04 +0100 | [diff] [blame] | 3066 | if (!atomic_read(&cic->ioc->nr_tasks) || !cfqd->cfq_slice_idle || |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3067 | (!cfq_cfqq_deep(cfqq) && sample_valid(cfqq->seek_samples) |
| 3068 | && CFQQ_SEEKY(cfqq))) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3069 | enable_idle = 0; |
| 3070 | else if (sample_valid(cic->ttime_samples)) { |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 3071 | if (cic->ttime_mean > cfqd->cfq_slice_idle) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3072 | enable_idle = 0; |
| 3073 | else |
| 3074 | enable_idle = 1; |
| 3075 | } |
| 3076 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3077 | if (old_idle != enable_idle) { |
| 3078 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); |
| 3079 | if (enable_idle) |
| 3080 | cfq_mark_cfqq_idle_window(cfqq); |
| 3081 | else |
| 3082 | cfq_clear_cfqq_idle_window(cfqq); |
| 3083 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3084 | } |
| 3085 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3086 | /* |
| 3087 | * Check if new_cfqq should preempt the currently active queue. Return 0 for |
| 3088 | * no or if we aren't sure, a 1 will cause a preempt. |
| 3089 | */ |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3090 | static bool |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3091 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3092 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3093 | { |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3094 | struct cfq_queue *cfqq; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3095 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3096 | cfqq = cfqd->active_queue; |
| 3097 | if (!cfqq) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3098 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3099 | |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3100 | if (cfq_class_idle(new_cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3101 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3102 | |
| 3103 | if (cfq_class_idle(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3104 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3105 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3106 | /* |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3107 | * if the new request is sync, but the currently running queue is |
| 3108 | * not, let the sync request have priority. |
| 3109 | */ |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3110 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3111 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3112 | |
Vivek Goyal | 8682e1f | 2009-12-03 12:59:50 -0500 | [diff] [blame] | 3113 | if (new_cfqq->cfqg != cfqq->cfqg) |
| 3114 | return false; |
| 3115 | |
| 3116 | if (cfq_slice_used(cfqq)) |
| 3117 | return true; |
| 3118 | |
| 3119 | /* Allow preemption only if we are idling on sync-noidle tree */ |
| 3120 | if (cfqd->serving_type == SYNC_NOIDLE_WORKLOAD && |
| 3121 | cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD && |
| 3122 | new_cfqq->service_tree->count == 2 && |
| 3123 | RB_EMPTY_ROOT(&cfqq->sort_list)) |
| 3124 | return true; |
| 3125 | |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3126 | /* |
| 3127 | * So both queues are sync. Let the new request get disk time if |
| 3128 | * it's a metadata request and the current queue is doing regular IO. |
| 3129 | */ |
| 3130 | if (rq_is_meta(rq) && !cfqq->meta_pending) |
Jens Axboe | e6ec4fe | 2009-11-03 20:21:35 +0100 | [diff] [blame] | 3131 | return true; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3132 | |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3133 | /* |
| 3134 | * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. |
| 3135 | */ |
| 3136 | if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3137 | return true; |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3138 | |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3139 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3140 | return false; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3141 | |
| 3142 | /* |
| 3143 | * if this request is as-good as one we would expect from the |
| 3144 | * current cfqq, let it preempt |
| 3145 | */ |
Jens Axboe | e00ef79 | 2009-11-04 08:54:55 +0100 | [diff] [blame] | 3146 | if (cfq_rq_close(cfqd, cfqq, rq)) |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3147 | return true; |
Jens Axboe | 1e3335d | 2007-02-14 19:59:49 +0100 | [diff] [blame] | 3148 | |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3149 | return false; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3150 | } |
| 3151 | |
| 3152 | /* |
| 3153 | * cfqq preempts the active queue. if we allowed preempt with no slice left, |
| 3154 | * let it have half of its nominal slice. |
| 3155 | */ |
| 3156 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 3157 | { |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3158 | cfq_log_cfqq(cfqd, cfqq, "preempt"); |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 3159 | cfq_slice_expired(cfqd, 1); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3160 | |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 3161 | /* |
| 3162 | * Put the new queue at the front of the of the current list, |
| 3163 | * so we know that it will be selected next. |
| 3164 | */ |
| 3165 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
Jens Axboe | edd75ff | 2007-04-19 12:03:34 +0200 | [diff] [blame] | 3166 | |
| 3167 | cfq_service_tree_add(cfqd, cfqq, 1); |
Jens Axboe | bf57225 | 2006-07-19 20:29:12 +0200 | [diff] [blame] | 3168 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3169 | cfqq->slice_end = 0; |
| 3170 | cfq_mark_cfqq_slice_new(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3171 | } |
| 3172 | |
| 3173 | /* |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3174 | * 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] | 3175 | * something we should do about it |
| 3176 | */ |
| 3177 | static void |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3178 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
| 3179 | struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3180 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3181 | struct cfq_io_context *cic = RQ_CIC(rq); |
Jens Axboe | 12e9fdd | 2006-06-01 10:09:56 +0200 | [diff] [blame] | 3182 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3183 | cfqd->rq_queued++; |
Jens Axboe | 374f84a | 2006-07-23 01:42:19 +0200 | [diff] [blame] | 3184 | if (rq_is_meta(rq)) |
| 3185 | cfqq->meta_pending++; |
| 3186 | |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 3187 | cfq_update_io_thinktime(cfqd, cic); |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3188 | cfq_update_io_seektime(cfqd, cfqq, rq); |
Jens Axboe | 9c2c38a | 2005-08-24 14:57:54 +0200 | [diff] [blame] | 3189 | cfq_update_idle_window(cfqd, cfqq, cic); |
| 3190 | |
Jeff Moyer | b2c18e1 | 2009-10-23 17:14:49 -0400 | [diff] [blame] | 3191 | cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3192 | |
| 3193 | if (cfqq == cfqd->active_queue) { |
| 3194 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 3195 | * Remember that we saw a request from this process, but |
| 3196 | * don't start queuing just yet. Otherwise we risk seeing lots |
| 3197 | * of tiny requests, because we disrupt the normal plugging |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3198 | * and merging. If the request is already larger than a single |
| 3199 | * page, let it rip immediately. For that case we assume that |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 3200 | * merging is already done. Ditto for a busy system that |
| 3201 | * has other work pending, don't risk delaying until the |
| 3202 | * idle timer unplug to continue working. |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3203 | */ |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3204 | if (cfq_cfqq_wait_request(cfqq)) { |
Jens Axboe | 2d87072 | 2009-04-15 12:12:46 +0200 | [diff] [blame] | 3205 | if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE || |
| 3206 | cfqd->busy_queues > 1) { |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3207 | del_timer(&cfqd->idle_slice_timer); |
Gui Jianfeng | 554554f | 2009-12-10 09:38:39 +0100 | [diff] [blame] | 3208 | cfq_clear_cfqq_wait_request(cfqq); |
Vivek Goyal | bf791937 | 2009-12-03 12:59:37 -0500 | [diff] [blame] | 3209 | __blk_run_queue(cfqd->queue); |
| 3210 | } else |
| 3211 | cfq_mark_cfqq_must_dispatch(cfqq); |
Jens Axboe | d6ceb25 | 2009-04-14 14:18:16 +0200 | [diff] [blame] | 3212 | } |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3213 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3214 | /* |
| 3215 | * not the active queue - expire current slice if it is |
| 3216 | * idle and has expired it's mean thinktime or this new queue |
Divyesh Shah | 3a9a3f6 | 2009-01-30 12:46:41 +0100 | [diff] [blame] | 3217 | * has some old slice time left and is of higher priority or |
| 3218 | * this new queue is RT and the current one is BE |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3219 | */ |
| 3220 | cfq_preempt_queue(cfqd, cfqq); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 3221 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3222 | } |
| 3223 | } |
| 3224 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3225 | static void cfq_insert_request(struct request_queue *q, struct request *rq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3226 | { |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3227 | struct cfq_data *cfqd = q->elevator->elevator_data; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3228 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3229 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3230 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 3231 | cfq_init_prio_data(cfqq, RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3232 | |
Jens Axboe | 30996f4 | 2009-10-05 11:03:39 +0200 | [diff] [blame] | 3233 | rq_set_fifo_time(rq, jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3234 | list_add_tail(&rq->queuelist, &cfqq->fifo); |
Corrado Zoccolo | aa6f6a3 | 2009-10-26 22:44:33 +0100 | [diff] [blame] | 3235 | cfq_add_rq_rb(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3236 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3237 | cfq_rq_enqueued(cfqd, cfqq, rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3238 | } |
| 3239 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3240 | /* |
| 3241 | * Update hw_tag based on peak queue depth over 50 samples under |
| 3242 | * sufficient load. |
| 3243 | */ |
| 3244 | static void cfq_update_hw_tag(struct cfq_data *cfqd) |
| 3245 | { |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3246 | struct cfq_queue *cfqq = cfqd->active_queue; |
| 3247 | |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3248 | if (rq_in_driver(cfqd) > cfqd->hw_tag_est_depth) |
| 3249 | cfqd->hw_tag_est_depth = rq_in_driver(cfqd); |
| 3250 | |
| 3251 | if (cfqd->hw_tag == 1) |
| 3252 | return; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3253 | |
| 3254 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 3255 | rq_in_driver(cfqd) <= CFQ_HW_QUEUE_MIN) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3256 | return; |
| 3257 | |
Shaohua Li | 1a1238a | 2009-10-27 08:46:23 +0100 | [diff] [blame] | 3258 | /* |
| 3259 | * If active queue hasn't enough requests and can idle, cfq might not |
| 3260 | * dispatch sufficient requests to hardware. Don't zero hw_tag in this |
| 3261 | * case |
| 3262 | */ |
| 3263 | if (cfqq && cfq_cfqq_idle_window(cfqq) && |
| 3264 | cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] < |
| 3265 | CFQ_HW_QUEUE_MIN && rq_in_driver(cfqd) < CFQ_HW_QUEUE_MIN) |
| 3266 | return; |
| 3267 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3268 | if (cfqd->hw_tag_samples++ < 50) |
| 3269 | return; |
| 3270 | |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3271 | if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN) |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3272 | cfqd->hw_tag = 1; |
| 3273 | else |
| 3274 | cfqd->hw_tag = 0; |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3275 | } |
| 3276 | |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3277 | static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
| 3278 | { |
| 3279 | struct cfq_io_context *cic = cfqd->active_cic; |
| 3280 | |
| 3281 | /* If there are other queues in the group, don't wait */ |
| 3282 | if (cfqq->cfqg->nr_cfqq > 1) |
| 3283 | return false; |
| 3284 | |
| 3285 | if (cfq_slice_used(cfqq)) |
| 3286 | return true; |
| 3287 | |
| 3288 | /* if slice left is less than think time, wait busy */ |
| 3289 | if (cic && sample_valid(cic->ttime_samples) |
| 3290 | && (cfqq->slice_end - jiffies < cic->ttime_mean)) |
| 3291 | return true; |
| 3292 | |
| 3293 | /* |
| 3294 | * If think times is less than a jiffy than ttime_mean=0 and above |
| 3295 | * will not be true. It might happen that slice has not expired yet |
| 3296 | * but will expire soon (4-5 ns) during select_queue(). To cover the |
| 3297 | * case where think time is less than a jiffy, mark the queue wait |
| 3298 | * busy if only 1 jiffy is left in the slice. |
| 3299 | */ |
| 3300 | if (cfqq->slice_end - jiffies == 1) |
| 3301 | return true; |
| 3302 | |
| 3303 | return false; |
| 3304 | } |
| 3305 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3306 | static void cfq_completed_request(struct request_queue *q, struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3307 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3308 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3309 | struct cfq_data *cfqd = cfqq->cfqd; |
Jens Axboe | 5380a10 | 2006-07-13 12:37:56 +0200 | [diff] [blame] | 3310 | const int sync = rq_is_sync(rq); |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3311 | unsigned long now; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3312 | |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3313 | now = jiffies; |
Vivek Goyal | 2868ef7 | 2009-12-03 12:59:48 -0500 | [diff] [blame] | 3314 | cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", !!rq_noidle(rq)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3315 | |
Aaron Carroll | 45333d5 | 2008-08-26 15:52:36 +0200 | [diff] [blame] | 3316 | cfq_update_hw_tag(cfqd); |
| 3317 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 3318 | WARN_ON(!cfqd->rq_in_driver[sync]); |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3319 | WARN_ON(!cfqq->dispatched); |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 3320 | cfqd->rq_in_driver[sync]--; |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3321 | cfqq->dispatched--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3322 | |
Jens Axboe | 3ed9a29 | 2007-04-23 08:33:33 +0200 | [diff] [blame] | 3323 | if (cfq_cfqq_sync(cfqq)) |
| 3324 | cfqd->sync_flight--; |
| 3325 | |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 3326 | if (sync) { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3327 | RQ_CIC(rq)->last_end_request = now; |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 3328 | if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) |
| 3329 | cfqd->last_delayed_sync = now; |
Vivek Goyal | 365722b | 2009-10-03 15:21:27 +0200 | [diff] [blame] | 3330 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3331 | |
| 3332 | /* |
| 3333 | * If this is the active queue, check if it needs to be expired, |
| 3334 | * or if we want to idle in case it has no pending requests. |
| 3335 | */ |
| 3336 | if (cfqd->active_queue == cfqq) { |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3337 | const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); |
| 3338 | |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3339 | if (cfq_cfqq_slice_new(cfqq)) { |
| 3340 | cfq_set_prio_slice(cfqd, cfqq); |
| 3341 | cfq_clear_cfqq_slice_new(cfqq); |
| 3342 | } |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3343 | |
| 3344 | /* |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3345 | * Should we wait for next request to come in before we expire |
| 3346 | * the queue. |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3347 | */ |
Vivek Goyal | 7667aa0 | 2009-12-08 17:52:58 -0500 | [diff] [blame] | 3348 | if (cfq_should_wait_busy(cfqd, cfqq)) { |
Vivek Goyal | f75edf2 | 2009-12-03 12:59:53 -0500 | [diff] [blame] | 3349 | cfqq->slice_end = jiffies + cfqd->cfq_slice_idle; |
| 3350 | cfq_mark_cfqq_wait_busy(cfqq); |
| 3351 | } |
| 3352 | |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3353 | /* |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3354 | * Idling is not enabled on: |
| 3355 | * - expired queues |
| 3356 | * - idle-priority queues |
| 3357 | * - async queues |
| 3358 | * - queues with still some requests queued |
| 3359 | * - when there is a close cooperator |
Jens Axboe | a36e71f | 2009-04-15 12:15:11 +0200 | [diff] [blame] | 3360 | */ |
Jens Axboe | 0871714 | 2008-01-28 11:38:15 +0100 | [diff] [blame] | 3361 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 3362 | cfq_slice_expired(cfqd, 1); |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3363 | else if (sync && cfqq_empty && |
| 3364 | !cfq_close_cooperator(cfqd, cfqq)) { |
| 3365 | cfqd->noidle_tree_requires_idle |= !rq_noidle(rq); |
| 3366 | /* |
| 3367 | * Idling is enabled for SYNC_WORKLOAD. |
| 3368 | * SYNC_NOIDLE_WORKLOAD idles at the end of the tree |
| 3369 | * only if we processed at least one !rq_noidle request |
| 3370 | */ |
| 3371 | if (cfqd->serving_type == SYNC_WORKLOAD |
Vivek Goyal | c04645e | 2009-12-03 12:59:56 -0500 | [diff] [blame] | 3372 | || cfqd->noidle_tree_requires_idle |
| 3373 | || cfqq->cfqg->nr_cfqq == 1) |
Corrado Zoccolo | 8e55063 | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3374 | cfq_arm_slice_timer(cfqd); |
| 3375 | } |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3376 | } |
Jens Axboe | 6d048f5 | 2007-04-25 12:44:27 +0200 | [diff] [blame] | 3377 | |
Jens Axboe | 5ad531d | 2009-07-03 12:57:48 +0200 | [diff] [blame] | 3378 | if (!rq_in_driver(cfqd)) |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3379 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3380 | } |
| 3381 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3382 | /* |
| 3383 | * we temporarily boost lower priority queues if they are holding fs exclusive |
| 3384 | * resources. they are boosted to normal prio (CLASS_BE/4) |
| 3385 | */ |
| 3386 | static void cfq_prio_boost(struct cfq_queue *cfqq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3387 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3388 | if (has_fs_excl()) { |
| 3389 | /* |
| 3390 | * boost idle prio on transactions that would lock out other |
| 3391 | * users of the filesystem |
| 3392 | */ |
| 3393 | if (cfq_class_idle(cfqq)) |
| 3394 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
| 3395 | if (cfqq->ioprio > IOPRIO_NORM) |
| 3396 | cfqq->ioprio = IOPRIO_NORM; |
| 3397 | } else { |
| 3398 | /* |
Corrado Zoccolo | dddb745 | 2009-11-02 10:40:37 +0100 | [diff] [blame] | 3399 | * unboost the queue (if needed) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3400 | */ |
Corrado Zoccolo | dddb745 | 2009-11-02 10:40:37 +0100 | [diff] [blame] | 3401 | cfqq->ioprio_class = cfqq->org_ioprio_class; |
| 3402 | cfqq->ioprio = cfqq->org_ioprio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3403 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3404 | } |
| 3405 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3406 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3407 | { |
Jens Axboe | 1b379d8 | 2009-08-11 08:26:11 +0200 | [diff] [blame] | 3408 | if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3409 | cfq_mark_cfqq_must_alloc_slice(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3410 | return ELV_MQUEUE_MUST; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3411 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3412 | |
| 3413 | return ELV_MQUEUE_MAY; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3414 | } |
| 3415 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3416 | static int cfq_may_queue(struct request_queue *q, int rw) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3417 | { |
| 3418 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 3419 | struct task_struct *tsk = current; |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3420 | struct cfq_io_context *cic; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3421 | struct cfq_queue *cfqq; |
| 3422 | |
| 3423 | /* |
| 3424 | * don't force setup of a queue from here, as a call to may_queue |
| 3425 | * does not necessarily imply that a request actually will be queued. |
| 3426 | * so just lookup a possibly existing queue, or return 'may queue' |
| 3427 | * if that fails |
| 3428 | */ |
Jens Axboe | 4ac845a | 2008-01-24 08:44:49 +0100 | [diff] [blame] | 3429 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3430 | if (!cic) |
| 3431 | return ELV_MQUEUE_MAY; |
| 3432 | |
Jens Axboe | b0b78f8 | 2009-04-08 10:56:08 +0200 | [diff] [blame] | 3433 | cfqq = cic_to_cfqq(cic, rw_is_sync(rw)); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3434 | if (cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 3435 | cfq_init_prio_data(cfqq, cic->ioc); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3436 | cfq_prio_boost(cfqq); |
| 3437 | |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3438 | return __cfq_may_queue(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3439 | } |
| 3440 | |
| 3441 | return ELV_MQUEUE_MAY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3442 | } |
| 3443 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3444 | /* |
| 3445 | * queue lock held here |
| 3446 | */ |
Jens Axboe | bb37b94 | 2006-12-01 10:42:33 +0100 | [diff] [blame] | 3447 | static void cfq_put_request(struct request *rq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3448 | { |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3449 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3450 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3451 | if (cfqq) { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3452 | const int rw = rq_data_dir(rq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3453 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3454 | BUG_ON(!cfqq->allocated[rw]); |
| 3455 | cfqq->allocated[rw]--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3456 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3457 | put_io_context(RQ_CIC(rq)->ioc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3458 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3459 | rq->elevator_private = NULL; |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3460 | rq->elevator_private2 = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3461 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3462 | cfq_put_queue(cfqq); |
| 3463 | } |
| 3464 | } |
| 3465 | |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3466 | static struct cfq_queue * |
| 3467 | cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_context *cic, |
| 3468 | struct cfq_queue *cfqq) |
| 3469 | { |
| 3470 | cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq); |
| 3471 | cic_set_cfqq(cic, cfqq->new_cfqq, 1); |
Jeff Moyer | b3b6d04 | 2009-10-23 17:14:51 -0400 | [diff] [blame] | 3472 | cfq_mark_cfqq_coop(cfqq->new_cfqq); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3473 | cfq_put_queue(cfqq); |
| 3474 | return cic_to_cfqq(cic, 1); |
| 3475 | } |
| 3476 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3477 | static int should_split_cfqq(struct cfq_queue *cfqq) |
| 3478 | { |
| 3479 | if (cfqq->seeky_start && |
| 3480 | time_after(jiffies, cfqq->seeky_start + CFQQ_COOP_TOUT)) |
| 3481 | return 1; |
| 3482 | return 0; |
| 3483 | } |
| 3484 | |
| 3485 | /* |
| 3486 | * Returns NULL if a new cfqq should be allocated, or the old cfqq if this |
| 3487 | * was the last process referring to said cfqq. |
| 3488 | */ |
| 3489 | static struct cfq_queue * |
| 3490 | split_cfqq(struct cfq_io_context *cic, struct cfq_queue *cfqq) |
| 3491 | { |
| 3492 | if (cfqq_process_refs(cfqq) == 1) { |
| 3493 | cfqq->seeky_start = 0; |
| 3494 | cfqq->pid = current->pid; |
| 3495 | cfq_clear_cfqq_coop(cfqq); |
| 3496 | return cfqq; |
| 3497 | } |
| 3498 | |
| 3499 | cic_set_cfqq(cic, NULL, 1); |
| 3500 | cfq_put_queue(cfqq); |
| 3501 | return NULL; |
| 3502 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3503 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3504 | * Allocate cfq data structures associated with this request. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3505 | */ |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3506 | static int |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3507 | 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] | 3508 | { |
| 3509 | struct cfq_data *cfqd = q->elevator->elevator_data; |
| 3510 | struct cfq_io_context *cic; |
| 3511 | const int rw = rq_data_dir(rq); |
Jens Axboe | a6151c3 | 2009-10-07 20:02:57 +0200 | [diff] [blame] | 3512 | const bool is_sync = rq_is_sync(rq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3513 | struct cfq_queue *cfqq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3514 | unsigned long flags; |
| 3515 | |
| 3516 | might_sleep_if(gfp_mask & __GFP_WAIT); |
| 3517 | |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3518 | cic = cfq_get_io_context(cfqd, gfp_mask); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3519 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3520 | spin_lock_irqsave(q->queue_lock, flags); |
| 3521 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3522 | if (!cic) |
| 3523 | goto queue_fail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3524 | |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3525 | new_queue: |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3526 | cfqq = cic_to_cfqq(cic, is_sync); |
Vivek Goyal | 32f2e80 | 2009-07-09 22:13:16 +0200 | [diff] [blame] | 3527 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
Jens Axboe | fd0928d | 2008-01-24 08:52:45 +0100 | [diff] [blame] | 3528 | cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3529 | cic_set_cfqq(cic, cfqq, is_sync); |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3530 | } else { |
| 3531 | /* |
Jeff Moyer | e6c5bc7 | 2009-10-23 17:14:52 -0400 | [diff] [blame] | 3532 | * If the queue was seeky for too long, break it apart. |
| 3533 | */ |
| 3534 | if (cfq_cfqq_coop(cfqq) && should_split_cfqq(cfqq)) { |
| 3535 | cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq"); |
| 3536 | cfqq = split_cfqq(cic, cfqq); |
| 3537 | if (!cfqq) |
| 3538 | goto new_queue; |
| 3539 | } |
| 3540 | |
| 3541 | /* |
Jeff Moyer | df5fe3e | 2009-10-23 17:14:50 -0400 | [diff] [blame] | 3542 | * Check to see if this queue is scheduled to merge with |
| 3543 | * another, closely cooperating queue. The merging of |
| 3544 | * queues happens here as it must be done in process context. |
| 3545 | * The reference on new_cfqq was taken in merge_cfqqs. |
| 3546 | */ |
| 3547 | if (cfqq->new_cfqq) |
| 3548 | cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq); |
Vasily Tarasov | 91fac31 | 2007-04-25 12:29:51 +0200 | [diff] [blame] | 3549 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3550 | |
| 3551 | cfqq->allocated[rw]++; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3552 | atomic_inc(&cfqq->ref); |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3553 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3554 | spin_unlock_irqrestore(q->queue_lock, flags); |
| 3555 | |
Jens Axboe | 5e70537 | 2006-07-13 12:39:25 +0200 | [diff] [blame] | 3556 | rq->elevator_private = cic; |
| 3557 | rq->elevator_private2 = cfqq; |
| 3558 | return 0; |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3559 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3560 | queue_fail: |
| 3561 | if (cic) |
| 3562 | put_io_context(cic->ioc); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3563 | |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3564 | cfq_schedule_dispatch(cfqd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3565 | spin_unlock_irqrestore(q->queue_lock, flags); |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3566 | cfq_log(cfqd, "set_request fail"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3567 | return 1; |
| 3568 | } |
| 3569 | |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 3570 | static void cfq_kick_queue(struct work_struct *work) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3571 | { |
David Howells | 65f27f3 | 2006-11-22 14:55:48 +0000 | [diff] [blame] | 3572 | struct cfq_data *cfqd = |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3573 | container_of(work, struct cfq_data, unplug_work); |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3574 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3575 | |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 3576 | spin_lock_irq(q->queue_lock); |
Tejun Heo | a7f5579 | 2009-04-23 11:05:17 +0900 | [diff] [blame] | 3577 | __blk_run_queue(cfqd->queue); |
Jens Axboe | 40bb54d | 2009-04-15 12:11:10 +0200 | [diff] [blame] | 3578 | spin_unlock_irq(q->queue_lock); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3579 | } |
| 3580 | |
| 3581 | /* |
| 3582 | * Timer running if the active_queue is currently idling inside its time slice |
| 3583 | */ |
| 3584 | static void cfq_idle_slice_timer(unsigned long data) |
| 3585 | { |
| 3586 | struct cfq_data *cfqd = (struct cfq_data *) data; |
| 3587 | struct cfq_queue *cfqq; |
| 3588 | unsigned long flags; |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 3589 | int timed_out = 1; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3590 | |
Jens Axboe | 7b67913 | 2008-05-30 12:23:07 +0200 | [diff] [blame] | 3591 | cfq_log(cfqd, "idle timer fired"); |
| 3592 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3593 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
| 3594 | |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 3595 | cfqq = cfqd->active_queue; |
| 3596 | if (cfqq) { |
Jens Axboe | 3c6bd2f | 2007-01-19 12:06:33 +1100 | [diff] [blame] | 3597 | timed_out = 0; |
| 3598 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3599 | /* |
Jens Axboe | b029195 | 2009-04-07 11:38:31 +0200 | [diff] [blame] | 3600 | * We saw a request before the queue expired, let it through |
| 3601 | */ |
| 3602 | if (cfq_cfqq_must_dispatch(cfqq)) |
| 3603 | goto out_kick; |
| 3604 | |
| 3605 | /* |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3606 | * expired |
| 3607 | */ |
Jens Axboe | 44f7c16 | 2007-01-19 11:51:58 +1100 | [diff] [blame] | 3608 | if (cfq_slice_used(cfqq)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3609 | goto expire; |
| 3610 | |
| 3611 | /* |
| 3612 | * only expire and reinvoke request handler, if there are |
| 3613 | * other queues with pending requests |
| 3614 | */ |
Jens Axboe | caaa5f9 | 2006-06-16 11:23:00 +0200 | [diff] [blame] | 3615 | if (!cfqd->busy_queues) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3616 | goto out_cont; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3617 | |
| 3618 | /* |
| 3619 | * not expired and it has a request pending, let it dispatch |
| 3620 | */ |
Jens Axboe | 75e5098 | 2009-04-07 08:56:14 +0200 | [diff] [blame] | 3621 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3622 | goto out_kick; |
Corrado Zoccolo | 76280af | 2009-11-26 10:02:58 +0100 | [diff] [blame] | 3623 | |
| 3624 | /* |
| 3625 | * Queue depth flag is reset only when the idle didn't succeed |
| 3626 | */ |
| 3627 | cfq_clear_cfqq_deep(cfqq); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3628 | } |
| 3629 | expire: |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 3630 | cfq_slice_expired(cfqd, timed_out); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3631 | out_kick: |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3632 | cfq_schedule_dispatch(cfqd); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3633 | out_cont: |
| 3634 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); |
| 3635 | } |
| 3636 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3637 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) |
| 3638 | { |
| 3639 | del_timer_sync(&cfqd->idle_slice_timer); |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3640 | cancel_work_sync(&cfqd->unplug_work); |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3641 | } |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3642 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3643 | static void cfq_put_async_queues(struct cfq_data *cfqd) |
| 3644 | { |
| 3645 | int i; |
| 3646 | |
| 3647 | for (i = 0; i < IOPRIO_BE_NR; i++) { |
| 3648 | if (cfqd->async_cfqq[0][i]) |
| 3649 | cfq_put_queue(cfqd->async_cfqq[0][i]); |
| 3650 | if (cfqd->async_cfqq[1][i]) |
| 3651 | cfq_put_queue(cfqd->async_cfqq[1][i]); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3652 | } |
Oleg Nesterov | 2389d1e | 2007-11-05 08:58:05 +0100 | [diff] [blame] | 3653 | |
| 3654 | if (cfqd->async_idle_cfqq) |
| 3655 | cfq_put_queue(cfqd->async_idle_cfqq); |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3656 | } |
| 3657 | |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 3658 | static void cfq_cfqd_free(struct rcu_head *head) |
| 3659 | { |
| 3660 | kfree(container_of(head, struct cfq_data, rcu)); |
| 3661 | } |
| 3662 | |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3663 | static void cfq_exit_queue(struct elevator_queue *e) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3664 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3665 | struct cfq_data *cfqd = e->elevator_data; |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3666 | struct request_queue *q = cfqd->queue; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3667 | |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3668 | cfq_shutdown_timer_wq(cfqd); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3669 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3670 | spin_lock_irq(q->queue_lock); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3671 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3672 | if (cfqd->active_queue) |
Jens Axboe | 6084cdd | 2007-04-23 08:25:00 +0200 | [diff] [blame] | 3673 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0); |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3674 | |
| 3675 | while (!list_empty(&cfqd->cic_list)) { |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3676 | struct cfq_io_context *cic = list_entry(cfqd->cic_list.next, |
| 3677 | struct cfq_io_context, |
| 3678 | queue_list); |
Jens Axboe | 89850f7 | 2006-07-22 16:48:31 +0200 | [diff] [blame] | 3679 | |
| 3680 | __cfq_exit_single_io_context(cfqd, cic); |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3681 | } |
Jens Axboe | e2d74ac | 2006-03-28 08:59:01 +0200 | [diff] [blame] | 3682 | |
Vasily Tarasov | c2dea2d | 2007-07-20 10:06:38 +0200 | [diff] [blame] | 3683 | cfq_put_async_queues(cfqd); |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3684 | cfq_release_cfq_groups(cfqd); |
| 3685 | blkiocg_del_blkio_group(&cfqd->root_group.blkg); |
Jens Axboe | 15c31be | 2007-07-10 13:43:25 +0200 | [diff] [blame] | 3686 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3687 | spin_unlock_irq(q->queue_lock); |
Al Viro | a90d742 | 2006-03-18 12:05:37 -0500 | [diff] [blame] | 3688 | |
| 3689 | cfq_shutdown_timer_wq(cfqd); |
| 3690 | |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3691 | /* Wait for cfqg->blkg->key accessors to exit their grace periods. */ |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 3692 | call_rcu(&cfqd->rcu, cfq_cfqd_free); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3693 | } |
| 3694 | |
Jens Axboe | 165125e | 2007-07-24 09:28:11 +0200 | [diff] [blame] | 3695 | static void *cfq_init_queue(struct request_queue *q) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3696 | { |
| 3697 | struct cfq_data *cfqd; |
Corrado Zoccolo | 718eee0 | 2009-10-26 22:45:29 +0100 | [diff] [blame] | 3698 | int i, j; |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3699 | struct cfq_group *cfqg; |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 3700 | struct cfq_rb_root *st; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3701 | |
Christoph Lameter | 94f6030 | 2007-07-17 04:03:29 -0700 | [diff] [blame] | 3702 | cfqd = kmalloc_node(sizeof(*cfqd), GFP_KERNEL | __GFP_ZERO, q->node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3703 | if (!cfqd) |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 3704 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3705 | |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 3706 | /* Init root service tree */ |
| 3707 | cfqd->grp_service_tree = CFQ_RB_ROOT; |
| 3708 | |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3709 | /* Init root group */ |
| 3710 | cfqg = &cfqd->root_group; |
Vivek Goyal | 615f025 | 2009-12-03 12:59:39 -0500 | [diff] [blame] | 3711 | for_each_cfqg_st(cfqg, i, j, st) |
| 3712 | *st = CFQ_RB_ROOT; |
Vivek Goyal | 1fa8f6d | 2009-12-03 12:59:41 -0500 | [diff] [blame] | 3713 | RB_CLEAR_NODE(&cfqg->rb_node); |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 3714 | |
Vivek Goyal | 25bc6b0 | 2009-12-03 12:59:43 -0500 | [diff] [blame] | 3715 | /* Give preference to root group over other groups */ |
| 3716 | cfqg->weight = 2*BLKIO_WEIGHT_DEFAULT; |
| 3717 | |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 3718 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
Vivek Goyal | b1c3576 | 2009-12-03 12:59:47 -0500 | [diff] [blame] | 3719 | /* |
| 3720 | * Take a reference to root group which we never drop. This is just |
| 3721 | * to make sure that cfq_put_cfqg() does not try to kfree root group |
| 3722 | */ |
| 3723 | atomic_set(&cfqg->ref, 1); |
Vivek Goyal | 2208419 | 2009-12-03 12:59:49 -0500 | [diff] [blame] | 3724 | blkiocg_add_blkio_group(&blkio_root_cgroup, &cfqg->blkg, (void *)cfqd, |
| 3725 | 0); |
Vivek Goyal | 25fb516 | 2009-12-03 12:59:46 -0500 | [diff] [blame] | 3726 | #endif |
Jens Axboe | 26a2ac0 | 2009-04-23 12:13:27 +0200 | [diff] [blame] | 3727 | /* |
| 3728 | * Not strictly needed (since RB_ROOT just clears the node and we |
| 3729 | * zeroed cfqd on alloc), but better be safe in case someone decides |
| 3730 | * to add magic to the rb code |
| 3731 | */ |
| 3732 | for (i = 0; i < CFQ_PRIO_LISTS; i++) |
| 3733 | cfqd->prio_trees[i] = RB_ROOT; |
| 3734 | |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 3735 | /* |
| 3736 | * Our fallback cfqq if cfq_find_alloc_queue() runs into OOM issues. |
| 3737 | * Grab a permanent reference to it, so that the normal code flow |
| 3738 | * will not attempt to free it. |
| 3739 | */ |
| 3740 | cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); |
| 3741 | atomic_inc(&cfqd->oom_cfqq.ref); |
Vivek Goyal | cdb16e8 | 2009-12-03 12:59:38 -0500 | [diff] [blame] | 3742 | cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, &cfqd->root_group); |
Jens Axboe | 6118b70 | 2009-06-30 09:34:12 +0200 | [diff] [blame] | 3743 | |
Al Viro | d9ff418 | 2006-03-18 13:51:22 -0500 | [diff] [blame] | 3744 | INIT_LIST_HEAD(&cfqd->cic_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3745 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3746 | cfqd->queue = q; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3747 | |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3748 | init_timer(&cfqd->idle_slice_timer); |
| 3749 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; |
| 3750 | cfqd->idle_slice_timer.data = (unsigned long) cfqd; |
| 3751 | |
Jens Axboe | 23e018a | 2009-10-05 08:52:35 +0200 | [diff] [blame] | 3752 | INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3753 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3754 | cfqd->cfq_quantum = cfq_quantum; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3755 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |
| 3756 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3757 | cfqd->cfq_back_max = cfq_back_max; |
| 3758 | cfqd->cfq_back_penalty = cfq_back_penalty; |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3759 | cfqd->cfq_slice[0] = cfq_slice_async; |
| 3760 | cfqd->cfq_slice[1] = cfq_slice_sync; |
| 3761 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; |
| 3762 | cfqd->cfq_slice_idle = cfq_slice_idle; |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3763 | cfqd->cfq_latency = 1; |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3764 | cfqd->cfq_group_isolation = 0; |
Corrado Zoccolo | e459dd0 | 2009-11-26 10:02:57 +0100 | [diff] [blame] | 3765 | cfqd->hw_tag = -1; |
Corrado Zoccolo | edc7113 | 2009-12-09 20:56:04 +0100 | [diff] [blame] | 3766 | /* |
| 3767 | * we optimistically start assuming sync ops weren't delayed in last |
| 3768 | * second, in order to have larger depth for async operations. |
| 3769 | */ |
Corrado Zoccolo | 573412b | 2009-12-06 11:48:52 +0100 | [diff] [blame] | 3770 | cfqd->last_delayed_sync = jiffies - HZ; |
Jens Axboe | bb729bc | 2009-12-06 09:54:19 +0100 | [diff] [blame] | 3771 | INIT_RCU_HEAD(&cfqd->rcu); |
Jens Axboe | bc1c116 | 2006-06-08 08:49:06 +0200 | [diff] [blame] | 3772 | return cfqd; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3773 | } |
| 3774 | |
| 3775 | static void cfq_slab_kill(void) |
| 3776 | { |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 3777 | /* |
| 3778 | * Caller already ensured that pending RCU callbacks are completed, |
| 3779 | * so we should have no busy allocations at this point. |
| 3780 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3781 | if (cfq_pool) |
| 3782 | kmem_cache_destroy(cfq_pool); |
| 3783 | if (cfq_ioc_pool) |
| 3784 | kmem_cache_destroy(cfq_ioc_pool); |
| 3785 | } |
| 3786 | |
| 3787 | static int __init cfq_slab_setup(void) |
| 3788 | { |
Christoph Lameter | 0a31bd5 | 2007-05-06 14:49:57 -0700 | [diff] [blame] | 3789 | cfq_pool = KMEM_CACHE(cfq_queue, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3790 | if (!cfq_pool) |
| 3791 | goto fail; |
| 3792 | |
Fabio Checconi | 34e6bbf | 2008-04-02 14:31:02 +0200 | [diff] [blame] | 3793 | cfq_ioc_pool = KMEM_CACHE(cfq_io_context, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3794 | if (!cfq_ioc_pool) |
| 3795 | goto fail; |
| 3796 | |
| 3797 | return 0; |
| 3798 | fail: |
| 3799 | cfq_slab_kill(); |
| 3800 | return -ENOMEM; |
| 3801 | } |
| 3802 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3803 | /* |
| 3804 | * sysfs parts below --> |
| 3805 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3806 | static ssize_t |
| 3807 | cfq_var_show(unsigned int var, char *page) |
| 3808 | { |
| 3809 | return sprintf(page, "%d\n", var); |
| 3810 | } |
| 3811 | |
| 3812 | static ssize_t |
| 3813 | cfq_var_store(unsigned int *var, const char *page, size_t count) |
| 3814 | { |
| 3815 | char *p = (char *) page; |
| 3816 | |
| 3817 | *var = simple_strtoul(p, &p, 10); |
| 3818 | return count; |
| 3819 | } |
| 3820 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3821 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3822 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3823 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3824 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3825 | unsigned int __data = __VAR; \ |
| 3826 | if (__CONV) \ |
| 3827 | __data = jiffies_to_msecs(__data); \ |
| 3828 | return cfq_var_show(__data, (page)); \ |
| 3829 | } |
| 3830 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3831 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); |
| 3832 | 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] | 3833 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); |
| 3834 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3835 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); |
| 3836 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); |
| 3837 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); |
| 3838 | SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3839 | SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3840 | SHOW_FUNCTION(cfq_group_isolation_show, cfqd->cfq_group_isolation, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3841 | #undef SHOW_FUNCTION |
| 3842 | |
| 3843 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ |
Jens Axboe | b374d18 | 2008-10-31 10:05:07 +0100 | [diff] [blame] | 3844 | 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] | 3845 | { \ |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3846 | struct cfq_data *cfqd = e->elevator_data; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3847 | unsigned int __data; \ |
| 3848 | int ret = cfq_var_store(&__data, (page), count); \ |
| 3849 | if (__data < (MIN)) \ |
| 3850 | __data = (MIN); \ |
| 3851 | else if (__data > (MAX)) \ |
| 3852 | __data = (MAX); \ |
| 3853 | if (__CONV) \ |
| 3854 | *(__PTR) = msecs_to_jiffies(__data); \ |
| 3855 | else \ |
| 3856 | *(__PTR) = __data; \ |
| 3857 | return ret; \ |
| 3858 | } |
| 3859 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); |
Jens Axboe | fe094d9 | 2008-01-31 13:08:54 +0100 | [diff] [blame] | 3860 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, |
| 3861 | UINT_MAX, 1); |
| 3862 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, |
| 3863 | UINT_MAX, 1); |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3864 | 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] | 3865 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, |
| 3866 | UINT_MAX, 0); |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3867 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); |
| 3868 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); |
| 3869 | 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] | 3870 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, |
| 3871 | UINT_MAX, 0); |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3872 | STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3873 | STORE_FUNCTION(cfq_group_isolation_store, &cfqd->cfq_group_isolation, 0, 1, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3874 | #undef STORE_FUNCTION |
| 3875 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3876 | #define CFQ_ATTR(name) \ |
| 3877 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) |
Jens Axboe | 3b18152 | 2005-06-27 10:56:24 +0200 | [diff] [blame] | 3878 | |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3879 | static struct elv_fs_entry cfq_attrs[] = { |
| 3880 | CFQ_ATTR(quantum), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3881 | CFQ_ATTR(fifo_expire_sync), |
| 3882 | CFQ_ATTR(fifo_expire_async), |
| 3883 | CFQ_ATTR(back_seek_max), |
| 3884 | CFQ_ATTR(back_seek_penalty), |
| 3885 | CFQ_ATTR(slice_sync), |
| 3886 | CFQ_ATTR(slice_async), |
| 3887 | CFQ_ATTR(slice_async_rq), |
| 3888 | CFQ_ATTR(slice_idle), |
Jens Axboe | 963b72f | 2009-10-03 19:42:18 +0200 | [diff] [blame] | 3889 | CFQ_ATTR(low_latency), |
Vivek Goyal | ae30c28 | 2009-12-03 12:59:55 -0500 | [diff] [blame] | 3890 | CFQ_ATTR(group_isolation), |
Al Viro | e572ec7 | 2006-03-18 22:27:18 -0500 | [diff] [blame] | 3891 | __ATTR_NULL |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3892 | }; |
| 3893 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3894 | static struct elevator_type iosched_cfq = { |
| 3895 | .ops = { |
| 3896 | .elevator_merge_fn = cfq_merge, |
| 3897 | .elevator_merged_fn = cfq_merged_request, |
| 3898 | .elevator_merge_req_fn = cfq_merged_requests, |
Jens Axboe | da77526 | 2006-12-20 11:04:12 +0100 | [diff] [blame] | 3899 | .elevator_allow_merge_fn = cfq_allow_merge, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3900 | .elevator_dispatch_fn = cfq_dispatch_requests, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3901 | .elevator_add_req_fn = cfq_insert_request, |
Jens Axboe | b4878f2 | 2005-10-20 16:42:29 +0200 | [diff] [blame] | 3902 | .elevator_activate_req_fn = cfq_activate_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3903 | .elevator_deactivate_req_fn = cfq_deactivate_request, |
| 3904 | .elevator_queue_empty_fn = cfq_queue_empty, |
| 3905 | .elevator_completed_req_fn = cfq_completed_request, |
Jens Axboe | 21183b0 | 2006-07-13 12:33:14 +0200 | [diff] [blame] | 3906 | .elevator_former_req_fn = elv_rb_former_request, |
| 3907 | .elevator_latter_req_fn = elv_rb_latter_request, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3908 | .elevator_set_req_fn = cfq_set_request, |
| 3909 | .elevator_put_req_fn = cfq_put_request, |
| 3910 | .elevator_may_queue_fn = cfq_may_queue, |
| 3911 | .elevator_init_fn = cfq_init_queue, |
| 3912 | .elevator_exit_fn = cfq_exit_queue, |
Jens Axboe | fc46379 | 2006-08-29 09:05:44 +0200 | [diff] [blame] | 3913 | .trim = cfq_free_io_context, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3914 | }, |
Al Viro | 3d1ab40 | 2006-03-18 18:35:43 -0500 | [diff] [blame] | 3915 | .elevator_attrs = cfq_attrs, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3916 | .elevator_name = "cfq", |
| 3917 | .elevator_owner = THIS_MODULE, |
| 3918 | }; |
| 3919 | |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3920 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
| 3921 | static struct blkio_policy_type blkio_policy_cfq = { |
| 3922 | .ops = { |
| 3923 | .blkio_unlink_group_fn = cfq_unlink_blkio_group, |
| 3924 | .blkio_update_group_weight_fn = cfq_update_blkio_group_weight, |
| 3925 | }, |
| 3926 | }; |
| 3927 | #else |
| 3928 | static struct blkio_policy_type blkio_policy_cfq; |
| 3929 | #endif |
| 3930 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3931 | static int __init cfq_init(void) |
| 3932 | { |
Jens Axboe | 22e2c50 | 2005-06-27 10:55:12 +0200 | [diff] [blame] | 3933 | /* |
| 3934 | * could be 0 on HZ < 1000 setups |
| 3935 | */ |
| 3936 | if (!cfq_slice_async) |
| 3937 | cfq_slice_async = 1; |
| 3938 | if (!cfq_slice_idle) |
| 3939 | cfq_slice_idle = 1; |
| 3940 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3941 | if (cfq_slab_setup()) |
| 3942 | return -ENOMEM; |
| 3943 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 3944 | elv_register(&iosched_cfq); |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3945 | blkio_policy_register(&blkio_policy_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3946 | |
Adrian Bunk | 2fdd82b | 2007-12-12 18:51:56 +0100 | [diff] [blame] | 3947 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3948 | } |
| 3949 | |
| 3950 | static void __exit cfq_exit(void) |
| 3951 | { |
Peter Zijlstra | 6e9a473 | 2006-09-30 23:28:10 -0700 | [diff] [blame] | 3952 | DECLARE_COMPLETION_ONSTACK(all_gone); |
Vivek Goyal | 3e25206 | 2009-12-04 10:36:42 -0500 | [diff] [blame] | 3953 | blkio_policy_unregister(&blkio_policy_cfq); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3954 | elv_unregister(&iosched_cfq); |
Al Viro | 334e94d | 2006-03-18 15:05:53 -0500 | [diff] [blame] | 3955 | ioc_gone = &all_gone; |
OGAWA Hirofumi | fba8227 | 2006-04-18 09:44:06 +0200 | [diff] [blame] | 3956 | /* ioc_gone's update must be visible before reading ioc_count */ |
| 3957 | smp_wmb(); |
Jens Axboe | d6de8be | 2008-05-28 14:46:59 +0200 | [diff] [blame] | 3958 | |
| 3959 | /* |
| 3960 | * this also protects us from entering cfq_slab_kill() with |
| 3961 | * pending RCU callbacks |
| 3962 | */ |
Tejun Heo | 245b2e7 | 2009-06-24 15:13:48 +0900 | [diff] [blame] | 3963 | if (elv_ioc_count_read(cfq_ioc_count)) |
Jens Axboe | 9a11b4e | 2008-05-29 09:32:08 +0200 | [diff] [blame] | 3964 | wait_for_completion(&all_gone); |
Christoph Hellwig | 83521d3 | 2005-10-30 15:01:39 -0800 | [diff] [blame] | 3965 | cfq_slab_kill(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3966 | } |
| 3967 | |
| 3968 | module_init(cfq_init); |
| 3969 | module_exit(cfq_exit); |
| 3970 | |
| 3971 | MODULE_AUTHOR("Jens Axboe"); |
| 3972 | MODULE_LICENSE("GPL"); |
| 3973 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |