Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
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 | * | |
0fe23479 | 7 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> |
1da177e4 | 8 | */ |
1da177e4 | 9 | #include <linux/module.h> |
5a0e3ad6 | 10 | #include <linux/slab.h> |
1cc9be68 AV |
11 | #include <linux/blkdev.h> |
12 | #include <linux/elevator.h> | |
ad5ebd2f | 13 | #include <linux/jiffies.h> |
1da177e4 | 14 | #include <linux/rbtree.h> |
22e2c507 | 15 | #include <linux/ioprio.h> |
7b679138 | 16 | #include <linux/blktrace_api.h> |
6e736be7 | 17 | #include "blk.h" |
629ed0b1 | 18 | #include "blk-cgroup.h" |
1da177e4 LT |
19 | |
20 | /* | |
21 | * tunables | |
22 | */ | |
fe094d98 | 23 | /* max queue in one round of service */ |
abc3c744 | 24 | static const int cfq_quantum = 8; |
64100099 | 25 | static const int cfq_fifo_expire[2] = { HZ / 4, HZ / 8 }; |
fe094d98 JA |
26 | /* maximum backwards seek, in KiB */ |
27 | static const int cfq_back_max = 16 * 1024; | |
28 | /* penalty of a backwards seek */ | |
29 | static const int cfq_back_penalty = 2; | |
64100099 | 30 | static const int cfq_slice_sync = HZ / 10; |
3b18152c | 31 | static int cfq_slice_async = HZ / 25; |
64100099 | 32 | static const int cfq_slice_async_rq = 2; |
caaa5f9f | 33 | static int cfq_slice_idle = HZ / 125; |
80bdf0c7 | 34 | static int cfq_group_idle = HZ / 125; |
5db5d642 CZ |
35 | static const int cfq_target_latency = HZ * 3/10; /* 300 ms */ |
36 | static const int cfq_hist_divisor = 4; | |
22e2c507 | 37 | |
d9e7620e | 38 | /* |
0871714e | 39 | * offset from end of service tree |
d9e7620e | 40 | */ |
0871714e | 41 | #define CFQ_IDLE_DELAY (HZ / 5) |
d9e7620e JA |
42 | |
43 | /* | |
44 | * below this threshold, we consider thinktime immediate | |
45 | */ | |
46 | #define CFQ_MIN_TT (2) | |
47 | ||
22e2c507 | 48 | #define CFQ_SLICE_SCALE (5) |
45333d5a | 49 | #define CFQ_HW_QUEUE_MIN (5) |
25bc6b07 | 50 | #define CFQ_SERVICE_SHIFT 12 |
22e2c507 | 51 | |
3dde36dd | 52 | #define CFQQ_SEEK_THR (sector_t)(8 * 100) |
e9ce335d | 53 | #define CFQQ_CLOSE_THR (sector_t)(8 * 1024) |
41647e7a | 54 | #define CFQQ_SECT_THR_NONROT (sector_t)(2 * 32) |
3dde36dd | 55 | #define CFQQ_SEEKY(cfqq) (hweight32(cfqq->seek_history) > 32/8) |
ae54abed | 56 | |
a612fddf TH |
57 | #define RQ_CIC(rq) icq_to_cic((rq)->elv.icq) |
58 | #define RQ_CFQQ(rq) (struct cfq_queue *) ((rq)->elv.priv[0]) | |
59 | #define RQ_CFQG(rq) (struct cfq_group *) ((rq)->elv.priv[1]) | |
1da177e4 | 60 | |
e18b890b | 61 | static struct kmem_cache *cfq_pool; |
1da177e4 | 62 | |
22e2c507 JA |
63 | #define CFQ_PRIO_LISTS IOPRIO_BE_NR |
64 | #define cfq_class_idle(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_IDLE) | |
22e2c507 JA |
65 | #define cfq_class_rt(cfqq) ((cfqq)->ioprio_class == IOPRIO_CLASS_RT) |
66 | ||
206dc69b | 67 | #define sample_valid(samples) ((samples) > 80) |
1fa8f6d6 | 68 | #define rb_entry_cfqg(node) rb_entry((node), struct cfq_group, rb_node) |
206dc69b | 69 | |
e48453c3 AA |
70 | /* blkio-related constants */ |
71 | #define CFQ_WEIGHT_MIN 10 | |
72 | #define CFQ_WEIGHT_MAX 1000 | |
73 | #define CFQ_WEIGHT_DEFAULT 500 | |
74 | ||
c5869807 TH |
75 | struct cfq_ttime { |
76 | unsigned long last_end_request; | |
77 | ||
78 | unsigned long ttime_total; | |
79 | unsigned long ttime_samples; | |
80 | unsigned long ttime_mean; | |
81 | }; | |
82 | ||
cc09e299 JA |
83 | /* |
84 | * Most of our rbtree usage is for sorting with min extraction, so | |
85 | * if we cache the leftmost node we don't have to walk down the tree | |
86 | * to find it. Idea borrowed from Ingo Molnars CFS scheduler. We should | |
87 | * move this into the elevator for the rq sorting as well. | |
88 | */ | |
89 | struct cfq_rb_root { | |
90 | struct rb_root rb; | |
91 | struct rb_node *left; | |
aa6f6a3d | 92 | unsigned count; |
1fa8f6d6 | 93 | u64 min_vdisktime; |
f5f2b6ce | 94 | struct cfq_ttime ttime; |
cc09e299 | 95 | }; |
f5f2b6ce SL |
96 | #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, \ |
97 | .ttime = {.last_end_request = jiffies,},} | |
cc09e299 | 98 | |
6118b70b JA |
99 | /* |
100 | * Per process-grouping structure | |
101 | */ | |
102 | struct cfq_queue { | |
103 | /* reference count */ | |
30d7b944 | 104 | int ref; |
6118b70b JA |
105 | /* various state flags, see below */ |
106 | unsigned int flags; | |
107 | /* parent cfq_data */ | |
108 | struct cfq_data *cfqd; | |
109 | /* service_tree member */ | |
110 | struct rb_node rb_node; | |
111 | /* service_tree key */ | |
112 | unsigned long rb_key; | |
113 | /* prio tree member */ | |
114 | struct rb_node p_node; | |
115 | /* prio tree root we belong to, if any */ | |
116 | struct rb_root *p_root; | |
117 | /* sorted list of pending requests */ | |
118 | struct rb_root sort_list; | |
119 | /* if fifo isn't expired, next request to serve */ | |
120 | struct request *next_rq; | |
121 | /* requests queued in sort_list */ | |
122 | int queued[2]; | |
123 | /* currently allocated requests */ | |
124 | int allocated[2]; | |
125 | /* fifo list of requests in sort_list */ | |
126 | struct list_head fifo; | |
127 | ||
dae739eb VG |
128 | /* time when queue got scheduled in to dispatch first request. */ |
129 | unsigned long dispatch_start; | |
f75edf2d | 130 | unsigned int allocated_slice; |
c4081ba5 | 131 | unsigned int slice_dispatch; |
dae739eb VG |
132 | /* time when first request from queue completed and slice started. */ |
133 | unsigned long slice_start; | |
6118b70b JA |
134 | unsigned long slice_end; |
135 | long slice_resid; | |
6118b70b | 136 | |
65299a3b CH |
137 | /* pending priority requests */ |
138 | int prio_pending; | |
6118b70b JA |
139 | /* number of requests that are on the dispatch list or inside driver */ |
140 | int dispatched; | |
141 | ||
142 | /* io prio of this group */ | |
143 | unsigned short ioprio, org_ioprio; | |
4aede84b | 144 | unsigned short ioprio_class; |
6118b70b | 145 | |
c4081ba5 RK |
146 | pid_t pid; |
147 | ||
3dde36dd | 148 | u32 seek_history; |
b2c18e1e JM |
149 | sector_t last_request_pos; |
150 | ||
aa6f6a3d | 151 | struct cfq_rb_root *service_tree; |
df5fe3e8 | 152 | struct cfq_queue *new_cfqq; |
cdb16e8f | 153 | struct cfq_group *cfqg; |
c4e7893e VG |
154 | /* Number of sectors dispatched from queue in single dispatch round */ |
155 | unsigned long nr_sectors; | |
6118b70b JA |
156 | }; |
157 | ||
c0324a02 | 158 | /* |
718eee05 | 159 | * First index in the service_trees. |
c0324a02 CZ |
160 | * IDLE is handled separately, so it has negative index |
161 | */ | |
3bf10fea | 162 | enum wl_class_t { |
c0324a02 | 163 | BE_WORKLOAD = 0, |
615f0259 VG |
164 | RT_WORKLOAD = 1, |
165 | IDLE_WORKLOAD = 2, | |
b4627321 | 166 | CFQ_PRIO_NR, |
c0324a02 CZ |
167 | }; |
168 | ||
718eee05 CZ |
169 | /* |
170 | * Second index in the service_trees. | |
171 | */ | |
172 | enum wl_type_t { | |
173 | ASYNC_WORKLOAD = 0, | |
174 | SYNC_NOIDLE_WORKLOAD = 1, | |
175 | SYNC_WORKLOAD = 2 | |
176 | }; | |
177 | ||
155fead9 TH |
178 | struct cfqg_stats { |
179 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
180 | /* total bytes transferred */ | |
181 | struct blkg_rwstat service_bytes; | |
182 | /* total IOs serviced, post merge */ | |
183 | struct blkg_rwstat serviced; | |
184 | /* number of ios merged */ | |
185 | struct blkg_rwstat merged; | |
186 | /* total time spent on device in ns, may not be accurate w/ queueing */ | |
187 | struct blkg_rwstat service_time; | |
188 | /* total time spent waiting in scheduler queue in ns */ | |
189 | struct blkg_rwstat wait_time; | |
190 | /* number of IOs queued up */ | |
191 | struct blkg_rwstat queued; | |
192 | /* total sectors transferred */ | |
193 | struct blkg_stat sectors; | |
194 | /* total disk time and nr sectors dispatched by this group */ | |
195 | struct blkg_stat time; | |
196 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
197 | /* time not charged to this cgroup */ | |
198 | struct blkg_stat unaccounted_time; | |
199 | /* sum of number of ios queued across all samples */ | |
200 | struct blkg_stat avg_queue_size_sum; | |
201 | /* count of samples taken for average */ | |
202 | struct blkg_stat avg_queue_size_samples; | |
203 | /* how many times this group has been removed from service tree */ | |
204 | struct blkg_stat dequeue; | |
205 | /* total time spent waiting for it to be assigned a timeslice. */ | |
206 | struct blkg_stat group_wait_time; | |
3c798398 | 207 | /* time spent idling for this blkcg_gq */ |
155fead9 TH |
208 | struct blkg_stat idle_time; |
209 | /* total time with empty current active q with other requests queued */ | |
210 | struct blkg_stat empty_time; | |
211 | /* fields after this shouldn't be cleared on stat reset */ | |
212 | uint64_t start_group_wait_time; | |
213 | uint64_t start_idle_time; | |
214 | uint64_t start_empty_time; | |
215 | uint16_t flags; | |
216 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
217 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ | |
218 | }; | |
219 | ||
e48453c3 AA |
220 | /* Per-cgroup data */ |
221 | struct cfq_group_data { | |
222 | /* must be the first member */ | |
223 | struct blkcg_policy_data pd; | |
224 | ||
225 | unsigned int weight; | |
226 | unsigned int leaf_weight; | |
227 | }; | |
228 | ||
cdb16e8f VG |
229 | /* This is per cgroup per device grouping structure */ |
230 | struct cfq_group { | |
f95a04af TH |
231 | /* must be the first member */ |
232 | struct blkg_policy_data pd; | |
233 | ||
1fa8f6d6 VG |
234 | /* group service_tree member */ |
235 | struct rb_node rb_node; | |
236 | ||
237 | /* group service_tree key */ | |
238 | u64 vdisktime; | |
e71357e1 | 239 | |
7918ffb5 TH |
240 | /* |
241 | * The number of active cfqgs and sum of their weights under this | |
242 | * cfqg. This covers this cfqg's leaf_weight and all children's | |
243 | * weights, but does not cover weights of further descendants. | |
244 | * | |
245 | * If a cfqg is on the service tree, it's active. An active cfqg | |
246 | * also activates its parent and contributes to the children_weight | |
247 | * of the parent. | |
248 | */ | |
249 | int nr_active; | |
250 | unsigned int children_weight; | |
251 | ||
1d3650f7 TH |
252 | /* |
253 | * vfraction is the fraction of vdisktime that the tasks in this | |
254 | * cfqg are entitled to. This is determined by compounding the | |
255 | * ratios walking up from this cfqg to the root. | |
256 | * | |
257 | * It is in fixed point w/ CFQ_SERVICE_SHIFT and the sum of all | |
258 | * vfractions on a service tree is approximately 1. The sum may | |
259 | * deviate a bit due to rounding errors and fluctuations caused by | |
260 | * cfqgs entering and leaving the service tree. | |
261 | */ | |
262 | unsigned int vfraction; | |
263 | ||
e71357e1 TH |
264 | /* |
265 | * There are two weights - (internal) weight is the weight of this | |
266 | * cfqg against the sibling cfqgs. leaf_weight is the wight of | |
267 | * this cfqg against the child cfqgs. For the root cfqg, both | |
268 | * weights are kept in sync for backward compatibility. | |
269 | */ | |
25bc6b07 | 270 | unsigned int weight; |
8184f93e | 271 | unsigned int new_weight; |
3381cb8d | 272 | unsigned int dev_weight; |
1fa8f6d6 | 273 | |
e71357e1 TH |
274 | unsigned int leaf_weight; |
275 | unsigned int new_leaf_weight; | |
276 | unsigned int dev_leaf_weight; | |
277 | ||
1fa8f6d6 VG |
278 | /* number of cfqq currently on this group */ |
279 | int nr_cfqq; | |
280 | ||
cdb16e8f | 281 | /* |
4495a7d4 | 282 | * Per group busy queues average. Useful for workload slice calc. We |
b4627321 VG |
283 | * create the array for each prio class but at run time it is used |
284 | * only for RT and BE class and slot for IDLE class remains unused. | |
285 | * This is primarily done to avoid confusion and a gcc warning. | |
286 | */ | |
287 | unsigned int busy_queues_avg[CFQ_PRIO_NR]; | |
288 | /* | |
289 | * rr lists of queues with requests. We maintain service trees for | |
290 | * RT and BE classes. These trees are subdivided in subclasses | |
291 | * of SYNC, SYNC_NOIDLE and ASYNC based on workload type. For IDLE | |
292 | * class there is no subclassification and all the cfq queues go on | |
293 | * a single tree service_tree_idle. | |
cdb16e8f VG |
294 | * Counts are embedded in the cfq_rb_root |
295 | */ | |
296 | struct cfq_rb_root service_trees[2][3]; | |
297 | struct cfq_rb_root service_tree_idle; | |
dae739eb | 298 | |
4d2ceea4 VG |
299 | unsigned long saved_wl_slice; |
300 | enum wl_type_t saved_wl_type; | |
301 | enum wl_class_t saved_wl_class; | |
4eef3049 | 302 | |
80bdf0c7 VG |
303 | /* number of requests that are on the dispatch list or inside driver */ |
304 | int dispatched; | |
7700fc4f | 305 | struct cfq_ttime ttime; |
0b39920b TH |
306 | struct cfqg_stats stats; /* stats for this cfqg */ |
307 | struct cfqg_stats dead_stats; /* stats pushed from dead children */ | |
cdb16e8f | 308 | }; |
718eee05 | 309 | |
c5869807 TH |
310 | struct cfq_io_cq { |
311 | struct io_cq icq; /* must be the first member */ | |
312 | struct cfq_queue *cfqq[2]; | |
313 | struct cfq_ttime ttime; | |
598971bf TH |
314 | int ioprio; /* the current ioprio */ |
315 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
f4da8072 | 316 | uint64_t blkcg_serial_nr; /* the current blkcg serial */ |
598971bf | 317 | #endif |
c5869807 TH |
318 | }; |
319 | ||
22e2c507 JA |
320 | /* |
321 | * Per block device queue structure | |
322 | */ | |
1da177e4 | 323 | struct cfq_data { |
165125e1 | 324 | struct request_queue *queue; |
1fa8f6d6 VG |
325 | /* Root service tree for cfq_groups */ |
326 | struct cfq_rb_root grp_service_tree; | |
f51b802c | 327 | struct cfq_group *root_group; |
22e2c507 | 328 | |
c0324a02 CZ |
329 | /* |
330 | * The priority currently being served | |
22e2c507 | 331 | */ |
4d2ceea4 VG |
332 | enum wl_class_t serving_wl_class; |
333 | enum wl_type_t serving_wl_type; | |
718eee05 | 334 | unsigned long workload_expires; |
cdb16e8f | 335 | struct cfq_group *serving_group; |
a36e71f9 JA |
336 | |
337 | /* | |
338 | * Each priority tree is sorted by next_request position. These | |
339 | * trees are used when determining if two or more queues are | |
340 | * interleaving requests (see cfq_close_cooperator). | |
341 | */ | |
342 | struct rb_root prio_trees[CFQ_PRIO_LISTS]; | |
343 | ||
22e2c507 | 344 | unsigned int busy_queues; |
ef8a41df | 345 | unsigned int busy_sync_queues; |
22e2c507 | 346 | |
53c583d2 CZ |
347 | int rq_in_driver; |
348 | int rq_in_flight[2]; | |
45333d5a AC |
349 | |
350 | /* | |
351 | * queue-depth detection | |
352 | */ | |
353 | int rq_queued; | |
25776e35 | 354 | int hw_tag; |
e459dd08 CZ |
355 | /* |
356 | * hw_tag can be | |
357 | * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection) | |
358 | * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth) | |
359 | * 0 => no NCQ | |
360 | */ | |
361 | int hw_tag_est_depth; | |
362 | unsigned int hw_tag_samples; | |
1da177e4 | 363 | |
22e2c507 JA |
364 | /* |
365 | * idle window management | |
366 | */ | |
367 | struct timer_list idle_slice_timer; | |
23e018a1 | 368 | struct work_struct unplug_work; |
1da177e4 | 369 | |
22e2c507 | 370 | struct cfq_queue *active_queue; |
c5869807 | 371 | struct cfq_io_cq *active_cic; |
22e2c507 | 372 | |
c2dea2d1 VT |
373 | /* |
374 | * async queue for each priority case | |
375 | */ | |
376 | struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; | |
377 | struct cfq_queue *async_idle_cfqq; | |
15c31be4 | 378 | |
6d048f53 | 379 | sector_t last_position; |
1da177e4 | 380 | |
1da177e4 LT |
381 | /* |
382 | * tunables, see top of file | |
383 | */ | |
384 | unsigned int cfq_quantum; | |
22e2c507 | 385 | unsigned int cfq_fifo_expire[2]; |
1da177e4 LT |
386 | unsigned int cfq_back_penalty; |
387 | unsigned int cfq_back_max; | |
22e2c507 JA |
388 | unsigned int cfq_slice[2]; |
389 | unsigned int cfq_slice_async_rq; | |
390 | unsigned int cfq_slice_idle; | |
80bdf0c7 | 391 | unsigned int cfq_group_idle; |
963b72fc | 392 | unsigned int cfq_latency; |
5bf14c07 | 393 | unsigned int cfq_target_latency; |
d9ff4187 | 394 | |
6118b70b JA |
395 | /* |
396 | * Fallback dummy cfqq for extreme OOM conditions | |
397 | */ | |
398 | struct cfq_queue oom_cfqq; | |
365722bb | 399 | |
573412b2 | 400 | unsigned long last_delayed_sync; |
1da177e4 LT |
401 | }; |
402 | ||
25fb5169 VG |
403 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd); |
404 | ||
34b98d03 | 405 | static struct cfq_rb_root *st_for(struct cfq_group *cfqg, |
3bf10fea | 406 | enum wl_class_t class, |
65b32a57 | 407 | enum wl_type_t type) |
c0324a02 | 408 | { |
1fa8f6d6 VG |
409 | if (!cfqg) |
410 | return NULL; | |
411 | ||
3bf10fea | 412 | if (class == IDLE_WORKLOAD) |
cdb16e8f | 413 | return &cfqg->service_tree_idle; |
c0324a02 | 414 | |
3bf10fea | 415 | return &cfqg->service_trees[class][type]; |
c0324a02 CZ |
416 | } |
417 | ||
3b18152c | 418 | enum cfqq_state_flags { |
b0b8d749 JA |
419 | CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ |
420 | CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ | |
b029195d | 421 | CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ |
b0b8d749 | 422 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ |
b0b8d749 JA |
423 | CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ |
424 | CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ | |
425 | CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ | |
44f7c160 | 426 | CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ |
91fac317 | 427 | CFQ_CFQQ_FLAG_sync, /* synchronous queue */ |
b3b6d040 | 428 | CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ |
ae54abed | 429 | CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */ |
76280aff | 430 | CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ |
f75edf2d | 431 | CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ |
3b18152c JA |
432 | }; |
433 | ||
434 | #define CFQ_CFQQ_FNS(name) \ | |
435 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ | |
436 | { \ | |
fe094d98 | 437 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ |
3b18152c JA |
438 | } \ |
439 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ | |
440 | { \ | |
fe094d98 | 441 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ |
3b18152c JA |
442 | } \ |
443 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ | |
444 | { \ | |
fe094d98 | 445 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ |
3b18152c JA |
446 | } |
447 | ||
448 | CFQ_CFQQ_FNS(on_rr); | |
449 | CFQ_CFQQ_FNS(wait_request); | |
b029195d | 450 | CFQ_CFQQ_FNS(must_dispatch); |
3b18152c | 451 | CFQ_CFQQ_FNS(must_alloc_slice); |
3b18152c JA |
452 | CFQ_CFQQ_FNS(fifo_expire); |
453 | CFQ_CFQQ_FNS(idle_window); | |
454 | CFQ_CFQQ_FNS(prio_changed); | |
44f7c160 | 455 | CFQ_CFQQ_FNS(slice_new); |
91fac317 | 456 | CFQ_CFQQ_FNS(sync); |
a36e71f9 | 457 | CFQ_CFQQ_FNS(coop); |
ae54abed | 458 | CFQ_CFQQ_FNS(split_coop); |
76280aff | 459 | CFQ_CFQQ_FNS(deep); |
f75edf2d | 460 | CFQ_CFQQ_FNS(wait_busy); |
3b18152c JA |
461 | #undef CFQ_CFQQ_FNS |
462 | ||
629ed0b1 | 463 | #if defined(CONFIG_CFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) |
2ce4d50f | 464 | |
155fead9 TH |
465 | /* cfqg stats flags */ |
466 | enum cfqg_stats_flags { | |
467 | CFQG_stats_waiting = 0, | |
468 | CFQG_stats_idling, | |
469 | CFQG_stats_empty, | |
629ed0b1 TH |
470 | }; |
471 | ||
155fead9 TH |
472 | #define CFQG_FLAG_FNS(name) \ |
473 | static inline void cfqg_stats_mark_##name(struct cfqg_stats *stats) \ | |
629ed0b1 | 474 | { \ |
155fead9 | 475 | stats->flags |= (1 << CFQG_stats_##name); \ |
629ed0b1 | 476 | } \ |
155fead9 | 477 | static inline void cfqg_stats_clear_##name(struct cfqg_stats *stats) \ |
629ed0b1 | 478 | { \ |
155fead9 | 479 | stats->flags &= ~(1 << CFQG_stats_##name); \ |
629ed0b1 | 480 | } \ |
155fead9 | 481 | static inline int cfqg_stats_##name(struct cfqg_stats *stats) \ |
629ed0b1 | 482 | { \ |
155fead9 | 483 | return (stats->flags & (1 << CFQG_stats_##name)) != 0; \ |
629ed0b1 TH |
484 | } \ |
485 | ||
155fead9 TH |
486 | CFQG_FLAG_FNS(waiting) |
487 | CFQG_FLAG_FNS(idling) | |
488 | CFQG_FLAG_FNS(empty) | |
489 | #undef CFQG_FLAG_FNS | |
629ed0b1 TH |
490 | |
491 | /* This should be called with the queue_lock held. */ | |
155fead9 | 492 | static void cfqg_stats_update_group_wait_time(struct cfqg_stats *stats) |
629ed0b1 TH |
493 | { |
494 | unsigned long long now; | |
495 | ||
155fead9 | 496 | if (!cfqg_stats_waiting(stats)) |
629ed0b1 TH |
497 | return; |
498 | ||
499 | now = sched_clock(); | |
500 | if (time_after64(now, stats->start_group_wait_time)) | |
501 | blkg_stat_add(&stats->group_wait_time, | |
502 | now - stats->start_group_wait_time); | |
155fead9 | 503 | cfqg_stats_clear_waiting(stats); |
629ed0b1 TH |
504 | } |
505 | ||
506 | /* This should be called with the queue_lock held. */ | |
155fead9 TH |
507 | static void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, |
508 | struct cfq_group *curr_cfqg) | |
629ed0b1 | 509 | { |
155fead9 | 510 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 511 | |
155fead9 | 512 | if (cfqg_stats_waiting(stats)) |
629ed0b1 | 513 | return; |
155fead9 | 514 | if (cfqg == curr_cfqg) |
629ed0b1 | 515 | return; |
155fead9 TH |
516 | stats->start_group_wait_time = sched_clock(); |
517 | cfqg_stats_mark_waiting(stats); | |
629ed0b1 TH |
518 | } |
519 | ||
520 | /* This should be called with the queue_lock held. */ | |
155fead9 | 521 | static void cfqg_stats_end_empty_time(struct cfqg_stats *stats) |
629ed0b1 TH |
522 | { |
523 | unsigned long long now; | |
524 | ||
155fead9 | 525 | if (!cfqg_stats_empty(stats)) |
629ed0b1 TH |
526 | return; |
527 | ||
528 | now = sched_clock(); | |
529 | if (time_after64(now, stats->start_empty_time)) | |
530 | blkg_stat_add(&stats->empty_time, | |
531 | now - stats->start_empty_time); | |
155fead9 | 532 | cfqg_stats_clear_empty(stats); |
629ed0b1 TH |
533 | } |
534 | ||
155fead9 | 535 | static void cfqg_stats_update_dequeue(struct cfq_group *cfqg) |
629ed0b1 | 536 | { |
155fead9 | 537 | blkg_stat_add(&cfqg->stats.dequeue, 1); |
629ed0b1 TH |
538 | } |
539 | ||
155fead9 | 540 | static void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) |
629ed0b1 | 541 | { |
155fead9 | 542 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 543 | |
4d5e80a7 | 544 | if (blkg_rwstat_total(&stats->queued)) |
629ed0b1 TH |
545 | return; |
546 | ||
547 | /* | |
548 | * group is already marked empty. This can happen if cfqq got new | |
549 | * request in parent group and moved to this group while being added | |
550 | * to service tree. Just ignore the event and move on. | |
551 | */ | |
155fead9 | 552 | if (cfqg_stats_empty(stats)) |
629ed0b1 TH |
553 | return; |
554 | ||
555 | stats->start_empty_time = sched_clock(); | |
155fead9 | 556 | cfqg_stats_mark_empty(stats); |
629ed0b1 TH |
557 | } |
558 | ||
155fead9 | 559 | static void cfqg_stats_update_idle_time(struct cfq_group *cfqg) |
629ed0b1 | 560 | { |
155fead9 | 561 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 562 | |
155fead9 | 563 | if (cfqg_stats_idling(stats)) { |
629ed0b1 TH |
564 | unsigned long long now = sched_clock(); |
565 | ||
566 | if (time_after64(now, stats->start_idle_time)) | |
567 | blkg_stat_add(&stats->idle_time, | |
568 | now - stats->start_idle_time); | |
155fead9 | 569 | cfqg_stats_clear_idling(stats); |
629ed0b1 TH |
570 | } |
571 | } | |
572 | ||
155fead9 | 573 | static void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) |
629ed0b1 | 574 | { |
155fead9 | 575 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 576 | |
155fead9 | 577 | BUG_ON(cfqg_stats_idling(stats)); |
629ed0b1 TH |
578 | |
579 | stats->start_idle_time = sched_clock(); | |
155fead9 | 580 | cfqg_stats_mark_idling(stats); |
629ed0b1 TH |
581 | } |
582 | ||
155fead9 | 583 | static void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) |
629ed0b1 | 584 | { |
155fead9 | 585 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 TH |
586 | |
587 | blkg_stat_add(&stats->avg_queue_size_sum, | |
4d5e80a7 | 588 | blkg_rwstat_total(&stats->queued)); |
629ed0b1 | 589 | blkg_stat_add(&stats->avg_queue_size_samples, 1); |
155fead9 | 590 | cfqg_stats_update_group_wait_time(stats); |
629ed0b1 TH |
591 | } |
592 | ||
593 | #else /* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */ | |
594 | ||
f48ec1d7 TH |
595 | static inline void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, struct cfq_group *curr_cfqg) { } |
596 | static inline void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { } | |
597 | static inline void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { } | |
598 | static inline void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) { } | |
599 | static inline void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { } | |
600 | static inline void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) { } | |
601 | static inline void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { } | |
629ed0b1 TH |
602 | |
603 | #endif /* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */ | |
604 | ||
605 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
2ce4d50f | 606 | |
4ceab71b JA |
607 | static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd) |
608 | { | |
609 | return pd ? container_of(pd, struct cfq_group, pd) : NULL; | |
610 | } | |
611 | ||
612 | static struct cfq_group_data | |
613 | *cpd_to_cfqgd(struct blkcg_policy_data *cpd) | |
614 | { | |
615 | return cpd ? container_of(cpd, struct cfq_group_data, pd) : NULL; | |
616 | } | |
617 | ||
618 | static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg) | |
619 | { | |
620 | return pd_to_blkg(&cfqg->pd); | |
621 | } | |
622 | ||
ffea73fc TH |
623 | static struct blkcg_policy blkcg_policy_cfq; |
624 | ||
625 | static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg) | |
626 | { | |
627 | return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq)); | |
628 | } | |
629 | ||
e48453c3 AA |
630 | static struct cfq_group_data *blkcg_to_cfqgd(struct blkcg *blkcg) |
631 | { | |
632 | return cpd_to_cfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_cfq)); | |
633 | } | |
634 | ||
d02f7aa8 | 635 | static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) |
7918ffb5 | 636 | { |
d02f7aa8 | 637 | struct blkcg_gq *pblkg = cfqg_to_blkg(cfqg)->parent; |
7918ffb5 | 638 | |
d02f7aa8 | 639 | return pblkg ? blkg_to_cfqg(pblkg) : NULL; |
7918ffb5 TH |
640 | } |
641 | ||
eb7d8c07 TH |
642 | static inline void cfqg_get(struct cfq_group *cfqg) |
643 | { | |
644 | return blkg_get(cfqg_to_blkg(cfqg)); | |
645 | } | |
646 | ||
647 | static inline void cfqg_put(struct cfq_group *cfqg) | |
648 | { | |
649 | return blkg_put(cfqg_to_blkg(cfqg)); | |
650 | } | |
651 | ||
54e7ed12 TH |
652 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) do { \ |
653 | char __pbuf[128]; \ | |
654 | \ | |
655 | blkg_path(cfqg_to_blkg((cfqq)->cfqg), __pbuf, sizeof(__pbuf)); \ | |
b226e5c4 VG |
656 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c %s " fmt, (cfqq)->pid, \ |
657 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ | |
658 | cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\ | |
54e7ed12 TH |
659 | __pbuf, ##args); \ |
660 | } while (0) | |
661 | ||
662 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do { \ | |
663 | char __pbuf[128]; \ | |
664 | \ | |
665 | blkg_path(cfqg_to_blkg(cfqg), __pbuf, sizeof(__pbuf)); \ | |
666 | blk_add_trace_msg((cfqd)->queue, "%s " fmt, __pbuf, ##args); \ | |
667 | } while (0) | |
2868ef7b | 668 | |
155fead9 TH |
669 | static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, |
670 | struct cfq_group *curr_cfqg, int rw) | |
2ce4d50f | 671 | { |
155fead9 TH |
672 | blkg_rwstat_add(&cfqg->stats.queued, rw, 1); |
673 | cfqg_stats_end_empty_time(&cfqg->stats); | |
674 | cfqg_stats_set_start_group_wait_time(cfqg, curr_cfqg); | |
2ce4d50f TH |
675 | } |
676 | ||
155fead9 TH |
677 | static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, |
678 | unsigned long time, unsigned long unaccounted_time) | |
2ce4d50f | 679 | { |
155fead9 | 680 | blkg_stat_add(&cfqg->stats.time, time); |
629ed0b1 | 681 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
155fead9 | 682 | blkg_stat_add(&cfqg->stats.unaccounted_time, unaccounted_time); |
629ed0b1 | 683 | #endif |
2ce4d50f TH |
684 | } |
685 | ||
155fead9 | 686 | static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int rw) |
2ce4d50f | 687 | { |
155fead9 | 688 | blkg_rwstat_add(&cfqg->stats.queued, rw, -1); |
2ce4d50f TH |
689 | } |
690 | ||
155fead9 | 691 | static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int rw) |
2ce4d50f | 692 | { |
155fead9 | 693 | blkg_rwstat_add(&cfqg->stats.merged, rw, 1); |
2ce4d50f TH |
694 | } |
695 | ||
155fead9 TH |
696 | static inline void cfqg_stats_update_dispatch(struct cfq_group *cfqg, |
697 | uint64_t bytes, int rw) | |
2ce4d50f | 698 | { |
155fead9 TH |
699 | blkg_stat_add(&cfqg->stats.sectors, bytes >> 9); |
700 | blkg_rwstat_add(&cfqg->stats.serviced, rw, 1); | |
701 | blkg_rwstat_add(&cfqg->stats.service_bytes, rw, bytes); | |
2ce4d50f TH |
702 | } |
703 | ||
155fead9 TH |
704 | static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, |
705 | uint64_t start_time, uint64_t io_start_time, int rw) | |
2ce4d50f | 706 | { |
155fead9 | 707 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 708 | unsigned long long now = sched_clock(); |
629ed0b1 TH |
709 | |
710 | if (time_after64(now, io_start_time)) | |
711 | blkg_rwstat_add(&stats->service_time, rw, now - io_start_time); | |
712 | if (time_after64(io_start_time, start_time)) | |
713 | blkg_rwstat_add(&stats->wait_time, rw, | |
714 | io_start_time - start_time); | |
2ce4d50f TH |
715 | } |
716 | ||
689665af TH |
717 | /* @stats = 0 */ |
718 | static void cfqg_stats_reset(struct cfqg_stats *stats) | |
155fead9 | 719 | { |
155fead9 TH |
720 | /* queued stats shouldn't be cleared */ |
721 | blkg_rwstat_reset(&stats->service_bytes); | |
722 | blkg_rwstat_reset(&stats->serviced); | |
723 | blkg_rwstat_reset(&stats->merged); | |
724 | blkg_rwstat_reset(&stats->service_time); | |
725 | blkg_rwstat_reset(&stats->wait_time); | |
726 | blkg_stat_reset(&stats->time); | |
727 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
728 | blkg_stat_reset(&stats->unaccounted_time); | |
729 | blkg_stat_reset(&stats->avg_queue_size_sum); | |
730 | blkg_stat_reset(&stats->avg_queue_size_samples); | |
731 | blkg_stat_reset(&stats->dequeue); | |
732 | blkg_stat_reset(&stats->group_wait_time); | |
733 | blkg_stat_reset(&stats->idle_time); | |
734 | blkg_stat_reset(&stats->empty_time); | |
735 | #endif | |
736 | } | |
737 | ||
0b39920b TH |
738 | /* @to += @from */ |
739 | static void cfqg_stats_merge(struct cfqg_stats *to, struct cfqg_stats *from) | |
740 | { | |
741 | /* queued stats shouldn't be cleared */ | |
742 | blkg_rwstat_merge(&to->service_bytes, &from->service_bytes); | |
743 | blkg_rwstat_merge(&to->serviced, &from->serviced); | |
744 | blkg_rwstat_merge(&to->merged, &from->merged); | |
745 | blkg_rwstat_merge(&to->service_time, &from->service_time); | |
746 | blkg_rwstat_merge(&to->wait_time, &from->wait_time); | |
747 | blkg_stat_merge(&from->time, &from->time); | |
748 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
749 | blkg_stat_merge(&to->unaccounted_time, &from->unaccounted_time); | |
750 | blkg_stat_merge(&to->avg_queue_size_sum, &from->avg_queue_size_sum); | |
751 | blkg_stat_merge(&to->avg_queue_size_samples, &from->avg_queue_size_samples); | |
752 | blkg_stat_merge(&to->dequeue, &from->dequeue); | |
753 | blkg_stat_merge(&to->group_wait_time, &from->group_wait_time); | |
754 | blkg_stat_merge(&to->idle_time, &from->idle_time); | |
755 | blkg_stat_merge(&to->empty_time, &from->empty_time); | |
756 | #endif | |
757 | } | |
758 | ||
759 | /* | |
760 | * Transfer @cfqg's stats to its parent's dead_stats so that the ancestors' | |
761 | * recursive stats can still account for the amount used by this cfqg after | |
762 | * it's gone. | |
763 | */ | |
764 | static void cfqg_stats_xfer_dead(struct cfq_group *cfqg) | |
765 | { | |
766 | struct cfq_group *parent = cfqg_parent(cfqg); | |
767 | ||
768 | lockdep_assert_held(cfqg_to_blkg(cfqg)->q->queue_lock); | |
769 | ||
770 | if (unlikely(!parent)) | |
771 | return; | |
772 | ||
773 | cfqg_stats_merge(&parent->dead_stats, &cfqg->stats); | |
774 | cfqg_stats_merge(&parent->dead_stats, &cfqg->dead_stats); | |
775 | cfqg_stats_reset(&cfqg->stats); | |
776 | cfqg_stats_reset(&cfqg->dead_stats); | |
777 | } | |
778 | ||
eb7d8c07 TH |
779 | #else /* CONFIG_CFQ_GROUP_IOSCHED */ |
780 | ||
d02f7aa8 | 781 | static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) { return NULL; } |
eb7d8c07 TH |
782 | static inline void cfqg_get(struct cfq_group *cfqg) { } |
783 | static inline void cfqg_put(struct cfq_group *cfqg) { } | |
784 | ||
7b679138 | 785 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
b226e5c4 VG |
786 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c " fmt, (cfqq)->pid, \ |
787 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ | |
788 | cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\ | |
789 | ##args) | |
4495a7d4 | 790 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0) |
eb7d8c07 | 791 | |
155fead9 TH |
792 | static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, |
793 | struct cfq_group *curr_cfqg, int rw) { } | |
794 | static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, | |
795 | unsigned long time, unsigned long unaccounted_time) { } | |
796 | static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int rw) { } | |
797 | static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int rw) { } | |
798 | static inline void cfqg_stats_update_dispatch(struct cfq_group *cfqg, | |
799 | uint64_t bytes, int rw) { } | |
800 | static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, | |
801 | uint64_t start_time, uint64_t io_start_time, int rw) { } | |
2ce4d50f | 802 | |
eb7d8c07 TH |
803 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ |
804 | ||
7b679138 JA |
805 | #define cfq_log(cfqd, fmt, args...) \ |
806 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) | |
807 | ||
615f0259 VG |
808 | /* Traverses through cfq group service trees */ |
809 | #define for_each_cfqg_st(cfqg, i, j, st) \ | |
810 | for (i = 0; i <= IDLE_WORKLOAD; i++) \ | |
811 | for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\ | |
812 | : &cfqg->service_tree_idle; \ | |
813 | (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \ | |
814 | (i == IDLE_WORKLOAD && j == 0); \ | |
815 | j++, st = i < IDLE_WORKLOAD ? \ | |
816 | &cfqg->service_trees[i][j]: NULL) \ | |
817 | ||
f5f2b6ce SL |
818 | static inline bool cfq_io_thinktime_big(struct cfq_data *cfqd, |
819 | struct cfq_ttime *ttime, bool group_idle) | |
820 | { | |
821 | unsigned long slice; | |
822 | if (!sample_valid(ttime->ttime_samples)) | |
823 | return false; | |
824 | if (group_idle) | |
825 | slice = cfqd->cfq_group_idle; | |
826 | else | |
827 | slice = cfqd->cfq_slice_idle; | |
828 | return ttime->ttime_mean > slice; | |
829 | } | |
615f0259 | 830 | |
02b35081 VG |
831 | static inline bool iops_mode(struct cfq_data *cfqd) |
832 | { | |
833 | /* | |
834 | * If we are not idling on queues and it is a NCQ drive, parallel | |
835 | * execution of requests is on and measuring time is not possible | |
836 | * in most of the cases until and unless we drive shallower queue | |
837 | * depths and that becomes a performance bottleneck. In such cases | |
838 | * switch to start providing fairness in terms of number of IOs. | |
839 | */ | |
840 | if (!cfqd->cfq_slice_idle && cfqd->hw_tag) | |
841 | return true; | |
842 | else | |
843 | return false; | |
844 | } | |
845 | ||
3bf10fea | 846 | static inline enum wl_class_t cfqq_class(struct cfq_queue *cfqq) |
c0324a02 CZ |
847 | { |
848 | if (cfq_class_idle(cfqq)) | |
849 | return IDLE_WORKLOAD; | |
850 | if (cfq_class_rt(cfqq)) | |
851 | return RT_WORKLOAD; | |
852 | return BE_WORKLOAD; | |
853 | } | |
854 | ||
718eee05 CZ |
855 | |
856 | static enum wl_type_t cfqq_type(struct cfq_queue *cfqq) | |
857 | { | |
858 | if (!cfq_cfqq_sync(cfqq)) | |
859 | return ASYNC_WORKLOAD; | |
860 | if (!cfq_cfqq_idle_window(cfqq)) | |
861 | return SYNC_NOIDLE_WORKLOAD; | |
862 | return SYNC_WORKLOAD; | |
863 | } | |
864 | ||
3bf10fea | 865 | static inline int cfq_group_busy_queues_wl(enum wl_class_t wl_class, |
58ff82f3 VG |
866 | struct cfq_data *cfqd, |
867 | struct cfq_group *cfqg) | |
c0324a02 | 868 | { |
3bf10fea | 869 | if (wl_class == IDLE_WORKLOAD) |
cdb16e8f | 870 | return cfqg->service_tree_idle.count; |
c0324a02 | 871 | |
34b98d03 VG |
872 | return cfqg->service_trees[wl_class][ASYNC_WORKLOAD].count + |
873 | cfqg->service_trees[wl_class][SYNC_NOIDLE_WORKLOAD].count + | |
874 | cfqg->service_trees[wl_class][SYNC_WORKLOAD].count; | |
c0324a02 CZ |
875 | } |
876 | ||
f26bd1f0 VG |
877 | static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, |
878 | struct cfq_group *cfqg) | |
879 | { | |
34b98d03 VG |
880 | return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count + |
881 | cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count; | |
f26bd1f0 VG |
882 | } |
883 | ||
165125e1 | 884 | static void cfq_dispatch_insert(struct request_queue *, struct request *); |
4f85cb96 | 885 | static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, bool is_sync, |
abede6da | 886 | struct cfq_io_cq *cic, struct bio *bio, |
4f85cb96 | 887 | gfp_t gfp_mask); |
91fac317 | 888 | |
c5869807 TH |
889 | static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq) |
890 | { | |
891 | /* cic->icq is the first member, %NULL will convert to %NULL */ | |
892 | return container_of(icq, struct cfq_io_cq, icq); | |
893 | } | |
894 | ||
47fdd4ca TH |
895 | static inline struct cfq_io_cq *cfq_cic_lookup(struct cfq_data *cfqd, |
896 | struct io_context *ioc) | |
897 | { | |
898 | if (ioc) | |
899 | return icq_to_cic(ioc_lookup_icq(ioc, cfqd->queue)); | |
900 | return NULL; | |
901 | } | |
902 | ||
c5869807 | 903 | static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_cq *cic, bool is_sync) |
91fac317 | 904 | { |
a6151c3a | 905 | return cic->cfqq[is_sync]; |
91fac317 VT |
906 | } |
907 | ||
c5869807 TH |
908 | static inline void cic_set_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq, |
909 | bool is_sync) | |
91fac317 | 910 | { |
a6151c3a | 911 | cic->cfqq[is_sync] = cfqq; |
91fac317 VT |
912 | } |
913 | ||
c5869807 | 914 | static inline struct cfq_data *cic_to_cfqd(struct cfq_io_cq *cic) |
bca4b914 | 915 | { |
c5869807 | 916 | return cic->icq.q->elevator->elevator_data; |
bca4b914 KK |
917 | } |
918 | ||
91fac317 VT |
919 | /* |
920 | * We regard a request as SYNC, if it's either a read or has the SYNC bit | |
921 | * set (in which case it could also be direct WRITE). | |
922 | */ | |
a6151c3a | 923 | static inline bool cfq_bio_sync(struct bio *bio) |
91fac317 | 924 | { |
7b6d91da | 925 | return bio_data_dir(bio) == READ || (bio->bi_rw & REQ_SYNC); |
91fac317 | 926 | } |
1da177e4 | 927 | |
99f95e52 AM |
928 | /* |
929 | * scheduler run of queue, if there are requests pending and no one in the | |
930 | * driver that will restart queueing | |
931 | */ | |
23e018a1 | 932 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) |
99f95e52 | 933 | { |
7b679138 JA |
934 | if (cfqd->busy_queues) { |
935 | cfq_log(cfqd, "schedule dispatch"); | |
59c3d45e | 936 | kblockd_schedule_work(&cfqd->unplug_work); |
7b679138 | 937 | } |
99f95e52 AM |
938 | } |
939 | ||
44f7c160 JA |
940 | /* |
941 | * Scale schedule slice based on io priority. Use the sync time slice only | |
942 | * if a queue is marked sync and has sync io queued. A sync queue with async | |
943 | * io only, should not get full sync slice length. | |
944 | */ | |
a6151c3a | 945 | static inline int cfq_prio_slice(struct cfq_data *cfqd, bool sync, |
d9e7620e | 946 | unsigned short prio) |
44f7c160 | 947 | { |
d9e7620e | 948 | const int base_slice = cfqd->cfq_slice[sync]; |
44f7c160 | 949 | |
d9e7620e JA |
950 | WARN_ON(prio >= IOPRIO_BE_NR); |
951 | ||
952 | return base_slice + (base_slice/CFQ_SLICE_SCALE * (4 - prio)); | |
953 | } | |
44f7c160 | 954 | |
d9e7620e JA |
955 | static inline int |
956 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
957 | { | |
958 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); | |
44f7c160 JA |
959 | } |
960 | ||
1d3650f7 TH |
961 | /** |
962 | * cfqg_scale_charge - scale disk time charge according to cfqg weight | |
963 | * @charge: disk time being charged | |
964 | * @vfraction: vfraction of the cfqg, fixed point w/ CFQ_SERVICE_SHIFT | |
965 | * | |
966 | * Scale @charge according to @vfraction, which is in range (0, 1]. The | |
967 | * scaling is inversely proportional. | |
968 | * | |
969 | * scaled = charge / vfraction | |
970 | * | |
971 | * The result is also in fixed point w/ CFQ_SERVICE_SHIFT. | |
972 | */ | |
973 | static inline u64 cfqg_scale_charge(unsigned long charge, | |
974 | unsigned int vfraction) | |
25bc6b07 | 975 | { |
1d3650f7 | 976 | u64 c = charge << CFQ_SERVICE_SHIFT; /* make it fixed point */ |
25bc6b07 | 977 | |
1d3650f7 TH |
978 | /* charge / vfraction */ |
979 | c <<= CFQ_SERVICE_SHIFT; | |
980 | do_div(c, vfraction); | |
981 | return c; | |
25bc6b07 VG |
982 | } |
983 | ||
984 | static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime) | |
985 | { | |
986 | s64 delta = (s64)(vdisktime - min_vdisktime); | |
987 | if (delta > 0) | |
988 | min_vdisktime = vdisktime; | |
989 | ||
990 | return min_vdisktime; | |
991 | } | |
992 | ||
993 | static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime) | |
994 | { | |
995 | s64 delta = (s64)(vdisktime - min_vdisktime); | |
996 | if (delta < 0) | |
997 | min_vdisktime = vdisktime; | |
998 | ||
999 | return min_vdisktime; | |
1000 | } | |
1001 | ||
1002 | static void update_min_vdisktime(struct cfq_rb_root *st) | |
1003 | { | |
25bc6b07 VG |
1004 | struct cfq_group *cfqg; |
1005 | ||
25bc6b07 VG |
1006 | if (st->left) { |
1007 | cfqg = rb_entry_cfqg(st->left); | |
a6032710 GJ |
1008 | st->min_vdisktime = max_vdisktime(st->min_vdisktime, |
1009 | cfqg->vdisktime); | |
25bc6b07 | 1010 | } |
25bc6b07 VG |
1011 | } |
1012 | ||
5db5d642 CZ |
1013 | /* |
1014 | * get averaged number of queues of RT/BE priority. | |
1015 | * average is updated, with a formula that gives more weight to higher numbers, | |
1016 | * to quickly follows sudden increases and decrease slowly | |
1017 | */ | |
1018 | ||
58ff82f3 VG |
1019 | static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd, |
1020 | struct cfq_group *cfqg, bool rt) | |
5869619c | 1021 | { |
5db5d642 CZ |
1022 | unsigned min_q, max_q; |
1023 | unsigned mult = cfq_hist_divisor - 1; | |
1024 | unsigned round = cfq_hist_divisor / 2; | |
58ff82f3 | 1025 | unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg); |
5db5d642 | 1026 | |
58ff82f3 VG |
1027 | min_q = min(cfqg->busy_queues_avg[rt], busy); |
1028 | max_q = max(cfqg->busy_queues_avg[rt], busy); | |
1029 | cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) / | |
5db5d642 | 1030 | cfq_hist_divisor; |
58ff82f3 VG |
1031 | return cfqg->busy_queues_avg[rt]; |
1032 | } | |
1033 | ||
1034 | static inline unsigned | |
1035 | cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
1036 | { | |
41cad6ab | 1037 | return cfqd->cfq_target_latency * cfqg->vfraction >> CFQ_SERVICE_SHIFT; |
5db5d642 CZ |
1038 | } |
1039 | ||
c553f8e3 | 1040 | static inline unsigned |
ba5bd520 | 1041 | cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
44f7c160 | 1042 | { |
5db5d642 CZ |
1043 | unsigned slice = cfq_prio_to_slice(cfqd, cfqq); |
1044 | if (cfqd->cfq_latency) { | |
58ff82f3 VG |
1045 | /* |
1046 | * interested queues (we consider only the ones with the same | |
1047 | * priority class in the cfq group) | |
1048 | */ | |
1049 | unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg, | |
1050 | cfq_class_rt(cfqq)); | |
5db5d642 CZ |
1051 | unsigned sync_slice = cfqd->cfq_slice[1]; |
1052 | unsigned expect_latency = sync_slice * iq; | |
58ff82f3 VG |
1053 | unsigned group_slice = cfq_group_slice(cfqd, cfqq->cfqg); |
1054 | ||
1055 | if (expect_latency > group_slice) { | |
5db5d642 CZ |
1056 | unsigned base_low_slice = 2 * cfqd->cfq_slice_idle; |
1057 | /* scale low_slice according to IO priority | |
1058 | * and sync vs async */ | |
1059 | unsigned low_slice = | |
1060 | min(slice, base_low_slice * slice / sync_slice); | |
1061 | /* the adapted slice value is scaled to fit all iqs | |
1062 | * into the target latency */ | |
58ff82f3 | 1063 | slice = max(slice * group_slice / expect_latency, |
5db5d642 CZ |
1064 | low_slice); |
1065 | } | |
1066 | } | |
c553f8e3 SL |
1067 | return slice; |
1068 | } | |
1069 | ||
1070 | static inline void | |
1071 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
1072 | { | |
ba5bd520 | 1073 | unsigned slice = cfq_scaled_cfqq_slice(cfqd, cfqq); |
c553f8e3 | 1074 | |
dae739eb | 1075 | cfqq->slice_start = jiffies; |
5db5d642 | 1076 | cfqq->slice_end = jiffies + slice; |
f75edf2d | 1077 | cfqq->allocated_slice = slice; |
7b679138 | 1078 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%lu", cfqq->slice_end - jiffies); |
44f7c160 JA |
1079 | } |
1080 | ||
1081 | /* | |
1082 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end | |
1083 | * isn't valid until the first request from the dispatch is activated | |
1084 | * and the slice time set. | |
1085 | */ | |
a6151c3a | 1086 | static inline bool cfq_slice_used(struct cfq_queue *cfqq) |
44f7c160 JA |
1087 | { |
1088 | if (cfq_cfqq_slice_new(cfqq)) | |
c1e44756 | 1089 | return false; |
44f7c160 | 1090 | if (time_before(jiffies, cfqq->slice_end)) |
c1e44756 | 1091 | return false; |
44f7c160 | 1092 | |
c1e44756 | 1093 | return true; |
44f7c160 JA |
1094 | } |
1095 | ||
1da177e4 | 1096 | /* |
5e705374 | 1097 | * Lifted from AS - choose which of rq1 and rq2 that is best served now. |
1da177e4 | 1098 | * We choose the request that is closest to the head right now. Distance |
e8a99053 | 1099 | * behind the head is penalized and only allowed to a certain extent. |
1da177e4 | 1100 | */ |
5e705374 | 1101 | static struct request * |
cf7c25cf | 1102 | cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, sector_t last) |
1da177e4 | 1103 | { |
cf7c25cf | 1104 | sector_t s1, s2, d1 = 0, d2 = 0; |
1da177e4 | 1105 | unsigned long back_max; |
e8a99053 AM |
1106 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ |
1107 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ | |
1108 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ | |
1da177e4 | 1109 | |
5e705374 JA |
1110 | if (rq1 == NULL || rq1 == rq2) |
1111 | return rq2; | |
1112 | if (rq2 == NULL) | |
1113 | return rq1; | |
9c2c38a1 | 1114 | |
229836bd NK |
1115 | if (rq_is_sync(rq1) != rq_is_sync(rq2)) |
1116 | return rq_is_sync(rq1) ? rq1 : rq2; | |
1117 | ||
65299a3b CH |
1118 | if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_PRIO) |
1119 | return rq1->cmd_flags & REQ_PRIO ? rq1 : rq2; | |
b53d1ed7 | 1120 | |
83096ebf TH |
1121 | s1 = blk_rq_pos(rq1); |
1122 | s2 = blk_rq_pos(rq2); | |
1da177e4 | 1123 | |
1da177e4 LT |
1124 | /* |
1125 | * by definition, 1KiB is 2 sectors | |
1126 | */ | |
1127 | back_max = cfqd->cfq_back_max * 2; | |
1128 | ||
1129 | /* | |
1130 | * Strict one way elevator _except_ in the case where we allow | |
1131 | * short backward seeks which are biased as twice the cost of a | |
1132 | * similar forward seek. | |
1133 | */ | |
1134 | if (s1 >= last) | |
1135 | d1 = s1 - last; | |
1136 | else if (s1 + back_max >= last) | |
1137 | d1 = (last - s1) * cfqd->cfq_back_penalty; | |
1138 | else | |
e8a99053 | 1139 | wrap |= CFQ_RQ1_WRAP; |
1da177e4 LT |
1140 | |
1141 | if (s2 >= last) | |
1142 | d2 = s2 - last; | |
1143 | else if (s2 + back_max >= last) | |
1144 | d2 = (last - s2) * cfqd->cfq_back_penalty; | |
1145 | else | |
e8a99053 | 1146 | wrap |= CFQ_RQ2_WRAP; |
1da177e4 LT |
1147 | |
1148 | /* Found required data */ | |
e8a99053 AM |
1149 | |
1150 | /* | |
1151 | * By doing switch() on the bit mask "wrap" we avoid having to | |
1152 | * check two variables for all permutations: --> faster! | |
1153 | */ | |
1154 | switch (wrap) { | |
5e705374 | 1155 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ |
e8a99053 | 1156 | if (d1 < d2) |
5e705374 | 1157 | return rq1; |
e8a99053 | 1158 | else if (d2 < d1) |
5e705374 | 1159 | return rq2; |
e8a99053 AM |
1160 | else { |
1161 | if (s1 >= s2) | |
5e705374 | 1162 | return rq1; |
e8a99053 | 1163 | else |
5e705374 | 1164 | return rq2; |
e8a99053 | 1165 | } |
1da177e4 | 1166 | |
e8a99053 | 1167 | case CFQ_RQ2_WRAP: |
5e705374 | 1168 | return rq1; |
e8a99053 | 1169 | case CFQ_RQ1_WRAP: |
5e705374 JA |
1170 | return rq2; |
1171 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ | |
e8a99053 AM |
1172 | default: |
1173 | /* | |
1174 | * Since both rqs are wrapped, | |
1175 | * start with the one that's further behind head | |
1176 | * (--> only *one* back seek required), | |
1177 | * since back seek takes more time than forward. | |
1178 | */ | |
1179 | if (s1 <= s2) | |
5e705374 | 1180 | return rq1; |
1da177e4 | 1181 | else |
5e705374 | 1182 | return rq2; |
1da177e4 LT |
1183 | } |
1184 | } | |
1185 | ||
498d3aa2 JA |
1186 | /* |
1187 | * The below is leftmost cache rbtree addon | |
1188 | */ | |
0871714e | 1189 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) |
cc09e299 | 1190 | { |
615f0259 VG |
1191 | /* Service tree is empty */ |
1192 | if (!root->count) | |
1193 | return NULL; | |
1194 | ||
cc09e299 JA |
1195 | if (!root->left) |
1196 | root->left = rb_first(&root->rb); | |
1197 | ||
0871714e JA |
1198 | if (root->left) |
1199 | return rb_entry(root->left, struct cfq_queue, rb_node); | |
1200 | ||
1201 | return NULL; | |
cc09e299 JA |
1202 | } |
1203 | ||
1fa8f6d6 VG |
1204 | static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root) |
1205 | { | |
1206 | if (!root->left) | |
1207 | root->left = rb_first(&root->rb); | |
1208 | ||
1209 | if (root->left) | |
1210 | return rb_entry_cfqg(root->left); | |
1211 | ||
1212 | return NULL; | |
1213 | } | |
1214 | ||
a36e71f9 JA |
1215 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
1216 | { | |
1217 | rb_erase(n, root); | |
1218 | RB_CLEAR_NODE(n); | |
1219 | } | |
1220 | ||
cc09e299 JA |
1221 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) |
1222 | { | |
1223 | if (root->left == n) | |
1224 | root->left = NULL; | |
a36e71f9 | 1225 | rb_erase_init(n, &root->rb); |
aa6f6a3d | 1226 | --root->count; |
cc09e299 JA |
1227 | } |
1228 | ||
1da177e4 LT |
1229 | /* |
1230 | * would be nice to take fifo expire time into account as well | |
1231 | */ | |
5e705374 JA |
1232 | static struct request * |
1233 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
1234 | struct request *last) | |
1da177e4 | 1235 | { |
21183b07 JA |
1236 | struct rb_node *rbnext = rb_next(&last->rb_node); |
1237 | struct rb_node *rbprev = rb_prev(&last->rb_node); | |
5e705374 | 1238 | struct request *next = NULL, *prev = NULL; |
1da177e4 | 1239 | |
21183b07 | 1240 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); |
1da177e4 LT |
1241 | |
1242 | if (rbprev) | |
5e705374 | 1243 | prev = rb_entry_rq(rbprev); |
1da177e4 | 1244 | |
21183b07 | 1245 | if (rbnext) |
5e705374 | 1246 | next = rb_entry_rq(rbnext); |
21183b07 JA |
1247 | else { |
1248 | rbnext = rb_first(&cfqq->sort_list); | |
1249 | if (rbnext && rbnext != &last->rb_node) | |
5e705374 | 1250 | next = rb_entry_rq(rbnext); |
21183b07 | 1251 | } |
1da177e4 | 1252 | |
cf7c25cf | 1253 | return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); |
1da177e4 LT |
1254 | } |
1255 | ||
d9e7620e JA |
1256 | static unsigned long cfq_slice_offset(struct cfq_data *cfqd, |
1257 | struct cfq_queue *cfqq) | |
1da177e4 | 1258 | { |
d9e7620e JA |
1259 | /* |
1260 | * just an approximation, should be ok. | |
1261 | */ | |
cdb16e8f | 1262 | return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - |
464191c6 | 1263 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); |
d9e7620e JA |
1264 | } |
1265 | ||
1fa8f6d6 VG |
1266 | static inline s64 |
1267 | cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1268 | { | |
1269 | return cfqg->vdisktime - st->min_vdisktime; | |
1270 | } | |
1271 | ||
1272 | static void | |
1273 | __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1274 | { | |
1275 | struct rb_node **node = &st->rb.rb_node; | |
1276 | struct rb_node *parent = NULL; | |
1277 | struct cfq_group *__cfqg; | |
1278 | s64 key = cfqg_key(st, cfqg); | |
1279 | int left = 1; | |
1280 | ||
1281 | while (*node != NULL) { | |
1282 | parent = *node; | |
1283 | __cfqg = rb_entry_cfqg(parent); | |
1284 | ||
1285 | if (key < cfqg_key(st, __cfqg)) | |
1286 | node = &parent->rb_left; | |
1287 | else { | |
1288 | node = &parent->rb_right; | |
1289 | left = 0; | |
1290 | } | |
1291 | } | |
1292 | ||
1293 | if (left) | |
1294 | st->left = &cfqg->rb_node; | |
1295 | ||
1296 | rb_link_node(&cfqg->rb_node, parent, node); | |
1297 | rb_insert_color(&cfqg->rb_node, &st->rb); | |
1298 | } | |
1299 | ||
7b5af5cf TM |
1300 | /* |
1301 | * This has to be called only on activation of cfqg | |
1302 | */ | |
1fa8f6d6 | 1303 | static void |
8184f93e JT |
1304 | cfq_update_group_weight(struct cfq_group *cfqg) |
1305 | { | |
3381cb8d | 1306 | if (cfqg->new_weight) { |
8184f93e | 1307 | cfqg->weight = cfqg->new_weight; |
3381cb8d | 1308 | cfqg->new_weight = 0; |
8184f93e | 1309 | } |
e15693ef TM |
1310 | } |
1311 | ||
1312 | static void | |
1313 | cfq_update_group_leaf_weight(struct cfq_group *cfqg) | |
1314 | { | |
1315 | BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node)); | |
e71357e1 TH |
1316 | |
1317 | if (cfqg->new_leaf_weight) { | |
1318 | cfqg->leaf_weight = cfqg->new_leaf_weight; | |
1319 | cfqg->new_leaf_weight = 0; | |
1320 | } | |
8184f93e JT |
1321 | } |
1322 | ||
1323 | static void | |
1324 | cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1325 | { | |
1d3650f7 | 1326 | unsigned int vfr = 1 << CFQ_SERVICE_SHIFT; /* start with 1 */ |
7918ffb5 | 1327 | struct cfq_group *pos = cfqg; |
1d3650f7 | 1328 | struct cfq_group *parent; |
7918ffb5 TH |
1329 | bool propagate; |
1330 | ||
1331 | /* add to the service tree */ | |
8184f93e JT |
1332 | BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node)); |
1333 | ||
7b5af5cf TM |
1334 | /* |
1335 | * Update leaf_weight. We cannot update weight at this point | |
1336 | * because cfqg might already have been activated and is | |
1337 | * contributing its current weight to the parent's child_weight. | |
1338 | */ | |
e15693ef | 1339 | cfq_update_group_leaf_weight(cfqg); |
8184f93e | 1340 | __cfq_group_service_tree_add(st, cfqg); |
7918ffb5 TH |
1341 | |
1342 | /* | |
1d3650f7 TH |
1343 | * Activate @cfqg and calculate the portion of vfraction @cfqg is |
1344 | * entitled to. vfraction is calculated by walking the tree | |
1345 | * towards the root calculating the fraction it has at each level. | |
1346 | * The compounded ratio is how much vfraction @cfqg owns. | |
1347 | * | |
1348 | * Start with the proportion tasks in this cfqg has against active | |
1349 | * children cfqgs - its leaf_weight against children_weight. | |
7918ffb5 TH |
1350 | */ |
1351 | propagate = !pos->nr_active++; | |
1352 | pos->children_weight += pos->leaf_weight; | |
1d3650f7 | 1353 | vfr = vfr * pos->leaf_weight / pos->children_weight; |
7918ffb5 | 1354 | |
1d3650f7 TH |
1355 | /* |
1356 | * Compound ->weight walking up the tree. Both activation and | |
1357 | * vfraction calculation are done in the same loop. Propagation | |
1358 | * stops once an already activated node is met. vfraction | |
1359 | * calculation should always continue to the root. | |
1360 | */ | |
d02f7aa8 | 1361 | while ((parent = cfqg_parent(pos))) { |
1d3650f7 | 1362 | if (propagate) { |
e15693ef | 1363 | cfq_update_group_weight(pos); |
1d3650f7 TH |
1364 | propagate = !parent->nr_active++; |
1365 | parent->children_weight += pos->weight; | |
1366 | } | |
1367 | vfr = vfr * pos->weight / parent->children_weight; | |
7918ffb5 TH |
1368 | pos = parent; |
1369 | } | |
1d3650f7 TH |
1370 | |
1371 | cfqg->vfraction = max_t(unsigned, vfr, 1); | |
8184f93e JT |
1372 | } |
1373 | ||
1374 | static void | |
1375 | cfq_group_notify_queue_add(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
1fa8f6d6 VG |
1376 | { |
1377 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
1378 | struct cfq_group *__cfqg; | |
1379 | struct rb_node *n; | |
1380 | ||
1381 | cfqg->nr_cfqq++; | |
760701bf | 1382 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
1fa8f6d6 VG |
1383 | return; |
1384 | ||
1385 | /* | |
1386 | * Currently put the group at the end. Later implement something | |
1387 | * so that groups get lesser vtime based on their weights, so that | |
25985edc | 1388 | * if group does not loose all if it was not continuously backlogged. |
1fa8f6d6 VG |
1389 | */ |
1390 | n = rb_last(&st->rb); | |
1391 | if (n) { | |
1392 | __cfqg = rb_entry_cfqg(n); | |
1393 | cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY; | |
1394 | } else | |
1395 | cfqg->vdisktime = st->min_vdisktime; | |
8184f93e JT |
1396 | cfq_group_service_tree_add(st, cfqg); |
1397 | } | |
1fa8f6d6 | 1398 | |
8184f93e JT |
1399 | static void |
1400 | cfq_group_service_tree_del(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1401 | { | |
7918ffb5 TH |
1402 | struct cfq_group *pos = cfqg; |
1403 | bool propagate; | |
1404 | ||
1405 | /* | |
1406 | * Undo activation from cfq_group_service_tree_add(). Deactivate | |
1407 | * @cfqg and propagate deactivation upwards. | |
1408 | */ | |
1409 | propagate = !--pos->nr_active; | |
1410 | pos->children_weight -= pos->leaf_weight; | |
1411 | ||
1412 | while (propagate) { | |
d02f7aa8 | 1413 | struct cfq_group *parent = cfqg_parent(pos); |
7918ffb5 TH |
1414 | |
1415 | /* @pos has 0 nr_active at this point */ | |
1416 | WARN_ON_ONCE(pos->children_weight); | |
1d3650f7 | 1417 | pos->vfraction = 0; |
7918ffb5 TH |
1418 | |
1419 | if (!parent) | |
1420 | break; | |
1421 | ||
1422 | propagate = !--parent->nr_active; | |
1423 | parent->children_weight -= pos->weight; | |
1424 | pos = parent; | |
1425 | } | |
1426 | ||
1427 | /* remove from the service tree */ | |
8184f93e JT |
1428 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
1429 | cfq_rb_erase(&cfqg->rb_node, st); | |
1fa8f6d6 VG |
1430 | } |
1431 | ||
1432 | static void | |
8184f93e | 1433 | cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg) |
1fa8f6d6 VG |
1434 | { |
1435 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
1436 | ||
1437 | BUG_ON(cfqg->nr_cfqq < 1); | |
1438 | cfqg->nr_cfqq--; | |
25bc6b07 | 1439 | |
1fa8f6d6 VG |
1440 | /* If there are other cfq queues under this group, don't delete it */ |
1441 | if (cfqg->nr_cfqq) | |
1442 | return; | |
1443 | ||
2868ef7b | 1444 | cfq_log_cfqg(cfqd, cfqg, "del_from_rr group"); |
8184f93e | 1445 | cfq_group_service_tree_del(st, cfqg); |
4d2ceea4 | 1446 | cfqg->saved_wl_slice = 0; |
155fead9 | 1447 | cfqg_stats_update_dequeue(cfqg); |
dae739eb VG |
1448 | } |
1449 | ||
167400d3 JT |
1450 | static inline unsigned int cfq_cfqq_slice_usage(struct cfq_queue *cfqq, |
1451 | unsigned int *unaccounted_time) | |
dae739eb | 1452 | { |
f75edf2d | 1453 | unsigned int slice_used; |
dae739eb VG |
1454 | |
1455 | /* | |
1456 | * Queue got expired before even a single request completed or | |
1457 | * got expired immediately after first request completion. | |
1458 | */ | |
1459 | if (!cfqq->slice_start || cfqq->slice_start == jiffies) { | |
1460 | /* | |
1461 | * Also charge the seek time incurred to the group, otherwise | |
1462 | * if there are mutiple queues in the group, each can dispatch | |
1463 | * a single request on seeky media and cause lots of seek time | |
1464 | * and group will never know it. | |
1465 | */ | |
1466 | slice_used = max_t(unsigned, (jiffies - cfqq->dispatch_start), | |
1467 | 1); | |
1468 | } else { | |
1469 | slice_used = jiffies - cfqq->slice_start; | |
167400d3 JT |
1470 | if (slice_used > cfqq->allocated_slice) { |
1471 | *unaccounted_time = slice_used - cfqq->allocated_slice; | |
f75edf2d | 1472 | slice_used = cfqq->allocated_slice; |
167400d3 JT |
1473 | } |
1474 | if (time_after(cfqq->slice_start, cfqq->dispatch_start)) | |
1475 | *unaccounted_time += cfqq->slice_start - | |
1476 | cfqq->dispatch_start; | |
dae739eb VG |
1477 | } |
1478 | ||
dae739eb VG |
1479 | return slice_used; |
1480 | } | |
1481 | ||
1482 | static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, | |
e5ff082e | 1483 | struct cfq_queue *cfqq) |
dae739eb VG |
1484 | { |
1485 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
167400d3 | 1486 | unsigned int used_sl, charge, unaccounted_sl = 0; |
f26bd1f0 VG |
1487 | int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) |
1488 | - cfqg->service_tree_idle.count; | |
1d3650f7 | 1489 | unsigned int vfr; |
f26bd1f0 VG |
1490 | |
1491 | BUG_ON(nr_sync < 0); | |
167400d3 | 1492 | used_sl = charge = cfq_cfqq_slice_usage(cfqq, &unaccounted_sl); |
dae739eb | 1493 | |
02b35081 VG |
1494 | if (iops_mode(cfqd)) |
1495 | charge = cfqq->slice_dispatch; | |
1496 | else if (!cfq_cfqq_sync(cfqq) && !nr_sync) | |
1497 | charge = cfqq->allocated_slice; | |
dae739eb | 1498 | |
1d3650f7 TH |
1499 | /* |
1500 | * Can't update vdisktime while on service tree and cfqg->vfraction | |
1501 | * is valid only while on it. Cache vfr, leave the service tree, | |
1502 | * update vdisktime and go back on. The re-addition to the tree | |
1503 | * will also update the weights as necessary. | |
1504 | */ | |
1505 | vfr = cfqg->vfraction; | |
8184f93e | 1506 | cfq_group_service_tree_del(st, cfqg); |
1d3650f7 | 1507 | cfqg->vdisktime += cfqg_scale_charge(charge, vfr); |
8184f93e | 1508 | cfq_group_service_tree_add(st, cfqg); |
dae739eb VG |
1509 | |
1510 | /* This group is being expired. Save the context */ | |
1511 | if (time_after(cfqd->workload_expires, jiffies)) { | |
4d2ceea4 | 1512 | cfqg->saved_wl_slice = cfqd->workload_expires |
dae739eb | 1513 | - jiffies; |
4d2ceea4 VG |
1514 | cfqg->saved_wl_type = cfqd->serving_wl_type; |
1515 | cfqg->saved_wl_class = cfqd->serving_wl_class; | |
dae739eb | 1516 | } else |
4d2ceea4 | 1517 | cfqg->saved_wl_slice = 0; |
2868ef7b VG |
1518 | |
1519 | cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime, | |
1520 | st->min_vdisktime); | |
fd16d263 JP |
1521 | cfq_log_cfqq(cfqq->cfqd, cfqq, |
1522 | "sl_used=%u disp=%u charge=%u iops=%u sect=%lu", | |
1523 | used_sl, cfqq->slice_dispatch, charge, | |
1524 | iops_mode(cfqd), cfqq->nr_sectors); | |
155fead9 TH |
1525 | cfqg_stats_update_timeslice_used(cfqg, used_sl, unaccounted_sl); |
1526 | cfqg_stats_set_start_empty_time(cfqg); | |
1fa8f6d6 VG |
1527 | } |
1528 | ||
f51b802c TH |
1529 | /** |
1530 | * cfq_init_cfqg_base - initialize base part of a cfq_group | |
1531 | * @cfqg: cfq_group to initialize | |
1532 | * | |
1533 | * Initialize the base part which is used whether %CONFIG_CFQ_GROUP_IOSCHED | |
1534 | * is enabled or not. | |
1535 | */ | |
1536 | static void cfq_init_cfqg_base(struct cfq_group *cfqg) | |
1537 | { | |
1538 | struct cfq_rb_root *st; | |
1539 | int i, j; | |
1540 | ||
1541 | for_each_cfqg_st(cfqg, i, j, st) | |
1542 | *st = CFQ_RB_ROOT; | |
1543 | RB_CLEAR_NODE(&cfqg->rb_node); | |
1544 | ||
1545 | cfqg->ttime.last_end_request = jiffies; | |
1546 | } | |
1547 | ||
25fb5169 | 1548 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
90d3839b PZ |
1549 | static void cfqg_stats_init(struct cfqg_stats *stats) |
1550 | { | |
1551 | blkg_rwstat_init(&stats->service_bytes); | |
1552 | blkg_rwstat_init(&stats->serviced); | |
1553 | blkg_rwstat_init(&stats->merged); | |
1554 | blkg_rwstat_init(&stats->service_time); | |
1555 | blkg_rwstat_init(&stats->wait_time); | |
1556 | blkg_rwstat_init(&stats->queued); | |
1557 | ||
1558 | blkg_stat_init(&stats->sectors); | |
1559 | blkg_stat_init(&stats->time); | |
1560 | ||
1561 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
1562 | blkg_stat_init(&stats->unaccounted_time); | |
1563 | blkg_stat_init(&stats->avg_queue_size_sum); | |
1564 | blkg_stat_init(&stats->avg_queue_size_samples); | |
1565 | blkg_stat_init(&stats->dequeue); | |
1566 | blkg_stat_init(&stats->group_wait_time); | |
1567 | blkg_stat_init(&stats->idle_time); | |
1568 | blkg_stat_init(&stats->empty_time); | |
1569 | #endif | |
1570 | } | |
1571 | ||
e48453c3 AA |
1572 | static void cfq_cpd_init(const struct blkcg *blkcg) |
1573 | { | |
1574 | struct cfq_group_data *cgd = | |
1575 | cpd_to_cfqgd(blkcg->pd[blkcg_policy_cfq.plid]); | |
1576 | ||
1577 | if (blkcg == &blkcg_root) { | |
1578 | cgd->weight = 2 * CFQ_WEIGHT_DEFAULT; | |
1579 | cgd->leaf_weight = 2 * CFQ_WEIGHT_DEFAULT; | |
1580 | } else { | |
1581 | cgd->weight = CFQ_WEIGHT_DEFAULT; | |
1582 | cgd->leaf_weight = CFQ_WEIGHT_DEFAULT; | |
1583 | } | |
1584 | } | |
1585 | ||
3c798398 | 1586 | static void cfq_pd_init(struct blkcg_gq *blkg) |
f469a7b4 | 1587 | { |
0381411e | 1588 | struct cfq_group *cfqg = blkg_to_cfqg(blkg); |
e48453c3 | 1589 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkg->blkcg); |
25fb5169 | 1590 | |
f51b802c | 1591 | cfq_init_cfqg_base(cfqg); |
e48453c3 AA |
1592 | cfqg->weight = cgd->weight; |
1593 | cfqg->leaf_weight = cgd->leaf_weight; | |
90d3839b PZ |
1594 | cfqg_stats_init(&cfqg->stats); |
1595 | cfqg_stats_init(&cfqg->dead_stats); | |
25fb5169 VG |
1596 | } |
1597 | ||
0b39920b TH |
1598 | static void cfq_pd_offline(struct blkcg_gq *blkg) |
1599 | { | |
1600 | /* | |
1601 | * @blkg is going offline and will be ignored by | |
1602 | * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so | |
1603 | * that they don't get lost. If IOs complete after this point, the | |
1604 | * stats for them will be lost. Oh well... | |
1605 | */ | |
1606 | cfqg_stats_xfer_dead(blkg_to_cfqg(blkg)); | |
1607 | } | |
1608 | ||
43114018 TH |
1609 | /* offset delta from cfqg->stats to cfqg->dead_stats */ |
1610 | static const int dead_stats_off_delta = offsetof(struct cfq_group, dead_stats) - | |
1611 | offsetof(struct cfq_group, stats); | |
1612 | ||
1613 | /* to be used by recursive prfill, sums live and dead stats recursively */ | |
1614 | static u64 cfqg_stat_pd_recursive_sum(struct blkg_policy_data *pd, int off) | |
1615 | { | |
1616 | u64 sum = 0; | |
1617 | ||
1618 | sum += blkg_stat_recursive_sum(pd, off); | |
1619 | sum += blkg_stat_recursive_sum(pd, off + dead_stats_off_delta); | |
1620 | return sum; | |
1621 | } | |
1622 | ||
1623 | /* to be used by recursive prfill, sums live and dead rwstats recursively */ | |
1624 | static struct blkg_rwstat cfqg_rwstat_pd_recursive_sum(struct blkg_policy_data *pd, | |
1625 | int off) | |
1626 | { | |
1627 | struct blkg_rwstat a, b; | |
1628 | ||
1629 | a = blkg_rwstat_recursive_sum(pd, off); | |
1630 | b = blkg_rwstat_recursive_sum(pd, off + dead_stats_off_delta); | |
1631 | blkg_rwstat_merge(&a, &b); | |
1632 | return a; | |
1633 | } | |
1634 | ||
689665af TH |
1635 | static void cfq_pd_reset_stats(struct blkcg_gq *blkg) |
1636 | { | |
1637 | struct cfq_group *cfqg = blkg_to_cfqg(blkg); | |
1638 | ||
1639 | cfqg_stats_reset(&cfqg->stats); | |
0b39920b | 1640 | cfqg_stats_reset(&cfqg->dead_stats); |
25fb5169 VG |
1641 | } |
1642 | ||
1643 | /* | |
3e59cf9d VG |
1644 | * Search for the cfq group current task belongs to. request_queue lock must |
1645 | * be held. | |
25fb5169 | 1646 | */ |
cd1604fa | 1647 | static struct cfq_group *cfq_lookup_create_cfqg(struct cfq_data *cfqd, |
3c798398 | 1648 | struct blkcg *blkcg) |
25fb5169 | 1649 | { |
f469a7b4 | 1650 | struct request_queue *q = cfqd->queue; |
cd1604fa | 1651 | struct cfq_group *cfqg = NULL; |
25fb5169 | 1652 | |
3c798398 TH |
1653 | /* avoid lookup for the common case where there's no blkcg */ |
1654 | if (blkcg == &blkcg_root) { | |
cd1604fa TH |
1655 | cfqg = cfqd->root_group; |
1656 | } else { | |
3c798398 | 1657 | struct blkcg_gq *blkg; |
f469a7b4 | 1658 | |
3c96cb32 | 1659 | blkg = blkg_lookup_create(blkcg, q); |
cd1604fa | 1660 | if (!IS_ERR(blkg)) |
0381411e | 1661 | cfqg = blkg_to_cfqg(blkg); |
cd1604fa | 1662 | } |
f469a7b4 | 1663 | |
25fb5169 VG |
1664 | return cfqg; |
1665 | } | |
1666 | ||
1667 | static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) | |
1668 | { | |
1669 | /* Currently, all async queues are mapped to root group */ | |
1670 | if (!cfq_cfqq_sync(cfqq)) | |
f51b802c | 1671 | cfqg = cfqq->cfqd->root_group; |
25fb5169 VG |
1672 | |
1673 | cfqq->cfqg = cfqg; | |
b1c35769 | 1674 | /* cfqq reference on cfqg */ |
eb7d8c07 | 1675 | cfqg_get(cfqg); |
b1c35769 VG |
1676 | } |
1677 | ||
f95a04af TH |
1678 | static u64 cfqg_prfill_weight_device(struct seq_file *sf, |
1679 | struct blkg_policy_data *pd, int off) | |
60c2bc2d | 1680 | { |
f95a04af | 1681 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
3381cb8d TH |
1682 | |
1683 | if (!cfqg->dev_weight) | |
60c2bc2d | 1684 | return 0; |
f95a04af | 1685 | return __blkg_prfill_u64(sf, pd, cfqg->dev_weight); |
60c2bc2d TH |
1686 | } |
1687 | ||
2da8ca82 | 1688 | static int cfqg_print_weight_device(struct seq_file *sf, void *v) |
60c2bc2d | 1689 | { |
2da8ca82 TH |
1690 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1691 | cfqg_prfill_weight_device, &blkcg_policy_cfq, | |
1692 | 0, false); | |
60c2bc2d TH |
1693 | return 0; |
1694 | } | |
1695 | ||
e71357e1 TH |
1696 | static u64 cfqg_prfill_leaf_weight_device(struct seq_file *sf, |
1697 | struct blkg_policy_data *pd, int off) | |
1698 | { | |
1699 | struct cfq_group *cfqg = pd_to_cfqg(pd); | |
1700 | ||
1701 | if (!cfqg->dev_leaf_weight) | |
1702 | return 0; | |
1703 | return __blkg_prfill_u64(sf, pd, cfqg->dev_leaf_weight); | |
1704 | } | |
1705 | ||
2da8ca82 | 1706 | static int cfqg_print_leaf_weight_device(struct seq_file *sf, void *v) |
e71357e1 | 1707 | { |
2da8ca82 TH |
1708 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1709 | cfqg_prfill_leaf_weight_device, &blkcg_policy_cfq, | |
1710 | 0, false); | |
e71357e1 TH |
1711 | return 0; |
1712 | } | |
1713 | ||
2da8ca82 | 1714 | static int cfq_print_weight(struct seq_file *sf, void *v) |
60c2bc2d | 1715 | { |
e48453c3 | 1716 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); |
9470e4a6 JA |
1717 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg); |
1718 | unsigned int val = 0; | |
e48453c3 | 1719 | |
9470e4a6 JA |
1720 | if (cgd) |
1721 | val = cgd->weight; | |
1722 | ||
1723 | seq_printf(sf, "%u\n", val); | |
60c2bc2d TH |
1724 | return 0; |
1725 | } | |
1726 | ||
2da8ca82 | 1727 | static int cfq_print_leaf_weight(struct seq_file *sf, void *v) |
e71357e1 | 1728 | { |
e48453c3 | 1729 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); |
9470e4a6 JA |
1730 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg); |
1731 | unsigned int val = 0; | |
1732 | ||
1733 | if (cgd) | |
1734 | val = cgd->leaf_weight; | |
e48453c3 | 1735 | |
9470e4a6 | 1736 | seq_printf(sf, "%u\n", val); |
e71357e1 TH |
1737 | return 0; |
1738 | } | |
1739 | ||
451af504 TH |
1740 | static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of, |
1741 | char *buf, size_t nbytes, loff_t off, | |
1742 | bool is_leaf_weight) | |
60c2bc2d | 1743 | { |
451af504 | 1744 | struct blkcg *blkcg = css_to_blkcg(of_css(of)); |
60c2bc2d | 1745 | struct blkg_conf_ctx ctx; |
3381cb8d | 1746 | struct cfq_group *cfqg; |
e48453c3 | 1747 | struct cfq_group_data *cfqgd; |
60c2bc2d TH |
1748 | int ret; |
1749 | ||
3c798398 | 1750 | ret = blkg_conf_prep(blkcg, &blkcg_policy_cfq, buf, &ctx); |
60c2bc2d TH |
1751 | if (ret) |
1752 | return ret; | |
1753 | ||
1754 | ret = -EINVAL; | |
3381cb8d | 1755 | cfqg = blkg_to_cfqg(ctx.blkg); |
e48453c3 | 1756 | cfqgd = blkcg_to_cfqgd(blkcg); |
a2b1693b | 1757 | if (!ctx.v || (ctx.v >= CFQ_WEIGHT_MIN && ctx.v <= CFQ_WEIGHT_MAX)) { |
e71357e1 TH |
1758 | if (!is_leaf_weight) { |
1759 | cfqg->dev_weight = ctx.v; | |
e48453c3 | 1760 | cfqg->new_weight = ctx.v ?: cfqgd->weight; |
e71357e1 TH |
1761 | } else { |
1762 | cfqg->dev_leaf_weight = ctx.v; | |
e48453c3 | 1763 | cfqg->new_leaf_weight = ctx.v ?: cfqgd->leaf_weight; |
e71357e1 | 1764 | } |
60c2bc2d TH |
1765 | ret = 0; |
1766 | } | |
1767 | ||
1768 | blkg_conf_finish(&ctx); | |
451af504 | 1769 | return ret ?: nbytes; |
60c2bc2d TH |
1770 | } |
1771 | ||
451af504 TH |
1772 | static ssize_t cfqg_set_weight_device(struct kernfs_open_file *of, |
1773 | char *buf, size_t nbytes, loff_t off) | |
e71357e1 | 1774 | { |
451af504 | 1775 | return __cfqg_set_weight_device(of, buf, nbytes, off, false); |
e71357e1 TH |
1776 | } |
1777 | ||
451af504 TH |
1778 | static ssize_t cfqg_set_leaf_weight_device(struct kernfs_open_file *of, |
1779 | char *buf, size_t nbytes, loff_t off) | |
e71357e1 | 1780 | { |
451af504 | 1781 | return __cfqg_set_weight_device(of, buf, nbytes, off, true); |
e71357e1 TH |
1782 | } |
1783 | ||
182446d0 TH |
1784 | static int __cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft, |
1785 | u64 val, bool is_leaf_weight) | |
60c2bc2d | 1786 | { |
182446d0 | 1787 | struct blkcg *blkcg = css_to_blkcg(css); |
3c798398 | 1788 | struct blkcg_gq *blkg; |
e48453c3 | 1789 | struct cfq_group_data *cfqgd; |
60c2bc2d | 1790 | |
3381cb8d | 1791 | if (val < CFQ_WEIGHT_MIN || val > CFQ_WEIGHT_MAX) |
60c2bc2d TH |
1792 | return -EINVAL; |
1793 | ||
1794 | spin_lock_irq(&blkcg->lock); | |
e48453c3 | 1795 | cfqgd = blkcg_to_cfqgd(blkcg); |
e71357e1 TH |
1796 | |
1797 | if (!is_leaf_weight) | |
e48453c3 | 1798 | cfqgd->weight = val; |
e71357e1 | 1799 | else |
e48453c3 | 1800 | cfqgd->leaf_weight = val; |
60c2bc2d | 1801 | |
b67bfe0d | 1802 | hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { |
3381cb8d | 1803 | struct cfq_group *cfqg = blkg_to_cfqg(blkg); |
60c2bc2d | 1804 | |
e71357e1 TH |
1805 | if (!cfqg) |
1806 | continue; | |
1807 | ||
1808 | if (!is_leaf_weight) { | |
1809 | if (!cfqg->dev_weight) | |
e48453c3 | 1810 | cfqg->new_weight = cfqgd->weight; |
e71357e1 TH |
1811 | } else { |
1812 | if (!cfqg->dev_leaf_weight) | |
e48453c3 | 1813 | cfqg->new_leaf_weight = cfqgd->leaf_weight; |
e71357e1 | 1814 | } |
60c2bc2d TH |
1815 | } |
1816 | ||
1817 | spin_unlock_irq(&blkcg->lock); | |
1818 | return 0; | |
1819 | } | |
1820 | ||
182446d0 TH |
1821 | static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft, |
1822 | u64 val) | |
e71357e1 | 1823 | { |
182446d0 | 1824 | return __cfq_set_weight(css, cft, val, false); |
e71357e1 TH |
1825 | } |
1826 | ||
182446d0 TH |
1827 | static int cfq_set_leaf_weight(struct cgroup_subsys_state *css, |
1828 | struct cftype *cft, u64 val) | |
e71357e1 | 1829 | { |
182446d0 | 1830 | return __cfq_set_weight(css, cft, val, true); |
e71357e1 TH |
1831 | } |
1832 | ||
2da8ca82 | 1833 | static int cfqg_print_stat(struct seq_file *sf, void *v) |
5bc4afb1 | 1834 | { |
2da8ca82 TH |
1835 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat, |
1836 | &blkcg_policy_cfq, seq_cft(sf)->private, false); | |
5bc4afb1 TH |
1837 | return 0; |
1838 | } | |
1839 | ||
2da8ca82 | 1840 | static int cfqg_print_rwstat(struct seq_file *sf, void *v) |
5bc4afb1 | 1841 | { |
2da8ca82 TH |
1842 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat, |
1843 | &blkcg_policy_cfq, seq_cft(sf)->private, true); | |
5bc4afb1 TH |
1844 | return 0; |
1845 | } | |
1846 | ||
43114018 TH |
1847 | static u64 cfqg_prfill_stat_recursive(struct seq_file *sf, |
1848 | struct blkg_policy_data *pd, int off) | |
1849 | { | |
1850 | u64 sum = cfqg_stat_pd_recursive_sum(pd, off); | |
1851 | ||
1852 | return __blkg_prfill_u64(sf, pd, sum); | |
1853 | } | |
1854 | ||
1855 | static u64 cfqg_prfill_rwstat_recursive(struct seq_file *sf, | |
1856 | struct blkg_policy_data *pd, int off) | |
1857 | { | |
1858 | struct blkg_rwstat sum = cfqg_rwstat_pd_recursive_sum(pd, off); | |
1859 | ||
1860 | return __blkg_prfill_rwstat(sf, pd, &sum); | |
1861 | } | |
1862 | ||
2da8ca82 | 1863 | static int cfqg_print_stat_recursive(struct seq_file *sf, void *v) |
43114018 | 1864 | { |
2da8ca82 TH |
1865 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1866 | cfqg_prfill_stat_recursive, &blkcg_policy_cfq, | |
1867 | seq_cft(sf)->private, false); | |
43114018 TH |
1868 | return 0; |
1869 | } | |
1870 | ||
2da8ca82 | 1871 | static int cfqg_print_rwstat_recursive(struct seq_file *sf, void *v) |
43114018 | 1872 | { |
2da8ca82 TH |
1873 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1874 | cfqg_prfill_rwstat_recursive, &blkcg_policy_cfq, | |
1875 | seq_cft(sf)->private, true); | |
43114018 TH |
1876 | return 0; |
1877 | } | |
1878 | ||
60c2bc2d | 1879 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
f95a04af TH |
1880 | static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf, |
1881 | struct blkg_policy_data *pd, int off) | |
60c2bc2d | 1882 | { |
f95a04af | 1883 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
155fead9 | 1884 | u64 samples = blkg_stat_read(&cfqg->stats.avg_queue_size_samples); |
60c2bc2d TH |
1885 | u64 v = 0; |
1886 | ||
1887 | if (samples) { | |
155fead9 | 1888 | v = blkg_stat_read(&cfqg->stats.avg_queue_size_sum); |
f3cff25f | 1889 | v = div64_u64(v, samples); |
60c2bc2d | 1890 | } |
f95a04af | 1891 | __blkg_prfill_u64(sf, pd, v); |
60c2bc2d TH |
1892 | return 0; |
1893 | } | |
1894 | ||
1895 | /* print avg_queue_size */ | |
2da8ca82 | 1896 | static int cfqg_print_avg_queue_size(struct seq_file *sf, void *v) |
60c2bc2d | 1897 | { |
2da8ca82 TH |
1898 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1899 | cfqg_prfill_avg_queue_size, &blkcg_policy_cfq, | |
1900 | 0, false); | |
60c2bc2d TH |
1901 | return 0; |
1902 | } | |
1903 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
1904 | ||
1905 | static struct cftype cfq_blkcg_files[] = { | |
1d3650f7 | 1906 | /* on root, weight is mapped to leaf_weight */ |
60c2bc2d TH |
1907 | { |
1908 | .name = "weight_device", | |
1d3650f7 | 1909 | .flags = CFTYPE_ONLY_ON_ROOT, |
2da8ca82 | 1910 | .seq_show = cfqg_print_leaf_weight_device, |
451af504 | 1911 | .write = cfqg_set_leaf_weight_device, |
60c2bc2d TH |
1912 | }, |
1913 | { | |
1914 | .name = "weight", | |
1d3650f7 | 1915 | .flags = CFTYPE_ONLY_ON_ROOT, |
2da8ca82 | 1916 | .seq_show = cfq_print_leaf_weight, |
1d3650f7 | 1917 | .write_u64 = cfq_set_leaf_weight, |
60c2bc2d | 1918 | }, |
e71357e1 | 1919 | |
1d3650f7 | 1920 | /* no such mapping necessary for !roots */ |
60c2bc2d TH |
1921 | { |
1922 | .name = "weight_device", | |
1d3650f7 | 1923 | .flags = CFTYPE_NOT_ON_ROOT, |
2da8ca82 | 1924 | .seq_show = cfqg_print_weight_device, |
451af504 | 1925 | .write = cfqg_set_weight_device, |
60c2bc2d TH |
1926 | }, |
1927 | { | |
1928 | .name = "weight", | |
1d3650f7 | 1929 | .flags = CFTYPE_NOT_ON_ROOT, |
2da8ca82 | 1930 | .seq_show = cfq_print_weight, |
3381cb8d | 1931 | .write_u64 = cfq_set_weight, |
60c2bc2d | 1932 | }, |
e71357e1 | 1933 | |
e71357e1 TH |
1934 | { |
1935 | .name = "leaf_weight_device", | |
2da8ca82 | 1936 | .seq_show = cfqg_print_leaf_weight_device, |
451af504 | 1937 | .write = cfqg_set_leaf_weight_device, |
e71357e1 TH |
1938 | }, |
1939 | { | |
1940 | .name = "leaf_weight", | |
2da8ca82 | 1941 | .seq_show = cfq_print_leaf_weight, |
e71357e1 TH |
1942 | .write_u64 = cfq_set_leaf_weight, |
1943 | }, | |
1944 | ||
43114018 | 1945 | /* statistics, covers only the tasks in the cfqg */ |
60c2bc2d TH |
1946 | { |
1947 | .name = "time", | |
5bc4afb1 | 1948 | .private = offsetof(struct cfq_group, stats.time), |
2da8ca82 | 1949 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
1950 | }, |
1951 | { | |
1952 | .name = "sectors", | |
5bc4afb1 | 1953 | .private = offsetof(struct cfq_group, stats.sectors), |
2da8ca82 | 1954 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
1955 | }, |
1956 | { | |
1957 | .name = "io_service_bytes", | |
5bc4afb1 | 1958 | .private = offsetof(struct cfq_group, stats.service_bytes), |
2da8ca82 | 1959 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
1960 | }, |
1961 | { | |
1962 | .name = "io_serviced", | |
5bc4afb1 | 1963 | .private = offsetof(struct cfq_group, stats.serviced), |
2da8ca82 | 1964 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
1965 | }, |
1966 | { | |
1967 | .name = "io_service_time", | |
5bc4afb1 | 1968 | .private = offsetof(struct cfq_group, stats.service_time), |
2da8ca82 | 1969 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
1970 | }, |
1971 | { | |
1972 | .name = "io_wait_time", | |
5bc4afb1 | 1973 | .private = offsetof(struct cfq_group, stats.wait_time), |
2da8ca82 | 1974 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
1975 | }, |
1976 | { | |
1977 | .name = "io_merged", | |
5bc4afb1 | 1978 | .private = offsetof(struct cfq_group, stats.merged), |
2da8ca82 | 1979 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
1980 | }, |
1981 | { | |
1982 | .name = "io_queued", | |
5bc4afb1 | 1983 | .private = offsetof(struct cfq_group, stats.queued), |
2da8ca82 | 1984 | .seq_show = cfqg_print_rwstat, |
60c2bc2d | 1985 | }, |
43114018 TH |
1986 | |
1987 | /* the same statictics which cover the cfqg and its descendants */ | |
1988 | { | |
1989 | .name = "time_recursive", | |
1990 | .private = offsetof(struct cfq_group, stats.time), | |
2da8ca82 | 1991 | .seq_show = cfqg_print_stat_recursive, |
43114018 TH |
1992 | }, |
1993 | { | |
1994 | .name = "sectors_recursive", | |
1995 | .private = offsetof(struct cfq_group, stats.sectors), | |
2da8ca82 | 1996 | .seq_show = cfqg_print_stat_recursive, |
43114018 TH |
1997 | }, |
1998 | { | |
1999 | .name = "io_service_bytes_recursive", | |
2000 | .private = offsetof(struct cfq_group, stats.service_bytes), | |
2da8ca82 | 2001 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2002 | }, |
2003 | { | |
2004 | .name = "io_serviced_recursive", | |
2005 | .private = offsetof(struct cfq_group, stats.serviced), | |
2da8ca82 | 2006 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2007 | }, |
2008 | { | |
2009 | .name = "io_service_time_recursive", | |
2010 | .private = offsetof(struct cfq_group, stats.service_time), | |
2da8ca82 | 2011 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2012 | }, |
2013 | { | |
2014 | .name = "io_wait_time_recursive", | |
2015 | .private = offsetof(struct cfq_group, stats.wait_time), | |
2da8ca82 | 2016 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2017 | }, |
2018 | { | |
2019 | .name = "io_merged_recursive", | |
2020 | .private = offsetof(struct cfq_group, stats.merged), | |
2da8ca82 | 2021 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2022 | }, |
2023 | { | |
2024 | .name = "io_queued_recursive", | |
2025 | .private = offsetof(struct cfq_group, stats.queued), | |
2da8ca82 | 2026 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 | 2027 | }, |
60c2bc2d TH |
2028 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
2029 | { | |
2030 | .name = "avg_queue_size", | |
2da8ca82 | 2031 | .seq_show = cfqg_print_avg_queue_size, |
60c2bc2d TH |
2032 | }, |
2033 | { | |
2034 | .name = "group_wait_time", | |
5bc4afb1 | 2035 | .private = offsetof(struct cfq_group, stats.group_wait_time), |
2da8ca82 | 2036 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2037 | }, |
2038 | { | |
2039 | .name = "idle_time", | |
5bc4afb1 | 2040 | .private = offsetof(struct cfq_group, stats.idle_time), |
2da8ca82 | 2041 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2042 | }, |
2043 | { | |
2044 | .name = "empty_time", | |
5bc4afb1 | 2045 | .private = offsetof(struct cfq_group, stats.empty_time), |
2da8ca82 | 2046 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2047 | }, |
2048 | { | |
2049 | .name = "dequeue", | |
5bc4afb1 | 2050 | .private = offsetof(struct cfq_group, stats.dequeue), |
2da8ca82 | 2051 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2052 | }, |
2053 | { | |
2054 | .name = "unaccounted_time", | |
5bc4afb1 | 2055 | .private = offsetof(struct cfq_group, stats.unaccounted_time), |
2da8ca82 | 2056 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2057 | }, |
2058 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
2059 | { } /* terminate */ | |
2060 | }; | |
25fb5169 | 2061 | #else /* GROUP_IOSCHED */ |
cd1604fa | 2062 | static struct cfq_group *cfq_lookup_create_cfqg(struct cfq_data *cfqd, |
3c798398 | 2063 | struct blkcg *blkcg) |
25fb5169 | 2064 | { |
f51b802c | 2065 | return cfqd->root_group; |
25fb5169 | 2066 | } |
7f1dc8a2 | 2067 | |
25fb5169 VG |
2068 | static inline void |
2069 | cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { | |
2070 | cfqq->cfqg = cfqg; | |
2071 | } | |
2072 | ||
2073 | #endif /* GROUP_IOSCHED */ | |
2074 | ||
498d3aa2 | 2075 | /* |
c0324a02 | 2076 | * The cfqd->service_trees holds all pending cfq_queue's that have |
498d3aa2 JA |
2077 | * requests waiting to be processed. It is sorted in the order that |
2078 | * we will service the queues. | |
2079 | */ | |
a36e71f9 | 2080 | static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
a6151c3a | 2081 | bool add_front) |
d9e7620e | 2082 | { |
0871714e JA |
2083 | struct rb_node **p, *parent; |
2084 | struct cfq_queue *__cfqq; | |
d9e7620e | 2085 | unsigned long rb_key; |
34b98d03 | 2086 | struct cfq_rb_root *st; |
498d3aa2 | 2087 | int left; |
dae739eb | 2088 | int new_cfqq = 1; |
ae30c286 | 2089 | |
34b98d03 | 2090 | st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq)); |
0871714e JA |
2091 | if (cfq_class_idle(cfqq)) { |
2092 | rb_key = CFQ_IDLE_DELAY; | |
34b98d03 | 2093 | parent = rb_last(&st->rb); |
0871714e JA |
2094 | if (parent && parent != &cfqq->rb_node) { |
2095 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); | |
2096 | rb_key += __cfqq->rb_key; | |
2097 | } else | |
2098 | rb_key += jiffies; | |
2099 | } else if (!add_front) { | |
b9c8946b JA |
2100 | /* |
2101 | * Get our rb key offset. Subtract any residual slice | |
2102 | * value carried from last service. A negative resid | |
2103 | * count indicates slice overrun, and this should position | |
2104 | * the next service time further away in the tree. | |
2105 | */ | |
edd75ffd | 2106 | rb_key = cfq_slice_offset(cfqd, cfqq) + jiffies; |
b9c8946b | 2107 | rb_key -= cfqq->slice_resid; |
edd75ffd | 2108 | cfqq->slice_resid = 0; |
48e025e6 CZ |
2109 | } else { |
2110 | rb_key = -HZ; | |
34b98d03 | 2111 | __cfqq = cfq_rb_first(st); |
48e025e6 CZ |
2112 | rb_key += __cfqq ? __cfqq->rb_key : jiffies; |
2113 | } | |
1da177e4 | 2114 | |
d9e7620e | 2115 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
dae739eb | 2116 | new_cfqq = 0; |
99f9628a | 2117 | /* |
d9e7620e | 2118 | * same position, nothing more to do |
99f9628a | 2119 | */ |
34b98d03 | 2120 | if (rb_key == cfqq->rb_key && cfqq->service_tree == st) |
d9e7620e | 2121 | return; |
1da177e4 | 2122 | |
aa6f6a3d CZ |
2123 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
2124 | cfqq->service_tree = NULL; | |
1da177e4 | 2125 | } |
d9e7620e | 2126 | |
498d3aa2 | 2127 | left = 1; |
0871714e | 2128 | parent = NULL; |
34b98d03 VG |
2129 | cfqq->service_tree = st; |
2130 | p = &st->rb.rb_node; | |
d9e7620e JA |
2131 | while (*p) { |
2132 | parent = *p; | |
2133 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); | |
2134 | ||
0c534e0a | 2135 | /* |
c0324a02 | 2136 | * sort by key, that represents service time. |
0c534e0a | 2137 | */ |
c0324a02 | 2138 | if (time_before(rb_key, __cfqq->rb_key)) |
1f23f121 | 2139 | p = &parent->rb_left; |
c0324a02 | 2140 | else { |
1f23f121 | 2141 | p = &parent->rb_right; |
cc09e299 | 2142 | left = 0; |
c0324a02 | 2143 | } |
d9e7620e JA |
2144 | } |
2145 | ||
cc09e299 | 2146 | if (left) |
34b98d03 | 2147 | st->left = &cfqq->rb_node; |
cc09e299 | 2148 | |
d9e7620e JA |
2149 | cfqq->rb_key = rb_key; |
2150 | rb_link_node(&cfqq->rb_node, parent, p); | |
34b98d03 VG |
2151 | rb_insert_color(&cfqq->rb_node, &st->rb); |
2152 | st->count++; | |
20359f27 | 2153 | if (add_front || !new_cfqq) |
dae739eb | 2154 | return; |
8184f93e | 2155 | cfq_group_notify_queue_add(cfqd, cfqq->cfqg); |
1da177e4 LT |
2156 | } |
2157 | ||
a36e71f9 | 2158 | static struct cfq_queue * |
f2d1f0ae JA |
2159 | cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, |
2160 | sector_t sector, struct rb_node **ret_parent, | |
2161 | struct rb_node ***rb_link) | |
a36e71f9 | 2162 | { |
a36e71f9 JA |
2163 | struct rb_node **p, *parent; |
2164 | struct cfq_queue *cfqq = NULL; | |
2165 | ||
2166 | parent = NULL; | |
2167 | p = &root->rb_node; | |
2168 | while (*p) { | |
2169 | struct rb_node **n; | |
2170 | ||
2171 | parent = *p; | |
2172 | cfqq = rb_entry(parent, struct cfq_queue, p_node); | |
2173 | ||
2174 | /* | |
2175 | * Sort strictly based on sector. Smallest to the left, | |
2176 | * largest to the right. | |
2177 | */ | |
2e46e8b2 | 2178 | if (sector > blk_rq_pos(cfqq->next_rq)) |
a36e71f9 | 2179 | n = &(*p)->rb_right; |
2e46e8b2 | 2180 | else if (sector < blk_rq_pos(cfqq->next_rq)) |
a36e71f9 JA |
2181 | n = &(*p)->rb_left; |
2182 | else | |
2183 | break; | |
2184 | p = n; | |
3ac6c9f8 | 2185 | cfqq = NULL; |
a36e71f9 JA |
2186 | } |
2187 | ||
2188 | *ret_parent = parent; | |
2189 | if (rb_link) | |
2190 | *rb_link = p; | |
3ac6c9f8 | 2191 | return cfqq; |
a36e71f9 JA |
2192 | } |
2193 | ||
2194 | static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2195 | { | |
a36e71f9 JA |
2196 | struct rb_node **p, *parent; |
2197 | struct cfq_queue *__cfqq; | |
2198 | ||
f2d1f0ae JA |
2199 | if (cfqq->p_root) { |
2200 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2201 | cfqq->p_root = NULL; | |
2202 | } | |
a36e71f9 JA |
2203 | |
2204 | if (cfq_class_idle(cfqq)) | |
2205 | return; | |
2206 | if (!cfqq->next_rq) | |
2207 | return; | |
2208 | ||
f2d1f0ae | 2209 | cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; |
2e46e8b2 TH |
2210 | __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, |
2211 | blk_rq_pos(cfqq->next_rq), &parent, &p); | |
3ac6c9f8 JA |
2212 | if (!__cfqq) { |
2213 | rb_link_node(&cfqq->p_node, parent, p); | |
f2d1f0ae JA |
2214 | rb_insert_color(&cfqq->p_node, cfqq->p_root); |
2215 | } else | |
2216 | cfqq->p_root = NULL; | |
a36e71f9 JA |
2217 | } |
2218 | ||
498d3aa2 JA |
2219 | /* |
2220 | * Update cfqq's position in the service tree. | |
2221 | */ | |
edd75ffd | 2222 | static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
6d048f53 | 2223 | { |
6d048f53 JA |
2224 | /* |
2225 | * Resorting requires the cfqq to be on the RR list already. | |
2226 | */ | |
a36e71f9 | 2227 | if (cfq_cfqq_on_rr(cfqq)) { |
edd75ffd | 2228 | cfq_service_tree_add(cfqd, cfqq, 0); |
a36e71f9 JA |
2229 | cfq_prio_tree_add(cfqd, cfqq); |
2230 | } | |
6d048f53 JA |
2231 | } |
2232 | ||
1da177e4 LT |
2233 | /* |
2234 | * add to busy list of queues for service, trying to be fair in ordering | |
22e2c507 | 2235 | * the pending list according to last request service |
1da177e4 | 2236 | */ |
febffd61 | 2237 | static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
1da177e4 | 2238 | { |
7b679138 | 2239 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); |
3b18152c JA |
2240 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
2241 | cfq_mark_cfqq_on_rr(cfqq); | |
1da177e4 | 2242 | cfqd->busy_queues++; |
ef8a41df SL |
2243 | if (cfq_cfqq_sync(cfqq)) |
2244 | cfqd->busy_sync_queues++; | |
1da177e4 | 2245 | |
edd75ffd | 2246 | cfq_resort_rr_list(cfqd, cfqq); |
1da177e4 LT |
2247 | } |
2248 | ||
498d3aa2 JA |
2249 | /* |
2250 | * Called when the cfqq no longer has requests pending, remove it from | |
2251 | * the service tree. | |
2252 | */ | |
febffd61 | 2253 | static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
1da177e4 | 2254 | { |
7b679138 | 2255 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); |
3b18152c JA |
2256 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
2257 | cfq_clear_cfqq_on_rr(cfqq); | |
1da177e4 | 2258 | |
aa6f6a3d CZ |
2259 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
2260 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); | |
2261 | cfqq->service_tree = NULL; | |
2262 | } | |
f2d1f0ae JA |
2263 | if (cfqq->p_root) { |
2264 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2265 | cfqq->p_root = NULL; | |
2266 | } | |
d9e7620e | 2267 | |
8184f93e | 2268 | cfq_group_notify_queue_del(cfqd, cfqq->cfqg); |
1da177e4 LT |
2269 | BUG_ON(!cfqd->busy_queues); |
2270 | cfqd->busy_queues--; | |
ef8a41df SL |
2271 | if (cfq_cfqq_sync(cfqq)) |
2272 | cfqd->busy_sync_queues--; | |
1da177e4 LT |
2273 | } |
2274 | ||
2275 | /* | |
2276 | * rb tree support functions | |
2277 | */ | |
febffd61 | 2278 | static void cfq_del_rq_rb(struct request *rq) |
1da177e4 | 2279 | { |
5e705374 | 2280 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
5e705374 | 2281 | const int sync = rq_is_sync(rq); |
1da177e4 | 2282 | |
b4878f24 JA |
2283 | BUG_ON(!cfqq->queued[sync]); |
2284 | cfqq->queued[sync]--; | |
1da177e4 | 2285 | |
5e705374 | 2286 | elv_rb_del(&cfqq->sort_list, rq); |
1da177e4 | 2287 | |
f04a6424 VG |
2288 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) { |
2289 | /* | |
2290 | * Queue will be deleted from service tree when we actually | |
2291 | * expire it later. Right now just remove it from prio tree | |
2292 | * as it is empty. | |
2293 | */ | |
2294 | if (cfqq->p_root) { | |
2295 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2296 | cfqq->p_root = NULL; | |
2297 | } | |
2298 | } | |
1da177e4 LT |
2299 | } |
2300 | ||
5e705374 | 2301 | static void cfq_add_rq_rb(struct request *rq) |
1da177e4 | 2302 | { |
5e705374 | 2303 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
1da177e4 | 2304 | struct cfq_data *cfqd = cfqq->cfqd; |
796d5116 | 2305 | struct request *prev; |
1da177e4 | 2306 | |
5380a101 | 2307 | cfqq->queued[rq_is_sync(rq)]++; |
1da177e4 | 2308 | |
796d5116 | 2309 | elv_rb_add(&cfqq->sort_list, rq); |
5fccbf61 JA |
2310 | |
2311 | if (!cfq_cfqq_on_rr(cfqq)) | |
2312 | cfq_add_cfqq_rr(cfqd, cfqq); | |
5044eed4 JA |
2313 | |
2314 | /* | |
2315 | * check if this request is a better next-serve candidate | |
2316 | */ | |
a36e71f9 | 2317 | prev = cfqq->next_rq; |
cf7c25cf | 2318 | cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq, cfqd->last_position); |
a36e71f9 JA |
2319 | |
2320 | /* | |
2321 | * adjust priority tree position, if ->next_rq changes | |
2322 | */ | |
2323 | if (prev != cfqq->next_rq) | |
2324 | cfq_prio_tree_add(cfqd, cfqq); | |
2325 | ||
5044eed4 | 2326 | BUG_ON(!cfqq->next_rq); |
1da177e4 LT |
2327 | } |
2328 | ||
febffd61 | 2329 | static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq) |
1da177e4 | 2330 | { |
5380a101 JA |
2331 | elv_rb_del(&cfqq->sort_list, rq); |
2332 | cfqq->queued[rq_is_sync(rq)]--; | |
155fead9 | 2333 | cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags); |
5e705374 | 2334 | cfq_add_rq_rb(rq); |
155fead9 TH |
2335 | cfqg_stats_update_io_add(RQ_CFQG(rq), cfqq->cfqd->serving_group, |
2336 | rq->cmd_flags); | |
1da177e4 LT |
2337 | } |
2338 | ||
206dc69b JA |
2339 | static struct request * |
2340 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) | |
1da177e4 | 2341 | { |
206dc69b | 2342 | struct task_struct *tsk = current; |
c5869807 | 2343 | struct cfq_io_cq *cic; |
206dc69b | 2344 | struct cfq_queue *cfqq; |
1da177e4 | 2345 | |
4ac845a2 | 2346 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
91fac317 VT |
2347 | if (!cic) |
2348 | return NULL; | |
2349 | ||
2350 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); | |
f73a1c7d KO |
2351 | if (cfqq) |
2352 | return elv_rb_find(&cfqq->sort_list, bio_end_sector(bio)); | |
1da177e4 | 2353 | |
1da177e4 LT |
2354 | return NULL; |
2355 | } | |
2356 | ||
165125e1 | 2357 | static void cfq_activate_request(struct request_queue *q, struct request *rq) |
1da177e4 | 2358 | { |
22e2c507 | 2359 | struct cfq_data *cfqd = q->elevator->elevator_data; |
3b18152c | 2360 | |
53c583d2 | 2361 | cfqd->rq_in_driver++; |
7b679138 | 2362 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", |
53c583d2 | 2363 | cfqd->rq_in_driver); |
25776e35 | 2364 | |
5b93629b | 2365 | cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); |
1da177e4 LT |
2366 | } |
2367 | ||
165125e1 | 2368 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) |
1da177e4 | 2369 | { |
b4878f24 JA |
2370 | struct cfq_data *cfqd = q->elevator->elevator_data; |
2371 | ||
53c583d2 CZ |
2372 | WARN_ON(!cfqd->rq_in_driver); |
2373 | cfqd->rq_in_driver--; | |
7b679138 | 2374 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", |
53c583d2 | 2375 | cfqd->rq_in_driver); |
1da177e4 LT |
2376 | } |
2377 | ||
b4878f24 | 2378 | static void cfq_remove_request(struct request *rq) |
1da177e4 | 2379 | { |
5e705374 | 2380 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
21183b07 | 2381 | |
5e705374 JA |
2382 | if (cfqq->next_rq == rq) |
2383 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); | |
1da177e4 | 2384 | |
b4878f24 | 2385 | list_del_init(&rq->queuelist); |
5e705374 | 2386 | cfq_del_rq_rb(rq); |
374f84ac | 2387 | |
45333d5a | 2388 | cfqq->cfqd->rq_queued--; |
155fead9 | 2389 | cfqg_stats_update_io_remove(RQ_CFQG(rq), rq->cmd_flags); |
65299a3b CH |
2390 | if (rq->cmd_flags & REQ_PRIO) { |
2391 | WARN_ON(!cfqq->prio_pending); | |
2392 | cfqq->prio_pending--; | |
b53d1ed7 | 2393 | } |
1da177e4 LT |
2394 | } |
2395 | ||
165125e1 JA |
2396 | static int cfq_merge(struct request_queue *q, struct request **req, |
2397 | struct bio *bio) | |
1da177e4 LT |
2398 | { |
2399 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
2400 | struct request *__rq; | |
1da177e4 | 2401 | |
206dc69b | 2402 | __rq = cfq_find_rq_fmerge(cfqd, bio); |
22e2c507 | 2403 | if (__rq && elv_rq_merge_ok(__rq, bio)) { |
9817064b JA |
2404 | *req = __rq; |
2405 | return ELEVATOR_FRONT_MERGE; | |
1da177e4 LT |
2406 | } |
2407 | ||
2408 | return ELEVATOR_NO_MERGE; | |
1da177e4 LT |
2409 | } |
2410 | ||
165125e1 | 2411 | static void cfq_merged_request(struct request_queue *q, struct request *req, |
21183b07 | 2412 | int type) |
1da177e4 | 2413 | { |
21183b07 | 2414 | if (type == ELEVATOR_FRONT_MERGE) { |
5e705374 | 2415 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
1da177e4 | 2416 | |
5e705374 | 2417 | cfq_reposition_rq_rb(cfqq, req); |
1da177e4 | 2418 | } |
1da177e4 LT |
2419 | } |
2420 | ||
812d4026 DS |
2421 | static void cfq_bio_merged(struct request_queue *q, struct request *req, |
2422 | struct bio *bio) | |
2423 | { | |
155fead9 | 2424 | cfqg_stats_update_io_merged(RQ_CFQG(req), bio->bi_rw); |
812d4026 DS |
2425 | } |
2426 | ||
1da177e4 | 2427 | static void |
165125e1 | 2428 | cfq_merged_requests(struct request_queue *q, struct request *rq, |
1da177e4 LT |
2429 | struct request *next) |
2430 | { | |
cf7c25cf | 2431 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
4a0b75c7 SL |
2432 | struct cfq_data *cfqd = q->elevator->elevator_data; |
2433 | ||
22e2c507 JA |
2434 | /* |
2435 | * reposition in fifo if next is older than rq | |
2436 | */ | |
2437 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && | |
8b4922d3 | 2438 | time_before(next->fifo_time, rq->fifo_time) && |
3d106fba | 2439 | cfqq == RQ_CFQQ(next)) { |
22e2c507 | 2440 | list_move(&rq->queuelist, &next->queuelist); |
8b4922d3 | 2441 | rq->fifo_time = next->fifo_time; |
30996f40 | 2442 | } |
22e2c507 | 2443 | |
cf7c25cf CZ |
2444 | if (cfqq->next_rq == next) |
2445 | cfqq->next_rq = rq; | |
b4878f24 | 2446 | cfq_remove_request(next); |
155fead9 | 2447 | cfqg_stats_update_io_merged(RQ_CFQG(rq), next->cmd_flags); |
4a0b75c7 SL |
2448 | |
2449 | cfqq = RQ_CFQQ(next); | |
2450 | /* | |
2451 | * all requests of this queue are merged to other queues, delete it | |
2452 | * from the service tree. If it's the active_queue, | |
2453 | * cfq_dispatch_requests() will choose to expire it or do idle | |
2454 | */ | |
2455 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list) && | |
2456 | cfqq != cfqd->active_queue) | |
2457 | cfq_del_cfqq_rr(cfqd, cfqq); | |
22e2c507 JA |
2458 | } |
2459 | ||
165125e1 | 2460 | static int cfq_allow_merge(struct request_queue *q, struct request *rq, |
da775265 JA |
2461 | struct bio *bio) |
2462 | { | |
2463 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
c5869807 | 2464 | struct cfq_io_cq *cic; |
da775265 | 2465 | struct cfq_queue *cfqq; |
da775265 JA |
2466 | |
2467 | /* | |
ec8acb69 | 2468 | * Disallow merge of a sync bio into an async request. |
da775265 | 2469 | */ |
91fac317 | 2470 | if (cfq_bio_sync(bio) && !rq_is_sync(rq)) |
a6151c3a | 2471 | return false; |
da775265 JA |
2472 | |
2473 | /* | |
f1a4f4d3 | 2474 | * Lookup the cfqq that this bio will be queued with and allow |
07c2bd37 | 2475 | * merge only if rq is queued there. |
f1a4f4d3 | 2476 | */ |
07c2bd37 TH |
2477 | cic = cfq_cic_lookup(cfqd, current->io_context); |
2478 | if (!cic) | |
2479 | return false; | |
719d3402 | 2480 | |
91fac317 | 2481 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
a6151c3a | 2482 | return cfqq == RQ_CFQQ(rq); |
da775265 JA |
2483 | } |
2484 | ||
812df48d DS |
2485 | static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
2486 | { | |
2487 | del_timer(&cfqd->idle_slice_timer); | |
155fead9 | 2488 | cfqg_stats_update_idle_time(cfqq->cfqg); |
812df48d DS |
2489 | } |
2490 | ||
febffd61 JA |
2491 | static void __cfq_set_active_queue(struct cfq_data *cfqd, |
2492 | struct cfq_queue *cfqq) | |
22e2c507 JA |
2493 | { |
2494 | if (cfqq) { | |
3bf10fea | 2495 | cfq_log_cfqq(cfqd, cfqq, "set_active wl_class:%d wl_type:%d", |
4d2ceea4 | 2496 | cfqd->serving_wl_class, cfqd->serving_wl_type); |
155fead9 | 2497 | cfqg_stats_update_avg_queue_size(cfqq->cfqg); |
62a37f6b JT |
2498 | cfqq->slice_start = 0; |
2499 | cfqq->dispatch_start = jiffies; | |
2500 | cfqq->allocated_slice = 0; | |
2501 | cfqq->slice_end = 0; | |
2502 | cfqq->slice_dispatch = 0; | |
2503 | cfqq->nr_sectors = 0; | |
2504 | ||
2505 | cfq_clear_cfqq_wait_request(cfqq); | |
2506 | cfq_clear_cfqq_must_dispatch(cfqq); | |
2507 | cfq_clear_cfqq_must_alloc_slice(cfqq); | |
2508 | cfq_clear_cfqq_fifo_expire(cfqq); | |
2509 | cfq_mark_cfqq_slice_new(cfqq); | |
2510 | ||
2511 | cfq_del_timer(cfqd, cfqq); | |
22e2c507 JA |
2512 | } |
2513 | ||
2514 | cfqd->active_queue = cfqq; | |
2515 | } | |
2516 | ||
7b14e3b5 JA |
2517 | /* |
2518 | * current cfqq expired its slice (or was too idle), select new one | |
2519 | */ | |
2520 | static void | |
2521 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
e5ff082e | 2522 | bool timed_out) |
7b14e3b5 | 2523 | { |
7b679138 JA |
2524 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); |
2525 | ||
7b14e3b5 | 2526 | if (cfq_cfqq_wait_request(cfqq)) |
812df48d | 2527 | cfq_del_timer(cfqd, cfqq); |
7b14e3b5 | 2528 | |
7b14e3b5 | 2529 | cfq_clear_cfqq_wait_request(cfqq); |
f75edf2d | 2530 | cfq_clear_cfqq_wait_busy(cfqq); |
7b14e3b5 | 2531 | |
ae54abed SL |
2532 | /* |
2533 | * If this cfqq is shared between multiple processes, check to | |
2534 | * make sure that those processes are still issuing I/Os within | |
2535 | * the mean seek distance. If not, it may be time to break the | |
2536 | * queues apart again. | |
2537 | */ | |
2538 | if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq)) | |
2539 | cfq_mark_cfqq_split_coop(cfqq); | |
2540 | ||
7b14e3b5 | 2541 | /* |
6084cdda | 2542 | * store what was left of this slice, if the queue idled/timed out |
7b14e3b5 | 2543 | */ |
c553f8e3 SL |
2544 | if (timed_out) { |
2545 | if (cfq_cfqq_slice_new(cfqq)) | |
ba5bd520 | 2546 | cfqq->slice_resid = cfq_scaled_cfqq_slice(cfqd, cfqq); |
c553f8e3 SL |
2547 | else |
2548 | cfqq->slice_resid = cfqq->slice_end - jiffies; | |
7b679138 JA |
2549 | cfq_log_cfqq(cfqd, cfqq, "resid=%ld", cfqq->slice_resid); |
2550 | } | |
7b14e3b5 | 2551 | |
e5ff082e | 2552 | cfq_group_served(cfqd, cfqq->cfqg, cfqq); |
dae739eb | 2553 | |
f04a6424 VG |
2554 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) |
2555 | cfq_del_cfqq_rr(cfqd, cfqq); | |
2556 | ||
edd75ffd | 2557 | cfq_resort_rr_list(cfqd, cfqq); |
7b14e3b5 JA |
2558 | |
2559 | if (cfqq == cfqd->active_queue) | |
2560 | cfqd->active_queue = NULL; | |
2561 | ||
2562 | if (cfqd->active_cic) { | |
11a3122f | 2563 | put_io_context(cfqd->active_cic->icq.ioc); |
7b14e3b5 JA |
2564 | cfqd->active_cic = NULL; |
2565 | } | |
7b14e3b5 JA |
2566 | } |
2567 | ||
e5ff082e | 2568 | static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out) |
7b14e3b5 JA |
2569 | { |
2570 | struct cfq_queue *cfqq = cfqd->active_queue; | |
2571 | ||
2572 | if (cfqq) | |
e5ff082e | 2573 | __cfq_slice_expired(cfqd, cfqq, timed_out); |
7b14e3b5 JA |
2574 | } |
2575 | ||
498d3aa2 JA |
2576 | /* |
2577 | * Get next queue for service. Unless we have a queue preemption, | |
2578 | * we'll simply select the first cfqq in the service tree. | |
2579 | */ | |
6d048f53 | 2580 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) |
22e2c507 | 2581 | { |
34b98d03 VG |
2582 | struct cfq_rb_root *st = st_for(cfqd->serving_group, |
2583 | cfqd->serving_wl_class, cfqd->serving_wl_type); | |
d9e7620e | 2584 | |
f04a6424 VG |
2585 | if (!cfqd->rq_queued) |
2586 | return NULL; | |
2587 | ||
1fa8f6d6 | 2588 | /* There is nothing to dispatch */ |
34b98d03 | 2589 | if (!st) |
1fa8f6d6 | 2590 | return NULL; |
34b98d03 | 2591 | if (RB_EMPTY_ROOT(&st->rb)) |
c0324a02 | 2592 | return NULL; |
34b98d03 | 2593 | return cfq_rb_first(st); |
6d048f53 JA |
2594 | } |
2595 | ||
f04a6424 VG |
2596 | static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd) |
2597 | { | |
25fb5169 | 2598 | struct cfq_group *cfqg; |
f04a6424 VG |
2599 | struct cfq_queue *cfqq; |
2600 | int i, j; | |
2601 | struct cfq_rb_root *st; | |
2602 | ||
2603 | if (!cfqd->rq_queued) | |
2604 | return NULL; | |
2605 | ||
25fb5169 VG |
2606 | cfqg = cfq_get_next_cfqg(cfqd); |
2607 | if (!cfqg) | |
2608 | return NULL; | |
2609 | ||
f04a6424 VG |
2610 | for_each_cfqg_st(cfqg, i, j, st) |
2611 | if ((cfqq = cfq_rb_first(st)) != NULL) | |
2612 | return cfqq; | |
2613 | return NULL; | |
2614 | } | |
2615 | ||
498d3aa2 JA |
2616 | /* |
2617 | * Get and set a new active queue for service. | |
2618 | */ | |
a36e71f9 JA |
2619 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, |
2620 | struct cfq_queue *cfqq) | |
6d048f53 | 2621 | { |
e00ef799 | 2622 | if (!cfqq) |
a36e71f9 | 2623 | cfqq = cfq_get_next_queue(cfqd); |
6d048f53 | 2624 | |
22e2c507 | 2625 | __cfq_set_active_queue(cfqd, cfqq); |
3b18152c | 2626 | return cfqq; |
22e2c507 JA |
2627 | } |
2628 | ||
d9e7620e JA |
2629 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, |
2630 | struct request *rq) | |
2631 | { | |
83096ebf TH |
2632 | if (blk_rq_pos(rq) >= cfqd->last_position) |
2633 | return blk_rq_pos(rq) - cfqd->last_position; | |
d9e7620e | 2634 | else |
83096ebf | 2635 | return cfqd->last_position - blk_rq_pos(rq); |
d9e7620e JA |
2636 | } |
2637 | ||
b2c18e1e | 2638 | static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
e9ce335d | 2639 | struct request *rq) |
6d048f53 | 2640 | { |
e9ce335d | 2641 | return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR; |
6d048f53 JA |
2642 | } |
2643 | ||
a36e71f9 JA |
2644 | static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, |
2645 | struct cfq_queue *cur_cfqq) | |
2646 | { | |
f2d1f0ae | 2647 | struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; |
a36e71f9 JA |
2648 | struct rb_node *parent, *node; |
2649 | struct cfq_queue *__cfqq; | |
2650 | sector_t sector = cfqd->last_position; | |
2651 | ||
2652 | if (RB_EMPTY_ROOT(root)) | |
2653 | return NULL; | |
2654 | ||
2655 | /* | |
2656 | * First, if we find a request starting at the end of the last | |
2657 | * request, choose it. | |
2658 | */ | |
f2d1f0ae | 2659 | __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); |
a36e71f9 JA |
2660 | if (__cfqq) |
2661 | return __cfqq; | |
2662 | ||
2663 | /* | |
2664 | * If the exact sector wasn't found, the parent of the NULL leaf | |
2665 | * will contain the closest sector. | |
2666 | */ | |
2667 | __cfqq = rb_entry(parent, struct cfq_queue, p_node); | |
e9ce335d | 2668 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
a36e71f9 JA |
2669 | return __cfqq; |
2670 | ||
2e46e8b2 | 2671 | if (blk_rq_pos(__cfqq->next_rq) < sector) |
a36e71f9 JA |
2672 | node = rb_next(&__cfqq->p_node); |
2673 | else | |
2674 | node = rb_prev(&__cfqq->p_node); | |
2675 | if (!node) | |
2676 | return NULL; | |
2677 | ||
2678 | __cfqq = rb_entry(node, struct cfq_queue, p_node); | |
e9ce335d | 2679 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
a36e71f9 JA |
2680 | return __cfqq; |
2681 | ||
2682 | return NULL; | |
2683 | } | |
2684 | ||
2685 | /* | |
2686 | * cfqd - obvious | |
2687 | * cur_cfqq - passed in so that we don't decide that the current queue is | |
2688 | * closely cooperating with itself. | |
2689 | * | |
2690 | * So, basically we're assuming that that cur_cfqq has dispatched at least | |
2691 | * one request, and that cfqd->last_position reflects a position on the disk | |
2692 | * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid | |
2693 | * assumption. | |
2694 | */ | |
2695 | static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, | |
b3b6d040 | 2696 | struct cfq_queue *cur_cfqq) |
6d048f53 | 2697 | { |
a36e71f9 JA |
2698 | struct cfq_queue *cfqq; |
2699 | ||
39c01b21 DS |
2700 | if (cfq_class_idle(cur_cfqq)) |
2701 | return NULL; | |
e6c5bc73 JM |
2702 | if (!cfq_cfqq_sync(cur_cfqq)) |
2703 | return NULL; | |
2704 | if (CFQQ_SEEKY(cur_cfqq)) | |
2705 | return NULL; | |
2706 | ||
b9d8f4c7 GJ |
2707 | /* |
2708 | * Don't search priority tree if it's the only queue in the group. | |
2709 | */ | |
2710 | if (cur_cfqq->cfqg->nr_cfqq == 1) | |
2711 | return NULL; | |
2712 | ||
6d048f53 | 2713 | /* |
d9e7620e JA |
2714 | * We should notice if some of the queues are cooperating, eg |
2715 | * working closely on the same area of the disk. In that case, | |
2716 | * we can group them together and don't waste time idling. | |
6d048f53 | 2717 | */ |
a36e71f9 JA |
2718 | cfqq = cfqq_close(cfqd, cur_cfqq); |
2719 | if (!cfqq) | |
2720 | return NULL; | |
2721 | ||
8682e1f1 VG |
2722 | /* If new queue belongs to different cfq_group, don't choose it */ |
2723 | if (cur_cfqq->cfqg != cfqq->cfqg) | |
2724 | return NULL; | |
2725 | ||
df5fe3e8 JM |
2726 | /* |
2727 | * It only makes sense to merge sync queues. | |
2728 | */ | |
2729 | if (!cfq_cfqq_sync(cfqq)) | |
2730 | return NULL; | |
e6c5bc73 JM |
2731 | if (CFQQ_SEEKY(cfqq)) |
2732 | return NULL; | |
df5fe3e8 | 2733 | |
c0324a02 CZ |
2734 | /* |
2735 | * Do not merge queues of different priority classes | |
2736 | */ | |
2737 | if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq)) | |
2738 | return NULL; | |
2739 | ||
a36e71f9 | 2740 | return cfqq; |
6d048f53 JA |
2741 | } |
2742 | ||
a6d44e98 CZ |
2743 | /* |
2744 | * Determine whether we should enforce idle window for this queue. | |
2745 | */ | |
2746 | ||
2747 | static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2748 | { | |
3bf10fea | 2749 | enum wl_class_t wl_class = cfqq_class(cfqq); |
34b98d03 | 2750 | struct cfq_rb_root *st = cfqq->service_tree; |
a6d44e98 | 2751 | |
34b98d03 VG |
2752 | BUG_ON(!st); |
2753 | BUG_ON(!st->count); | |
f04a6424 | 2754 | |
b6508c16 VG |
2755 | if (!cfqd->cfq_slice_idle) |
2756 | return false; | |
2757 | ||
a6d44e98 | 2758 | /* We never do for idle class queues. */ |
3bf10fea | 2759 | if (wl_class == IDLE_WORKLOAD) |
a6d44e98 CZ |
2760 | return false; |
2761 | ||
2762 | /* We do for queues that were marked with idle window flag. */ | |
3c764b7a SL |
2763 | if (cfq_cfqq_idle_window(cfqq) && |
2764 | !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)) | |
a6d44e98 CZ |
2765 | return true; |
2766 | ||
2767 | /* | |
2768 | * Otherwise, we do only if they are the last ones | |
2769 | * in their service tree. | |
2770 | */ | |
34b98d03 VG |
2771 | if (st->count == 1 && cfq_cfqq_sync(cfqq) && |
2772 | !cfq_io_thinktime_big(cfqd, &st->ttime, false)) | |
c1e44756 | 2773 | return true; |
34b98d03 | 2774 | cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", st->count); |
c1e44756 | 2775 | return false; |
a6d44e98 CZ |
2776 | } |
2777 | ||
6d048f53 | 2778 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) |
22e2c507 | 2779 | { |
1792669c | 2780 | struct cfq_queue *cfqq = cfqd->active_queue; |
c5869807 | 2781 | struct cfq_io_cq *cic; |
80bdf0c7 | 2782 | unsigned long sl, group_idle = 0; |
7b14e3b5 | 2783 | |
a68bbddb | 2784 | /* |
f7d7b7a7 JA |
2785 | * SSD device without seek penalty, disable idling. But only do so |
2786 | * for devices that support queuing, otherwise we still have a problem | |
2787 | * with sync vs async workloads. | |
a68bbddb | 2788 | */ |
f7d7b7a7 | 2789 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) |
a68bbddb JA |
2790 | return; |
2791 | ||
dd67d051 | 2792 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); |
6d048f53 | 2793 | WARN_ON(cfq_cfqq_slice_new(cfqq)); |
22e2c507 JA |
2794 | |
2795 | /* | |
2796 | * idle is disabled, either manually or by past process history | |
2797 | */ | |
80bdf0c7 VG |
2798 | if (!cfq_should_idle(cfqd, cfqq)) { |
2799 | /* no queue idling. Check for group idling */ | |
2800 | if (cfqd->cfq_group_idle) | |
2801 | group_idle = cfqd->cfq_group_idle; | |
2802 | else | |
2803 | return; | |
2804 | } | |
6d048f53 | 2805 | |
7b679138 | 2806 | /* |
8e550632 | 2807 | * still active requests from this queue, don't idle |
7b679138 | 2808 | */ |
8e550632 | 2809 | if (cfqq->dispatched) |
7b679138 JA |
2810 | return; |
2811 | ||
22e2c507 JA |
2812 | /* |
2813 | * task has exited, don't wait | |
2814 | */ | |
206dc69b | 2815 | cic = cfqd->active_cic; |
f6e8d01b | 2816 | if (!cic || !atomic_read(&cic->icq.ioc->active_ref)) |
6d048f53 JA |
2817 | return; |
2818 | ||
355b659c CZ |
2819 | /* |
2820 | * If our average think time is larger than the remaining time | |
2821 | * slice, then don't idle. This avoids overrunning the allotted | |
2822 | * time slice. | |
2823 | */ | |
383cd721 SL |
2824 | if (sample_valid(cic->ttime.ttime_samples) && |
2825 | (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) { | |
fd16d263 | 2826 | cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%lu", |
383cd721 | 2827 | cic->ttime.ttime_mean); |
355b659c | 2828 | return; |
b1ffe737 | 2829 | } |
355b659c | 2830 | |
80bdf0c7 VG |
2831 | /* There are other queues in the group, don't do group idle */ |
2832 | if (group_idle && cfqq->cfqg->nr_cfqq > 1) | |
2833 | return; | |
2834 | ||
3b18152c | 2835 | cfq_mark_cfqq_wait_request(cfqq); |
22e2c507 | 2836 | |
80bdf0c7 VG |
2837 | if (group_idle) |
2838 | sl = cfqd->cfq_group_idle; | |
2839 | else | |
2840 | sl = cfqd->cfq_slice_idle; | |
206dc69b | 2841 | |
7b14e3b5 | 2842 | mod_timer(&cfqd->idle_slice_timer, jiffies + sl); |
155fead9 | 2843 | cfqg_stats_set_start_idle_time(cfqq->cfqg); |
80bdf0c7 VG |
2844 | cfq_log_cfqq(cfqd, cfqq, "arm_idle: %lu group_idle: %d", sl, |
2845 | group_idle ? 1 : 0); | |
1da177e4 LT |
2846 | } |
2847 | ||
498d3aa2 JA |
2848 | /* |
2849 | * Move request from internal lists to the request queue dispatch list. | |
2850 | */ | |
165125e1 | 2851 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) |
1da177e4 | 2852 | { |
3ed9a296 | 2853 | struct cfq_data *cfqd = q->elevator->elevator_data; |
5e705374 | 2854 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
22e2c507 | 2855 | |
7b679138 JA |
2856 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); |
2857 | ||
06d21886 | 2858 | cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); |
5380a101 | 2859 | cfq_remove_request(rq); |
6d048f53 | 2860 | cfqq->dispatched++; |
80bdf0c7 | 2861 | (RQ_CFQG(rq))->dispatched++; |
5380a101 | 2862 | elv_dispatch_sort(q, rq); |
3ed9a296 | 2863 | |
53c583d2 | 2864 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++; |
c4e7893e | 2865 | cfqq->nr_sectors += blk_rq_sectors(rq); |
155fead9 | 2866 | cfqg_stats_update_dispatch(cfqq->cfqg, blk_rq_bytes(rq), rq->cmd_flags); |
1da177e4 LT |
2867 | } |
2868 | ||
2869 | /* | |
2870 | * return expired entry, or NULL to just start from scratch in rbtree | |
2871 | */ | |
febffd61 | 2872 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) |
1da177e4 | 2873 | { |
30996f40 | 2874 | struct request *rq = NULL; |
1da177e4 | 2875 | |
3b18152c | 2876 | if (cfq_cfqq_fifo_expire(cfqq)) |
1da177e4 | 2877 | return NULL; |
cb887411 JA |
2878 | |
2879 | cfq_mark_cfqq_fifo_expire(cfqq); | |
2880 | ||
89850f7e JA |
2881 | if (list_empty(&cfqq->fifo)) |
2882 | return NULL; | |
1da177e4 | 2883 | |
89850f7e | 2884 | rq = rq_entry_fifo(cfqq->fifo.next); |
8b4922d3 | 2885 | if (time_before(jiffies, rq->fifo_time)) |
7b679138 | 2886 | rq = NULL; |
1da177e4 | 2887 | |
30996f40 | 2888 | cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); |
6d048f53 | 2889 | return rq; |
1da177e4 LT |
2890 | } |
2891 | ||
22e2c507 JA |
2892 | static inline int |
2893 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2894 | { | |
2895 | const int base_rq = cfqd->cfq_slice_async_rq; | |
1da177e4 | 2896 | |
22e2c507 | 2897 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); |
1da177e4 | 2898 | |
b9f8ce05 | 2899 | return 2 * base_rq * (IOPRIO_BE_NR - cfqq->ioprio); |
1da177e4 LT |
2900 | } |
2901 | ||
df5fe3e8 JM |
2902 | /* |
2903 | * Must be called with the queue_lock held. | |
2904 | */ | |
2905 | static int cfqq_process_refs(struct cfq_queue *cfqq) | |
2906 | { | |
2907 | int process_refs, io_refs; | |
2908 | ||
2909 | io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE]; | |
30d7b944 | 2910 | process_refs = cfqq->ref - io_refs; |
df5fe3e8 JM |
2911 | BUG_ON(process_refs < 0); |
2912 | return process_refs; | |
2913 | } | |
2914 | ||
2915 | static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) | |
2916 | { | |
e6c5bc73 | 2917 | int process_refs, new_process_refs; |
df5fe3e8 JM |
2918 | struct cfq_queue *__cfqq; |
2919 | ||
c10b61f0 JM |
2920 | /* |
2921 | * If there are no process references on the new_cfqq, then it is | |
2922 | * unsafe to follow the ->new_cfqq chain as other cfqq's in the | |
2923 | * chain may have dropped their last reference (not just their | |
2924 | * last process reference). | |
2925 | */ | |
2926 | if (!cfqq_process_refs(new_cfqq)) | |
2927 | return; | |
2928 | ||
df5fe3e8 JM |
2929 | /* Avoid a circular list and skip interim queue merges */ |
2930 | while ((__cfqq = new_cfqq->new_cfqq)) { | |
2931 | if (__cfqq == cfqq) | |
2932 | return; | |
2933 | new_cfqq = __cfqq; | |
2934 | } | |
2935 | ||
2936 | process_refs = cfqq_process_refs(cfqq); | |
c10b61f0 | 2937 | new_process_refs = cfqq_process_refs(new_cfqq); |
df5fe3e8 JM |
2938 | /* |
2939 | * If the process for the cfqq has gone away, there is no | |
2940 | * sense in merging the queues. | |
2941 | */ | |
c10b61f0 | 2942 | if (process_refs == 0 || new_process_refs == 0) |
df5fe3e8 JM |
2943 | return; |
2944 | ||
e6c5bc73 JM |
2945 | /* |
2946 | * Merge in the direction of the lesser amount of work. | |
2947 | */ | |
e6c5bc73 JM |
2948 | if (new_process_refs >= process_refs) { |
2949 | cfqq->new_cfqq = new_cfqq; | |
30d7b944 | 2950 | new_cfqq->ref += process_refs; |
e6c5bc73 JM |
2951 | } else { |
2952 | new_cfqq->new_cfqq = cfqq; | |
30d7b944 | 2953 | cfqq->ref += new_process_refs; |
e6c5bc73 | 2954 | } |
df5fe3e8 JM |
2955 | } |
2956 | ||
6d816ec7 | 2957 | static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd, |
3bf10fea | 2958 | struct cfq_group *cfqg, enum wl_class_t wl_class) |
718eee05 CZ |
2959 | { |
2960 | struct cfq_queue *queue; | |
2961 | int i; | |
2962 | bool key_valid = false; | |
2963 | unsigned long lowest_key = 0; | |
2964 | enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; | |
2965 | ||
65b32a57 VG |
2966 | for (i = 0; i <= SYNC_WORKLOAD; ++i) { |
2967 | /* select the one with lowest rb_key */ | |
34b98d03 | 2968 | queue = cfq_rb_first(st_for(cfqg, wl_class, i)); |
718eee05 CZ |
2969 | if (queue && |
2970 | (!key_valid || time_before(queue->rb_key, lowest_key))) { | |
2971 | lowest_key = queue->rb_key; | |
2972 | cur_best = i; | |
2973 | key_valid = true; | |
2974 | } | |
2975 | } | |
2976 | ||
2977 | return cur_best; | |
2978 | } | |
2979 | ||
6d816ec7 VG |
2980 | static void |
2981 | choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
718eee05 | 2982 | { |
718eee05 CZ |
2983 | unsigned slice; |
2984 | unsigned count; | |
cdb16e8f | 2985 | struct cfq_rb_root *st; |
58ff82f3 | 2986 | unsigned group_slice; |
4d2ceea4 | 2987 | enum wl_class_t original_class = cfqd->serving_wl_class; |
1fa8f6d6 | 2988 | |
718eee05 | 2989 | /* Choose next priority. RT > BE > IDLE */ |
58ff82f3 | 2990 | if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) |
4d2ceea4 | 2991 | cfqd->serving_wl_class = RT_WORKLOAD; |
58ff82f3 | 2992 | else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg)) |
4d2ceea4 | 2993 | cfqd->serving_wl_class = BE_WORKLOAD; |
718eee05 | 2994 | else { |
4d2ceea4 | 2995 | cfqd->serving_wl_class = IDLE_WORKLOAD; |
718eee05 CZ |
2996 | cfqd->workload_expires = jiffies + 1; |
2997 | return; | |
2998 | } | |
2999 | ||
4d2ceea4 | 3000 | if (original_class != cfqd->serving_wl_class) |
e4ea0c16 SL |
3001 | goto new_workload; |
3002 | ||
718eee05 CZ |
3003 | /* |
3004 | * For RT and BE, we have to choose also the type | |
3005 | * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload | |
3006 | * expiration time | |
3007 | */ | |
34b98d03 | 3008 | st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type); |
cdb16e8f | 3009 | count = st->count; |
718eee05 CZ |
3010 | |
3011 | /* | |
65b32a57 | 3012 | * check workload expiration, and that we still have other queues ready |
718eee05 | 3013 | */ |
65b32a57 | 3014 | if (count && !time_after(jiffies, cfqd->workload_expires)) |
718eee05 CZ |
3015 | return; |
3016 | ||
e4ea0c16 | 3017 | new_workload: |
718eee05 | 3018 | /* otherwise select new workload type */ |
6d816ec7 | 3019 | cfqd->serving_wl_type = cfq_choose_wl_type(cfqd, cfqg, |
4d2ceea4 | 3020 | cfqd->serving_wl_class); |
34b98d03 | 3021 | st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type); |
cdb16e8f | 3022 | count = st->count; |
718eee05 CZ |
3023 | |
3024 | /* | |
3025 | * the workload slice is computed as a fraction of target latency | |
3026 | * proportional to the number of queues in that workload, over | |
3027 | * all the queues in the same priority class | |
3028 | */ | |
58ff82f3 VG |
3029 | group_slice = cfq_group_slice(cfqd, cfqg); |
3030 | ||
3031 | slice = group_slice * count / | |
4d2ceea4 VG |
3032 | max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_wl_class], |
3033 | cfq_group_busy_queues_wl(cfqd->serving_wl_class, cfqd, | |
3bf10fea | 3034 | cfqg)); |
718eee05 | 3035 | |
4d2ceea4 | 3036 | if (cfqd->serving_wl_type == ASYNC_WORKLOAD) { |
f26bd1f0 VG |
3037 | unsigned int tmp; |
3038 | ||
3039 | /* | |
3040 | * Async queues are currently system wide. Just taking | |
3041 | * proportion of queues with-in same group will lead to higher | |
3042 | * async ratio system wide as generally root group is going | |
3043 | * to have higher weight. A more accurate thing would be to | |
3044 | * calculate system wide asnc/sync ratio. | |
3045 | */ | |
5bf14c07 TM |
3046 | tmp = cfqd->cfq_target_latency * |
3047 | cfqg_busy_async_queues(cfqd, cfqg); | |
f26bd1f0 VG |
3048 | tmp = tmp/cfqd->busy_queues; |
3049 | slice = min_t(unsigned, slice, tmp); | |
3050 | ||
718eee05 CZ |
3051 | /* async workload slice is scaled down according to |
3052 | * the sync/async slice ratio. */ | |
3053 | slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1]; | |
f26bd1f0 | 3054 | } else |
718eee05 CZ |
3055 | /* sync workload slice is at least 2 * cfq_slice_idle */ |
3056 | slice = max(slice, 2 * cfqd->cfq_slice_idle); | |
3057 | ||
3058 | slice = max_t(unsigned, slice, CFQ_MIN_TT); | |
b1ffe737 | 3059 | cfq_log(cfqd, "workload slice:%d", slice); |
718eee05 CZ |
3060 | cfqd->workload_expires = jiffies + slice; |
3061 | } | |
3062 | ||
1fa8f6d6 VG |
3063 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) |
3064 | { | |
3065 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
25bc6b07 | 3066 | struct cfq_group *cfqg; |
1fa8f6d6 VG |
3067 | |
3068 | if (RB_EMPTY_ROOT(&st->rb)) | |
3069 | return NULL; | |
25bc6b07 | 3070 | cfqg = cfq_rb_first_group(st); |
25bc6b07 VG |
3071 | update_min_vdisktime(st); |
3072 | return cfqg; | |
1fa8f6d6 VG |
3073 | } |
3074 | ||
cdb16e8f VG |
3075 | static void cfq_choose_cfqg(struct cfq_data *cfqd) |
3076 | { | |
1fa8f6d6 VG |
3077 | struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); |
3078 | ||
3079 | cfqd->serving_group = cfqg; | |
dae739eb VG |
3080 | |
3081 | /* Restore the workload type data */ | |
4d2ceea4 VG |
3082 | if (cfqg->saved_wl_slice) { |
3083 | cfqd->workload_expires = jiffies + cfqg->saved_wl_slice; | |
3084 | cfqd->serving_wl_type = cfqg->saved_wl_type; | |
3085 | cfqd->serving_wl_class = cfqg->saved_wl_class; | |
66ae2919 GJ |
3086 | } else |
3087 | cfqd->workload_expires = jiffies - 1; | |
3088 | ||
6d816ec7 | 3089 | choose_wl_class_and_type(cfqd, cfqg); |
cdb16e8f VG |
3090 | } |
3091 | ||
22e2c507 | 3092 | /* |
498d3aa2 JA |
3093 | * Select a queue for service. If we have a current active queue, |
3094 | * check whether to continue servicing it, or retrieve and set a new one. | |
22e2c507 | 3095 | */ |
1b5ed5e1 | 3096 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) |
1da177e4 | 3097 | { |
a36e71f9 | 3098 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
1da177e4 | 3099 | |
22e2c507 JA |
3100 | cfqq = cfqd->active_queue; |
3101 | if (!cfqq) | |
3102 | goto new_queue; | |
1da177e4 | 3103 | |
f04a6424 VG |
3104 | if (!cfqd->rq_queued) |
3105 | return NULL; | |
c244bb50 VG |
3106 | |
3107 | /* | |
3108 | * We were waiting for group to get backlogged. Expire the queue | |
3109 | */ | |
3110 | if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list)) | |
3111 | goto expire; | |
3112 | ||
22e2c507 | 3113 | /* |
6d048f53 | 3114 | * The active queue has run out of time, expire it and select new. |
22e2c507 | 3115 | */ |
7667aa06 VG |
3116 | if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) { |
3117 | /* | |
3118 | * If slice had not expired at the completion of last request | |
3119 | * we might not have turned on wait_busy flag. Don't expire | |
3120 | * the queue yet. Allow the group to get backlogged. | |
3121 | * | |
3122 | * The very fact that we have used the slice, that means we | |
3123 | * have been idling all along on this queue and it should be | |
3124 | * ok to wait for this request to complete. | |
3125 | */ | |
82bbbf28 VG |
3126 | if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list) |
3127 | && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { | |
3128 | cfqq = NULL; | |
7667aa06 | 3129 | goto keep_queue; |
82bbbf28 | 3130 | } else |
80bdf0c7 | 3131 | goto check_group_idle; |
7667aa06 | 3132 | } |
1da177e4 | 3133 | |
22e2c507 | 3134 | /* |
6d048f53 JA |
3135 | * The active queue has requests and isn't expired, allow it to |
3136 | * dispatch. | |
22e2c507 | 3137 | */ |
dd67d051 | 3138 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
22e2c507 | 3139 | goto keep_queue; |
6d048f53 | 3140 | |
a36e71f9 JA |
3141 | /* |
3142 | * If another queue has a request waiting within our mean seek | |
3143 | * distance, let it run. The expire code will check for close | |
3144 | * cooperators and put the close queue at the front of the service | |
df5fe3e8 | 3145 | * tree. If possible, merge the expiring queue with the new cfqq. |
a36e71f9 | 3146 | */ |
b3b6d040 | 3147 | new_cfqq = cfq_close_cooperator(cfqd, cfqq); |
df5fe3e8 JM |
3148 | if (new_cfqq) { |
3149 | if (!cfqq->new_cfqq) | |
3150 | cfq_setup_merge(cfqq, new_cfqq); | |
a36e71f9 | 3151 | goto expire; |
df5fe3e8 | 3152 | } |
a36e71f9 | 3153 | |
6d048f53 JA |
3154 | /* |
3155 | * No requests pending. If the active queue still has requests in | |
3156 | * flight or is idling for a new request, allow either of these | |
3157 | * conditions to happen (or time out) before selecting a new queue. | |
3158 | */ | |
80bdf0c7 VG |
3159 | if (timer_pending(&cfqd->idle_slice_timer)) { |
3160 | cfqq = NULL; | |
3161 | goto keep_queue; | |
3162 | } | |
3163 | ||
8e1ac665 SL |
3164 | /* |
3165 | * This is a deep seek queue, but the device is much faster than | |
3166 | * the queue can deliver, don't idle | |
3167 | **/ | |
3168 | if (CFQQ_SEEKY(cfqq) && cfq_cfqq_idle_window(cfqq) && | |
3169 | (cfq_cfqq_slice_new(cfqq) || | |
3170 | (cfqq->slice_end - jiffies > jiffies - cfqq->slice_start))) { | |
3171 | cfq_clear_cfqq_deep(cfqq); | |
3172 | cfq_clear_cfqq_idle_window(cfqq); | |
3173 | } | |
3174 | ||
80bdf0c7 VG |
3175 | if (cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { |
3176 | cfqq = NULL; | |
3177 | goto keep_queue; | |
3178 | } | |
3179 | ||
3180 | /* | |
3181 | * If group idle is enabled and there are requests dispatched from | |
3182 | * this group, wait for requests to complete. | |
3183 | */ | |
3184 | check_group_idle: | |
7700fc4f SL |
3185 | if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1 && |
3186 | cfqq->cfqg->dispatched && | |
3187 | !cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) { | |
caaa5f9f JA |
3188 | cfqq = NULL; |
3189 | goto keep_queue; | |
22e2c507 JA |
3190 | } |
3191 | ||
3b18152c | 3192 | expire: |
e5ff082e | 3193 | cfq_slice_expired(cfqd, 0); |
3b18152c | 3194 | new_queue: |
718eee05 CZ |
3195 | /* |
3196 | * Current queue expired. Check if we have to switch to a new | |
3197 | * service tree | |
3198 | */ | |
3199 | if (!new_cfqq) | |
cdb16e8f | 3200 | cfq_choose_cfqg(cfqd); |
718eee05 | 3201 | |
a36e71f9 | 3202 | cfqq = cfq_set_active_queue(cfqd, new_cfqq); |
22e2c507 | 3203 | keep_queue: |
3b18152c | 3204 | return cfqq; |
22e2c507 JA |
3205 | } |
3206 | ||
febffd61 | 3207 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) |
d9e7620e JA |
3208 | { |
3209 | int dispatched = 0; | |
3210 | ||
3211 | while (cfqq->next_rq) { | |
3212 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); | |
3213 | dispatched++; | |
3214 | } | |
3215 | ||
3216 | BUG_ON(!list_empty(&cfqq->fifo)); | |
f04a6424 VG |
3217 | |
3218 | /* By default cfqq is not expired if it is empty. Do it explicitly */ | |
e5ff082e | 3219 | __cfq_slice_expired(cfqq->cfqd, cfqq, 0); |
d9e7620e JA |
3220 | return dispatched; |
3221 | } | |
3222 | ||
498d3aa2 JA |
3223 | /* |
3224 | * Drain our current requests. Used for barriers and when switching | |
3225 | * io schedulers on-the-fly. | |
3226 | */ | |
d9e7620e | 3227 | static int cfq_forced_dispatch(struct cfq_data *cfqd) |
1b5ed5e1 | 3228 | { |
0871714e | 3229 | struct cfq_queue *cfqq; |
d9e7620e | 3230 | int dispatched = 0; |
cdb16e8f | 3231 | |
3440c49f | 3232 | /* Expire the timeslice of the current active queue first */ |
e5ff082e | 3233 | cfq_slice_expired(cfqd, 0); |
3440c49f DS |
3234 | while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) { |
3235 | __cfq_set_active_queue(cfqd, cfqq); | |
f04a6424 | 3236 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); |
3440c49f | 3237 | } |
1b5ed5e1 | 3238 | |
1b5ed5e1 TH |
3239 | BUG_ON(cfqd->busy_queues); |
3240 | ||
6923715a | 3241 | cfq_log(cfqd, "forced_dispatch=%d", dispatched); |
1b5ed5e1 TH |
3242 | return dispatched; |
3243 | } | |
3244 | ||
abc3c744 SL |
3245 | static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, |
3246 | struct cfq_queue *cfqq) | |
3247 | { | |
3248 | /* the queue hasn't finished any request, can't estimate */ | |
3249 | if (cfq_cfqq_slice_new(cfqq)) | |
c1e44756 | 3250 | return true; |
abc3c744 SL |
3251 | if (time_after(jiffies + cfqd->cfq_slice_idle * cfqq->dispatched, |
3252 | cfqq->slice_end)) | |
c1e44756 | 3253 | return true; |
abc3c744 | 3254 | |
c1e44756 | 3255 | return false; |
abc3c744 SL |
3256 | } |
3257 | ||
0b182d61 | 3258 | static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
2f5cb738 | 3259 | { |
2f5cb738 | 3260 | unsigned int max_dispatch; |
22e2c507 | 3261 | |
5ad531db JA |
3262 | /* |
3263 | * Drain async requests before we start sync IO | |
3264 | */ | |
53c583d2 | 3265 | if (cfq_should_idle(cfqd, cfqq) && cfqd->rq_in_flight[BLK_RW_ASYNC]) |
0b182d61 | 3266 | return false; |
5ad531db | 3267 | |
2f5cb738 JA |
3268 | /* |
3269 | * If this is an async queue and we have sync IO in flight, let it wait | |
3270 | */ | |
53c583d2 | 3271 | if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq)) |
0b182d61 | 3272 | return false; |
2f5cb738 | 3273 | |
abc3c744 | 3274 | max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1); |
2f5cb738 JA |
3275 | if (cfq_class_idle(cfqq)) |
3276 | max_dispatch = 1; | |
b4878f24 | 3277 | |
2f5cb738 JA |
3278 | /* |
3279 | * Does this cfqq already have too much IO in flight? | |
3280 | */ | |
3281 | if (cfqq->dispatched >= max_dispatch) { | |
ef8a41df | 3282 | bool promote_sync = false; |
2f5cb738 JA |
3283 | /* |
3284 | * idle queue must always only have a single IO in flight | |
3285 | */ | |
3ed9a296 | 3286 | if (cfq_class_idle(cfqq)) |
0b182d61 | 3287 | return false; |
3ed9a296 | 3288 | |
ef8a41df | 3289 | /* |
c4ade94f LS |
3290 | * If there is only one sync queue |
3291 | * we can ignore async queue here and give the sync | |
ef8a41df SL |
3292 | * queue no dispatch limit. The reason is a sync queue can |
3293 | * preempt async queue, limiting the sync queue doesn't make | |
3294 | * sense. This is useful for aiostress test. | |
3295 | */ | |
c4ade94f LS |
3296 | if (cfq_cfqq_sync(cfqq) && cfqd->busy_sync_queues == 1) |
3297 | promote_sync = true; | |
ef8a41df | 3298 | |
2f5cb738 JA |
3299 | /* |
3300 | * We have other queues, don't allow more IO from this one | |
3301 | */ | |
ef8a41df SL |
3302 | if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq) && |
3303 | !promote_sync) | |
0b182d61 | 3304 | return false; |
9ede209e | 3305 | |
365722bb | 3306 | /* |
474b18cc | 3307 | * Sole queue user, no limit |
365722bb | 3308 | */ |
ef8a41df | 3309 | if (cfqd->busy_queues == 1 || promote_sync) |
abc3c744 SL |
3310 | max_dispatch = -1; |
3311 | else | |
3312 | /* | |
3313 | * Normally we start throttling cfqq when cfq_quantum/2 | |
3314 | * requests have been dispatched. But we can drive | |
3315 | * deeper queue depths at the beginning of slice | |
3316 | * subjected to upper limit of cfq_quantum. | |
3317 | * */ | |
3318 | max_dispatch = cfqd->cfq_quantum; | |
8e296755 JA |
3319 | } |
3320 | ||
3321 | /* | |
3322 | * Async queues must wait a bit before being allowed dispatch. | |
3323 | * We also ramp up the dispatch depth gradually for async IO, | |
3324 | * based on the last sync IO we serviced | |
3325 | */ | |
963b72fc | 3326 | if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { |
573412b2 | 3327 | unsigned long last_sync = jiffies - cfqd->last_delayed_sync; |
8e296755 | 3328 | unsigned int depth; |
365722bb | 3329 | |
61f0c1dc | 3330 | depth = last_sync / cfqd->cfq_slice[1]; |
e00c54c3 JA |
3331 | if (!depth && !cfqq->dispatched) |
3332 | depth = 1; | |
8e296755 JA |
3333 | if (depth < max_dispatch) |
3334 | max_dispatch = depth; | |
2f5cb738 | 3335 | } |
3ed9a296 | 3336 | |
0b182d61 JA |
3337 | /* |
3338 | * If we're below the current max, allow a dispatch | |
3339 | */ | |
3340 | return cfqq->dispatched < max_dispatch; | |
3341 | } | |
3342 | ||
3343 | /* | |
3344 | * Dispatch a request from cfqq, moving them to the request queue | |
3345 | * dispatch list. | |
3346 | */ | |
3347 | static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3348 | { | |
3349 | struct request *rq; | |
3350 | ||
3351 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); | |
3352 | ||
3353 | if (!cfq_may_dispatch(cfqd, cfqq)) | |
3354 | return false; | |
3355 | ||
3356 | /* | |
3357 | * follow expired path, else get first next available | |
3358 | */ | |
3359 | rq = cfq_check_fifo(cfqq); | |
3360 | if (!rq) | |
3361 | rq = cfqq->next_rq; | |
3362 | ||
3363 | /* | |
3364 | * insert request into driver dispatch list | |
3365 | */ | |
3366 | cfq_dispatch_insert(cfqd->queue, rq); | |
3367 | ||
3368 | if (!cfqd->active_cic) { | |
c5869807 | 3369 | struct cfq_io_cq *cic = RQ_CIC(rq); |
0b182d61 | 3370 | |
c5869807 | 3371 | atomic_long_inc(&cic->icq.ioc->refcount); |
0b182d61 JA |
3372 | cfqd->active_cic = cic; |
3373 | } | |
3374 | ||
3375 | return true; | |
3376 | } | |
3377 | ||
3378 | /* | |
3379 | * Find the cfqq that we need to service and move a request from that to the | |
3380 | * dispatch list | |
3381 | */ | |
3382 | static int cfq_dispatch_requests(struct request_queue *q, int force) | |
3383 | { | |
3384 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
3385 | struct cfq_queue *cfqq; | |
3386 | ||
3387 | if (!cfqd->busy_queues) | |
3388 | return 0; | |
3389 | ||
3390 | if (unlikely(force)) | |
3391 | return cfq_forced_dispatch(cfqd); | |
3392 | ||
3393 | cfqq = cfq_select_queue(cfqd); | |
3394 | if (!cfqq) | |
8e296755 JA |
3395 | return 0; |
3396 | ||
2f5cb738 | 3397 | /* |
0b182d61 | 3398 | * Dispatch a request from this cfqq, if it is allowed |
2f5cb738 | 3399 | */ |
0b182d61 JA |
3400 | if (!cfq_dispatch_request(cfqd, cfqq)) |
3401 | return 0; | |
3402 | ||
2f5cb738 | 3403 | cfqq->slice_dispatch++; |
b029195d | 3404 | cfq_clear_cfqq_must_dispatch(cfqq); |
22e2c507 | 3405 | |
2f5cb738 JA |
3406 | /* |
3407 | * expire an async queue immediately if it has used up its slice. idle | |
3408 | * queue always expire after 1 dispatch round. | |
3409 | */ | |
3410 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && | |
3411 | cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || | |
3412 | cfq_class_idle(cfqq))) { | |
3413 | cfqq->slice_end = jiffies + 1; | |
e5ff082e | 3414 | cfq_slice_expired(cfqd, 0); |
1da177e4 LT |
3415 | } |
3416 | ||
b217a903 | 3417 | cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); |
2f5cb738 | 3418 | return 1; |
1da177e4 LT |
3419 | } |
3420 | ||
1da177e4 | 3421 | /* |
5e705374 JA |
3422 | * task holds one reference to the queue, dropped when task exits. each rq |
3423 | * in-flight on this queue also holds a reference, dropped when rq is freed. | |
1da177e4 | 3424 | * |
b1c35769 | 3425 | * Each cfq queue took a reference on the parent group. Drop it now. |
1da177e4 LT |
3426 | * queue lock must be held here. |
3427 | */ | |
3428 | static void cfq_put_queue(struct cfq_queue *cfqq) | |
3429 | { | |
22e2c507 | 3430 | struct cfq_data *cfqd = cfqq->cfqd; |
0bbfeb83 | 3431 | struct cfq_group *cfqg; |
22e2c507 | 3432 | |
30d7b944 | 3433 | BUG_ON(cfqq->ref <= 0); |
1da177e4 | 3434 | |
30d7b944 SL |
3435 | cfqq->ref--; |
3436 | if (cfqq->ref) | |
1da177e4 LT |
3437 | return; |
3438 | ||
7b679138 | 3439 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); |
1da177e4 | 3440 | BUG_ON(rb_first(&cfqq->sort_list)); |
22e2c507 | 3441 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); |
b1c35769 | 3442 | cfqg = cfqq->cfqg; |
1da177e4 | 3443 | |
28f95cbc | 3444 | if (unlikely(cfqd->active_queue == cfqq)) { |
e5ff082e | 3445 | __cfq_slice_expired(cfqd, cfqq, 0); |
23e018a1 | 3446 | cfq_schedule_dispatch(cfqd); |
28f95cbc | 3447 | } |
22e2c507 | 3448 | |
f04a6424 | 3449 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
1da177e4 | 3450 | kmem_cache_free(cfq_pool, cfqq); |
eb7d8c07 | 3451 | cfqg_put(cfqg); |
1da177e4 LT |
3452 | } |
3453 | ||
d02a2c07 | 3454 | static void cfq_put_cooperator(struct cfq_queue *cfqq) |
1da177e4 | 3455 | { |
df5fe3e8 JM |
3456 | struct cfq_queue *__cfqq, *next; |
3457 | ||
df5fe3e8 JM |
3458 | /* |
3459 | * If this queue was scheduled to merge with another queue, be | |
3460 | * sure to drop the reference taken on that queue (and others in | |
3461 | * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. | |
3462 | */ | |
3463 | __cfqq = cfqq->new_cfqq; | |
3464 | while (__cfqq) { | |
3465 | if (__cfqq == cfqq) { | |
3466 | WARN(1, "cfqq->new_cfqq loop detected\n"); | |
3467 | break; | |
3468 | } | |
3469 | next = __cfqq->new_cfqq; | |
3470 | cfq_put_queue(__cfqq); | |
3471 | __cfqq = next; | |
3472 | } | |
d02a2c07 SL |
3473 | } |
3474 | ||
3475 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3476 | { | |
3477 | if (unlikely(cfqq == cfqd->active_queue)) { | |
3478 | __cfq_slice_expired(cfqd, cfqq, 0); | |
3479 | cfq_schedule_dispatch(cfqd); | |
3480 | } | |
3481 | ||
3482 | cfq_put_cooperator(cfqq); | |
df5fe3e8 | 3483 | |
89850f7e JA |
3484 | cfq_put_queue(cfqq); |
3485 | } | |
22e2c507 | 3486 | |
9b84cacd TH |
3487 | static void cfq_init_icq(struct io_cq *icq) |
3488 | { | |
3489 | struct cfq_io_cq *cic = icq_to_cic(icq); | |
3490 | ||
3491 | cic->ttime.last_end_request = jiffies; | |
3492 | } | |
3493 | ||
c5869807 | 3494 | static void cfq_exit_icq(struct io_cq *icq) |
89850f7e | 3495 | { |
c5869807 | 3496 | struct cfq_io_cq *cic = icq_to_cic(icq); |
283287a5 | 3497 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
4faa3c81 | 3498 | |
ff6657c6 JA |
3499 | if (cic->cfqq[BLK_RW_ASYNC]) { |
3500 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]); | |
3501 | cic->cfqq[BLK_RW_ASYNC] = NULL; | |
12a05732 AV |
3502 | } |
3503 | ||
ff6657c6 JA |
3504 | if (cic->cfqq[BLK_RW_SYNC]) { |
3505 | cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_SYNC]); | |
3506 | cic->cfqq[BLK_RW_SYNC] = NULL; | |
12a05732 | 3507 | } |
89850f7e JA |
3508 | } |
3509 | ||
abede6da | 3510 | static void cfq_init_prio_data(struct cfq_queue *cfqq, struct cfq_io_cq *cic) |
22e2c507 JA |
3511 | { |
3512 | struct task_struct *tsk = current; | |
3513 | int ioprio_class; | |
3514 | ||
3b18152c | 3515 | if (!cfq_cfqq_prio_changed(cfqq)) |
22e2c507 JA |
3516 | return; |
3517 | ||
598971bf | 3518 | ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio); |
22e2c507 | 3519 | switch (ioprio_class) { |
fe094d98 JA |
3520 | default: |
3521 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); | |
3522 | case IOPRIO_CLASS_NONE: | |
3523 | /* | |
6d63c275 | 3524 | * no prio set, inherit CPU scheduling settings |
fe094d98 JA |
3525 | */ |
3526 | cfqq->ioprio = task_nice_ioprio(tsk); | |
6d63c275 | 3527 | cfqq->ioprio_class = task_nice_ioclass(tsk); |
fe094d98 JA |
3528 | break; |
3529 | case IOPRIO_CLASS_RT: | |
598971bf | 3530 | cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio); |
fe094d98 JA |
3531 | cfqq->ioprio_class = IOPRIO_CLASS_RT; |
3532 | break; | |
3533 | case IOPRIO_CLASS_BE: | |
598971bf | 3534 | cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio); |
fe094d98 JA |
3535 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
3536 | break; | |
3537 | case IOPRIO_CLASS_IDLE: | |
3538 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; | |
3539 | cfqq->ioprio = 7; | |
3540 | cfq_clear_cfqq_idle_window(cfqq); | |
3541 | break; | |
22e2c507 JA |
3542 | } |
3543 | ||
3544 | /* | |
3545 | * keep track of original prio settings in case we have to temporarily | |
3546 | * elevate the priority of this queue | |
3547 | */ | |
3548 | cfqq->org_ioprio = cfqq->ioprio; | |
3b18152c | 3549 | cfq_clear_cfqq_prio_changed(cfqq); |
22e2c507 JA |
3550 | } |
3551 | ||
598971bf | 3552 | static void check_ioprio_changed(struct cfq_io_cq *cic, struct bio *bio) |
22e2c507 | 3553 | { |
598971bf | 3554 | int ioprio = cic->icq.ioc->ioprio; |
bca4b914 | 3555 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
478a82b0 | 3556 | struct cfq_queue *cfqq; |
35e6077c | 3557 | |
598971bf TH |
3558 | /* |
3559 | * Check whether ioprio has changed. The condition may trigger | |
3560 | * spuriously on a newly created cic but there's no harm. | |
3561 | */ | |
3562 | if (unlikely(!cfqd) || likely(cic->ioprio == ioprio)) | |
caaa5f9f JA |
3563 | return; |
3564 | ||
ff6657c6 | 3565 | cfqq = cic->cfqq[BLK_RW_ASYNC]; |
caaa5f9f JA |
3566 | if (cfqq) { |
3567 | struct cfq_queue *new_cfqq; | |
abede6da TH |
3568 | new_cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic, bio, |
3569 | GFP_ATOMIC); | |
caaa5f9f | 3570 | if (new_cfqq) { |
ff6657c6 | 3571 | cic->cfqq[BLK_RW_ASYNC] = new_cfqq; |
caaa5f9f JA |
3572 | cfq_put_queue(cfqq); |
3573 | } | |
22e2c507 | 3574 | } |
caaa5f9f | 3575 | |
ff6657c6 | 3576 | cfqq = cic->cfqq[BLK_RW_SYNC]; |
caaa5f9f JA |
3577 | if (cfqq) |
3578 | cfq_mark_cfqq_prio_changed(cfqq); | |
598971bf TH |
3579 | |
3580 | cic->ioprio = ioprio; | |
22e2c507 JA |
3581 | } |
3582 | ||
d5036d77 | 3583 | static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
a6151c3a | 3584 | pid_t pid, bool is_sync) |
d5036d77 JA |
3585 | { |
3586 | RB_CLEAR_NODE(&cfqq->rb_node); | |
3587 | RB_CLEAR_NODE(&cfqq->p_node); | |
3588 | INIT_LIST_HEAD(&cfqq->fifo); | |
3589 | ||
30d7b944 | 3590 | cfqq->ref = 0; |
d5036d77 JA |
3591 | cfqq->cfqd = cfqd; |
3592 | ||
3593 | cfq_mark_cfqq_prio_changed(cfqq); | |
3594 | ||
3595 | if (is_sync) { | |
3596 | if (!cfq_class_idle(cfqq)) | |
3597 | cfq_mark_cfqq_idle_window(cfqq); | |
3598 | cfq_mark_cfqq_sync(cfqq); | |
3599 | } | |
3600 | cfqq->pid = pid; | |
3601 | } | |
3602 | ||
24610333 | 3603 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
598971bf | 3604 | static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) |
24610333 | 3605 | { |
bca4b914 | 3606 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
598971bf | 3607 | struct cfq_queue *sync_cfqq; |
f4da8072 | 3608 | uint64_t serial_nr; |
24610333 | 3609 | |
598971bf | 3610 | rcu_read_lock(); |
f4da8072 | 3611 | serial_nr = bio_blkcg(bio)->css.serial_nr; |
598971bf | 3612 | rcu_read_unlock(); |
24610333 | 3613 | |
598971bf TH |
3614 | /* |
3615 | * Check whether blkcg has changed. The condition may trigger | |
3616 | * spuriously on a newly created cic but there's no harm. | |
3617 | */ | |
f4da8072 | 3618 | if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr)) |
598971bf | 3619 | return; |
24610333 | 3620 | |
598971bf | 3621 | sync_cfqq = cic_to_cfqq(cic, 1); |
24610333 VG |
3622 | if (sync_cfqq) { |
3623 | /* | |
3624 | * Drop reference to sync queue. A new sync queue will be | |
3625 | * assigned in new group upon arrival of a fresh request. | |
3626 | */ | |
3627 | cfq_log_cfqq(cfqd, sync_cfqq, "changed cgroup"); | |
3628 | cic_set_cfqq(cic, NULL, 1); | |
3629 | cfq_put_queue(sync_cfqq); | |
3630 | } | |
598971bf | 3631 | |
f4da8072 | 3632 | cic->blkcg_serial_nr = serial_nr; |
24610333 | 3633 | } |
598971bf TH |
3634 | #else |
3635 | static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { } | |
24610333 VG |
3636 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ |
3637 | ||
22e2c507 | 3638 | static struct cfq_queue * |
abede6da TH |
3639 | cfq_find_alloc_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, |
3640 | struct bio *bio, gfp_t gfp_mask) | |
22e2c507 | 3641 | { |
3c798398 | 3642 | struct blkcg *blkcg; |
22e2c507 | 3643 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
cdb16e8f | 3644 | struct cfq_group *cfqg; |
22e2c507 JA |
3645 | |
3646 | retry: | |
2a7f1244 TH |
3647 | rcu_read_lock(); |
3648 | ||
3c798398 | 3649 | blkcg = bio_blkcg(bio); |
cd1604fa | 3650 | cfqg = cfq_lookup_create_cfqg(cfqd, blkcg); |
69abaffe KK |
3651 | if (!cfqg) { |
3652 | cfqq = &cfqd->oom_cfqq; | |
3653 | goto out; | |
3654 | } | |
3655 | ||
91fac317 | 3656 | cfqq = cic_to_cfqq(cic, is_sync); |
22e2c507 | 3657 | |
6118b70b JA |
3658 | /* |
3659 | * Always try a new alloc if we fell back to the OOM cfqq | |
3660 | * originally, since it should just be a temporary situation. | |
3661 | */ | |
3662 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { | |
3663 | cfqq = NULL; | |
22e2c507 JA |
3664 | if (new_cfqq) { |
3665 | cfqq = new_cfqq; | |
3666 | new_cfqq = NULL; | |
3667 | } else if (gfp_mask & __GFP_WAIT) { | |
2a7f1244 | 3668 | rcu_read_unlock(); |
22e2c507 | 3669 | spin_unlock_irq(cfqd->queue->queue_lock); |
94f6030c | 3670 | new_cfqq = kmem_cache_alloc_node(cfq_pool, |
6118b70b | 3671 | gfp_mask | __GFP_ZERO, |
94f6030c | 3672 | cfqd->queue->node); |
22e2c507 | 3673 | spin_lock_irq(cfqd->queue->queue_lock); |
6118b70b JA |
3674 | if (new_cfqq) |
3675 | goto retry; | |
a3cc86c2 GC |
3676 | else |
3677 | return &cfqd->oom_cfqq; | |
22e2c507 | 3678 | } else { |
94f6030c CL |
3679 | cfqq = kmem_cache_alloc_node(cfq_pool, |
3680 | gfp_mask | __GFP_ZERO, | |
3681 | cfqd->queue->node); | |
22e2c507 JA |
3682 | } |
3683 | ||
6118b70b JA |
3684 | if (cfqq) { |
3685 | cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); | |
abede6da | 3686 | cfq_init_prio_data(cfqq, cic); |
cdb16e8f | 3687 | cfq_link_cfqq_cfqg(cfqq, cfqg); |
6118b70b JA |
3688 | cfq_log_cfqq(cfqd, cfqq, "alloced"); |
3689 | } else | |
3690 | cfqq = &cfqd->oom_cfqq; | |
22e2c507 | 3691 | } |
69abaffe | 3692 | out: |
22e2c507 JA |
3693 | if (new_cfqq) |
3694 | kmem_cache_free(cfq_pool, new_cfqq); | |
3695 | ||
2a7f1244 | 3696 | rcu_read_unlock(); |
22e2c507 JA |
3697 | return cfqq; |
3698 | } | |
3699 | ||
c2dea2d1 VT |
3700 | static struct cfq_queue ** |
3701 | cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio) | |
3702 | { | |
fe094d98 | 3703 | switch (ioprio_class) { |
c2dea2d1 VT |
3704 | case IOPRIO_CLASS_RT: |
3705 | return &cfqd->async_cfqq[0][ioprio]; | |
598971bf TH |
3706 | case IOPRIO_CLASS_NONE: |
3707 | ioprio = IOPRIO_NORM; | |
3708 | /* fall through */ | |
c2dea2d1 VT |
3709 | case IOPRIO_CLASS_BE: |
3710 | return &cfqd->async_cfqq[1][ioprio]; | |
3711 | case IOPRIO_CLASS_IDLE: | |
3712 | return &cfqd->async_idle_cfqq; | |
3713 | default: | |
3714 | BUG(); | |
3715 | } | |
3716 | } | |
3717 | ||
15c31be4 | 3718 | static struct cfq_queue * |
abede6da | 3719 | cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, |
4f85cb96 | 3720 | struct bio *bio, gfp_t gfp_mask) |
15c31be4 | 3721 | { |
c6ce1943 JM |
3722 | int ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio); |
3723 | int ioprio = IOPRIO_PRIO_DATA(cic->ioprio); | |
c2dea2d1 | 3724 | struct cfq_queue **async_cfqq = NULL; |
15c31be4 JA |
3725 | struct cfq_queue *cfqq = NULL; |
3726 | ||
c2dea2d1 | 3727 | if (!is_sync) { |
c6ce1943 JM |
3728 | if (!ioprio_valid(cic->ioprio)) { |
3729 | struct task_struct *tsk = current; | |
3730 | ioprio = task_nice_ioprio(tsk); | |
3731 | ioprio_class = task_nice_ioclass(tsk); | |
3732 | } | |
c2dea2d1 VT |
3733 | async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio); |
3734 | cfqq = *async_cfqq; | |
3735 | } | |
3736 | ||
6118b70b | 3737 | if (!cfqq) |
abede6da | 3738 | cfqq = cfq_find_alloc_queue(cfqd, is_sync, cic, bio, gfp_mask); |
15c31be4 JA |
3739 | |
3740 | /* | |
3741 | * pin the queue now that it's allocated, scheduler exit will prune it | |
3742 | */ | |
c2dea2d1 | 3743 | if (!is_sync && !(*async_cfqq)) { |
30d7b944 | 3744 | cfqq->ref++; |
c2dea2d1 | 3745 | *async_cfqq = cfqq; |
15c31be4 JA |
3746 | } |
3747 | ||
30d7b944 | 3748 | cfqq->ref++; |
15c31be4 JA |
3749 | return cfqq; |
3750 | } | |
3751 | ||
22e2c507 | 3752 | static void |
383cd721 | 3753 | __cfq_update_io_thinktime(struct cfq_ttime *ttime, unsigned long slice_idle) |
1da177e4 | 3754 | { |
383cd721 SL |
3755 | unsigned long elapsed = jiffies - ttime->last_end_request; |
3756 | elapsed = min(elapsed, 2UL * slice_idle); | |
db3b5848 | 3757 | |
383cd721 SL |
3758 | ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8; |
3759 | ttime->ttime_total = (7*ttime->ttime_total + 256*elapsed) / 8; | |
3760 | ttime->ttime_mean = (ttime->ttime_total + 128) / ttime->ttime_samples; | |
3761 | } | |
3762 | ||
3763 | static void | |
3764 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
c5869807 | 3765 | struct cfq_io_cq *cic) |
383cd721 | 3766 | { |
f5f2b6ce | 3767 | if (cfq_cfqq_sync(cfqq)) { |
383cd721 | 3768 | __cfq_update_io_thinktime(&cic->ttime, cfqd->cfq_slice_idle); |
f5f2b6ce SL |
3769 | __cfq_update_io_thinktime(&cfqq->service_tree->ttime, |
3770 | cfqd->cfq_slice_idle); | |
3771 | } | |
7700fc4f SL |
3772 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3773 | __cfq_update_io_thinktime(&cfqq->cfqg->ttime, cfqd->cfq_group_idle); | |
3774 | #endif | |
22e2c507 | 3775 | } |
1da177e4 | 3776 | |
206dc69b | 3777 | static void |
b2c18e1e | 3778 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
6d048f53 | 3779 | struct request *rq) |
206dc69b | 3780 | { |
3dde36dd | 3781 | sector_t sdist = 0; |
41647e7a | 3782 | sector_t n_sec = blk_rq_sectors(rq); |
3dde36dd CZ |
3783 | if (cfqq->last_request_pos) { |
3784 | if (cfqq->last_request_pos < blk_rq_pos(rq)) | |
3785 | sdist = blk_rq_pos(rq) - cfqq->last_request_pos; | |
3786 | else | |
3787 | sdist = cfqq->last_request_pos - blk_rq_pos(rq); | |
3788 | } | |
206dc69b | 3789 | |
3dde36dd | 3790 | cfqq->seek_history <<= 1; |
41647e7a CZ |
3791 | if (blk_queue_nonrot(cfqd->queue)) |
3792 | cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT); | |
3793 | else | |
3794 | cfqq->seek_history |= (sdist > CFQQ_SEEK_THR); | |
206dc69b | 3795 | } |
1da177e4 | 3796 | |
22e2c507 JA |
3797 | /* |
3798 | * Disable idle window if the process thinks too long or seeks so much that | |
3799 | * it doesn't matter | |
3800 | */ | |
3801 | static void | |
3802 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
c5869807 | 3803 | struct cfq_io_cq *cic) |
22e2c507 | 3804 | { |
7b679138 | 3805 | int old_idle, enable_idle; |
1be92f2f | 3806 | |
0871714e JA |
3807 | /* |
3808 | * Don't idle for async or idle io prio class | |
3809 | */ | |
3810 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) | |
1be92f2f JA |
3811 | return; |
3812 | ||
c265a7f4 | 3813 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); |
1da177e4 | 3814 | |
76280aff CZ |
3815 | if (cfqq->queued[0] + cfqq->queued[1] >= 4) |
3816 | cfq_mark_cfqq_deep(cfqq); | |
3817 | ||
749ef9f8 CZ |
3818 | if (cfqq->next_rq && (cfqq->next_rq->cmd_flags & REQ_NOIDLE)) |
3819 | enable_idle = 0; | |
f6e8d01b | 3820 | else if (!atomic_read(&cic->icq.ioc->active_ref) || |
c5869807 TH |
3821 | !cfqd->cfq_slice_idle || |
3822 | (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq))) | |
22e2c507 | 3823 | enable_idle = 0; |
383cd721 SL |
3824 | else if (sample_valid(cic->ttime.ttime_samples)) { |
3825 | if (cic->ttime.ttime_mean > cfqd->cfq_slice_idle) | |
22e2c507 JA |
3826 | enable_idle = 0; |
3827 | else | |
3828 | enable_idle = 1; | |
1da177e4 LT |
3829 | } |
3830 | ||
7b679138 JA |
3831 | if (old_idle != enable_idle) { |
3832 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); | |
3833 | if (enable_idle) | |
3834 | cfq_mark_cfqq_idle_window(cfqq); | |
3835 | else | |
3836 | cfq_clear_cfqq_idle_window(cfqq); | |
3837 | } | |
22e2c507 | 3838 | } |
1da177e4 | 3839 | |
22e2c507 JA |
3840 | /* |
3841 | * Check if new_cfqq should preempt the currently active queue. Return 0 for | |
3842 | * no or if we aren't sure, a 1 will cause a preempt. | |
3843 | */ | |
a6151c3a | 3844 | static bool |
22e2c507 | 3845 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, |
5e705374 | 3846 | struct request *rq) |
22e2c507 | 3847 | { |
6d048f53 | 3848 | struct cfq_queue *cfqq; |
22e2c507 | 3849 | |
6d048f53 JA |
3850 | cfqq = cfqd->active_queue; |
3851 | if (!cfqq) | |
a6151c3a | 3852 | return false; |
22e2c507 | 3853 | |
6d048f53 | 3854 | if (cfq_class_idle(new_cfqq)) |
a6151c3a | 3855 | return false; |
22e2c507 JA |
3856 | |
3857 | if (cfq_class_idle(cfqq)) | |
a6151c3a | 3858 | return true; |
1e3335de | 3859 | |
875feb63 DS |
3860 | /* |
3861 | * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice. | |
3862 | */ | |
3863 | if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq)) | |
3864 | return false; | |
3865 | ||
374f84ac JA |
3866 | /* |
3867 | * if the new request is sync, but the currently running queue is | |
3868 | * not, let the sync request have priority. | |
3869 | */ | |
5e705374 | 3870 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) |
a6151c3a | 3871 | return true; |
1e3335de | 3872 | |
8682e1f1 VG |
3873 | if (new_cfqq->cfqg != cfqq->cfqg) |
3874 | return false; | |
3875 | ||
3876 | if (cfq_slice_used(cfqq)) | |
3877 | return true; | |
3878 | ||
3879 | /* Allow preemption only if we are idling on sync-noidle tree */ | |
4d2ceea4 | 3880 | if (cfqd->serving_wl_type == SYNC_NOIDLE_WORKLOAD && |
8682e1f1 VG |
3881 | cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD && |
3882 | new_cfqq->service_tree->count == 2 && | |
3883 | RB_EMPTY_ROOT(&cfqq->sort_list)) | |
3884 | return true; | |
3885 | ||
b53d1ed7 JA |
3886 | /* |
3887 | * So both queues are sync. Let the new request get disk time if | |
3888 | * it's a metadata request and the current queue is doing regular IO. | |
3889 | */ | |
65299a3b | 3890 | if ((rq->cmd_flags & REQ_PRIO) && !cfqq->prio_pending) |
b53d1ed7 JA |
3891 | return true; |
3892 | ||
3a9a3f6c DS |
3893 | /* |
3894 | * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. | |
3895 | */ | |
3896 | if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) | |
a6151c3a | 3897 | return true; |
3a9a3f6c | 3898 | |
d2d59e18 SL |
3899 | /* An idle queue should not be idle now for some reason */ |
3900 | if (RB_EMPTY_ROOT(&cfqq->sort_list) && !cfq_should_idle(cfqd, cfqq)) | |
3901 | return true; | |
3902 | ||
1e3335de | 3903 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) |
a6151c3a | 3904 | return false; |
1e3335de JA |
3905 | |
3906 | /* | |
3907 | * if this request is as-good as one we would expect from the | |
3908 | * current cfqq, let it preempt | |
3909 | */ | |
e9ce335d | 3910 | if (cfq_rq_close(cfqd, cfqq, rq)) |
a6151c3a | 3911 | return true; |
1e3335de | 3912 | |
a6151c3a | 3913 | return false; |
22e2c507 JA |
3914 | } |
3915 | ||
3916 | /* | |
3917 | * cfqq preempts the active queue. if we allowed preempt with no slice left, | |
3918 | * let it have half of its nominal slice. | |
3919 | */ | |
3920 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3921 | { | |
df0793ab SL |
3922 | enum wl_type_t old_type = cfqq_type(cfqd->active_queue); |
3923 | ||
7b679138 | 3924 | cfq_log_cfqq(cfqd, cfqq, "preempt"); |
df0793ab | 3925 | cfq_slice_expired(cfqd, 1); |
22e2c507 | 3926 | |
f8ae6e3e SL |
3927 | /* |
3928 | * workload type is changed, don't save slice, otherwise preempt | |
3929 | * doesn't happen | |
3930 | */ | |
df0793ab | 3931 | if (old_type != cfqq_type(cfqq)) |
4d2ceea4 | 3932 | cfqq->cfqg->saved_wl_slice = 0; |
f8ae6e3e | 3933 | |
bf572256 JA |
3934 | /* |
3935 | * Put the new queue at the front of the of the current list, | |
3936 | * so we know that it will be selected next. | |
3937 | */ | |
3938 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); | |
edd75ffd JA |
3939 | |
3940 | cfq_service_tree_add(cfqd, cfqq, 1); | |
eda5e0c9 | 3941 | |
62a37f6b JT |
3942 | cfqq->slice_end = 0; |
3943 | cfq_mark_cfqq_slice_new(cfqq); | |
22e2c507 JA |
3944 | } |
3945 | ||
22e2c507 | 3946 | /* |
5e705374 | 3947 | * Called when a new fs request (rq) is added (to cfqq). Check if there's |
22e2c507 JA |
3948 | * something we should do about it |
3949 | */ | |
3950 | static void | |
5e705374 JA |
3951 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
3952 | struct request *rq) | |
22e2c507 | 3953 | { |
c5869807 | 3954 | struct cfq_io_cq *cic = RQ_CIC(rq); |
12e9fddd | 3955 | |
45333d5a | 3956 | cfqd->rq_queued++; |
65299a3b CH |
3957 | if (rq->cmd_flags & REQ_PRIO) |
3958 | cfqq->prio_pending++; | |
374f84ac | 3959 | |
383cd721 | 3960 | cfq_update_io_thinktime(cfqd, cfqq, cic); |
b2c18e1e | 3961 | cfq_update_io_seektime(cfqd, cfqq, rq); |
9c2c38a1 JA |
3962 | cfq_update_idle_window(cfqd, cfqq, cic); |
3963 | ||
b2c18e1e | 3964 | cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); |
22e2c507 JA |
3965 | |
3966 | if (cfqq == cfqd->active_queue) { | |
3967 | /* | |
b029195d JA |
3968 | * Remember that we saw a request from this process, but |
3969 | * don't start queuing just yet. Otherwise we risk seeing lots | |
3970 | * of tiny requests, because we disrupt the normal plugging | |
d6ceb25e JA |
3971 | * and merging. If the request is already larger than a single |
3972 | * page, let it rip immediately. For that case we assume that | |
2d870722 JA |
3973 | * merging is already done. Ditto for a busy system that |
3974 | * has other work pending, don't risk delaying until the | |
3975 | * idle timer unplug to continue working. | |
22e2c507 | 3976 | */ |
d6ceb25e | 3977 | if (cfq_cfqq_wait_request(cfqq)) { |
2d870722 JA |
3978 | if (blk_rq_bytes(rq) > PAGE_CACHE_SIZE || |
3979 | cfqd->busy_queues > 1) { | |
812df48d | 3980 | cfq_del_timer(cfqd, cfqq); |
554554f6 | 3981 | cfq_clear_cfqq_wait_request(cfqq); |
24ecfbe2 | 3982 | __blk_run_queue(cfqd->queue); |
a11cdaa7 | 3983 | } else { |
155fead9 | 3984 | cfqg_stats_update_idle_time(cfqq->cfqg); |
bf791937 | 3985 | cfq_mark_cfqq_must_dispatch(cfqq); |
a11cdaa7 | 3986 | } |
d6ceb25e | 3987 | } |
5e705374 | 3988 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { |
22e2c507 JA |
3989 | /* |
3990 | * not the active queue - expire current slice if it is | |
3991 | * idle and has expired it's mean thinktime or this new queue | |
3a9a3f6c DS |
3992 | * has some old slice time left and is of higher priority or |
3993 | * this new queue is RT and the current one is BE | |
22e2c507 JA |
3994 | */ |
3995 | cfq_preempt_queue(cfqd, cfqq); | |
24ecfbe2 | 3996 | __blk_run_queue(cfqd->queue); |
22e2c507 | 3997 | } |
1da177e4 LT |
3998 | } |
3999 | ||
165125e1 | 4000 | static void cfq_insert_request(struct request_queue *q, struct request *rq) |
1da177e4 | 4001 | { |
b4878f24 | 4002 | struct cfq_data *cfqd = q->elevator->elevator_data; |
5e705374 | 4003 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
22e2c507 | 4004 | |
7b679138 | 4005 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); |
abede6da | 4006 | cfq_init_prio_data(cfqq, RQ_CIC(rq)); |
1da177e4 | 4007 | |
8b4922d3 | 4008 | rq->fifo_time = jiffies + cfqd->cfq_fifo_expire[rq_is_sync(rq)]; |
22e2c507 | 4009 | list_add_tail(&rq->queuelist, &cfqq->fifo); |
aa6f6a3d | 4010 | cfq_add_rq_rb(rq); |
155fead9 TH |
4011 | cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group, |
4012 | rq->cmd_flags); | |
5e705374 | 4013 | cfq_rq_enqueued(cfqd, cfqq, rq); |
1da177e4 LT |
4014 | } |
4015 | ||
45333d5a AC |
4016 | /* |
4017 | * Update hw_tag based on peak queue depth over 50 samples under | |
4018 | * sufficient load. | |
4019 | */ | |
4020 | static void cfq_update_hw_tag(struct cfq_data *cfqd) | |
4021 | { | |
1a1238a7 SL |
4022 | struct cfq_queue *cfqq = cfqd->active_queue; |
4023 | ||
53c583d2 CZ |
4024 | if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth) |
4025 | cfqd->hw_tag_est_depth = cfqd->rq_in_driver; | |
e459dd08 CZ |
4026 | |
4027 | if (cfqd->hw_tag == 1) | |
4028 | return; | |
45333d5a AC |
4029 | |
4030 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && | |
53c583d2 | 4031 | cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN) |
45333d5a AC |
4032 | return; |
4033 | ||
1a1238a7 SL |
4034 | /* |
4035 | * If active queue hasn't enough requests and can idle, cfq might not | |
4036 | * dispatch sufficient requests to hardware. Don't zero hw_tag in this | |
4037 | * case | |
4038 | */ | |
4039 | if (cfqq && cfq_cfqq_idle_window(cfqq) && | |
4040 | cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] < | |
53c583d2 | 4041 | CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN) |
1a1238a7 SL |
4042 | return; |
4043 | ||
45333d5a AC |
4044 | if (cfqd->hw_tag_samples++ < 50) |
4045 | return; | |
4046 | ||
e459dd08 | 4047 | if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN) |
45333d5a AC |
4048 | cfqd->hw_tag = 1; |
4049 | else | |
4050 | cfqd->hw_tag = 0; | |
45333d5a AC |
4051 | } |
4052 | ||
7667aa06 VG |
4053 | static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
4054 | { | |
c5869807 | 4055 | struct cfq_io_cq *cic = cfqd->active_cic; |
7667aa06 | 4056 | |
02a8f01b JT |
4057 | /* If the queue already has requests, don't wait */ |
4058 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) | |
4059 | return false; | |
4060 | ||
7667aa06 VG |
4061 | /* If there are other queues in the group, don't wait */ |
4062 | if (cfqq->cfqg->nr_cfqq > 1) | |
4063 | return false; | |
4064 | ||
7700fc4f SL |
4065 | /* the only queue in the group, but think time is big */ |
4066 | if (cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) | |
4067 | return false; | |
4068 | ||
7667aa06 VG |
4069 | if (cfq_slice_used(cfqq)) |
4070 | return true; | |
4071 | ||
4072 | /* if slice left is less than think time, wait busy */ | |
383cd721 SL |
4073 | if (cic && sample_valid(cic->ttime.ttime_samples) |
4074 | && (cfqq->slice_end - jiffies < cic->ttime.ttime_mean)) | |
7667aa06 VG |
4075 | return true; |
4076 | ||
4077 | /* | |
4078 | * If think times is less than a jiffy than ttime_mean=0 and above | |
4079 | * will not be true. It might happen that slice has not expired yet | |
4080 | * but will expire soon (4-5 ns) during select_queue(). To cover the | |
4081 | * case where think time is less than a jiffy, mark the queue wait | |
4082 | * busy if only 1 jiffy is left in the slice. | |
4083 | */ | |
4084 | if (cfqq->slice_end - jiffies == 1) | |
4085 | return true; | |
4086 | ||
4087 | return false; | |
4088 | } | |
4089 | ||
165125e1 | 4090 | static void cfq_completed_request(struct request_queue *q, struct request *rq) |
1da177e4 | 4091 | { |
5e705374 | 4092 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
b4878f24 | 4093 | struct cfq_data *cfqd = cfqq->cfqd; |
5380a101 | 4094 | const int sync = rq_is_sync(rq); |
b4878f24 | 4095 | unsigned long now; |
1da177e4 | 4096 | |
b4878f24 | 4097 | now = jiffies; |
33659ebb CH |
4098 | cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", |
4099 | !!(rq->cmd_flags & REQ_NOIDLE)); | |
1da177e4 | 4100 | |
45333d5a AC |
4101 | cfq_update_hw_tag(cfqd); |
4102 | ||
53c583d2 | 4103 | WARN_ON(!cfqd->rq_in_driver); |
6d048f53 | 4104 | WARN_ON(!cfqq->dispatched); |
53c583d2 | 4105 | cfqd->rq_in_driver--; |
6d048f53 | 4106 | cfqq->dispatched--; |
80bdf0c7 | 4107 | (RQ_CFQG(rq))->dispatched--; |
155fead9 TH |
4108 | cfqg_stats_update_completion(cfqq->cfqg, rq_start_time_ns(rq), |
4109 | rq_io_start_time_ns(rq), rq->cmd_flags); | |
1da177e4 | 4110 | |
53c583d2 | 4111 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--; |
3ed9a296 | 4112 | |
365722bb | 4113 | if (sync) { |
34b98d03 | 4114 | struct cfq_rb_root *st; |
f5f2b6ce | 4115 | |
383cd721 | 4116 | RQ_CIC(rq)->ttime.last_end_request = now; |
f5f2b6ce SL |
4117 | |
4118 | if (cfq_cfqq_on_rr(cfqq)) | |
34b98d03 | 4119 | st = cfqq->service_tree; |
f5f2b6ce | 4120 | else |
34b98d03 VG |
4121 | st = st_for(cfqq->cfqg, cfqq_class(cfqq), |
4122 | cfqq_type(cfqq)); | |
4123 | ||
4124 | st->ttime.last_end_request = now; | |
573412b2 CZ |
4125 | if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now)) |
4126 | cfqd->last_delayed_sync = now; | |
365722bb | 4127 | } |
caaa5f9f | 4128 | |
7700fc4f SL |
4129 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
4130 | cfqq->cfqg->ttime.last_end_request = now; | |
4131 | #endif | |
4132 | ||
caaa5f9f JA |
4133 | /* |
4134 | * If this is the active queue, check if it needs to be expired, | |
4135 | * or if we want to idle in case it has no pending requests. | |
4136 | */ | |
4137 | if (cfqd->active_queue == cfqq) { | |
a36e71f9 JA |
4138 | const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); |
4139 | ||
44f7c160 JA |
4140 | if (cfq_cfqq_slice_new(cfqq)) { |
4141 | cfq_set_prio_slice(cfqd, cfqq); | |
4142 | cfq_clear_cfqq_slice_new(cfqq); | |
4143 | } | |
f75edf2d VG |
4144 | |
4145 | /* | |
7667aa06 VG |
4146 | * Should we wait for next request to come in before we expire |
4147 | * the queue. | |
f75edf2d | 4148 | */ |
7667aa06 | 4149 | if (cfq_should_wait_busy(cfqd, cfqq)) { |
80bdf0c7 VG |
4150 | unsigned long extend_sl = cfqd->cfq_slice_idle; |
4151 | if (!cfqd->cfq_slice_idle) | |
4152 | extend_sl = cfqd->cfq_group_idle; | |
4153 | cfqq->slice_end = jiffies + extend_sl; | |
f75edf2d | 4154 | cfq_mark_cfqq_wait_busy(cfqq); |
b1ffe737 | 4155 | cfq_log_cfqq(cfqd, cfqq, "will busy wait"); |
f75edf2d VG |
4156 | } |
4157 | ||
a36e71f9 | 4158 | /* |
8e550632 CZ |
4159 | * Idling is not enabled on: |
4160 | * - expired queues | |
4161 | * - idle-priority queues | |
4162 | * - async queues | |
4163 | * - queues with still some requests queued | |
4164 | * - when there is a close cooperator | |
a36e71f9 | 4165 | */ |
0871714e | 4166 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) |
e5ff082e | 4167 | cfq_slice_expired(cfqd, 1); |
8e550632 CZ |
4168 | else if (sync && cfqq_empty && |
4169 | !cfq_close_cooperator(cfqd, cfqq)) { | |
749ef9f8 | 4170 | cfq_arm_slice_timer(cfqd); |
8e550632 | 4171 | } |
caaa5f9f | 4172 | } |
6d048f53 | 4173 | |
53c583d2 | 4174 | if (!cfqd->rq_in_driver) |
23e018a1 | 4175 | cfq_schedule_dispatch(cfqd); |
1da177e4 LT |
4176 | } |
4177 | ||
89850f7e | 4178 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) |
22e2c507 | 4179 | { |
1b379d8d | 4180 | if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { |
3b18152c | 4181 | cfq_mark_cfqq_must_alloc_slice(cfqq); |
22e2c507 | 4182 | return ELV_MQUEUE_MUST; |
3b18152c | 4183 | } |
1da177e4 | 4184 | |
22e2c507 | 4185 | return ELV_MQUEUE_MAY; |
22e2c507 JA |
4186 | } |
4187 | ||
165125e1 | 4188 | static int cfq_may_queue(struct request_queue *q, int rw) |
22e2c507 JA |
4189 | { |
4190 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
4191 | struct task_struct *tsk = current; | |
c5869807 | 4192 | struct cfq_io_cq *cic; |
22e2c507 JA |
4193 | struct cfq_queue *cfqq; |
4194 | ||
4195 | /* | |
4196 | * don't force setup of a queue from here, as a call to may_queue | |
4197 | * does not necessarily imply that a request actually will be queued. | |
4198 | * so just lookup a possibly existing queue, or return 'may queue' | |
4199 | * if that fails | |
4200 | */ | |
4ac845a2 | 4201 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
91fac317 VT |
4202 | if (!cic) |
4203 | return ELV_MQUEUE_MAY; | |
4204 | ||
b0b78f81 | 4205 | cfqq = cic_to_cfqq(cic, rw_is_sync(rw)); |
22e2c507 | 4206 | if (cfqq) { |
abede6da | 4207 | cfq_init_prio_data(cfqq, cic); |
22e2c507 | 4208 | |
89850f7e | 4209 | return __cfq_may_queue(cfqq); |
22e2c507 JA |
4210 | } |
4211 | ||
4212 | return ELV_MQUEUE_MAY; | |
1da177e4 LT |
4213 | } |
4214 | ||
1da177e4 LT |
4215 | /* |
4216 | * queue lock held here | |
4217 | */ | |
bb37b94c | 4218 | static void cfq_put_request(struct request *rq) |
1da177e4 | 4219 | { |
5e705374 | 4220 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
1da177e4 | 4221 | |
5e705374 | 4222 | if (cfqq) { |
22e2c507 | 4223 | const int rw = rq_data_dir(rq); |
1da177e4 | 4224 | |
22e2c507 JA |
4225 | BUG_ON(!cfqq->allocated[rw]); |
4226 | cfqq->allocated[rw]--; | |
1da177e4 | 4227 | |
7f1dc8a2 | 4228 | /* Put down rq reference on cfqg */ |
eb7d8c07 | 4229 | cfqg_put(RQ_CFQG(rq)); |
a612fddf TH |
4230 | rq->elv.priv[0] = NULL; |
4231 | rq->elv.priv[1] = NULL; | |
7f1dc8a2 | 4232 | |
1da177e4 LT |
4233 | cfq_put_queue(cfqq); |
4234 | } | |
4235 | } | |
4236 | ||
df5fe3e8 | 4237 | static struct cfq_queue * |
c5869807 | 4238 | cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_cq *cic, |
df5fe3e8 JM |
4239 | struct cfq_queue *cfqq) |
4240 | { | |
4241 | cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq); | |
4242 | cic_set_cfqq(cic, cfqq->new_cfqq, 1); | |
b3b6d040 | 4243 | cfq_mark_cfqq_coop(cfqq->new_cfqq); |
df5fe3e8 JM |
4244 | cfq_put_queue(cfqq); |
4245 | return cic_to_cfqq(cic, 1); | |
4246 | } | |
4247 | ||
e6c5bc73 JM |
4248 | /* |
4249 | * Returns NULL if a new cfqq should be allocated, or the old cfqq if this | |
4250 | * was the last process referring to said cfqq. | |
4251 | */ | |
4252 | static struct cfq_queue * | |
c5869807 | 4253 | split_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq) |
e6c5bc73 JM |
4254 | { |
4255 | if (cfqq_process_refs(cfqq) == 1) { | |
e6c5bc73 JM |
4256 | cfqq->pid = current->pid; |
4257 | cfq_clear_cfqq_coop(cfqq); | |
ae54abed | 4258 | cfq_clear_cfqq_split_coop(cfqq); |
e6c5bc73 JM |
4259 | return cfqq; |
4260 | } | |
4261 | ||
4262 | cic_set_cfqq(cic, NULL, 1); | |
d02a2c07 SL |
4263 | |
4264 | cfq_put_cooperator(cfqq); | |
4265 | ||
e6c5bc73 JM |
4266 | cfq_put_queue(cfqq); |
4267 | return NULL; | |
4268 | } | |
1da177e4 | 4269 | /* |
22e2c507 | 4270 | * Allocate cfq data structures associated with this request. |
1da177e4 | 4271 | */ |
22e2c507 | 4272 | static int |
852c788f TH |
4273 | cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio, |
4274 | gfp_t gfp_mask) | |
1da177e4 LT |
4275 | { |
4276 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
f1f8cc94 | 4277 | struct cfq_io_cq *cic = icq_to_cic(rq->elv.icq); |
1da177e4 | 4278 | const int rw = rq_data_dir(rq); |
a6151c3a | 4279 | const bool is_sync = rq_is_sync(rq); |
22e2c507 | 4280 | struct cfq_queue *cfqq; |
1da177e4 LT |
4281 | |
4282 | might_sleep_if(gfp_mask & __GFP_WAIT); | |
4283 | ||
216284c3 | 4284 | spin_lock_irq(q->queue_lock); |
f1f8cc94 | 4285 | |
598971bf TH |
4286 | check_ioprio_changed(cic, bio); |
4287 | check_blkcg_changed(cic, bio); | |
e6c5bc73 | 4288 | new_queue: |
91fac317 | 4289 | cfqq = cic_to_cfqq(cic, is_sync); |
32f2e807 | 4290 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
abede6da | 4291 | cfqq = cfq_get_queue(cfqd, is_sync, cic, bio, gfp_mask); |
91fac317 | 4292 | cic_set_cfqq(cic, cfqq, is_sync); |
df5fe3e8 | 4293 | } else { |
e6c5bc73 JM |
4294 | /* |
4295 | * If the queue was seeky for too long, break it apart. | |
4296 | */ | |
ae54abed | 4297 | if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) { |
e6c5bc73 JM |
4298 | cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq"); |
4299 | cfqq = split_cfqq(cic, cfqq); | |
4300 | if (!cfqq) | |
4301 | goto new_queue; | |
4302 | } | |
4303 | ||
df5fe3e8 JM |
4304 | /* |
4305 | * Check to see if this queue is scheduled to merge with | |
4306 | * another, closely cooperating queue. The merging of | |
4307 | * queues happens here as it must be done in process context. | |
4308 | * The reference on new_cfqq was taken in merge_cfqqs. | |
4309 | */ | |
4310 | if (cfqq->new_cfqq) | |
4311 | cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq); | |
91fac317 | 4312 | } |
1da177e4 LT |
4313 | |
4314 | cfqq->allocated[rw]++; | |
1da177e4 | 4315 | |
6fae9c25 | 4316 | cfqq->ref++; |
eb7d8c07 | 4317 | cfqg_get(cfqq->cfqg); |
a612fddf | 4318 | rq->elv.priv[0] = cfqq; |
1adaf3dd | 4319 | rq->elv.priv[1] = cfqq->cfqg; |
216284c3 | 4320 | spin_unlock_irq(q->queue_lock); |
5e705374 | 4321 | return 0; |
1da177e4 LT |
4322 | } |
4323 | ||
65f27f38 | 4324 | static void cfq_kick_queue(struct work_struct *work) |
22e2c507 | 4325 | { |
65f27f38 | 4326 | struct cfq_data *cfqd = |
23e018a1 | 4327 | container_of(work, struct cfq_data, unplug_work); |
165125e1 | 4328 | struct request_queue *q = cfqd->queue; |
22e2c507 | 4329 | |
40bb54d1 | 4330 | spin_lock_irq(q->queue_lock); |
24ecfbe2 | 4331 | __blk_run_queue(cfqd->queue); |
40bb54d1 | 4332 | spin_unlock_irq(q->queue_lock); |
22e2c507 JA |
4333 | } |
4334 | ||
4335 | /* | |
4336 | * Timer running if the active_queue is currently idling inside its time slice | |
4337 | */ | |
4338 | static void cfq_idle_slice_timer(unsigned long data) | |
4339 | { | |
4340 | struct cfq_data *cfqd = (struct cfq_data *) data; | |
4341 | struct cfq_queue *cfqq; | |
4342 | unsigned long flags; | |
3c6bd2f8 | 4343 | int timed_out = 1; |
22e2c507 | 4344 | |
7b679138 JA |
4345 | cfq_log(cfqd, "idle timer fired"); |
4346 | ||
22e2c507 JA |
4347 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
4348 | ||
fe094d98 JA |
4349 | cfqq = cfqd->active_queue; |
4350 | if (cfqq) { | |
3c6bd2f8 JA |
4351 | timed_out = 0; |
4352 | ||
b029195d JA |
4353 | /* |
4354 | * We saw a request before the queue expired, let it through | |
4355 | */ | |
4356 | if (cfq_cfqq_must_dispatch(cfqq)) | |
4357 | goto out_kick; | |
4358 | ||
22e2c507 JA |
4359 | /* |
4360 | * expired | |
4361 | */ | |
44f7c160 | 4362 | if (cfq_slice_used(cfqq)) |
22e2c507 JA |
4363 | goto expire; |
4364 | ||
4365 | /* | |
4366 | * only expire and reinvoke request handler, if there are | |
4367 | * other queues with pending requests | |
4368 | */ | |
caaa5f9f | 4369 | if (!cfqd->busy_queues) |
22e2c507 | 4370 | goto out_cont; |
22e2c507 JA |
4371 | |
4372 | /* | |
4373 | * not expired and it has a request pending, let it dispatch | |
4374 | */ | |
75e50984 | 4375 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
22e2c507 | 4376 | goto out_kick; |
76280aff CZ |
4377 | |
4378 | /* | |
4379 | * Queue depth flag is reset only when the idle didn't succeed | |
4380 | */ | |
4381 | cfq_clear_cfqq_deep(cfqq); | |
22e2c507 JA |
4382 | } |
4383 | expire: | |
e5ff082e | 4384 | cfq_slice_expired(cfqd, timed_out); |
22e2c507 | 4385 | out_kick: |
23e018a1 | 4386 | cfq_schedule_dispatch(cfqd); |
22e2c507 JA |
4387 | out_cont: |
4388 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); | |
4389 | } | |
4390 | ||
3b18152c JA |
4391 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) |
4392 | { | |
4393 | del_timer_sync(&cfqd->idle_slice_timer); | |
23e018a1 | 4394 | cancel_work_sync(&cfqd->unplug_work); |
3b18152c | 4395 | } |
22e2c507 | 4396 | |
c2dea2d1 VT |
4397 | static void cfq_put_async_queues(struct cfq_data *cfqd) |
4398 | { | |
4399 | int i; | |
4400 | ||
4401 | for (i = 0; i < IOPRIO_BE_NR; i++) { | |
4402 | if (cfqd->async_cfqq[0][i]) | |
4403 | cfq_put_queue(cfqd->async_cfqq[0][i]); | |
4404 | if (cfqd->async_cfqq[1][i]) | |
4405 | cfq_put_queue(cfqd->async_cfqq[1][i]); | |
c2dea2d1 | 4406 | } |
2389d1ef ON |
4407 | |
4408 | if (cfqd->async_idle_cfqq) | |
4409 | cfq_put_queue(cfqd->async_idle_cfqq); | |
c2dea2d1 VT |
4410 | } |
4411 | ||
b374d18a | 4412 | static void cfq_exit_queue(struct elevator_queue *e) |
1da177e4 | 4413 | { |
22e2c507 | 4414 | struct cfq_data *cfqd = e->elevator_data; |
165125e1 | 4415 | struct request_queue *q = cfqd->queue; |
22e2c507 | 4416 | |
3b18152c | 4417 | cfq_shutdown_timer_wq(cfqd); |
e2d74ac0 | 4418 | |
d9ff4187 | 4419 | spin_lock_irq(q->queue_lock); |
e2d74ac0 | 4420 | |
d9ff4187 | 4421 | if (cfqd->active_queue) |
e5ff082e | 4422 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0); |
e2d74ac0 | 4423 | |
c2dea2d1 | 4424 | cfq_put_async_queues(cfqd); |
03aa264a TH |
4425 | |
4426 | spin_unlock_irq(q->queue_lock); | |
4427 | ||
a90d742e AV |
4428 | cfq_shutdown_timer_wq(cfqd); |
4429 | ||
ffea73fc TH |
4430 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
4431 | blkcg_deactivate_policy(q, &blkcg_policy_cfq); | |
4432 | #else | |
f51b802c | 4433 | kfree(cfqd->root_group); |
2abae55f | 4434 | #endif |
56edf7d7 | 4435 | kfree(cfqd); |
1da177e4 LT |
4436 | } |
4437 | ||
d50235b7 | 4438 | static int cfq_init_queue(struct request_queue *q, struct elevator_type *e) |
1da177e4 LT |
4439 | { |
4440 | struct cfq_data *cfqd; | |
3c798398 | 4441 | struct blkcg_gq *blkg __maybe_unused; |
a2b1693b | 4442 | int i, ret; |
d50235b7 JM |
4443 | struct elevator_queue *eq; |
4444 | ||
4445 | eq = elevator_alloc(q, e); | |
4446 | if (!eq) | |
4447 | return -ENOMEM; | |
1da177e4 | 4448 | |
c1b511eb | 4449 | cfqd = kzalloc_node(sizeof(*cfqd), GFP_KERNEL, q->node); |
d50235b7 JM |
4450 | if (!cfqd) { |
4451 | kobject_put(&eq->kobj); | |
b2fab5ac | 4452 | return -ENOMEM; |
d50235b7 JM |
4453 | } |
4454 | eq->elevator_data = cfqd; | |
80b15c73 | 4455 | |
f51b802c | 4456 | cfqd->queue = q; |
d50235b7 JM |
4457 | spin_lock_irq(q->queue_lock); |
4458 | q->elevator = eq; | |
4459 | spin_unlock_irq(q->queue_lock); | |
f51b802c | 4460 | |
1fa8f6d6 VG |
4461 | /* Init root service tree */ |
4462 | cfqd->grp_service_tree = CFQ_RB_ROOT; | |
4463 | ||
f51b802c | 4464 | /* Init root group and prefer root group over other groups by default */ |
25fb5169 | 4465 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4466 | ret = blkcg_activate_policy(q, &blkcg_policy_cfq); |
a2b1693b TH |
4467 | if (ret) |
4468 | goto out_free; | |
f51b802c | 4469 | |
a2b1693b | 4470 | cfqd->root_group = blkg_to_cfqg(q->root_blkg); |
f51b802c | 4471 | #else |
a2b1693b | 4472 | ret = -ENOMEM; |
f51b802c TH |
4473 | cfqd->root_group = kzalloc_node(sizeof(*cfqd->root_group), |
4474 | GFP_KERNEL, cfqd->queue->node); | |
a2b1693b TH |
4475 | if (!cfqd->root_group) |
4476 | goto out_free; | |
5624a4e4 | 4477 | |
a2b1693b TH |
4478 | cfq_init_cfqg_base(cfqd->root_group); |
4479 | #endif | |
3381cb8d | 4480 | cfqd->root_group->weight = 2 * CFQ_WEIGHT_DEFAULT; |
e71357e1 | 4481 | cfqd->root_group->leaf_weight = 2 * CFQ_WEIGHT_DEFAULT; |
5624a4e4 | 4482 | |
26a2ac00 JA |
4483 | /* |
4484 | * Not strictly needed (since RB_ROOT just clears the node and we | |
4485 | * zeroed cfqd on alloc), but better be safe in case someone decides | |
4486 | * to add magic to the rb code | |
4487 | */ | |
4488 | for (i = 0; i < CFQ_PRIO_LISTS; i++) | |
4489 | cfqd->prio_trees[i] = RB_ROOT; | |
4490 | ||
6118b70b JA |
4491 | /* |
4492 | * Our fallback cfqq if cfq_find_alloc_queue() runs into OOM issues. | |
4493 | * Grab a permanent reference to it, so that the normal code flow | |
f51b802c TH |
4494 | * will not attempt to free it. oom_cfqq is linked to root_group |
4495 | * but shouldn't hold a reference as it'll never be unlinked. Lose | |
4496 | * the reference from linking right away. | |
6118b70b JA |
4497 | */ |
4498 | cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); | |
30d7b944 | 4499 | cfqd->oom_cfqq.ref++; |
1adaf3dd TH |
4500 | |
4501 | spin_lock_irq(q->queue_lock); | |
f51b802c | 4502 | cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, cfqd->root_group); |
eb7d8c07 | 4503 | cfqg_put(cfqd->root_group); |
1adaf3dd | 4504 | spin_unlock_irq(q->queue_lock); |
1da177e4 | 4505 | |
22e2c507 JA |
4506 | init_timer(&cfqd->idle_slice_timer); |
4507 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; | |
4508 | cfqd->idle_slice_timer.data = (unsigned long) cfqd; | |
4509 | ||
23e018a1 | 4510 | INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); |
22e2c507 | 4511 | |
1da177e4 | 4512 | cfqd->cfq_quantum = cfq_quantum; |
22e2c507 JA |
4513 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |
4514 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; | |
1da177e4 LT |
4515 | cfqd->cfq_back_max = cfq_back_max; |
4516 | cfqd->cfq_back_penalty = cfq_back_penalty; | |
22e2c507 JA |
4517 | cfqd->cfq_slice[0] = cfq_slice_async; |
4518 | cfqd->cfq_slice[1] = cfq_slice_sync; | |
5bf14c07 | 4519 | cfqd->cfq_target_latency = cfq_target_latency; |
22e2c507 | 4520 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; |
0bb97947 | 4521 | cfqd->cfq_slice_idle = cfq_slice_idle; |
80bdf0c7 | 4522 | cfqd->cfq_group_idle = cfq_group_idle; |
963b72fc | 4523 | cfqd->cfq_latency = 1; |
e459dd08 | 4524 | cfqd->hw_tag = -1; |
edc71131 CZ |
4525 | /* |
4526 | * we optimistically start assuming sync ops weren't delayed in last | |
4527 | * second, in order to have larger depth for async operations. | |
4528 | */ | |
573412b2 | 4529 | cfqd->last_delayed_sync = jiffies - HZ; |
b2fab5ac | 4530 | return 0; |
a2b1693b TH |
4531 | |
4532 | out_free: | |
4533 | kfree(cfqd); | |
d50235b7 | 4534 | kobject_put(&eq->kobj); |
a2b1693b | 4535 | return ret; |
1da177e4 LT |
4536 | } |
4537 | ||
0bb97947 JA |
4538 | static void cfq_registered_queue(struct request_queue *q) |
4539 | { | |
4540 | struct elevator_queue *e = q->elevator; | |
4541 | struct cfq_data *cfqd = e->elevator_data; | |
4542 | ||
4543 | /* | |
4544 | * Default to IOPS mode with no idling for SSDs | |
4545 | */ | |
4546 | if (blk_queue_nonrot(q)) | |
4547 | cfqd->cfq_slice_idle = 0; | |
4548 | } | |
4549 | ||
1da177e4 LT |
4550 | /* |
4551 | * sysfs parts below --> | |
4552 | */ | |
1da177e4 LT |
4553 | static ssize_t |
4554 | cfq_var_show(unsigned int var, char *page) | |
4555 | { | |
176167ad | 4556 | return sprintf(page, "%u\n", var); |
1da177e4 LT |
4557 | } |
4558 | ||
4559 | static ssize_t | |
4560 | cfq_var_store(unsigned int *var, const char *page, size_t count) | |
4561 | { | |
4562 | char *p = (char *) page; | |
4563 | ||
4564 | *var = simple_strtoul(p, &p, 10); | |
4565 | return count; | |
4566 | } | |
4567 | ||
1da177e4 | 4568 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ |
b374d18a | 4569 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
1da177e4 | 4570 | { \ |
3d1ab40f | 4571 | struct cfq_data *cfqd = e->elevator_data; \ |
1da177e4 LT |
4572 | unsigned int __data = __VAR; \ |
4573 | if (__CONV) \ | |
4574 | __data = jiffies_to_msecs(__data); \ | |
4575 | return cfq_var_show(__data, (page)); \ | |
4576 | } | |
4577 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); | |
22e2c507 JA |
4578 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); |
4579 | SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1); | |
e572ec7e AV |
4580 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); |
4581 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); | |
22e2c507 | 4582 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); |
80bdf0c7 | 4583 | SHOW_FUNCTION(cfq_group_idle_show, cfqd->cfq_group_idle, 1); |
22e2c507 JA |
4584 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); |
4585 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); | |
4586 | SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); | |
963b72fc | 4587 | SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); |
5bf14c07 | 4588 | SHOW_FUNCTION(cfq_target_latency_show, cfqd->cfq_target_latency, 1); |
1da177e4 LT |
4589 | #undef SHOW_FUNCTION |
4590 | ||
4591 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ | |
b374d18a | 4592 | static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ |
1da177e4 | 4593 | { \ |
3d1ab40f | 4594 | struct cfq_data *cfqd = e->elevator_data; \ |
1da177e4 LT |
4595 | unsigned int __data; \ |
4596 | int ret = cfq_var_store(&__data, (page), count); \ | |
4597 | if (__data < (MIN)) \ | |
4598 | __data = (MIN); \ | |
4599 | else if (__data > (MAX)) \ | |
4600 | __data = (MAX); \ | |
4601 | if (__CONV) \ | |
4602 | *(__PTR) = msecs_to_jiffies(__data); \ | |
4603 | else \ | |
4604 | *(__PTR) = __data; \ | |
4605 | return ret; \ | |
4606 | } | |
4607 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); | |
fe094d98 JA |
4608 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, |
4609 | UINT_MAX, 1); | |
4610 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, | |
4611 | UINT_MAX, 1); | |
e572ec7e | 4612 | STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0); |
fe094d98 JA |
4613 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, |
4614 | UINT_MAX, 0); | |
22e2c507 | 4615 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); |
80bdf0c7 | 4616 | STORE_FUNCTION(cfq_group_idle_store, &cfqd->cfq_group_idle, 0, UINT_MAX, 1); |
22e2c507 JA |
4617 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); |
4618 | STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1); | |
fe094d98 JA |
4619 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, |
4620 | UINT_MAX, 0); | |
963b72fc | 4621 | STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); |
5bf14c07 | 4622 | STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1, UINT_MAX, 1); |
1da177e4 LT |
4623 | #undef STORE_FUNCTION |
4624 | ||
e572ec7e AV |
4625 | #define CFQ_ATTR(name) \ |
4626 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) | |
4627 | ||
4628 | static struct elv_fs_entry cfq_attrs[] = { | |
4629 | CFQ_ATTR(quantum), | |
e572ec7e AV |
4630 | CFQ_ATTR(fifo_expire_sync), |
4631 | CFQ_ATTR(fifo_expire_async), | |
4632 | CFQ_ATTR(back_seek_max), | |
4633 | CFQ_ATTR(back_seek_penalty), | |
4634 | CFQ_ATTR(slice_sync), | |
4635 | CFQ_ATTR(slice_async), | |
4636 | CFQ_ATTR(slice_async_rq), | |
4637 | CFQ_ATTR(slice_idle), | |
80bdf0c7 | 4638 | CFQ_ATTR(group_idle), |
963b72fc | 4639 | CFQ_ATTR(low_latency), |
5bf14c07 | 4640 | CFQ_ATTR(target_latency), |
e572ec7e | 4641 | __ATTR_NULL |
1da177e4 LT |
4642 | }; |
4643 | ||
1da177e4 LT |
4644 | static struct elevator_type iosched_cfq = { |
4645 | .ops = { | |
4646 | .elevator_merge_fn = cfq_merge, | |
4647 | .elevator_merged_fn = cfq_merged_request, | |
4648 | .elevator_merge_req_fn = cfq_merged_requests, | |
da775265 | 4649 | .elevator_allow_merge_fn = cfq_allow_merge, |
812d4026 | 4650 | .elevator_bio_merged_fn = cfq_bio_merged, |
b4878f24 | 4651 | .elevator_dispatch_fn = cfq_dispatch_requests, |
1da177e4 | 4652 | .elevator_add_req_fn = cfq_insert_request, |
b4878f24 | 4653 | .elevator_activate_req_fn = cfq_activate_request, |
1da177e4 | 4654 | .elevator_deactivate_req_fn = cfq_deactivate_request, |
1da177e4 | 4655 | .elevator_completed_req_fn = cfq_completed_request, |
21183b07 JA |
4656 | .elevator_former_req_fn = elv_rb_former_request, |
4657 | .elevator_latter_req_fn = elv_rb_latter_request, | |
9b84cacd | 4658 | .elevator_init_icq_fn = cfq_init_icq, |
7e5a8794 | 4659 | .elevator_exit_icq_fn = cfq_exit_icq, |
1da177e4 LT |
4660 | .elevator_set_req_fn = cfq_set_request, |
4661 | .elevator_put_req_fn = cfq_put_request, | |
4662 | .elevator_may_queue_fn = cfq_may_queue, | |
4663 | .elevator_init_fn = cfq_init_queue, | |
4664 | .elevator_exit_fn = cfq_exit_queue, | |
0bb97947 | 4665 | .elevator_registered_fn = cfq_registered_queue, |
1da177e4 | 4666 | }, |
3d3c2379 TH |
4667 | .icq_size = sizeof(struct cfq_io_cq), |
4668 | .icq_align = __alignof__(struct cfq_io_cq), | |
3d1ab40f | 4669 | .elevator_attrs = cfq_attrs, |
3d3c2379 | 4670 | .elevator_name = "cfq", |
1da177e4 LT |
4671 | .elevator_owner = THIS_MODULE, |
4672 | }; | |
4673 | ||
3e252066 | 4674 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4675 | static struct blkcg_policy blkcg_policy_cfq = { |
f9fcc2d3 | 4676 | .pd_size = sizeof(struct cfq_group), |
e48453c3 | 4677 | .cpd_size = sizeof(struct cfq_group_data), |
f9fcc2d3 TH |
4678 | .cftypes = cfq_blkcg_files, |
4679 | ||
e48453c3 | 4680 | .cpd_init_fn = cfq_cpd_init, |
f9fcc2d3 | 4681 | .pd_init_fn = cfq_pd_init, |
0b39920b | 4682 | .pd_offline_fn = cfq_pd_offline, |
f9fcc2d3 | 4683 | .pd_reset_stats_fn = cfq_pd_reset_stats, |
3e252066 | 4684 | }; |
3e252066 VG |
4685 | #endif |
4686 | ||
1da177e4 LT |
4687 | static int __init cfq_init(void) |
4688 | { | |
3d3c2379 TH |
4689 | int ret; |
4690 | ||
22e2c507 JA |
4691 | /* |
4692 | * could be 0 on HZ < 1000 setups | |
4693 | */ | |
4694 | if (!cfq_slice_async) | |
4695 | cfq_slice_async = 1; | |
4696 | if (!cfq_slice_idle) | |
4697 | cfq_slice_idle = 1; | |
4698 | ||
80bdf0c7 VG |
4699 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
4700 | if (!cfq_group_idle) | |
4701 | cfq_group_idle = 1; | |
8bd435b3 | 4702 | |
3c798398 | 4703 | ret = blkcg_policy_register(&blkcg_policy_cfq); |
8bd435b3 TH |
4704 | if (ret) |
4705 | return ret; | |
ffea73fc TH |
4706 | #else |
4707 | cfq_group_idle = 0; | |
4708 | #endif | |
8bd435b3 | 4709 | |
fd794956 | 4710 | ret = -ENOMEM; |
3d3c2379 TH |
4711 | cfq_pool = KMEM_CACHE(cfq_queue, 0); |
4712 | if (!cfq_pool) | |
8bd435b3 | 4713 | goto err_pol_unreg; |
1da177e4 | 4714 | |
3d3c2379 | 4715 | ret = elv_register(&iosched_cfq); |
8bd435b3 TH |
4716 | if (ret) |
4717 | goto err_free_pool; | |
3d3c2379 | 4718 | |
2fdd82bd | 4719 | return 0; |
8bd435b3 TH |
4720 | |
4721 | err_free_pool: | |
4722 | kmem_cache_destroy(cfq_pool); | |
4723 | err_pol_unreg: | |
ffea73fc | 4724 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4725 | blkcg_policy_unregister(&blkcg_policy_cfq); |
ffea73fc | 4726 | #endif |
8bd435b3 | 4727 | return ret; |
1da177e4 LT |
4728 | } |
4729 | ||
4730 | static void __exit cfq_exit(void) | |
4731 | { | |
ffea73fc | 4732 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4733 | blkcg_policy_unregister(&blkcg_policy_cfq); |
ffea73fc | 4734 | #endif |
1da177e4 | 4735 | elv_unregister(&iosched_cfq); |
3d3c2379 | 4736 | kmem_cache_destroy(cfq_pool); |
1da177e4 LT |
4737 | } |
4738 | ||
4739 | module_init(cfq_init); | |
4740 | module_exit(cfq_exit); | |
4741 | ||
4742 | MODULE_AUTHOR("Jens Axboe"); | |
4743 | MODULE_LICENSE("GPL"); | |
4744 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |