Commit | Line | Data |
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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> | |
9a7f38c4 | 13 | #include <linux/ktime.h> |
1da177e4 | 14 | #include <linux/rbtree.h> |
22e2c507 | 15 | #include <linux/ioprio.h> |
7b679138 | 16 | #include <linux/blktrace_api.h> |
eea8f41c | 17 | #include <linux/blk-cgroup.h> |
6e736be7 | 18 | #include "blk.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; |
9a7f38c4 | 25 | static const u64 cfq_fifo_expire[2] = { NSEC_PER_SEC / 4, NSEC_PER_SEC / 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; | |
9a7f38c4 JM |
30 | static const u64 cfq_slice_sync = NSEC_PER_SEC / 10; |
31 | static u64 cfq_slice_async = NSEC_PER_SEC / 25; | |
64100099 | 32 | static const int cfq_slice_async_rq = 2; |
9a7f38c4 JM |
33 | static u64 cfq_slice_idle = NSEC_PER_SEC / 125; |
34 | static u64 cfq_group_idle = NSEC_PER_SEC / 125; | |
35 | static const u64 cfq_target_latency = (u64)NSEC_PER_SEC * 3/10; /* 300 ms */ | |
5db5d642 | 36 | static const int cfq_hist_divisor = 4; |
22e2c507 | 37 | |
d9e7620e | 38 | /* |
0871714e | 39 | * offset from end of service tree |
d9e7620e | 40 | */ |
9a7f38c4 | 41 | #define CFQ_IDLE_DELAY (NSEC_PER_SEC / 5) |
d9e7620e JA |
42 | |
43 | /* | |
44 | * below this threshold, we consider thinktime immediate | |
45 | */ | |
9a7f38c4 | 46 | #define CFQ_MIN_TT (2 * NSEC_PER_SEC / HZ) |
d9e7620e | 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 | 70 | /* blkio-related constants */ |
3ecca629 TH |
71 | #define CFQ_WEIGHT_LEGACY_MIN 10 |
72 | #define CFQ_WEIGHT_LEGACY_DFL 500 | |
73 | #define CFQ_WEIGHT_LEGACY_MAX 1000 | |
e48453c3 | 74 | |
c5869807 | 75 | struct cfq_ttime { |
9a7f38c4 | 76 | u64 last_end_request; |
c5869807 | 77 | |
9a7f38c4 JM |
78 | u64 ttime_total; |
79 | u64 ttime_mean; | |
c5869807 | 80 | unsigned long ttime_samples; |
c5869807 TH |
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 | 96 | #define CFQ_RB_ROOT (struct cfq_rb_root) { .rb = RB_ROOT, \ |
9a7f38c4 | 97 | .ttime = {.last_end_request = ktime_get_ns(),},} |
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 */ | |
9a7f38c4 | 112 | u64 rb_key; |
6118b70b JA |
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 | 128 | /* time when queue got scheduled in to dispatch first request. */ |
9a7f38c4 JM |
129 | u64 dispatch_start; |
130 | u64 allocated_slice; | |
131 | u64 slice_dispatch; | |
dae739eb | 132 | /* time when first request from queue completed and slice started. */ |
9a7f38c4 JM |
133 | u64 slice_start; |
134 | u64 slice_end; | |
93fdf147 | 135 | s64 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; | |
b8269db4 | 144 | unsigned short ioprio_class, org_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 | |
155fead9 TH |
180 | /* number of ios merged */ |
181 | struct blkg_rwstat merged; | |
182 | /* total time spent on device in ns, may not be accurate w/ queueing */ | |
183 | struct blkg_rwstat service_time; | |
184 | /* total time spent waiting in scheduler queue in ns */ | |
185 | struct blkg_rwstat wait_time; | |
186 | /* number of IOs queued up */ | |
187 | struct blkg_rwstat queued; | |
155fead9 TH |
188 | /* total disk time and nr sectors dispatched by this group */ |
189 | struct blkg_stat time; | |
190 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
191 | /* time not charged to this cgroup */ | |
192 | struct blkg_stat unaccounted_time; | |
193 | /* sum of number of ios queued across all samples */ | |
194 | struct blkg_stat avg_queue_size_sum; | |
195 | /* count of samples taken for average */ | |
196 | struct blkg_stat avg_queue_size_samples; | |
197 | /* how many times this group has been removed from service tree */ | |
198 | struct blkg_stat dequeue; | |
199 | /* total time spent waiting for it to be assigned a timeslice. */ | |
200 | struct blkg_stat group_wait_time; | |
3c798398 | 201 | /* time spent idling for this blkcg_gq */ |
155fead9 TH |
202 | struct blkg_stat idle_time; |
203 | /* total time with empty current active q with other requests queued */ | |
204 | struct blkg_stat empty_time; | |
205 | /* fields after this shouldn't be cleared on stat reset */ | |
206 | uint64_t start_group_wait_time; | |
207 | uint64_t start_idle_time; | |
208 | uint64_t start_empty_time; | |
209 | uint16_t flags; | |
210 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
211 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ | |
212 | }; | |
213 | ||
e48453c3 AA |
214 | /* Per-cgroup data */ |
215 | struct cfq_group_data { | |
216 | /* must be the first member */ | |
81437648 | 217 | struct blkcg_policy_data cpd; |
e48453c3 AA |
218 | |
219 | unsigned int weight; | |
220 | unsigned int leaf_weight; | |
221 | }; | |
222 | ||
cdb16e8f VG |
223 | /* This is per cgroup per device grouping structure */ |
224 | struct cfq_group { | |
f95a04af TH |
225 | /* must be the first member */ |
226 | struct blkg_policy_data pd; | |
227 | ||
1fa8f6d6 VG |
228 | /* group service_tree member */ |
229 | struct rb_node rb_node; | |
230 | ||
231 | /* group service_tree key */ | |
232 | u64 vdisktime; | |
e71357e1 | 233 | |
7918ffb5 TH |
234 | /* |
235 | * The number of active cfqgs and sum of their weights under this | |
236 | * cfqg. This covers this cfqg's leaf_weight and all children's | |
237 | * weights, but does not cover weights of further descendants. | |
238 | * | |
239 | * If a cfqg is on the service tree, it's active. An active cfqg | |
240 | * also activates its parent and contributes to the children_weight | |
241 | * of the parent. | |
242 | */ | |
243 | int nr_active; | |
244 | unsigned int children_weight; | |
245 | ||
1d3650f7 TH |
246 | /* |
247 | * vfraction is the fraction of vdisktime that the tasks in this | |
248 | * cfqg are entitled to. This is determined by compounding the | |
249 | * ratios walking up from this cfqg to the root. | |
250 | * | |
251 | * It is in fixed point w/ CFQ_SERVICE_SHIFT and the sum of all | |
252 | * vfractions on a service tree is approximately 1. The sum may | |
253 | * deviate a bit due to rounding errors and fluctuations caused by | |
254 | * cfqgs entering and leaving the service tree. | |
255 | */ | |
256 | unsigned int vfraction; | |
257 | ||
e71357e1 TH |
258 | /* |
259 | * There are two weights - (internal) weight is the weight of this | |
260 | * cfqg against the sibling cfqgs. leaf_weight is the wight of | |
261 | * this cfqg against the child cfqgs. For the root cfqg, both | |
262 | * weights are kept in sync for backward compatibility. | |
263 | */ | |
25bc6b07 | 264 | unsigned int weight; |
8184f93e | 265 | unsigned int new_weight; |
3381cb8d | 266 | unsigned int dev_weight; |
1fa8f6d6 | 267 | |
e71357e1 TH |
268 | unsigned int leaf_weight; |
269 | unsigned int new_leaf_weight; | |
270 | unsigned int dev_leaf_weight; | |
271 | ||
1fa8f6d6 VG |
272 | /* number of cfqq currently on this group */ |
273 | int nr_cfqq; | |
274 | ||
cdb16e8f | 275 | /* |
4495a7d4 | 276 | * Per group busy queues average. Useful for workload slice calc. We |
b4627321 VG |
277 | * create the array for each prio class but at run time it is used |
278 | * only for RT and BE class and slot for IDLE class remains unused. | |
279 | * This is primarily done to avoid confusion and a gcc warning. | |
280 | */ | |
281 | unsigned int busy_queues_avg[CFQ_PRIO_NR]; | |
282 | /* | |
283 | * rr lists of queues with requests. We maintain service trees for | |
284 | * RT and BE classes. These trees are subdivided in subclasses | |
285 | * of SYNC, SYNC_NOIDLE and ASYNC based on workload type. For IDLE | |
286 | * class there is no subclassification and all the cfq queues go on | |
287 | * a single tree service_tree_idle. | |
cdb16e8f VG |
288 | * Counts are embedded in the cfq_rb_root |
289 | */ | |
290 | struct cfq_rb_root service_trees[2][3]; | |
291 | struct cfq_rb_root service_tree_idle; | |
dae739eb | 292 | |
9a7f38c4 | 293 | u64 saved_wl_slice; |
4d2ceea4 VG |
294 | enum wl_type_t saved_wl_type; |
295 | enum wl_class_t saved_wl_class; | |
4eef3049 | 296 | |
80bdf0c7 VG |
297 | /* number of requests that are on the dispatch list or inside driver */ |
298 | int dispatched; | |
7700fc4f | 299 | struct cfq_ttime ttime; |
0b39920b | 300 | struct cfqg_stats stats; /* stats for this cfqg */ |
60a83707 TH |
301 | |
302 | /* async queue for each priority case */ | |
303 | struct cfq_queue *async_cfqq[2][IOPRIO_BE_NR]; | |
304 | struct cfq_queue *async_idle_cfqq; | |
305 | ||
cdb16e8f | 306 | }; |
718eee05 | 307 | |
c5869807 TH |
308 | struct cfq_io_cq { |
309 | struct io_cq icq; /* must be the first member */ | |
310 | struct cfq_queue *cfqq[2]; | |
311 | struct cfq_ttime ttime; | |
598971bf TH |
312 | int ioprio; /* the current ioprio */ |
313 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
f4da8072 | 314 | uint64_t blkcg_serial_nr; /* the current blkcg serial */ |
598971bf | 315 | #endif |
c5869807 TH |
316 | }; |
317 | ||
22e2c507 JA |
318 | /* |
319 | * Per block device queue structure | |
320 | */ | |
1da177e4 | 321 | struct cfq_data { |
165125e1 | 322 | struct request_queue *queue; |
1fa8f6d6 VG |
323 | /* Root service tree for cfq_groups */ |
324 | struct cfq_rb_root grp_service_tree; | |
f51b802c | 325 | struct cfq_group *root_group; |
22e2c507 | 326 | |
c0324a02 CZ |
327 | /* |
328 | * The priority currently being served | |
22e2c507 | 329 | */ |
4d2ceea4 VG |
330 | enum wl_class_t serving_wl_class; |
331 | enum wl_type_t serving_wl_type; | |
9a7f38c4 | 332 | u64 workload_expires; |
cdb16e8f | 333 | struct cfq_group *serving_group; |
a36e71f9 JA |
334 | |
335 | /* | |
336 | * Each priority tree is sorted by next_request position. These | |
337 | * trees are used when determining if two or more queues are | |
338 | * interleaving requests (see cfq_close_cooperator). | |
339 | */ | |
340 | struct rb_root prio_trees[CFQ_PRIO_LISTS]; | |
341 | ||
22e2c507 | 342 | unsigned int busy_queues; |
ef8a41df | 343 | unsigned int busy_sync_queues; |
22e2c507 | 344 | |
53c583d2 CZ |
345 | int rq_in_driver; |
346 | int rq_in_flight[2]; | |
45333d5a AC |
347 | |
348 | /* | |
349 | * queue-depth detection | |
350 | */ | |
351 | int rq_queued; | |
25776e35 | 352 | int hw_tag; |
e459dd08 CZ |
353 | /* |
354 | * hw_tag can be | |
355 | * -1 => indeterminate, (cfq will behave as if NCQ is present, to allow better detection) | |
356 | * 1 => NCQ is present (hw_tag_est_depth is the estimated max depth) | |
357 | * 0 => no NCQ | |
358 | */ | |
359 | int hw_tag_est_depth; | |
360 | unsigned int hw_tag_samples; | |
1da177e4 | 361 | |
22e2c507 JA |
362 | /* |
363 | * idle window management | |
364 | */ | |
91148325 | 365 | struct hrtimer idle_slice_timer; |
23e018a1 | 366 | struct work_struct unplug_work; |
1da177e4 | 367 | |
22e2c507 | 368 | struct cfq_queue *active_queue; |
c5869807 | 369 | struct cfq_io_cq *active_cic; |
22e2c507 | 370 | |
6d048f53 | 371 | sector_t last_position; |
1da177e4 | 372 | |
1da177e4 LT |
373 | /* |
374 | * tunables, see top of file | |
375 | */ | |
376 | unsigned int cfq_quantum; | |
1da177e4 LT |
377 | unsigned int cfq_back_penalty; |
378 | unsigned int cfq_back_max; | |
22e2c507 | 379 | unsigned int cfq_slice_async_rq; |
963b72fc | 380 | unsigned int cfq_latency; |
9a7f38c4 JM |
381 | u64 cfq_fifo_expire[2]; |
382 | u64 cfq_slice[2]; | |
383 | u64 cfq_slice_idle; | |
384 | u64 cfq_group_idle; | |
385 | u64 cfq_target_latency; | |
d9ff4187 | 386 | |
6118b70b JA |
387 | /* |
388 | * Fallback dummy cfqq for extreme OOM conditions | |
389 | */ | |
390 | struct cfq_queue oom_cfqq; | |
365722bb | 391 | |
9a7f38c4 | 392 | u64 last_delayed_sync; |
1da177e4 LT |
393 | }; |
394 | ||
25fb5169 | 395 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd); |
60a83707 | 396 | static void cfq_put_queue(struct cfq_queue *cfqq); |
25fb5169 | 397 | |
34b98d03 | 398 | static struct cfq_rb_root *st_for(struct cfq_group *cfqg, |
3bf10fea | 399 | enum wl_class_t class, |
65b32a57 | 400 | enum wl_type_t type) |
c0324a02 | 401 | { |
1fa8f6d6 VG |
402 | if (!cfqg) |
403 | return NULL; | |
404 | ||
3bf10fea | 405 | if (class == IDLE_WORKLOAD) |
cdb16e8f | 406 | return &cfqg->service_tree_idle; |
c0324a02 | 407 | |
3bf10fea | 408 | return &cfqg->service_trees[class][type]; |
c0324a02 CZ |
409 | } |
410 | ||
3b18152c | 411 | enum cfqq_state_flags { |
b0b8d749 JA |
412 | CFQ_CFQQ_FLAG_on_rr = 0, /* on round-robin busy list */ |
413 | CFQ_CFQQ_FLAG_wait_request, /* waiting for a request */ | |
b029195d | 414 | CFQ_CFQQ_FLAG_must_dispatch, /* must be allowed a dispatch */ |
b0b8d749 | 415 | CFQ_CFQQ_FLAG_must_alloc_slice, /* per-slice must_alloc flag */ |
b0b8d749 JA |
416 | CFQ_CFQQ_FLAG_fifo_expire, /* FIFO checked in this slice */ |
417 | CFQ_CFQQ_FLAG_idle_window, /* slice idling enabled */ | |
418 | CFQ_CFQQ_FLAG_prio_changed, /* task priority has changed */ | |
44f7c160 | 419 | CFQ_CFQQ_FLAG_slice_new, /* no requests dispatched in slice */ |
91fac317 | 420 | CFQ_CFQQ_FLAG_sync, /* synchronous queue */ |
b3b6d040 | 421 | CFQ_CFQQ_FLAG_coop, /* cfqq is shared */ |
ae54abed | 422 | CFQ_CFQQ_FLAG_split_coop, /* shared cfqq will be splitted */ |
76280aff | 423 | CFQ_CFQQ_FLAG_deep, /* sync cfqq experienced large depth */ |
f75edf2d | 424 | CFQ_CFQQ_FLAG_wait_busy, /* Waiting for next request */ |
3b18152c JA |
425 | }; |
426 | ||
427 | #define CFQ_CFQQ_FNS(name) \ | |
428 | static inline void cfq_mark_cfqq_##name(struct cfq_queue *cfqq) \ | |
429 | { \ | |
fe094d98 | 430 | (cfqq)->flags |= (1 << CFQ_CFQQ_FLAG_##name); \ |
3b18152c JA |
431 | } \ |
432 | static inline void cfq_clear_cfqq_##name(struct cfq_queue *cfqq) \ | |
433 | { \ | |
fe094d98 | 434 | (cfqq)->flags &= ~(1 << CFQ_CFQQ_FLAG_##name); \ |
3b18152c JA |
435 | } \ |
436 | static inline int cfq_cfqq_##name(const struct cfq_queue *cfqq) \ | |
437 | { \ | |
fe094d98 | 438 | return ((cfqq)->flags & (1 << CFQ_CFQQ_FLAG_##name)) != 0; \ |
3b18152c JA |
439 | } |
440 | ||
441 | CFQ_CFQQ_FNS(on_rr); | |
442 | CFQ_CFQQ_FNS(wait_request); | |
b029195d | 443 | CFQ_CFQQ_FNS(must_dispatch); |
3b18152c | 444 | CFQ_CFQQ_FNS(must_alloc_slice); |
3b18152c JA |
445 | CFQ_CFQQ_FNS(fifo_expire); |
446 | CFQ_CFQQ_FNS(idle_window); | |
447 | CFQ_CFQQ_FNS(prio_changed); | |
44f7c160 | 448 | CFQ_CFQQ_FNS(slice_new); |
91fac317 | 449 | CFQ_CFQQ_FNS(sync); |
a36e71f9 | 450 | CFQ_CFQQ_FNS(coop); |
ae54abed | 451 | CFQ_CFQQ_FNS(split_coop); |
76280aff | 452 | CFQ_CFQQ_FNS(deep); |
f75edf2d | 453 | CFQ_CFQQ_FNS(wait_busy); |
3b18152c JA |
454 | #undef CFQ_CFQQ_FNS |
455 | ||
629ed0b1 | 456 | #if defined(CONFIG_CFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) |
2ce4d50f | 457 | |
155fead9 TH |
458 | /* cfqg stats flags */ |
459 | enum cfqg_stats_flags { | |
460 | CFQG_stats_waiting = 0, | |
461 | CFQG_stats_idling, | |
462 | CFQG_stats_empty, | |
629ed0b1 TH |
463 | }; |
464 | ||
155fead9 TH |
465 | #define CFQG_FLAG_FNS(name) \ |
466 | static inline void cfqg_stats_mark_##name(struct cfqg_stats *stats) \ | |
629ed0b1 | 467 | { \ |
155fead9 | 468 | stats->flags |= (1 << CFQG_stats_##name); \ |
629ed0b1 | 469 | } \ |
155fead9 | 470 | static inline void cfqg_stats_clear_##name(struct cfqg_stats *stats) \ |
629ed0b1 | 471 | { \ |
155fead9 | 472 | stats->flags &= ~(1 << CFQG_stats_##name); \ |
629ed0b1 | 473 | } \ |
155fead9 | 474 | static inline int cfqg_stats_##name(struct cfqg_stats *stats) \ |
629ed0b1 | 475 | { \ |
155fead9 | 476 | return (stats->flags & (1 << CFQG_stats_##name)) != 0; \ |
629ed0b1 TH |
477 | } \ |
478 | ||
155fead9 TH |
479 | CFQG_FLAG_FNS(waiting) |
480 | CFQG_FLAG_FNS(idling) | |
481 | CFQG_FLAG_FNS(empty) | |
482 | #undef CFQG_FLAG_FNS | |
629ed0b1 TH |
483 | |
484 | /* This should be called with the queue_lock held. */ | |
155fead9 | 485 | static void cfqg_stats_update_group_wait_time(struct cfqg_stats *stats) |
629ed0b1 TH |
486 | { |
487 | unsigned long long now; | |
488 | ||
155fead9 | 489 | if (!cfqg_stats_waiting(stats)) |
629ed0b1 TH |
490 | return; |
491 | ||
492 | now = sched_clock(); | |
493 | if (time_after64(now, stats->start_group_wait_time)) | |
494 | blkg_stat_add(&stats->group_wait_time, | |
495 | now - stats->start_group_wait_time); | |
155fead9 | 496 | cfqg_stats_clear_waiting(stats); |
629ed0b1 TH |
497 | } |
498 | ||
499 | /* This should be called with the queue_lock held. */ | |
155fead9 TH |
500 | static void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, |
501 | struct cfq_group *curr_cfqg) | |
629ed0b1 | 502 | { |
155fead9 | 503 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 504 | |
155fead9 | 505 | if (cfqg_stats_waiting(stats)) |
629ed0b1 | 506 | return; |
155fead9 | 507 | if (cfqg == curr_cfqg) |
629ed0b1 | 508 | return; |
155fead9 TH |
509 | stats->start_group_wait_time = sched_clock(); |
510 | cfqg_stats_mark_waiting(stats); | |
629ed0b1 TH |
511 | } |
512 | ||
513 | /* This should be called with the queue_lock held. */ | |
155fead9 | 514 | static void cfqg_stats_end_empty_time(struct cfqg_stats *stats) |
629ed0b1 TH |
515 | { |
516 | unsigned long long now; | |
517 | ||
155fead9 | 518 | if (!cfqg_stats_empty(stats)) |
629ed0b1 TH |
519 | return; |
520 | ||
521 | now = sched_clock(); | |
522 | if (time_after64(now, stats->start_empty_time)) | |
523 | blkg_stat_add(&stats->empty_time, | |
524 | now - stats->start_empty_time); | |
155fead9 | 525 | cfqg_stats_clear_empty(stats); |
629ed0b1 TH |
526 | } |
527 | ||
155fead9 | 528 | static void cfqg_stats_update_dequeue(struct cfq_group *cfqg) |
629ed0b1 | 529 | { |
155fead9 | 530 | blkg_stat_add(&cfqg->stats.dequeue, 1); |
629ed0b1 TH |
531 | } |
532 | ||
155fead9 | 533 | static void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) |
629ed0b1 | 534 | { |
155fead9 | 535 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 536 | |
4d5e80a7 | 537 | if (blkg_rwstat_total(&stats->queued)) |
629ed0b1 TH |
538 | return; |
539 | ||
540 | /* | |
541 | * group is already marked empty. This can happen if cfqq got new | |
542 | * request in parent group and moved to this group while being added | |
543 | * to service tree. Just ignore the event and move on. | |
544 | */ | |
155fead9 | 545 | if (cfqg_stats_empty(stats)) |
629ed0b1 TH |
546 | return; |
547 | ||
548 | stats->start_empty_time = sched_clock(); | |
155fead9 | 549 | cfqg_stats_mark_empty(stats); |
629ed0b1 TH |
550 | } |
551 | ||
155fead9 | 552 | static void cfqg_stats_update_idle_time(struct cfq_group *cfqg) |
629ed0b1 | 553 | { |
155fead9 | 554 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 555 | |
155fead9 | 556 | if (cfqg_stats_idling(stats)) { |
629ed0b1 TH |
557 | unsigned long long now = sched_clock(); |
558 | ||
559 | if (time_after64(now, stats->start_idle_time)) | |
560 | blkg_stat_add(&stats->idle_time, | |
561 | now - stats->start_idle_time); | |
155fead9 | 562 | cfqg_stats_clear_idling(stats); |
629ed0b1 TH |
563 | } |
564 | } | |
565 | ||
155fead9 | 566 | static void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) |
629ed0b1 | 567 | { |
155fead9 | 568 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 569 | |
155fead9 | 570 | BUG_ON(cfqg_stats_idling(stats)); |
629ed0b1 TH |
571 | |
572 | stats->start_idle_time = sched_clock(); | |
155fead9 | 573 | cfqg_stats_mark_idling(stats); |
629ed0b1 TH |
574 | } |
575 | ||
155fead9 | 576 | static void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) |
629ed0b1 | 577 | { |
155fead9 | 578 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 TH |
579 | |
580 | blkg_stat_add(&stats->avg_queue_size_sum, | |
4d5e80a7 | 581 | blkg_rwstat_total(&stats->queued)); |
629ed0b1 | 582 | blkg_stat_add(&stats->avg_queue_size_samples, 1); |
155fead9 | 583 | cfqg_stats_update_group_wait_time(stats); |
629ed0b1 TH |
584 | } |
585 | ||
586 | #else /* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */ | |
587 | ||
f48ec1d7 TH |
588 | static inline void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, struct cfq_group *curr_cfqg) { } |
589 | static inline void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { } | |
590 | static inline void cfqg_stats_update_dequeue(struct cfq_group *cfqg) { } | |
591 | static inline void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) { } | |
592 | static inline void cfqg_stats_update_idle_time(struct cfq_group *cfqg) { } | |
593 | static inline void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) { } | |
594 | static inline void cfqg_stats_update_avg_queue_size(struct cfq_group *cfqg) { } | |
629ed0b1 TH |
595 | |
596 | #endif /* CONFIG_CFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */ | |
597 | ||
598 | #ifdef CONFIG_CFQ_GROUP_IOSCHED | |
2ce4d50f | 599 | |
4ceab71b JA |
600 | static inline struct cfq_group *pd_to_cfqg(struct blkg_policy_data *pd) |
601 | { | |
602 | return pd ? container_of(pd, struct cfq_group, pd) : NULL; | |
603 | } | |
604 | ||
605 | static struct cfq_group_data | |
606 | *cpd_to_cfqgd(struct blkcg_policy_data *cpd) | |
607 | { | |
81437648 | 608 | return cpd ? container_of(cpd, struct cfq_group_data, cpd) : NULL; |
4ceab71b JA |
609 | } |
610 | ||
611 | static inline struct blkcg_gq *cfqg_to_blkg(struct cfq_group *cfqg) | |
612 | { | |
613 | return pd_to_blkg(&cfqg->pd); | |
614 | } | |
615 | ||
ffea73fc TH |
616 | static struct blkcg_policy blkcg_policy_cfq; |
617 | ||
618 | static inline struct cfq_group *blkg_to_cfqg(struct blkcg_gq *blkg) | |
619 | { | |
620 | return pd_to_cfqg(blkg_to_pd(blkg, &blkcg_policy_cfq)); | |
621 | } | |
622 | ||
e48453c3 AA |
623 | static struct cfq_group_data *blkcg_to_cfqgd(struct blkcg *blkcg) |
624 | { | |
625 | return cpd_to_cfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_cfq)); | |
626 | } | |
627 | ||
d02f7aa8 | 628 | static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) |
7918ffb5 | 629 | { |
d02f7aa8 | 630 | struct blkcg_gq *pblkg = cfqg_to_blkg(cfqg)->parent; |
7918ffb5 | 631 | |
d02f7aa8 | 632 | return pblkg ? blkg_to_cfqg(pblkg) : NULL; |
7918ffb5 TH |
633 | } |
634 | ||
3984aa55 JK |
635 | static inline bool cfqg_is_descendant(struct cfq_group *cfqg, |
636 | struct cfq_group *ancestor) | |
637 | { | |
638 | return cgroup_is_descendant(cfqg_to_blkg(cfqg)->blkcg->css.cgroup, | |
639 | cfqg_to_blkg(ancestor)->blkcg->css.cgroup); | |
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 | 669 | static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, |
63a4cc24 MC |
670 | struct cfq_group *curr_cfqg, int op, |
671 | int op_flags) | |
2ce4d50f | 672 | { |
63a4cc24 | 673 | blkg_rwstat_add(&cfqg->stats.queued, op, op_flags, 1); |
155fead9 TH |
674 | cfqg_stats_end_empty_time(&cfqg->stats); |
675 | cfqg_stats_set_start_group_wait_time(cfqg, curr_cfqg); | |
2ce4d50f TH |
676 | } |
677 | ||
155fead9 | 678 | static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, |
9a7f38c4 | 679 | uint64_t time, unsigned long unaccounted_time) |
2ce4d50f | 680 | { |
155fead9 | 681 | blkg_stat_add(&cfqg->stats.time, time); |
629ed0b1 | 682 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
155fead9 | 683 | blkg_stat_add(&cfqg->stats.unaccounted_time, unaccounted_time); |
629ed0b1 | 684 | #endif |
2ce4d50f TH |
685 | } |
686 | ||
63a4cc24 MC |
687 | static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int op, |
688 | int op_flags) | |
2ce4d50f | 689 | { |
63a4cc24 | 690 | blkg_rwstat_add(&cfqg->stats.queued, op, op_flags, -1); |
2ce4d50f TH |
691 | } |
692 | ||
63a4cc24 MC |
693 | static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int op, |
694 | int op_flags) | |
2ce4d50f | 695 | { |
63a4cc24 | 696 | blkg_rwstat_add(&cfqg->stats.merged, op, op_flags, 1); |
2ce4d50f TH |
697 | } |
698 | ||
155fead9 | 699 | static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, |
63a4cc24 MC |
700 | uint64_t start_time, uint64_t io_start_time, int op, |
701 | int op_flags) | |
2ce4d50f | 702 | { |
155fead9 | 703 | struct cfqg_stats *stats = &cfqg->stats; |
629ed0b1 | 704 | unsigned long long now = sched_clock(); |
629ed0b1 TH |
705 | |
706 | if (time_after64(now, io_start_time)) | |
63a4cc24 MC |
707 | blkg_rwstat_add(&stats->service_time, op, op_flags, |
708 | now - io_start_time); | |
629ed0b1 | 709 | if (time_after64(io_start_time, start_time)) |
63a4cc24 | 710 | blkg_rwstat_add(&stats->wait_time, op, op_flags, |
629ed0b1 | 711 | io_start_time - start_time); |
2ce4d50f TH |
712 | } |
713 | ||
689665af TH |
714 | /* @stats = 0 */ |
715 | static void cfqg_stats_reset(struct cfqg_stats *stats) | |
155fead9 | 716 | { |
155fead9 | 717 | /* queued stats shouldn't be cleared */ |
155fead9 TH |
718 | blkg_rwstat_reset(&stats->merged); |
719 | blkg_rwstat_reset(&stats->service_time); | |
720 | blkg_rwstat_reset(&stats->wait_time); | |
721 | blkg_stat_reset(&stats->time); | |
722 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
723 | blkg_stat_reset(&stats->unaccounted_time); | |
724 | blkg_stat_reset(&stats->avg_queue_size_sum); | |
725 | blkg_stat_reset(&stats->avg_queue_size_samples); | |
726 | blkg_stat_reset(&stats->dequeue); | |
727 | blkg_stat_reset(&stats->group_wait_time); | |
728 | blkg_stat_reset(&stats->idle_time); | |
729 | blkg_stat_reset(&stats->empty_time); | |
730 | #endif | |
731 | } | |
732 | ||
0b39920b | 733 | /* @to += @from */ |
e6269c44 | 734 | static void cfqg_stats_add_aux(struct cfqg_stats *to, struct cfqg_stats *from) |
0b39920b TH |
735 | { |
736 | /* queued stats shouldn't be cleared */ | |
e6269c44 TH |
737 | blkg_rwstat_add_aux(&to->merged, &from->merged); |
738 | blkg_rwstat_add_aux(&to->service_time, &from->service_time); | |
739 | blkg_rwstat_add_aux(&to->wait_time, &from->wait_time); | |
740 | blkg_stat_add_aux(&from->time, &from->time); | |
0b39920b | 741 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
e6269c44 TH |
742 | blkg_stat_add_aux(&to->unaccounted_time, &from->unaccounted_time); |
743 | blkg_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum); | |
744 | blkg_stat_add_aux(&to->avg_queue_size_samples, &from->avg_queue_size_samples); | |
745 | blkg_stat_add_aux(&to->dequeue, &from->dequeue); | |
746 | blkg_stat_add_aux(&to->group_wait_time, &from->group_wait_time); | |
747 | blkg_stat_add_aux(&to->idle_time, &from->idle_time); | |
748 | blkg_stat_add_aux(&to->empty_time, &from->empty_time); | |
0b39920b TH |
749 | #endif |
750 | } | |
751 | ||
752 | /* | |
e6269c44 | 753 | * Transfer @cfqg's stats to its parent's aux counts so that the ancestors' |
0b39920b TH |
754 | * recursive stats can still account for the amount used by this cfqg after |
755 | * it's gone. | |
756 | */ | |
757 | static void cfqg_stats_xfer_dead(struct cfq_group *cfqg) | |
758 | { | |
759 | struct cfq_group *parent = cfqg_parent(cfqg); | |
760 | ||
761 | lockdep_assert_held(cfqg_to_blkg(cfqg)->q->queue_lock); | |
762 | ||
763 | if (unlikely(!parent)) | |
764 | return; | |
765 | ||
e6269c44 | 766 | cfqg_stats_add_aux(&parent->stats, &cfqg->stats); |
0b39920b | 767 | cfqg_stats_reset(&cfqg->stats); |
0b39920b TH |
768 | } |
769 | ||
eb7d8c07 TH |
770 | #else /* CONFIG_CFQ_GROUP_IOSCHED */ |
771 | ||
d02f7aa8 | 772 | static inline struct cfq_group *cfqg_parent(struct cfq_group *cfqg) { return NULL; } |
3984aa55 JK |
773 | static inline bool cfqg_is_descendant(struct cfq_group *cfqg, |
774 | struct cfq_group *ancestor) | |
775 | { | |
776 | return true; | |
777 | } | |
eb7d8c07 TH |
778 | static inline void cfqg_get(struct cfq_group *cfqg) { } |
779 | static inline void cfqg_put(struct cfq_group *cfqg) { } | |
780 | ||
7b679138 | 781 | #define cfq_log_cfqq(cfqd, cfqq, fmt, args...) \ |
b226e5c4 VG |
782 | blk_add_trace_msg((cfqd)->queue, "cfq%d%c%c " fmt, (cfqq)->pid, \ |
783 | cfq_cfqq_sync((cfqq)) ? 'S' : 'A', \ | |
784 | cfqq_type((cfqq)) == SYNC_NOIDLE_WORKLOAD ? 'N' : ' ',\ | |
785 | ##args) | |
4495a7d4 | 786 | #define cfq_log_cfqg(cfqd, cfqg, fmt, args...) do {} while (0) |
eb7d8c07 | 787 | |
155fead9 | 788 | static inline void cfqg_stats_update_io_add(struct cfq_group *cfqg, |
63a4cc24 | 789 | struct cfq_group *curr_cfqg, int op, int op_flags) { } |
155fead9 | 790 | static inline void cfqg_stats_update_timeslice_used(struct cfq_group *cfqg, |
9a7f38c4 | 791 | uint64_t time, unsigned long unaccounted_time) { } |
63a4cc24 MC |
792 | static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, int op, |
793 | int op_flags) { } | |
794 | static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, int op, | |
795 | int op_flags) { } | |
155fead9 | 796 | static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, |
63a4cc24 MC |
797 | uint64_t start_time, uint64_t io_start_time, int op, |
798 | int op_flags) { } | |
2ce4d50f | 799 | |
eb7d8c07 TH |
800 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ |
801 | ||
7b679138 JA |
802 | #define cfq_log(cfqd, fmt, args...) \ |
803 | blk_add_trace_msg((cfqd)->queue, "cfq " fmt, ##args) | |
804 | ||
615f0259 VG |
805 | /* Traverses through cfq group service trees */ |
806 | #define for_each_cfqg_st(cfqg, i, j, st) \ | |
807 | for (i = 0; i <= IDLE_WORKLOAD; i++) \ | |
808 | for (j = 0, st = i < IDLE_WORKLOAD ? &cfqg->service_trees[i][j]\ | |
809 | : &cfqg->service_tree_idle; \ | |
810 | (i < IDLE_WORKLOAD && j <= SYNC_WORKLOAD) || \ | |
811 | (i == IDLE_WORKLOAD && j == 0); \ | |
812 | j++, st = i < IDLE_WORKLOAD ? \ | |
813 | &cfqg->service_trees[i][j]: NULL) \ | |
814 | ||
f5f2b6ce SL |
815 | static inline bool cfq_io_thinktime_big(struct cfq_data *cfqd, |
816 | struct cfq_ttime *ttime, bool group_idle) | |
817 | { | |
9a7f38c4 | 818 | u64 slice; |
f5f2b6ce SL |
819 | if (!sample_valid(ttime->ttime_samples)) |
820 | return false; | |
821 | if (group_idle) | |
822 | slice = cfqd->cfq_group_idle; | |
823 | else | |
824 | slice = cfqd->cfq_slice_idle; | |
825 | return ttime->ttime_mean > slice; | |
826 | } | |
615f0259 | 827 | |
02b35081 VG |
828 | static inline bool iops_mode(struct cfq_data *cfqd) |
829 | { | |
830 | /* | |
831 | * If we are not idling on queues and it is a NCQ drive, parallel | |
832 | * execution of requests is on and measuring time is not possible | |
833 | * in most of the cases until and unless we drive shallower queue | |
834 | * depths and that becomes a performance bottleneck. In such cases | |
835 | * switch to start providing fairness in terms of number of IOs. | |
836 | */ | |
837 | if (!cfqd->cfq_slice_idle && cfqd->hw_tag) | |
838 | return true; | |
839 | else | |
840 | return false; | |
841 | } | |
842 | ||
3bf10fea | 843 | static inline enum wl_class_t cfqq_class(struct cfq_queue *cfqq) |
c0324a02 CZ |
844 | { |
845 | if (cfq_class_idle(cfqq)) | |
846 | return IDLE_WORKLOAD; | |
847 | if (cfq_class_rt(cfqq)) | |
848 | return RT_WORKLOAD; | |
849 | return BE_WORKLOAD; | |
850 | } | |
851 | ||
718eee05 CZ |
852 | |
853 | static enum wl_type_t cfqq_type(struct cfq_queue *cfqq) | |
854 | { | |
855 | if (!cfq_cfqq_sync(cfqq)) | |
856 | return ASYNC_WORKLOAD; | |
857 | if (!cfq_cfqq_idle_window(cfqq)) | |
858 | return SYNC_NOIDLE_WORKLOAD; | |
859 | return SYNC_WORKLOAD; | |
860 | } | |
861 | ||
3bf10fea | 862 | static inline int cfq_group_busy_queues_wl(enum wl_class_t wl_class, |
58ff82f3 VG |
863 | struct cfq_data *cfqd, |
864 | struct cfq_group *cfqg) | |
c0324a02 | 865 | { |
3bf10fea | 866 | if (wl_class == IDLE_WORKLOAD) |
cdb16e8f | 867 | return cfqg->service_tree_idle.count; |
c0324a02 | 868 | |
34b98d03 VG |
869 | return cfqg->service_trees[wl_class][ASYNC_WORKLOAD].count + |
870 | cfqg->service_trees[wl_class][SYNC_NOIDLE_WORKLOAD].count + | |
871 | cfqg->service_trees[wl_class][SYNC_WORKLOAD].count; | |
c0324a02 CZ |
872 | } |
873 | ||
f26bd1f0 VG |
874 | static inline int cfqg_busy_async_queues(struct cfq_data *cfqd, |
875 | struct cfq_group *cfqg) | |
876 | { | |
34b98d03 VG |
877 | return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count + |
878 | cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count; | |
f26bd1f0 VG |
879 | } |
880 | ||
165125e1 | 881 | static void cfq_dispatch_insert(struct request_queue *, struct request *); |
4f85cb96 | 882 | static struct cfq_queue *cfq_get_queue(struct cfq_data *cfqd, bool is_sync, |
2da8de0b | 883 | struct cfq_io_cq *cic, struct bio *bio); |
91fac317 | 884 | |
c5869807 TH |
885 | static inline struct cfq_io_cq *icq_to_cic(struct io_cq *icq) |
886 | { | |
887 | /* cic->icq is the first member, %NULL will convert to %NULL */ | |
888 | return container_of(icq, struct cfq_io_cq, icq); | |
889 | } | |
890 | ||
47fdd4ca TH |
891 | static inline struct cfq_io_cq *cfq_cic_lookup(struct cfq_data *cfqd, |
892 | struct io_context *ioc) | |
893 | { | |
894 | if (ioc) | |
895 | return icq_to_cic(ioc_lookup_icq(ioc, cfqd->queue)); | |
896 | return NULL; | |
897 | } | |
898 | ||
c5869807 | 899 | static inline struct cfq_queue *cic_to_cfqq(struct cfq_io_cq *cic, bool is_sync) |
91fac317 | 900 | { |
a6151c3a | 901 | return cic->cfqq[is_sync]; |
91fac317 VT |
902 | } |
903 | ||
c5869807 TH |
904 | static inline void cic_set_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq, |
905 | bool is_sync) | |
91fac317 | 906 | { |
a6151c3a | 907 | cic->cfqq[is_sync] = cfqq; |
91fac317 VT |
908 | } |
909 | ||
c5869807 | 910 | static inline struct cfq_data *cic_to_cfqd(struct cfq_io_cq *cic) |
bca4b914 | 911 | { |
c5869807 | 912 | return cic->icq.q->elevator->elevator_data; |
bca4b914 KK |
913 | } |
914 | ||
91fac317 VT |
915 | /* |
916 | * We regard a request as SYNC, if it's either a read or has the SYNC bit | |
917 | * set (in which case it could also be direct WRITE). | |
918 | */ | |
a6151c3a | 919 | static inline bool cfq_bio_sync(struct bio *bio) |
91fac317 | 920 | { |
7b6d91da | 921 | return bio_data_dir(bio) == READ || (bio->bi_rw & REQ_SYNC); |
91fac317 | 922 | } |
1da177e4 | 923 | |
99f95e52 AM |
924 | /* |
925 | * scheduler run of queue, if there are requests pending and no one in the | |
926 | * driver that will restart queueing | |
927 | */ | |
23e018a1 | 928 | static inline void cfq_schedule_dispatch(struct cfq_data *cfqd) |
99f95e52 | 929 | { |
7b679138 JA |
930 | if (cfqd->busy_queues) { |
931 | cfq_log(cfqd, "schedule dispatch"); | |
59c3d45e | 932 | kblockd_schedule_work(&cfqd->unplug_work); |
7b679138 | 933 | } |
99f95e52 AM |
934 | } |
935 | ||
44f7c160 JA |
936 | /* |
937 | * Scale schedule slice based on io priority. Use the sync time slice only | |
938 | * if a queue is marked sync and has sync io queued. A sync queue with async | |
939 | * io only, should not get full sync slice length. | |
940 | */ | |
9a7f38c4 | 941 | static inline u64 cfq_prio_slice(struct cfq_data *cfqd, bool sync, |
d9e7620e | 942 | unsigned short prio) |
44f7c160 | 943 | { |
9a7f38c4 JM |
944 | u64 base_slice = cfqd->cfq_slice[sync]; |
945 | u64 slice = div_u64(base_slice, CFQ_SLICE_SCALE); | |
44f7c160 | 946 | |
d9e7620e JA |
947 | WARN_ON(prio >= IOPRIO_BE_NR); |
948 | ||
9a7f38c4 | 949 | return base_slice + (slice * (4 - prio)); |
d9e7620e | 950 | } |
44f7c160 | 951 | |
9a7f38c4 | 952 | static inline u64 |
d9e7620e JA |
953 | cfq_prio_to_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
954 | { | |
955 | return cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio); | |
44f7c160 JA |
956 | } |
957 | ||
1d3650f7 TH |
958 | /** |
959 | * cfqg_scale_charge - scale disk time charge according to cfqg weight | |
960 | * @charge: disk time being charged | |
961 | * @vfraction: vfraction of the cfqg, fixed point w/ CFQ_SERVICE_SHIFT | |
962 | * | |
963 | * Scale @charge according to @vfraction, which is in range (0, 1]. The | |
964 | * scaling is inversely proportional. | |
965 | * | |
966 | * scaled = charge / vfraction | |
967 | * | |
968 | * The result is also in fixed point w/ CFQ_SERVICE_SHIFT. | |
969 | */ | |
9a7f38c4 | 970 | static inline u64 cfqg_scale_charge(u64 charge, |
1d3650f7 | 971 | unsigned int vfraction) |
25bc6b07 | 972 | { |
1d3650f7 | 973 | u64 c = charge << CFQ_SERVICE_SHIFT; /* make it fixed point */ |
25bc6b07 | 974 | |
1d3650f7 TH |
975 | /* charge / vfraction */ |
976 | c <<= CFQ_SERVICE_SHIFT; | |
9a7f38c4 | 977 | return div_u64(c, vfraction); |
25bc6b07 VG |
978 | } |
979 | ||
980 | static inline u64 max_vdisktime(u64 min_vdisktime, u64 vdisktime) | |
981 | { | |
982 | s64 delta = (s64)(vdisktime - min_vdisktime); | |
983 | if (delta > 0) | |
984 | min_vdisktime = vdisktime; | |
985 | ||
986 | return min_vdisktime; | |
987 | } | |
988 | ||
989 | static inline u64 min_vdisktime(u64 min_vdisktime, u64 vdisktime) | |
990 | { | |
991 | s64 delta = (s64)(vdisktime - min_vdisktime); | |
992 | if (delta < 0) | |
993 | min_vdisktime = vdisktime; | |
994 | ||
995 | return min_vdisktime; | |
996 | } | |
997 | ||
998 | static void update_min_vdisktime(struct cfq_rb_root *st) | |
999 | { | |
25bc6b07 VG |
1000 | struct cfq_group *cfqg; |
1001 | ||
25bc6b07 VG |
1002 | if (st->left) { |
1003 | cfqg = rb_entry_cfqg(st->left); | |
a6032710 GJ |
1004 | st->min_vdisktime = max_vdisktime(st->min_vdisktime, |
1005 | cfqg->vdisktime); | |
25bc6b07 | 1006 | } |
25bc6b07 VG |
1007 | } |
1008 | ||
5db5d642 CZ |
1009 | /* |
1010 | * get averaged number of queues of RT/BE priority. | |
1011 | * average is updated, with a formula that gives more weight to higher numbers, | |
1012 | * to quickly follows sudden increases and decrease slowly | |
1013 | */ | |
1014 | ||
58ff82f3 VG |
1015 | static inline unsigned cfq_group_get_avg_queues(struct cfq_data *cfqd, |
1016 | struct cfq_group *cfqg, bool rt) | |
5869619c | 1017 | { |
5db5d642 CZ |
1018 | unsigned min_q, max_q; |
1019 | unsigned mult = cfq_hist_divisor - 1; | |
1020 | unsigned round = cfq_hist_divisor / 2; | |
58ff82f3 | 1021 | unsigned busy = cfq_group_busy_queues_wl(rt, cfqd, cfqg); |
5db5d642 | 1022 | |
58ff82f3 VG |
1023 | min_q = min(cfqg->busy_queues_avg[rt], busy); |
1024 | max_q = max(cfqg->busy_queues_avg[rt], busy); | |
1025 | cfqg->busy_queues_avg[rt] = (mult * max_q + min_q + round) / | |
5db5d642 | 1026 | cfq_hist_divisor; |
58ff82f3 VG |
1027 | return cfqg->busy_queues_avg[rt]; |
1028 | } | |
1029 | ||
9a7f38c4 | 1030 | static inline u64 |
58ff82f3 VG |
1031 | cfq_group_slice(struct cfq_data *cfqd, struct cfq_group *cfqg) |
1032 | { | |
41cad6ab | 1033 | return cfqd->cfq_target_latency * cfqg->vfraction >> CFQ_SERVICE_SHIFT; |
5db5d642 CZ |
1034 | } |
1035 | ||
9a7f38c4 | 1036 | static inline u64 |
ba5bd520 | 1037 | cfq_scaled_cfqq_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
44f7c160 | 1038 | { |
9a7f38c4 | 1039 | u64 slice = cfq_prio_to_slice(cfqd, cfqq); |
5db5d642 | 1040 | if (cfqd->cfq_latency) { |
58ff82f3 VG |
1041 | /* |
1042 | * interested queues (we consider only the ones with the same | |
1043 | * priority class in the cfq group) | |
1044 | */ | |
1045 | unsigned iq = cfq_group_get_avg_queues(cfqd, cfqq->cfqg, | |
1046 | cfq_class_rt(cfqq)); | |
9a7f38c4 JM |
1047 | u64 sync_slice = cfqd->cfq_slice[1]; |
1048 | u64 expect_latency = sync_slice * iq; | |
1049 | u64 group_slice = cfq_group_slice(cfqd, cfqq->cfqg); | |
58ff82f3 VG |
1050 | |
1051 | if (expect_latency > group_slice) { | |
9a7f38c4 JM |
1052 | u64 base_low_slice = 2 * cfqd->cfq_slice_idle; |
1053 | u64 low_slice; | |
1054 | ||
5db5d642 CZ |
1055 | /* scale low_slice according to IO priority |
1056 | * and sync vs async */ | |
9a7f38c4 JM |
1057 | low_slice = div64_u64(base_low_slice*slice, sync_slice); |
1058 | low_slice = min(slice, low_slice); | |
5db5d642 CZ |
1059 | /* the adapted slice value is scaled to fit all iqs |
1060 | * into the target latency */ | |
9a7f38c4 JM |
1061 | slice = div64_u64(slice*group_slice, expect_latency); |
1062 | slice = max(slice, low_slice); | |
5db5d642 CZ |
1063 | } |
1064 | } | |
c553f8e3 SL |
1065 | return slice; |
1066 | } | |
1067 | ||
1068 | static inline void | |
1069 | cfq_set_prio_slice(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
1070 | { | |
9a7f38c4 JM |
1071 | u64 slice = cfq_scaled_cfqq_slice(cfqd, cfqq); |
1072 | u64 now = ktime_get_ns(); | |
c553f8e3 | 1073 | |
9a7f38c4 JM |
1074 | cfqq->slice_start = now; |
1075 | cfqq->slice_end = now + slice; | |
f75edf2d | 1076 | cfqq->allocated_slice = slice; |
9a7f38c4 | 1077 | cfq_log_cfqq(cfqd, cfqq, "set_slice=%llu", cfqq->slice_end - now); |
44f7c160 JA |
1078 | } |
1079 | ||
1080 | /* | |
1081 | * We need to wrap this check in cfq_cfqq_slice_new(), since ->slice_end | |
1082 | * isn't valid until the first request from the dispatch is activated | |
1083 | * and the slice time set. | |
1084 | */ | |
a6151c3a | 1085 | static inline bool cfq_slice_used(struct cfq_queue *cfqq) |
44f7c160 JA |
1086 | { |
1087 | if (cfq_cfqq_slice_new(cfqq)) | |
c1e44756 | 1088 | return false; |
9a7f38c4 | 1089 | if (ktime_get_ns() < cfqq->slice_end) |
c1e44756 | 1090 | return false; |
44f7c160 | 1091 | |
c1e44756 | 1092 | return true; |
44f7c160 JA |
1093 | } |
1094 | ||
1da177e4 | 1095 | /* |
5e705374 | 1096 | * Lifted from AS - choose which of rq1 and rq2 that is best served now. |
1da177e4 | 1097 | * We choose the request that is closest to the head right now. Distance |
e8a99053 | 1098 | * behind the head is penalized and only allowed to a certain extent. |
1da177e4 | 1099 | */ |
5e705374 | 1100 | static struct request * |
cf7c25cf | 1101 | cfq_choose_req(struct cfq_data *cfqd, struct request *rq1, struct request *rq2, sector_t last) |
1da177e4 | 1102 | { |
cf7c25cf | 1103 | sector_t s1, s2, d1 = 0, d2 = 0; |
1da177e4 | 1104 | unsigned long back_max; |
e8a99053 AM |
1105 | #define CFQ_RQ1_WRAP 0x01 /* request 1 wraps */ |
1106 | #define CFQ_RQ2_WRAP 0x02 /* request 2 wraps */ | |
1107 | unsigned wrap = 0; /* bit mask: requests behind the disk head? */ | |
1da177e4 | 1108 | |
5e705374 JA |
1109 | if (rq1 == NULL || rq1 == rq2) |
1110 | return rq2; | |
1111 | if (rq2 == NULL) | |
1112 | return rq1; | |
9c2c38a1 | 1113 | |
229836bd NK |
1114 | if (rq_is_sync(rq1) != rq_is_sync(rq2)) |
1115 | return rq_is_sync(rq1) ? rq1 : rq2; | |
1116 | ||
65299a3b CH |
1117 | if ((rq1->cmd_flags ^ rq2->cmd_flags) & REQ_PRIO) |
1118 | return rq1->cmd_flags & REQ_PRIO ? rq1 : rq2; | |
b53d1ed7 | 1119 | |
83096ebf TH |
1120 | s1 = blk_rq_pos(rq1); |
1121 | s2 = blk_rq_pos(rq2); | |
1da177e4 | 1122 | |
1da177e4 LT |
1123 | /* |
1124 | * by definition, 1KiB is 2 sectors | |
1125 | */ | |
1126 | back_max = cfqd->cfq_back_max * 2; | |
1127 | ||
1128 | /* | |
1129 | * Strict one way elevator _except_ in the case where we allow | |
1130 | * short backward seeks which are biased as twice the cost of a | |
1131 | * similar forward seek. | |
1132 | */ | |
1133 | if (s1 >= last) | |
1134 | d1 = s1 - last; | |
1135 | else if (s1 + back_max >= last) | |
1136 | d1 = (last - s1) * cfqd->cfq_back_penalty; | |
1137 | else | |
e8a99053 | 1138 | wrap |= CFQ_RQ1_WRAP; |
1da177e4 LT |
1139 | |
1140 | if (s2 >= last) | |
1141 | d2 = s2 - last; | |
1142 | else if (s2 + back_max >= last) | |
1143 | d2 = (last - s2) * cfqd->cfq_back_penalty; | |
1144 | else | |
e8a99053 | 1145 | wrap |= CFQ_RQ2_WRAP; |
1da177e4 LT |
1146 | |
1147 | /* Found required data */ | |
e8a99053 AM |
1148 | |
1149 | /* | |
1150 | * By doing switch() on the bit mask "wrap" we avoid having to | |
1151 | * check two variables for all permutations: --> faster! | |
1152 | */ | |
1153 | switch (wrap) { | |
5e705374 | 1154 | case 0: /* common case for CFQ: rq1 and rq2 not wrapped */ |
e8a99053 | 1155 | if (d1 < d2) |
5e705374 | 1156 | return rq1; |
e8a99053 | 1157 | else if (d2 < d1) |
5e705374 | 1158 | return rq2; |
e8a99053 AM |
1159 | else { |
1160 | if (s1 >= s2) | |
5e705374 | 1161 | return rq1; |
e8a99053 | 1162 | else |
5e705374 | 1163 | return rq2; |
e8a99053 | 1164 | } |
1da177e4 | 1165 | |
e8a99053 | 1166 | case CFQ_RQ2_WRAP: |
5e705374 | 1167 | return rq1; |
e8a99053 | 1168 | case CFQ_RQ1_WRAP: |
5e705374 JA |
1169 | return rq2; |
1170 | case (CFQ_RQ1_WRAP|CFQ_RQ2_WRAP): /* both rqs wrapped */ | |
e8a99053 AM |
1171 | default: |
1172 | /* | |
1173 | * Since both rqs are wrapped, | |
1174 | * start with the one that's further behind head | |
1175 | * (--> only *one* back seek required), | |
1176 | * since back seek takes more time than forward. | |
1177 | */ | |
1178 | if (s1 <= s2) | |
5e705374 | 1179 | return rq1; |
1da177e4 | 1180 | else |
5e705374 | 1181 | return rq2; |
1da177e4 LT |
1182 | } |
1183 | } | |
1184 | ||
498d3aa2 JA |
1185 | /* |
1186 | * The below is leftmost cache rbtree addon | |
1187 | */ | |
0871714e | 1188 | static struct cfq_queue *cfq_rb_first(struct cfq_rb_root *root) |
cc09e299 | 1189 | { |
615f0259 VG |
1190 | /* Service tree is empty */ |
1191 | if (!root->count) | |
1192 | return NULL; | |
1193 | ||
cc09e299 JA |
1194 | if (!root->left) |
1195 | root->left = rb_first(&root->rb); | |
1196 | ||
0871714e JA |
1197 | if (root->left) |
1198 | return rb_entry(root->left, struct cfq_queue, rb_node); | |
1199 | ||
1200 | return NULL; | |
cc09e299 JA |
1201 | } |
1202 | ||
1fa8f6d6 VG |
1203 | static struct cfq_group *cfq_rb_first_group(struct cfq_rb_root *root) |
1204 | { | |
1205 | if (!root->left) | |
1206 | root->left = rb_first(&root->rb); | |
1207 | ||
1208 | if (root->left) | |
1209 | return rb_entry_cfqg(root->left); | |
1210 | ||
1211 | return NULL; | |
1212 | } | |
1213 | ||
a36e71f9 JA |
1214 | static void rb_erase_init(struct rb_node *n, struct rb_root *root) |
1215 | { | |
1216 | rb_erase(n, root); | |
1217 | RB_CLEAR_NODE(n); | |
1218 | } | |
1219 | ||
cc09e299 JA |
1220 | static void cfq_rb_erase(struct rb_node *n, struct cfq_rb_root *root) |
1221 | { | |
1222 | if (root->left == n) | |
1223 | root->left = NULL; | |
a36e71f9 | 1224 | rb_erase_init(n, &root->rb); |
aa6f6a3d | 1225 | --root->count; |
cc09e299 JA |
1226 | } |
1227 | ||
1da177e4 LT |
1228 | /* |
1229 | * would be nice to take fifo expire time into account as well | |
1230 | */ | |
5e705374 JA |
1231 | static struct request * |
1232 | cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
1233 | struct request *last) | |
1da177e4 | 1234 | { |
21183b07 JA |
1235 | struct rb_node *rbnext = rb_next(&last->rb_node); |
1236 | struct rb_node *rbprev = rb_prev(&last->rb_node); | |
5e705374 | 1237 | struct request *next = NULL, *prev = NULL; |
1da177e4 | 1238 | |
21183b07 | 1239 | BUG_ON(RB_EMPTY_NODE(&last->rb_node)); |
1da177e4 LT |
1240 | |
1241 | if (rbprev) | |
5e705374 | 1242 | prev = rb_entry_rq(rbprev); |
1da177e4 | 1243 | |
21183b07 | 1244 | if (rbnext) |
5e705374 | 1245 | next = rb_entry_rq(rbnext); |
21183b07 JA |
1246 | else { |
1247 | rbnext = rb_first(&cfqq->sort_list); | |
1248 | if (rbnext && rbnext != &last->rb_node) | |
5e705374 | 1249 | next = rb_entry_rq(rbnext); |
21183b07 | 1250 | } |
1da177e4 | 1251 | |
cf7c25cf | 1252 | return cfq_choose_req(cfqd, next, prev, blk_rq_pos(last)); |
1da177e4 LT |
1253 | } |
1254 | ||
9a7f38c4 JM |
1255 | static u64 cfq_slice_offset(struct cfq_data *cfqd, |
1256 | struct cfq_queue *cfqq) | |
1da177e4 | 1257 | { |
d9e7620e JA |
1258 | /* |
1259 | * just an approximation, should be ok. | |
1260 | */ | |
cdb16e8f | 1261 | return (cfqq->cfqg->nr_cfqq - 1) * (cfq_prio_slice(cfqd, 1, 0) - |
464191c6 | 1262 | cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); |
d9e7620e JA |
1263 | } |
1264 | ||
1fa8f6d6 VG |
1265 | static inline s64 |
1266 | cfqg_key(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1267 | { | |
1268 | return cfqg->vdisktime - st->min_vdisktime; | |
1269 | } | |
1270 | ||
1271 | static void | |
1272 | __cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1273 | { | |
1274 | struct rb_node **node = &st->rb.rb_node; | |
1275 | struct rb_node *parent = NULL; | |
1276 | struct cfq_group *__cfqg; | |
1277 | s64 key = cfqg_key(st, cfqg); | |
1278 | int left = 1; | |
1279 | ||
1280 | while (*node != NULL) { | |
1281 | parent = *node; | |
1282 | __cfqg = rb_entry_cfqg(parent); | |
1283 | ||
1284 | if (key < cfqg_key(st, __cfqg)) | |
1285 | node = &parent->rb_left; | |
1286 | else { | |
1287 | node = &parent->rb_right; | |
1288 | left = 0; | |
1289 | } | |
1290 | } | |
1291 | ||
1292 | if (left) | |
1293 | st->left = &cfqg->rb_node; | |
1294 | ||
1295 | rb_link_node(&cfqg->rb_node, parent, node); | |
1296 | rb_insert_color(&cfqg->rb_node, &st->rb); | |
1297 | } | |
1298 | ||
7b5af5cf TM |
1299 | /* |
1300 | * This has to be called only on activation of cfqg | |
1301 | */ | |
1fa8f6d6 | 1302 | static void |
8184f93e JT |
1303 | cfq_update_group_weight(struct cfq_group *cfqg) |
1304 | { | |
3381cb8d | 1305 | if (cfqg->new_weight) { |
8184f93e | 1306 | cfqg->weight = cfqg->new_weight; |
3381cb8d | 1307 | cfqg->new_weight = 0; |
8184f93e | 1308 | } |
e15693ef TM |
1309 | } |
1310 | ||
1311 | static void | |
1312 | cfq_update_group_leaf_weight(struct cfq_group *cfqg) | |
1313 | { | |
1314 | BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node)); | |
e71357e1 TH |
1315 | |
1316 | if (cfqg->new_leaf_weight) { | |
1317 | cfqg->leaf_weight = cfqg->new_leaf_weight; | |
1318 | cfqg->new_leaf_weight = 0; | |
1319 | } | |
8184f93e JT |
1320 | } |
1321 | ||
1322 | static void | |
1323 | cfq_group_service_tree_add(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1324 | { | |
1d3650f7 | 1325 | unsigned int vfr = 1 << CFQ_SERVICE_SHIFT; /* start with 1 */ |
7918ffb5 | 1326 | struct cfq_group *pos = cfqg; |
1d3650f7 | 1327 | struct cfq_group *parent; |
7918ffb5 TH |
1328 | bool propagate; |
1329 | ||
1330 | /* add to the service tree */ | |
8184f93e JT |
1331 | BUG_ON(!RB_EMPTY_NODE(&cfqg->rb_node)); |
1332 | ||
7b5af5cf TM |
1333 | /* |
1334 | * Update leaf_weight. We cannot update weight at this point | |
1335 | * because cfqg might already have been activated and is | |
1336 | * contributing its current weight to the parent's child_weight. | |
1337 | */ | |
e15693ef | 1338 | cfq_update_group_leaf_weight(cfqg); |
8184f93e | 1339 | __cfq_group_service_tree_add(st, cfqg); |
7918ffb5 TH |
1340 | |
1341 | /* | |
1d3650f7 TH |
1342 | * Activate @cfqg and calculate the portion of vfraction @cfqg is |
1343 | * entitled to. vfraction is calculated by walking the tree | |
1344 | * towards the root calculating the fraction it has at each level. | |
1345 | * The compounded ratio is how much vfraction @cfqg owns. | |
1346 | * | |
1347 | * Start with the proportion tasks in this cfqg has against active | |
1348 | * children cfqgs - its leaf_weight against children_weight. | |
7918ffb5 TH |
1349 | */ |
1350 | propagate = !pos->nr_active++; | |
1351 | pos->children_weight += pos->leaf_weight; | |
1d3650f7 | 1352 | vfr = vfr * pos->leaf_weight / pos->children_weight; |
7918ffb5 | 1353 | |
1d3650f7 TH |
1354 | /* |
1355 | * Compound ->weight walking up the tree. Both activation and | |
1356 | * vfraction calculation are done in the same loop. Propagation | |
1357 | * stops once an already activated node is met. vfraction | |
1358 | * calculation should always continue to the root. | |
1359 | */ | |
d02f7aa8 | 1360 | while ((parent = cfqg_parent(pos))) { |
1d3650f7 | 1361 | if (propagate) { |
e15693ef | 1362 | cfq_update_group_weight(pos); |
1d3650f7 TH |
1363 | propagate = !parent->nr_active++; |
1364 | parent->children_weight += pos->weight; | |
1365 | } | |
1366 | vfr = vfr * pos->weight / parent->children_weight; | |
7918ffb5 TH |
1367 | pos = parent; |
1368 | } | |
1d3650f7 TH |
1369 | |
1370 | cfqg->vfraction = max_t(unsigned, vfr, 1); | |
8184f93e JT |
1371 | } |
1372 | ||
1373 | static void | |
1374 | cfq_group_notify_queue_add(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
1fa8f6d6 VG |
1375 | { |
1376 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
1377 | struct cfq_group *__cfqg; | |
1378 | struct rb_node *n; | |
1379 | ||
1380 | cfqg->nr_cfqq++; | |
760701bf | 1381 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
1fa8f6d6 VG |
1382 | return; |
1383 | ||
1384 | /* | |
1385 | * Currently put the group at the end. Later implement something | |
1386 | * so that groups get lesser vtime based on their weights, so that | |
25985edc | 1387 | * if group does not loose all if it was not continuously backlogged. |
1fa8f6d6 VG |
1388 | */ |
1389 | n = rb_last(&st->rb); | |
1390 | if (n) { | |
1391 | __cfqg = rb_entry_cfqg(n); | |
1392 | cfqg->vdisktime = __cfqg->vdisktime + CFQ_IDLE_DELAY; | |
1393 | } else | |
1394 | cfqg->vdisktime = st->min_vdisktime; | |
8184f93e JT |
1395 | cfq_group_service_tree_add(st, cfqg); |
1396 | } | |
1fa8f6d6 | 1397 | |
8184f93e JT |
1398 | static void |
1399 | cfq_group_service_tree_del(struct cfq_rb_root *st, struct cfq_group *cfqg) | |
1400 | { | |
7918ffb5 TH |
1401 | struct cfq_group *pos = cfqg; |
1402 | bool propagate; | |
1403 | ||
1404 | /* | |
1405 | * Undo activation from cfq_group_service_tree_add(). Deactivate | |
1406 | * @cfqg and propagate deactivation upwards. | |
1407 | */ | |
1408 | propagate = !--pos->nr_active; | |
1409 | pos->children_weight -= pos->leaf_weight; | |
1410 | ||
1411 | while (propagate) { | |
d02f7aa8 | 1412 | struct cfq_group *parent = cfqg_parent(pos); |
7918ffb5 TH |
1413 | |
1414 | /* @pos has 0 nr_active at this point */ | |
1415 | WARN_ON_ONCE(pos->children_weight); | |
1d3650f7 | 1416 | pos->vfraction = 0; |
7918ffb5 TH |
1417 | |
1418 | if (!parent) | |
1419 | break; | |
1420 | ||
1421 | propagate = !--parent->nr_active; | |
1422 | parent->children_weight -= pos->weight; | |
1423 | pos = parent; | |
1424 | } | |
1425 | ||
1426 | /* remove from the service tree */ | |
8184f93e JT |
1427 | if (!RB_EMPTY_NODE(&cfqg->rb_node)) |
1428 | cfq_rb_erase(&cfqg->rb_node, st); | |
1fa8f6d6 VG |
1429 | } |
1430 | ||
1431 | static void | |
8184f93e | 1432 | cfq_group_notify_queue_del(struct cfq_data *cfqd, struct cfq_group *cfqg) |
1fa8f6d6 VG |
1433 | { |
1434 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
1435 | ||
1436 | BUG_ON(cfqg->nr_cfqq < 1); | |
1437 | cfqg->nr_cfqq--; | |
25bc6b07 | 1438 | |
1fa8f6d6 VG |
1439 | /* If there are other cfq queues under this group, don't delete it */ |
1440 | if (cfqg->nr_cfqq) | |
1441 | return; | |
1442 | ||
2868ef7b | 1443 | cfq_log_cfqg(cfqd, cfqg, "del_from_rr group"); |
8184f93e | 1444 | cfq_group_service_tree_del(st, cfqg); |
4d2ceea4 | 1445 | cfqg->saved_wl_slice = 0; |
155fead9 | 1446 | cfqg_stats_update_dequeue(cfqg); |
dae739eb VG |
1447 | } |
1448 | ||
9a7f38c4 JM |
1449 | static inline u64 cfq_cfqq_slice_usage(struct cfq_queue *cfqq, |
1450 | u64 *unaccounted_time) | |
dae739eb | 1451 | { |
9a7f38c4 JM |
1452 | u64 slice_used; |
1453 | u64 now = ktime_get_ns(); | |
dae739eb VG |
1454 | |
1455 | /* | |
1456 | * Queue got expired before even a single request completed or | |
1457 | * got expired immediately after first request completion. | |
1458 | */ | |
9a7f38c4 | 1459 | if (!cfqq->slice_start || cfqq->slice_start == now) { |
dae739eb VG |
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 | */ | |
9a7f38c4 | 1466 | slice_used = max_t(u64, (now - cfqq->dispatch_start), 1); |
dae739eb | 1467 | } else { |
9a7f38c4 | 1468 | slice_used = now - cfqq->slice_start; |
167400d3 JT |
1469 | if (slice_used > cfqq->allocated_slice) { |
1470 | *unaccounted_time = slice_used - cfqq->allocated_slice; | |
f75edf2d | 1471 | slice_used = cfqq->allocated_slice; |
167400d3 | 1472 | } |
9a7f38c4 | 1473 | if (cfqq->slice_start > cfqq->dispatch_start) |
167400d3 JT |
1474 | *unaccounted_time += cfqq->slice_start - |
1475 | cfqq->dispatch_start; | |
dae739eb VG |
1476 | } |
1477 | ||
dae739eb VG |
1478 | return slice_used; |
1479 | } | |
1480 | ||
1481 | static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg, | |
e5ff082e | 1482 | struct cfq_queue *cfqq) |
dae739eb VG |
1483 | { |
1484 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
9a7f38c4 | 1485 | u64 used_sl, charge, unaccounted_sl = 0; |
f26bd1f0 VG |
1486 | int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg) |
1487 | - cfqg->service_tree_idle.count; | |
1d3650f7 | 1488 | unsigned int vfr; |
9a7f38c4 | 1489 | u64 now = ktime_get_ns(); |
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 */ | |
9a7f38c4 JM |
1511 | if (cfqd->workload_expires > now) { |
1512 | cfqg->saved_wl_slice = cfqd->workload_expires - now; | |
4d2ceea4 VG |
1513 | cfqg->saved_wl_type = cfqd->serving_wl_type; |
1514 | cfqg->saved_wl_class = cfqd->serving_wl_class; | |
dae739eb | 1515 | } else |
4d2ceea4 | 1516 | cfqg->saved_wl_slice = 0; |
2868ef7b VG |
1517 | |
1518 | cfq_log_cfqg(cfqd, cfqg, "served: vt=%llu min_vt=%llu", cfqg->vdisktime, | |
1519 | st->min_vdisktime); | |
fd16d263 | 1520 | cfq_log_cfqq(cfqq->cfqd, cfqq, |
9a7f38c4 | 1521 | "sl_used=%llu disp=%llu charge=%llu iops=%u sect=%lu", |
fd16d263 JP |
1522 | used_sl, cfqq->slice_dispatch, charge, |
1523 | iops_mode(cfqd), cfqq->nr_sectors); | |
155fead9 TH |
1524 | cfqg_stats_update_timeslice_used(cfqg, used_sl, unaccounted_sl); |
1525 | cfqg_stats_set_start_empty_time(cfqg); | |
1fa8f6d6 VG |
1526 | } |
1527 | ||
f51b802c TH |
1528 | /** |
1529 | * cfq_init_cfqg_base - initialize base part of a cfq_group | |
1530 | * @cfqg: cfq_group to initialize | |
1531 | * | |
1532 | * Initialize the base part which is used whether %CONFIG_CFQ_GROUP_IOSCHED | |
1533 | * is enabled or not. | |
1534 | */ | |
1535 | static void cfq_init_cfqg_base(struct cfq_group *cfqg) | |
1536 | { | |
1537 | struct cfq_rb_root *st; | |
1538 | int i, j; | |
1539 | ||
1540 | for_each_cfqg_st(cfqg, i, j, st) | |
1541 | *st = CFQ_RB_ROOT; | |
1542 | RB_CLEAR_NODE(&cfqg->rb_node); | |
1543 | ||
9a7f38c4 | 1544 | cfqg->ttime.last_end_request = ktime_get_ns(); |
f51b802c TH |
1545 | } |
1546 | ||
25fb5169 | 1547 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
69d7fde5 TH |
1548 | static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val, |
1549 | bool on_dfl, bool reset_dev, bool is_leaf_weight); | |
1550 | ||
24bdb8ef | 1551 | static void cfqg_stats_exit(struct cfqg_stats *stats) |
90d3839b | 1552 | { |
24bdb8ef TH |
1553 | blkg_rwstat_exit(&stats->merged); |
1554 | blkg_rwstat_exit(&stats->service_time); | |
1555 | blkg_rwstat_exit(&stats->wait_time); | |
1556 | blkg_rwstat_exit(&stats->queued); | |
24bdb8ef TH |
1557 | blkg_stat_exit(&stats->time); |
1558 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
1559 | blkg_stat_exit(&stats->unaccounted_time); | |
1560 | blkg_stat_exit(&stats->avg_queue_size_sum); | |
1561 | blkg_stat_exit(&stats->avg_queue_size_samples); | |
1562 | blkg_stat_exit(&stats->dequeue); | |
1563 | blkg_stat_exit(&stats->group_wait_time); | |
1564 | blkg_stat_exit(&stats->idle_time); | |
1565 | blkg_stat_exit(&stats->empty_time); | |
1566 | #endif | |
1567 | } | |
1568 | ||
1569 | static int cfqg_stats_init(struct cfqg_stats *stats, gfp_t gfp) | |
1570 | { | |
77ea7338 | 1571 | if (blkg_rwstat_init(&stats->merged, gfp) || |
24bdb8ef TH |
1572 | blkg_rwstat_init(&stats->service_time, gfp) || |
1573 | blkg_rwstat_init(&stats->wait_time, gfp) || | |
1574 | blkg_rwstat_init(&stats->queued, gfp) || | |
24bdb8ef TH |
1575 | blkg_stat_init(&stats->time, gfp)) |
1576 | goto err; | |
90d3839b PZ |
1577 | |
1578 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
24bdb8ef TH |
1579 | if (blkg_stat_init(&stats->unaccounted_time, gfp) || |
1580 | blkg_stat_init(&stats->avg_queue_size_sum, gfp) || | |
1581 | blkg_stat_init(&stats->avg_queue_size_samples, gfp) || | |
1582 | blkg_stat_init(&stats->dequeue, gfp) || | |
1583 | blkg_stat_init(&stats->group_wait_time, gfp) || | |
1584 | blkg_stat_init(&stats->idle_time, gfp) || | |
1585 | blkg_stat_init(&stats->empty_time, gfp)) | |
1586 | goto err; | |
90d3839b | 1587 | #endif |
24bdb8ef TH |
1588 | return 0; |
1589 | err: | |
1590 | cfqg_stats_exit(stats); | |
1591 | return -ENOMEM; | |
90d3839b PZ |
1592 | } |
1593 | ||
e4a9bde9 TH |
1594 | static struct blkcg_policy_data *cfq_cpd_alloc(gfp_t gfp) |
1595 | { | |
1596 | struct cfq_group_data *cgd; | |
1597 | ||
1598 | cgd = kzalloc(sizeof(*cgd), GFP_KERNEL); | |
1599 | if (!cgd) | |
1600 | return NULL; | |
1601 | return &cgd->cpd; | |
1602 | } | |
1603 | ||
81437648 | 1604 | static void cfq_cpd_init(struct blkcg_policy_data *cpd) |
e48453c3 | 1605 | { |
81437648 | 1606 | struct cfq_group_data *cgd = cpd_to_cfqgd(cpd); |
9e10a130 | 1607 | unsigned int weight = cgroup_subsys_on_dfl(io_cgrp_subsys) ? |
69d7fde5 | 1608 | CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL; |
e48453c3 | 1609 | |
69d7fde5 TH |
1610 | if (cpd_to_blkcg(cpd) == &blkcg_root) |
1611 | weight *= 2; | |
1612 | ||
1613 | cgd->weight = weight; | |
1614 | cgd->leaf_weight = weight; | |
e48453c3 AA |
1615 | } |
1616 | ||
e4a9bde9 TH |
1617 | static void cfq_cpd_free(struct blkcg_policy_data *cpd) |
1618 | { | |
1619 | kfree(cpd_to_cfqgd(cpd)); | |
1620 | } | |
1621 | ||
69d7fde5 TH |
1622 | static void cfq_cpd_bind(struct blkcg_policy_data *cpd) |
1623 | { | |
1624 | struct blkcg *blkcg = cpd_to_blkcg(cpd); | |
9e10a130 | 1625 | bool on_dfl = cgroup_subsys_on_dfl(io_cgrp_subsys); |
69d7fde5 TH |
1626 | unsigned int weight = on_dfl ? CGROUP_WEIGHT_DFL : CFQ_WEIGHT_LEGACY_DFL; |
1627 | ||
1628 | if (blkcg == &blkcg_root) | |
1629 | weight *= 2; | |
1630 | ||
1631 | WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, false)); | |
1632 | WARN_ON_ONCE(__cfq_set_weight(&blkcg->css, weight, on_dfl, true, true)); | |
1633 | } | |
1634 | ||
001bea73 TH |
1635 | static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node) |
1636 | { | |
b2ce2643 TH |
1637 | struct cfq_group *cfqg; |
1638 | ||
1639 | cfqg = kzalloc_node(sizeof(*cfqg), gfp, node); | |
1640 | if (!cfqg) | |
1641 | return NULL; | |
1642 | ||
1643 | cfq_init_cfqg_base(cfqg); | |
24bdb8ef TH |
1644 | if (cfqg_stats_init(&cfqg->stats, gfp)) { |
1645 | kfree(cfqg); | |
1646 | return NULL; | |
1647 | } | |
b2ce2643 TH |
1648 | |
1649 | return &cfqg->pd; | |
001bea73 TH |
1650 | } |
1651 | ||
a9520cd6 | 1652 | static void cfq_pd_init(struct blkg_policy_data *pd) |
f469a7b4 | 1653 | { |
a9520cd6 TH |
1654 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
1655 | struct cfq_group_data *cgd = blkcg_to_cfqgd(pd->blkg->blkcg); | |
25fb5169 | 1656 | |
e48453c3 AA |
1657 | cfqg->weight = cgd->weight; |
1658 | cfqg->leaf_weight = cgd->leaf_weight; | |
25fb5169 VG |
1659 | } |
1660 | ||
a9520cd6 | 1661 | static void cfq_pd_offline(struct blkg_policy_data *pd) |
0b39920b | 1662 | { |
a9520cd6 | 1663 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
60a83707 TH |
1664 | int i; |
1665 | ||
1666 | for (i = 0; i < IOPRIO_BE_NR; i++) { | |
1667 | if (cfqg->async_cfqq[0][i]) | |
1668 | cfq_put_queue(cfqg->async_cfqq[0][i]); | |
1669 | if (cfqg->async_cfqq[1][i]) | |
1670 | cfq_put_queue(cfqg->async_cfqq[1][i]); | |
1671 | } | |
1672 | ||
1673 | if (cfqg->async_idle_cfqq) | |
1674 | cfq_put_queue(cfqg->async_idle_cfqq); | |
1675 | ||
0b39920b TH |
1676 | /* |
1677 | * @blkg is going offline and will be ignored by | |
1678 | * blkg_[rw]stat_recursive_sum(). Transfer stats to the parent so | |
1679 | * that they don't get lost. If IOs complete after this point, the | |
1680 | * stats for them will be lost. Oh well... | |
1681 | */ | |
60a83707 | 1682 | cfqg_stats_xfer_dead(cfqg); |
0b39920b TH |
1683 | } |
1684 | ||
001bea73 TH |
1685 | static void cfq_pd_free(struct blkg_policy_data *pd) |
1686 | { | |
24bdb8ef TH |
1687 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
1688 | ||
1689 | cfqg_stats_exit(&cfqg->stats); | |
1690 | return kfree(cfqg); | |
001bea73 TH |
1691 | } |
1692 | ||
a9520cd6 | 1693 | static void cfq_pd_reset_stats(struct blkg_policy_data *pd) |
689665af | 1694 | { |
a9520cd6 | 1695 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
689665af TH |
1696 | |
1697 | cfqg_stats_reset(&cfqg->stats); | |
25fb5169 VG |
1698 | } |
1699 | ||
ae118896 TH |
1700 | static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd, |
1701 | struct blkcg *blkcg) | |
25fb5169 | 1702 | { |
ae118896 | 1703 | struct blkcg_gq *blkg; |
f469a7b4 | 1704 | |
ae118896 TH |
1705 | blkg = blkg_lookup(blkcg, cfqd->queue); |
1706 | if (likely(blkg)) | |
1707 | return blkg_to_cfqg(blkg); | |
1708 | return NULL; | |
25fb5169 VG |
1709 | } |
1710 | ||
1711 | static void cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) | |
1712 | { | |
25fb5169 | 1713 | cfqq->cfqg = cfqg; |
b1c35769 | 1714 | /* cfqq reference on cfqg */ |
eb7d8c07 | 1715 | cfqg_get(cfqg); |
b1c35769 VG |
1716 | } |
1717 | ||
f95a04af TH |
1718 | static u64 cfqg_prfill_weight_device(struct seq_file *sf, |
1719 | struct blkg_policy_data *pd, int off) | |
60c2bc2d | 1720 | { |
f95a04af | 1721 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
3381cb8d TH |
1722 | |
1723 | if (!cfqg->dev_weight) | |
60c2bc2d | 1724 | return 0; |
f95a04af | 1725 | return __blkg_prfill_u64(sf, pd, cfqg->dev_weight); |
60c2bc2d TH |
1726 | } |
1727 | ||
2da8ca82 | 1728 | static int cfqg_print_weight_device(struct seq_file *sf, void *v) |
60c2bc2d | 1729 | { |
2da8ca82 TH |
1730 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1731 | cfqg_prfill_weight_device, &blkcg_policy_cfq, | |
1732 | 0, false); | |
60c2bc2d TH |
1733 | return 0; |
1734 | } | |
1735 | ||
e71357e1 TH |
1736 | static u64 cfqg_prfill_leaf_weight_device(struct seq_file *sf, |
1737 | struct blkg_policy_data *pd, int off) | |
1738 | { | |
1739 | struct cfq_group *cfqg = pd_to_cfqg(pd); | |
1740 | ||
1741 | if (!cfqg->dev_leaf_weight) | |
1742 | return 0; | |
1743 | return __blkg_prfill_u64(sf, pd, cfqg->dev_leaf_weight); | |
1744 | } | |
1745 | ||
2da8ca82 | 1746 | static int cfqg_print_leaf_weight_device(struct seq_file *sf, void *v) |
e71357e1 | 1747 | { |
2da8ca82 TH |
1748 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1749 | cfqg_prfill_leaf_weight_device, &blkcg_policy_cfq, | |
1750 | 0, false); | |
e71357e1 TH |
1751 | return 0; |
1752 | } | |
1753 | ||
2da8ca82 | 1754 | static int cfq_print_weight(struct seq_file *sf, void *v) |
60c2bc2d | 1755 | { |
e48453c3 | 1756 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); |
9470e4a6 JA |
1757 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg); |
1758 | unsigned int val = 0; | |
e48453c3 | 1759 | |
9470e4a6 JA |
1760 | if (cgd) |
1761 | val = cgd->weight; | |
1762 | ||
1763 | seq_printf(sf, "%u\n", val); | |
60c2bc2d TH |
1764 | return 0; |
1765 | } | |
1766 | ||
2da8ca82 | 1767 | static int cfq_print_leaf_weight(struct seq_file *sf, void *v) |
e71357e1 | 1768 | { |
e48453c3 | 1769 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); |
9470e4a6 JA |
1770 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg); |
1771 | unsigned int val = 0; | |
1772 | ||
1773 | if (cgd) | |
1774 | val = cgd->leaf_weight; | |
e48453c3 | 1775 | |
9470e4a6 | 1776 | seq_printf(sf, "%u\n", val); |
e71357e1 TH |
1777 | return 0; |
1778 | } | |
1779 | ||
451af504 TH |
1780 | static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of, |
1781 | char *buf, size_t nbytes, loff_t off, | |
2ee867dc | 1782 | bool on_dfl, bool is_leaf_weight) |
60c2bc2d | 1783 | { |
69d7fde5 TH |
1784 | unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN; |
1785 | unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX; | |
451af504 | 1786 | struct blkcg *blkcg = css_to_blkcg(of_css(of)); |
60c2bc2d | 1787 | struct blkg_conf_ctx ctx; |
3381cb8d | 1788 | struct cfq_group *cfqg; |
e48453c3 | 1789 | struct cfq_group_data *cfqgd; |
60c2bc2d | 1790 | int ret; |
36aa9e5f | 1791 | u64 v; |
60c2bc2d | 1792 | |
3c798398 | 1793 | ret = blkg_conf_prep(blkcg, &blkcg_policy_cfq, buf, &ctx); |
60c2bc2d TH |
1794 | if (ret) |
1795 | return ret; | |
1796 | ||
2ee867dc TH |
1797 | if (sscanf(ctx.body, "%llu", &v) == 1) { |
1798 | /* require "default" on dfl */ | |
1799 | ret = -ERANGE; | |
1800 | if (!v && on_dfl) | |
1801 | goto out_finish; | |
1802 | } else if (!strcmp(strim(ctx.body), "default")) { | |
1803 | v = 0; | |
1804 | } else { | |
1805 | ret = -EINVAL; | |
36aa9e5f | 1806 | goto out_finish; |
2ee867dc | 1807 | } |
36aa9e5f | 1808 | |
3381cb8d | 1809 | cfqg = blkg_to_cfqg(ctx.blkg); |
e48453c3 | 1810 | cfqgd = blkcg_to_cfqgd(blkcg); |
ae994ea9 | 1811 | |
20386ce0 | 1812 | ret = -ERANGE; |
69d7fde5 | 1813 | if (!v || (v >= min && v <= max)) { |
e71357e1 | 1814 | if (!is_leaf_weight) { |
36aa9e5f TH |
1815 | cfqg->dev_weight = v; |
1816 | cfqg->new_weight = v ?: cfqgd->weight; | |
e71357e1 | 1817 | } else { |
36aa9e5f TH |
1818 | cfqg->dev_leaf_weight = v; |
1819 | cfqg->new_leaf_weight = v ?: cfqgd->leaf_weight; | |
e71357e1 | 1820 | } |
60c2bc2d TH |
1821 | ret = 0; |
1822 | } | |
36aa9e5f | 1823 | out_finish: |
60c2bc2d | 1824 | blkg_conf_finish(&ctx); |
451af504 | 1825 | return ret ?: nbytes; |
60c2bc2d TH |
1826 | } |
1827 | ||
451af504 TH |
1828 | static ssize_t cfqg_set_weight_device(struct kernfs_open_file *of, |
1829 | char *buf, size_t nbytes, loff_t off) | |
e71357e1 | 1830 | { |
2ee867dc | 1831 | return __cfqg_set_weight_device(of, buf, nbytes, off, false, false); |
e71357e1 TH |
1832 | } |
1833 | ||
451af504 TH |
1834 | static ssize_t cfqg_set_leaf_weight_device(struct kernfs_open_file *of, |
1835 | char *buf, size_t nbytes, loff_t off) | |
e71357e1 | 1836 | { |
2ee867dc | 1837 | return __cfqg_set_weight_device(of, buf, nbytes, off, false, true); |
e71357e1 TH |
1838 | } |
1839 | ||
dd165eb3 | 1840 | static int __cfq_set_weight(struct cgroup_subsys_state *css, u64 val, |
69d7fde5 | 1841 | bool on_dfl, bool reset_dev, bool is_leaf_weight) |
60c2bc2d | 1842 | { |
69d7fde5 TH |
1843 | unsigned int min = on_dfl ? CGROUP_WEIGHT_MIN : CFQ_WEIGHT_LEGACY_MIN; |
1844 | unsigned int max = on_dfl ? CGROUP_WEIGHT_MAX : CFQ_WEIGHT_LEGACY_MAX; | |
182446d0 | 1845 | struct blkcg *blkcg = css_to_blkcg(css); |
3c798398 | 1846 | struct blkcg_gq *blkg; |
e48453c3 | 1847 | struct cfq_group_data *cfqgd; |
ae994ea9 | 1848 | int ret = 0; |
60c2bc2d | 1849 | |
69d7fde5 TH |
1850 | if (val < min || val > max) |
1851 | return -ERANGE; | |
60c2bc2d TH |
1852 | |
1853 | spin_lock_irq(&blkcg->lock); | |
e48453c3 | 1854 | cfqgd = blkcg_to_cfqgd(blkcg); |
ae994ea9 JA |
1855 | if (!cfqgd) { |
1856 | ret = -EINVAL; | |
1857 | goto out; | |
1858 | } | |
e71357e1 TH |
1859 | |
1860 | if (!is_leaf_weight) | |
e48453c3 | 1861 | cfqgd->weight = val; |
e71357e1 | 1862 | else |
e48453c3 | 1863 | cfqgd->leaf_weight = val; |
60c2bc2d | 1864 | |
b67bfe0d | 1865 | hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) { |
3381cb8d | 1866 | struct cfq_group *cfqg = blkg_to_cfqg(blkg); |
60c2bc2d | 1867 | |
e71357e1 TH |
1868 | if (!cfqg) |
1869 | continue; | |
1870 | ||
1871 | if (!is_leaf_weight) { | |
69d7fde5 TH |
1872 | if (reset_dev) |
1873 | cfqg->dev_weight = 0; | |
e71357e1 | 1874 | if (!cfqg->dev_weight) |
e48453c3 | 1875 | cfqg->new_weight = cfqgd->weight; |
e71357e1 | 1876 | } else { |
69d7fde5 TH |
1877 | if (reset_dev) |
1878 | cfqg->dev_leaf_weight = 0; | |
e71357e1 | 1879 | if (!cfqg->dev_leaf_weight) |
e48453c3 | 1880 | cfqg->new_leaf_weight = cfqgd->leaf_weight; |
e71357e1 | 1881 | } |
60c2bc2d TH |
1882 | } |
1883 | ||
ae994ea9 | 1884 | out: |
60c2bc2d | 1885 | spin_unlock_irq(&blkcg->lock); |
ae994ea9 | 1886 | return ret; |
60c2bc2d TH |
1887 | } |
1888 | ||
182446d0 TH |
1889 | static int cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft, |
1890 | u64 val) | |
e71357e1 | 1891 | { |
69d7fde5 | 1892 | return __cfq_set_weight(css, val, false, false, false); |
e71357e1 TH |
1893 | } |
1894 | ||
182446d0 TH |
1895 | static int cfq_set_leaf_weight(struct cgroup_subsys_state *css, |
1896 | struct cftype *cft, u64 val) | |
e71357e1 | 1897 | { |
69d7fde5 | 1898 | return __cfq_set_weight(css, val, false, false, true); |
e71357e1 TH |
1899 | } |
1900 | ||
2da8ca82 | 1901 | static int cfqg_print_stat(struct seq_file *sf, void *v) |
5bc4afb1 | 1902 | { |
2da8ca82 TH |
1903 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat, |
1904 | &blkcg_policy_cfq, seq_cft(sf)->private, false); | |
5bc4afb1 TH |
1905 | return 0; |
1906 | } | |
1907 | ||
2da8ca82 | 1908 | static int cfqg_print_rwstat(struct seq_file *sf, void *v) |
5bc4afb1 | 1909 | { |
2da8ca82 TH |
1910 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat, |
1911 | &blkcg_policy_cfq, seq_cft(sf)->private, true); | |
5bc4afb1 TH |
1912 | return 0; |
1913 | } | |
1914 | ||
43114018 TH |
1915 | static u64 cfqg_prfill_stat_recursive(struct seq_file *sf, |
1916 | struct blkg_policy_data *pd, int off) | |
1917 | { | |
f12c74ca TH |
1918 | u64 sum = blkg_stat_recursive_sum(pd_to_blkg(pd), |
1919 | &blkcg_policy_cfq, off); | |
43114018 TH |
1920 | return __blkg_prfill_u64(sf, pd, sum); |
1921 | } | |
1922 | ||
1923 | static u64 cfqg_prfill_rwstat_recursive(struct seq_file *sf, | |
1924 | struct blkg_policy_data *pd, int off) | |
1925 | { | |
f12c74ca TH |
1926 | struct blkg_rwstat sum = blkg_rwstat_recursive_sum(pd_to_blkg(pd), |
1927 | &blkcg_policy_cfq, off); | |
43114018 TH |
1928 | return __blkg_prfill_rwstat(sf, pd, &sum); |
1929 | } | |
1930 | ||
2da8ca82 | 1931 | static int cfqg_print_stat_recursive(struct seq_file *sf, void *v) |
43114018 | 1932 | { |
2da8ca82 TH |
1933 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1934 | cfqg_prfill_stat_recursive, &blkcg_policy_cfq, | |
1935 | seq_cft(sf)->private, false); | |
43114018 TH |
1936 | return 0; |
1937 | } | |
1938 | ||
2da8ca82 | 1939 | static int cfqg_print_rwstat_recursive(struct seq_file *sf, void *v) |
43114018 | 1940 | { |
2da8ca82 TH |
1941 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
1942 | cfqg_prfill_rwstat_recursive, &blkcg_policy_cfq, | |
1943 | seq_cft(sf)->private, true); | |
43114018 TH |
1944 | return 0; |
1945 | } | |
1946 | ||
702747ca TH |
1947 | static u64 cfqg_prfill_sectors(struct seq_file *sf, struct blkg_policy_data *pd, |
1948 | int off) | |
1949 | { | |
1950 | u64 sum = blkg_rwstat_total(&pd->blkg->stat_bytes); | |
1951 | ||
1952 | return __blkg_prfill_u64(sf, pd, sum >> 9); | |
1953 | } | |
1954 | ||
1955 | static int cfqg_print_stat_sectors(struct seq_file *sf, void *v) | |
1956 | { | |
1957 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1958 | cfqg_prfill_sectors, &blkcg_policy_cfq, 0, false); | |
1959 | return 0; | |
1960 | } | |
1961 | ||
1962 | static u64 cfqg_prfill_sectors_recursive(struct seq_file *sf, | |
1963 | struct blkg_policy_data *pd, int off) | |
1964 | { | |
1965 | struct blkg_rwstat tmp = blkg_rwstat_recursive_sum(pd->blkg, NULL, | |
1966 | offsetof(struct blkcg_gq, stat_bytes)); | |
1967 | u64 sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) + | |
1968 | atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]); | |
1969 | ||
1970 | return __blkg_prfill_u64(sf, pd, sum >> 9); | |
1971 | } | |
1972 | ||
1973 | static int cfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v) | |
1974 | { | |
1975 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), | |
1976 | cfqg_prfill_sectors_recursive, &blkcg_policy_cfq, 0, | |
1977 | false); | |
1978 | return 0; | |
1979 | } | |
1980 | ||
60c2bc2d | 1981 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
f95a04af TH |
1982 | static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf, |
1983 | struct blkg_policy_data *pd, int off) | |
60c2bc2d | 1984 | { |
f95a04af | 1985 | struct cfq_group *cfqg = pd_to_cfqg(pd); |
155fead9 | 1986 | u64 samples = blkg_stat_read(&cfqg->stats.avg_queue_size_samples); |
60c2bc2d TH |
1987 | u64 v = 0; |
1988 | ||
1989 | if (samples) { | |
155fead9 | 1990 | v = blkg_stat_read(&cfqg->stats.avg_queue_size_sum); |
f3cff25f | 1991 | v = div64_u64(v, samples); |
60c2bc2d | 1992 | } |
f95a04af | 1993 | __blkg_prfill_u64(sf, pd, v); |
60c2bc2d TH |
1994 | return 0; |
1995 | } | |
1996 | ||
1997 | /* print avg_queue_size */ | |
2da8ca82 | 1998 | static int cfqg_print_avg_queue_size(struct seq_file *sf, void *v) |
60c2bc2d | 1999 | { |
2da8ca82 TH |
2000 | blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), |
2001 | cfqg_prfill_avg_queue_size, &blkcg_policy_cfq, | |
2002 | 0, false); | |
60c2bc2d TH |
2003 | return 0; |
2004 | } | |
2005 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
2006 | ||
880f50e2 | 2007 | static struct cftype cfq_blkcg_legacy_files[] = { |
1d3650f7 | 2008 | /* on root, weight is mapped to leaf_weight */ |
60c2bc2d TH |
2009 | { |
2010 | .name = "weight_device", | |
1d3650f7 | 2011 | .flags = CFTYPE_ONLY_ON_ROOT, |
2da8ca82 | 2012 | .seq_show = cfqg_print_leaf_weight_device, |
451af504 | 2013 | .write = cfqg_set_leaf_weight_device, |
60c2bc2d TH |
2014 | }, |
2015 | { | |
2016 | .name = "weight", | |
1d3650f7 | 2017 | .flags = CFTYPE_ONLY_ON_ROOT, |
2da8ca82 | 2018 | .seq_show = cfq_print_leaf_weight, |
1d3650f7 | 2019 | .write_u64 = cfq_set_leaf_weight, |
60c2bc2d | 2020 | }, |
e71357e1 | 2021 | |
1d3650f7 | 2022 | /* no such mapping necessary for !roots */ |
60c2bc2d TH |
2023 | { |
2024 | .name = "weight_device", | |
1d3650f7 | 2025 | .flags = CFTYPE_NOT_ON_ROOT, |
2da8ca82 | 2026 | .seq_show = cfqg_print_weight_device, |
451af504 | 2027 | .write = cfqg_set_weight_device, |
60c2bc2d TH |
2028 | }, |
2029 | { | |
2030 | .name = "weight", | |
1d3650f7 | 2031 | .flags = CFTYPE_NOT_ON_ROOT, |
2da8ca82 | 2032 | .seq_show = cfq_print_weight, |
3381cb8d | 2033 | .write_u64 = cfq_set_weight, |
60c2bc2d | 2034 | }, |
e71357e1 | 2035 | |
e71357e1 TH |
2036 | { |
2037 | .name = "leaf_weight_device", | |
2da8ca82 | 2038 | .seq_show = cfqg_print_leaf_weight_device, |
451af504 | 2039 | .write = cfqg_set_leaf_weight_device, |
e71357e1 TH |
2040 | }, |
2041 | { | |
2042 | .name = "leaf_weight", | |
2da8ca82 | 2043 | .seq_show = cfq_print_leaf_weight, |
e71357e1 TH |
2044 | .write_u64 = cfq_set_leaf_weight, |
2045 | }, | |
2046 | ||
43114018 | 2047 | /* statistics, covers only the tasks in the cfqg */ |
60c2bc2d TH |
2048 | { |
2049 | .name = "time", | |
5bc4afb1 | 2050 | .private = offsetof(struct cfq_group, stats.time), |
2da8ca82 | 2051 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2052 | }, |
2053 | { | |
2054 | .name = "sectors", | |
702747ca | 2055 | .seq_show = cfqg_print_stat_sectors, |
60c2bc2d TH |
2056 | }, |
2057 | { | |
2058 | .name = "io_service_bytes", | |
77ea7338 TH |
2059 | .private = (unsigned long)&blkcg_policy_cfq, |
2060 | .seq_show = blkg_print_stat_bytes, | |
60c2bc2d TH |
2061 | }, |
2062 | { | |
2063 | .name = "io_serviced", | |
77ea7338 TH |
2064 | .private = (unsigned long)&blkcg_policy_cfq, |
2065 | .seq_show = blkg_print_stat_ios, | |
60c2bc2d TH |
2066 | }, |
2067 | { | |
2068 | .name = "io_service_time", | |
5bc4afb1 | 2069 | .private = offsetof(struct cfq_group, stats.service_time), |
2da8ca82 | 2070 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
2071 | }, |
2072 | { | |
2073 | .name = "io_wait_time", | |
5bc4afb1 | 2074 | .private = offsetof(struct cfq_group, stats.wait_time), |
2da8ca82 | 2075 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
2076 | }, |
2077 | { | |
2078 | .name = "io_merged", | |
5bc4afb1 | 2079 | .private = offsetof(struct cfq_group, stats.merged), |
2da8ca82 | 2080 | .seq_show = cfqg_print_rwstat, |
60c2bc2d TH |
2081 | }, |
2082 | { | |
2083 | .name = "io_queued", | |
5bc4afb1 | 2084 | .private = offsetof(struct cfq_group, stats.queued), |
2da8ca82 | 2085 | .seq_show = cfqg_print_rwstat, |
60c2bc2d | 2086 | }, |
43114018 TH |
2087 | |
2088 | /* the same statictics which cover the cfqg and its descendants */ | |
2089 | { | |
2090 | .name = "time_recursive", | |
2091 | .private = offsetof(struct cfq_group, stats.time), | |
2da8ca82 | 2092 | .seq_show = cfqg_print_stat_recursive, |
43114018 TH |
2093 | }, |
2094 | { | |
2095 | .name = "sectors_recursive", | |
702747ca | 2096 | .seq_show = cfqg_print_stat_sectors_recursive, |
43114018 TH |
2097 | }, |
2098 | { | |
2099 | .name = "io_service_bytes_recursive", | |
77ea7338 TH |
2100 | .private = (unsigned long)&blkcg_policy_cfq, |
2101 | .seq_show = blkg_print_stat_bytes_recursive, | |
43114018 TH |
2102 | }, |
2103 | { | |
2104 | .name = "io_serviced_recursive", | |
77ea7338 TH |
2105 | .private = (unsigned long)&blkcg_policy_cfq, |
2106 | .seq_show = blkg_print_stat_ios_recursive, | |
43114018 TH |
2107 | }, |
2108 | { | |
2109 | .name = "io_service_time_recursive", | |
2110 | .private = offsetof(struct cfq_group, stats.service_time), | |
2da8ca82 | 2111 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2112 | }, |
2113 | { | |
2114 | .name = "io_wait_time_recursive", | |
2115 | .private = offsetof(struct cfq_group, stats.wait_time), | |
2da8ca82 | 2116 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2117 | }, |
2118 | { | |
2119 | .name = "io_merged_recursive", | |
2120 | .private = offsetof(struct cfq_group, stats.merged), | |
2da8ca82 | 2121 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 TH |
2122 | }, |
2123 | { | |
2124 | .name = "io_queued_recursive", | |
2125 | .private = offsetof(struct cfq_group, stats.queued), | |
2da8ca82 | 2126 | .seq_show = cfqg_print_rwstat_recursive, |
43114018 | 2127 | }, |
60c2bc2d TH |
2128 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
2129 | { | |
2130 | .name = "avg_queue_size", | |
2da8ca82 | 2131 | .seq_show = cfqg_print_avg_queue_size, |
60c2bc2d TH |
2132 | }, |
2133 | { | |
2134 | .name = "group_wait_time", | |
5bc4afb1 | 2135 | .private = offsetof(struct cfq_group, stats.group_wait_time), |
2da8ca82 | 2136 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2137 | }, |
2138 | { | |
2139 | .name = "idle_time", | |
5bc4afb1 | 2140 | .private = offsetof(struct cfq_group, stats.idle_time), |
2da8ca82 | 2141 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2142 | }, |
2143 | { | |
2144 | .name = "empty_time", | |
5bc4afb1 | 2145 | .private = offsetof(struct cfq_group, stats.empty_time), |
2da8ca82 | 2146 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2147 | }, |
2148 | { | |
2149 | .name = "dequeue", | |
5bc4afb1 | 2150 | .private = offsetof(struct cfq_group, stats.dequeue), |
2da8ca82 | 2151 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2152 | }, |
2153 | { | |
2154 | .name = "unaccounted_time", | |
5bc4afb1 | 2155 | .private = offsetof(struct cfq_group, stats.unaccounted_time), |
2da8ca82 | 2156 | .seq_show = cfqg_print_stat, |
60c2bc2d TH |
2157 | }, |
2158 | #endif /* CONFIG_DEBUG_BLK_CGROUP */ | |
2159 | { } /* terminate */ | |
2160 | }; | |
2ee867dc TH |
2161 | |
2162 | static int cfq_print_weight_on_dfl(struct seq_file *sf, void *v) | |
2163 | { | |
2164 | struct blkcg *blkcg = css_to_blkcg(seq_css(sf)); | |
2165 | struct cfq_group_data *cgd = blkcg_to_cfqgd(blkcg); | |
2166 | ||
2167 | seq_printf(sf, "default %u\n", cgd->weight); | |
2168 | blkcg_print_blkgs(sf, blkcg, cfqg_prfill_weight_device, | |
2169 | &blkcg_policy_cfq, 0, false); | |
2170 | return 0; | |
2171 | } | |
2172 | ||
2173 | static ssize_t cfq_set_weight_on_dfl(struct kernfs_open_file *of, | |
2174 | char *buf, size_t nbytes, loff_t off) | |
2175 | { | |
2176 | char *endp; | |
2177 | int ret; | |
2178 | u64 v; | |
2179 | ||
2180 | buf = strim(buf); | |
2181 | ||
2182 | /* "WEIGHT" or "default WEIGHT" sets the default weight */ | |
2183 | v = simple_strtoull(buf, &endp, 0); | |
2184 | if (*endp == '\0' || sscanf(buf, "default %llu", &v) == 1) { | |
69d7fde5 | 2185 | ret = __cfq_set_weight(of_css(of), v, true, false, false); |
2ee867dc TH |
2186 | return ret ?: nbytes; |
2187 | } | |
2188 | ||
2189 | /* "MAJ:MIN WEIGHT" */ | |
2190 | return __cfqg_set_weight_device(of, buf, nbytes, off, true, false); | |
2191 | } | |
2192 | ||
2193 | static struct cftype cfq_blkcg_files[] = { | |
2194 | { | |
2195 | .name = "weight", | |
2196 | .flags = CFTYPE_NOT_ON_ROOT, | |
2197 | .seq_show = cfq_print_weight_on_dfl, | |
2198 | .write = cfq_set_weight_on_dfl, | |
2199 | }, | |
2200 | { } /* terminate */ | |
2201 | }; | |
2202 | ||
25fb5169 | 2203 | #else /* GROUP_IOSCHED */ |
ae118896 TH |
2204 | static struct cfq_group *cfq_lookup_cfqg(struct cfq_data *cfqd, |
2205 | struct blkcg *blkcg) | |
25fb5169 | 2206 | { |
f51b802c | 2207 | return cfqd->root_group; |
25fb5169 | 2208 | } |
7f1dc8a2 | 2209 | |
25fb5169 VG |
2210 | static inline void |
2211 | cfq_link_cfqq_cfqg(struct cfq_queue *cfqq, struct cfq_group *cfqg) { | |
2212 | cfqq->cfqg = cfqg; | |
2213 | } | |
2214 | ||
2215 | #endif /* GROUP_IOSCHED */ | |
2216 | ||
498d3aa2 | 2217 | /* |
c0324a02 | 2218 | * The cfqd->service_trees holds all pending cfq_queue's that have |
498d3aa2 JA |
2219 | * requests waiting to be processed. It is sorted in the order that |
2220 | * we will service the queues. | |
2221 | */ | |
a36e71f9 | 2222 | static void cfq_service_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
a6151c3a | 2223 | bool add_front) |
d9e7620e | 2224 | { |
0871714e JA |
2225 | struct rb_node **p, *parent; |
2226 | struct cfq_queue *__cfqq; | |
9a7f38c4 | 2227 | u64 rb_key; |
34b98d03 | 2228 | struct cfq_rb_root *st; |
498d3aa2 | 2229 | int left; |
dae739eb | 2230 | int new_cfqq = 1; |
9a7f38c4 | 2231 | u64 now = ktime_get_ns(); |
ae30c286 | 2232 | |
34b98d03 | 2233 | st = st_for(cfqq->cfqg, cfqq_class(cfqq), cfqq_type(cfqq)); |
0871714e JA |
2234 | if (cfq_class_idle(cfqq)) { |
2235 | rb_key = CFQ_IDLE_DELAY; | |
34b98d03 | 2236 | parent = rb_last(&st->rb); |
0871714e JA |
2237 | if (parent && parent != &cfqq->rb_node) { |
2238 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); | |
2239 | rb_key += __cfqq->rb_key; | |
2240 | } else | |
9a7f38c4 | 2241 | rb_key += now; |
0871714e | 2242 | } else if (!add_front) { |
b9c8946b JA |
2243 | /* |
2244 | * Get our rb key offset. Subtract any residual slice | |
2245 | * value carried from last service. A negative resid | |
2246 | * count indicates slice overrun, and this should position | |
2247 | * the next service time further away in the tree. | |
2248 | */ | |
9a7f38c4 | 2249 | rb_key = cfq_slice_offset(cfqd, cfqq) + now; |
b9c8946b | 2250 | rb_key -= cfqq->slice_resid; |
edd75ffd | 2251 | cfqq->slice_resid = 0; |
48e025e6 | 2252 | } else { |
9a7f38c4 | 2253 | rb_key = -NSEC_PER_SEC; |
34b98d03 | 2254 | __cfqq = cfq_rb_first(st); |
9a7f38c4 | 2255 | rb_key += __cfqq ? __cfqq->rb_key : now; |
48e025e6 | 2256 | } |
1da177e4 | 2257 | |
d9e7620e | 2258 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
dae739eb | 2259 | new_cfqq = 0; |
99f9628a | 2260 | /* |
d9e7620e | 2261 | * same position, nothing more to do |
99f9628a | 2262 | */ |
34b98d03 | 2263 | if (rb_key == cfqq->rb_key && cfqq->service_tree == st) |
d9e7620e | 2264 | return; |
1da177e4 | 2265 | |
aa6f6a3d CZ |
2266 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); |
2267 | cfqq->service_tree = NULL; | |
1da177e4 | 2268 | } |
d9e7620e | 2269 | |
498d3aa2 | 2270 | left = 1; |
0871714e | 2271 | parent = NULL; |
34b98d03 VG |
2272 | cfqq->service_tree = st; |
2273 | p = &st->rb.rb_node; | |
d9e7620e JA |
2274 | while (*p) { |
2275 | parent = *p; | |
2276 | __cfqq = rb_entry(parent, struct cfq_queue, rb_node); | |
2277 | ||
0c534e0a | 2278 | /* |
c0324a02 | 2279 | * sort by key, that represents service time. |
0c534e0a | 2280 | */ |
9a7f38c4 | 2281 | if (rb_key < __cfqq->rb_key) |
1f23f121 | 2282 | p = &parent->rb_left; |
c0324a02 | 2283 | else { |
1f23f121 | 2284 | p = &parent->rb_right; |
cc09e299 | 2285 | left = 0; |
c0324a02 | 2286 | } |
d9e7620e JA |
2287 | } |
2288 | ||
cc09e299 | 2289 | if (left) |
34b98d03 | 2290 | st->left = &cfqq->rb_node; |
cc09e299 | 2291 | |
d9e7620e JA |
2292 | cfqq->rb_key = rb_key; |
2293 | rb_link_node(&cfqq->rb_node, parent, p); | |
34b98d03 VG |
2294 | rb_insert_color(&cfqq->rb_node, &st->rb); |
2295 | st->count++; | |
20359f27 | 2296 | if (add_front || !new_cfqq) |
dae739eb | 2297 | return; |
8184f93e | 2298 | cfq_group_notify_queue_add(cfqd, cfqq->cfqg); |
1da177e4 LT |
2299 | } |
2300 | ||
a36e71f9 | 2301 | static struct cfq_queue * |
f2d1f0ae JA |
2302 | cfq_prio_tree_lookup(struct cfq_data *cfqd, struct rb_root *root, |
2303 | sector_t sector, struct rb_node **ret_parent, | |
2304 | struct rb_node ***rb_link) | |
a36e71f9 | 2305 | { |
a36e71f9 JA |
2306 | struct rb_node **p, *parent; |
2307 | struct cfq_queue *cfqq = NULL; | |
2308 | ||
2309 | parent = NULL; | |
2310 | p = &root->rb_node; | |
2311 | while (*p) { | |
2312 | struct rb_node **n; | |
2313 | ||
2314 | parent = *p; | |
2315 | cfqq = rb_entry(parent, struct cfq_queue, p_node); | |
2316 | ||
2317 | /* | |
2318 | * Sort strictly based on sector. Smallest to the left, | |
2319 | * largest to the right. | |
2320 | */ | |
2e46e8b2 | 2321 | if (sector > blk_rq_pos(cfqq->next_rq)) |
a36e71f9 | 2322 | n = &(*p)->rb_right; |
2e46e8b2 | 2323 | else if (sector < blk_rq_pos(cfqq->next_rq)) |
a36e71f9 JA |
2324 | n = &(*p)->rb_left; |
2325 | else | |
2326 | break; | |
2327 | p = n; | |
3ac6c9f8 | 2328 | cfqq = NULL; |
a36e71f9 JA |
2329 | } |
2330 | ||
2331 | *ret_parent = parent; | |
2332 | if (rb_link) | |
2333 | *rb_link = p; | |
3ac6c9f8 | 2334 | return cfqq; |
a36e71f9 JA |
2335 | } |
2336 | ||
2337 | static void cfq_prio_tree_add(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2338 | { | |
a36e71f9 JA |
2339 | struct rb_node **p, *parent; |
2340 | struct cfq_queue *__cfqq; | |
2341 | ||
f2d1f0ae JA |
2342 | if (cfqq->p_root) { |
2343 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2344 | cfqq->p_root = NULL; | |
2345 | } | |
a36e71f9 JA |
2346 | |
2347 | if (cfq_class_idle(cfqq)) | |
2348 | return; | |
2349 | if (!cfqq->next_rq) | |
2350 | return; | |
2351 | ||
f2d1f0ae | 2352 | cfqq->p_root = &cfqd->prio_trees[cfqq->org_ioprio]; |
2e46e8b2 TH |
2353 | __cfqq = cfq_prio_tree_lookup(cfqd, cfqq->p_root, |
2354 | blk_rq_pos(cfqq->next_rq), &parent, &p); | |
3ac6c9f8 JA |
2355 | if (!__cfqq) { |
2356 | rb_link_node(&cfqq->p_node, parent, p); | |
f2d1f0ae JA |
2357 | rb_insert_color(&cfqq->p_node, cfqq->p_root); |
2358 | } else | |
2359 | cfqq->p_root = NULL; | |
a36e71f9 JA |
2360 | } |
2361 | ||
498d3aa2 JA |
2362 | /* |
2363 | * Update cfqq's position in the service tree. | |
2364 | */ | |
edd75ffd | 2365 | static void cfq_resort_rr_list(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
6d048f53 | 2366 | { |
6d048f53 JA |
2367 | /* |
2368 | * Resorting requires the cfqq to be on the RR list already. | |
2369 | */ | |
a36e71f9 | 2370 | if (cfq_cfqq_on_rr(cfqq)) { |
edd75ffd | 2371 | cfq_service_tree_add(cfqd, cfqq, 0); |
a36e71f9 JA |
2372 | cfq_prio_tree_add(cfqd, cfqq); |
2373 | } | |
6d048f53 JA |
2374 | } |
2375 | ||
1da177e4 LT |
2376 | /* |
2377 | * add to busy list of queues for service, trying to be fair in ordering | |
22e2c507 | 2378 | * the pending list according to last request service |
1da177e4 | 2379 | */ |
febffd61 | 2380 | static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
1da177e4 | 2381 | { |
7b679138 | 2382 | cfq_log_cfqq(cfqd, cfqq, "add_to_rr"); |
3b18152c JA |
2383 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
2384 | cfq_mark_cfqq_on_rr(cfqq); | |
1da177e4 | 2385 | cfqd->busy_queues++; |
ef8a41df SL |
2386 | if (cfq_cfqq_sync(cfqq)) |
2387 | cfqd->busy_sync_queues++; | |
1da177e4 | 2388 | |
edd75ffd | 2389 | cfq_resort_rr_list(cfqd, cfqq); |
1da177e4 LT |
2390 | } |
2391 | ||
498d3aa2 JA |
2392 | /* |
2393 | * Called when the cfqq no longer has requests pending, remove it from | |
2394 | * the service tree. | |
2395 | */ | |
febffd61 | 2396 | static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
1da177e4 | 2397 | { |
7b679138 | 2398 | cfq_log_cfqq(cfqd, cfqq, "del_from_rr"); |
3b18152c JA |
2399 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); |
2400 | cfq_clear_cfqq_on_rr(cfqq); | |
1da177e4 | 2401 | |
aa6f6a3d CZ |
2402 | if (!RB_EMPTY_NODE(&cfqq->rb_node)) { |
2403 | cfq_rb_erase(&cfqq->rb_node, cfqq->service_tree); | |
2404 | cfqq->service_tree = NULL; | |
2405 | } | |
f2d1f0ae JA |
2406 | if (cfqq->p_root) { |
2407 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2408 | cfqq->p_root = NULL; | |
2409 | } | |
d9e7620e | 2410 | |
8184f93e | 2411 | cfq_group_notify_queue_del(cfqd, cfqq->cfqg); |
1da177e4 LT |
2412 | BUG_ON(!cfqd->busy_queues); |
2413 | cfqd->busy_queues--; | |
ef8a41df SL |
2414 | if (cfq_cfqq_sync(cfqq)) |
2415 | cfqd->busy_sync_queues--; | |
1da177e4 LT |
2416 | } |
2417 | ||
2418 | /* | |
2419 | * rb tree support functions | |
2420 | */ | |
febffd61 | 2421 | static void cfq_del_rq_rb(struct request *rq) |
1da177e4 | 2422 | { |
5e705374 | 2423 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
5e705374 | 2424 | const int sync = rq_is_sync(rq); |
1da177e4 | 2425 | |
b4878f24 JA |
2426 | BUG_ON(!cfqq->queued[sync]); |
2427 | cfqq->queued[sync]--; | |
1da177e4 | 2428 | |
5e705374 | 2429 | elv_rb_del(&cfqq->sort_list, rq); |
1da177e4 | 2430 | |
f04a6424 VG |
2431 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) { |
2432 | /* | |
2433 | * Queue will be deleted from service tree when we actually | |
2434 | * expire it later. Right now just remove it from prio tree | |
2435 | * as it is empty. | |
2436 | */ | |
2437 | if (cfqq->p_root) { | |
2438 | rb_erase(&cfqq->p_node, cfqq->p_root); | |
2439 | cfqq->p_root = NULL; | |
2440 | } | |
2441 | } | |
1da177e4 LT |
2442 | } |
2443 | ||
5e705374 | 2444 | static void cfq_add_rq_rb(struct request *rq) |
1da177e4 | 2445 | { |
5e705374 | 2446 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
1da177e4 | 2447 | struct cfq_data *cfqd = cfqq->cfqd; |
796d5116 | 2448 | struct request *prev; |
1da177e4 | 2449 | |
5380a101 | 2450 | cfqq->queued[rq_is_sync(rq)]++; |
1da177e4 | 2451 | |
796d5116 | 2452 | elv_rb_add(&cfqq->sort_list, rq); |
5fccbf61 JA |
2453 | |
2454 | if (!cfq_cfqq_on_rr(cfqq)) | |
2455 | cfq_add_cfqq_rr(cfqd, cfqq); | |
5044eed4 JA |
2456 | |
2457 | /* | |
2458 | * check if this request is a better next-serve candidate | |
2459 | */ | |
a36e71f9 | 2460 | prev = cfqq->next_rq; |
cf7c25cf | 2461 | cfqq->next_rq = cfq_choose_req(cfqd, cfqq->next_rq, rq, cfqd->last_position); |
a36e71f9 JA |
2462 | |
2463 | /* | |
2464 | * adjust priority tree position, if ->next_rq changes | |
2465 | */ | |
2466 | if (prev != cfqq->next_rq) | |
2467 | cfq_prio_tree_add(cfqd, cfqq); | |
2468 | ||
5044eed4 | 2469 | BUG_ON(!cfqq->next_rq); |
1da177e4 LT |
2470 | } |
2471 | ||
febffd61 | 2472 | static void cfq_reposition_rq_rb(struct cfq_queue *cfqq, struct request *rq) |
1da177e4 | 2473 | { |
5380a101 JA |
2474 | elv_rb_del(&cfqq->sort_list, rq); |
2475 | cfqq->queued[rq_is_sync(rq)]--; | |
63a4cc24 | 2476 | cfqg_stats_update_io_remove(RQ_CFQG(rq), req_op(rq), rq->cmd_flags); |
5e705374 | 2477 | cfq_add_rq_rb(rq); |
155fead9 | 2478 | cfqg_stats_update_io_add(RQ_CFQG(rq), cfqq->cfqd->serving_group, |
63a4cc24 | 2479 | req_op(rq), rq->cmd_flags); |
1da177e4 LT |
2480 | } |
2481 | ||
206dc69b JA |
2482 | static struct request * |
2483 | cfq_find_rq_fmerge(struct cfq_data *cfqd, struct bio *bio) | |
1da177e4 | 2484 | { |
206dc69b | 2485 | struct task_struct *tsk = current; |
c5869807 | 2486 | struct cfq_io_cq *cic; |
206dc69b | 2487 | struct cfq_queue *cfqq; |
1da177e4 | 2488 | |
4ac845a2 | 2489 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
91fac317 VT |
2490 | if (!cic) |
2491 | return NULL; | |
2492 | ||
2493 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); | |
f73a1c7d KO |
2494 | if (cfqq) |
2495 | return elv_rb_find(&cfqq->sort_list, bio_end_sector(bio)); | |
1da177e4 | 2496 | |
1da177e4 LT |
2497 | return NULL; |
2498 | } | |
2499 | ||
165125e1 | 2500 | static void cfq_activate_request(struct request_queue *q, struct request *rq) |
1da177e4 | 2501 | { |
22e2c507 | 2502 | struct cfq_data *cfqd = q->elevator->elevator_data; |
3b18152c | 2503 | |
53c583d2 | 2504 | cfqd->rq_in_driver++; |
7b679138 | 2505 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d", |
53c583d2 | 2506 | cfqd->rq_in_driver); |
25776e35 | 2507 | |
5b93629b | 2508 | cfqd->last_position = blk_rq_pos(rq) + blk_rq_sectors(rq); |
1da177e4 LT |
2509 | } |
2510 | ||
165125e1 | 2511 | static void cfq_deactivate_request(struct request_queue *q, struct request *rq) |
1da177e4 | 2512 | { |
b4878f24 JA |
2513 | struct cfq_data *cfqd = q->elevator->elevator_data; |
2514 | ||
53c583d2 CZ |
2515 | WARN_ON(!cfqd->rq_in_driver); |
2516 | cfqd->rq_in_driver--; | |
7b679138 | 2517 | cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "deactivate rq, drv=%d", |
53c583d2 | 2518 | cfqd->rq_in_driver); |
1da177e4 LT |
2519 | } |
2520 | ||
b4878f24 | 2521 | static void cfq_remove_request(struct request *rq) |
1da177e4 | 2522 | { |
5e705374 | 2523 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
21183b07 | 2524 | |
5e705374 JA |
2525 | if (cfqq->next_rq == rq) |
2526 | cfqq->next_rq = cfq_find_next_rq(cfqq->cfqd, cfqq, rq); | |
1da177e4 | 2527 | |
b4878f24 | 2528 | list_del_init(&rq->queuelist); |
5e705374 | 2529 | cfq_del_rq_rb(rq); |
374f84ac | 2530 | |
45333d5a | 2531 | cfqq->cfqd->rq_queued--; |
63a4cc24 | 2532 | cfqg_stats_update_io_remove(RQ_CFQG(rq), req_op(rq), rq->cmd_flags); |
65299a3b CH |
2533 | if (rq->cmd_flags & REQ_PRIO) { |
2534 | WARN_ON(!cfqq->prio_pending); | |
2535 | cfqq->prio_pending--; | |
b53d1ed7 | 2536 | } |
1da177e4 LT |
2537 | } |
2538 | ||
165125e1 JA |
2539 | static int cfq_merge(struct request_queue *q, struct request **req, |
2540 | struct bio *bio) | |
1da177e4 LT |
2541 | { |
2542 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
2543 | struct request *__rq; | |
1da177e4 | 2544 | |
206dc69b | 2545 | __rq = cfq_find_rq_fmerge(cfqd, bio); |
22e2c507 | 2546 | if (__rq && elv_rq_merge_ok(__rq, bio)) { |
9817064b JA |
2547 | *req = __rq; |
2548 | return ELEVATOR_FRONT_MERGE; | |
1da177e4 LT |
2549 | } |
2550 | ||
2551 | return ELEVATOR_NO_MERGE; | |
1da177e4 LT |
2552 | } |
2553 | ||
165125e1 | 2554 | static void cfq_merged_request(struct request_queue *q, struct request *req, |
21183b07 | 2555 | int type) |
1da177e4 | 2556 | { |
21183b07 | 2557 | if (type == ELEVATOR_FRONT_MERGE) { |
5e705374 | 2558 | struct cfq_queue *cfqq = RQ_CFQQ(req); |
1da177e4 | 2559 | |
5e705374 | 2560 | cfq_reposition_rq_rb(cfqq, req); |
1da177e4 | 2561 | } |
1da177e4 LT |
2562 | } |
2563 | ||
812d4026 DS |
2564 | static void cfq_bio_merged(struct request_queue *q, struct request *req, |
2565 | struct bio *bio) | |
2566 | { | |
63a4cc24 | 2567 | cfqg_stats_update_io_merged(RQ_CFQG(req), bio_op(bio), bio->bi_rw); |
812d4026 DS |
2568 | } |
2569 | ||
1da177e4 | 2570 | static void |
165125e1 | 2571 | cfq_merged_requests(struct request_queue *q, struct request *rq, |
1da177e4 LT |
2572 | struct request *next) |
2573 | { | |
cf7c25cf | 2574 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
4a0b75c7 SL |
2575 | struct cfq_data *cfqd = q->elevator->elevator_data; |
2576 | ||
22e2c507 JA |
2577 | /* |
2578 | * reposition in fifo if next is older than rq | |
2579 | */ | |
2580 | if (!list_empty(&rq->queuelist) && !list_empty(&next->queuelist) && | |
9a7f38c4 | 2581 | next->fifo_time < rq->fifo_time && |
3d106fba | 2582 | cfqq == RQ_CFQQ(next)) { |
22e2c507 | 2583 | list_move(&rq->queuelist, &next->queuelist); |
8b4922d3 | 2584 | rq->fifo_time = next->fifo_time; |
30996f40 | 2585 | } |
22e2c507 | 2586 | |
cf7c25cf CZ |
2587 | if (cfqq->next_rq == next) |
2588 | cfqq->next_rq = rq; | |
b4878f24 | 2589 | cfq_remove_request(next); |
63a4cc24 | 2590 | cfqg_stats_update_io_merged(RQ_CFQG(rq), req_op(next), next->cmd_flags); |
4a0b75c7 SL |
2591 | |
2592 | cfqq = RQ_CFQQ(next); | |
2593 | /* | |
2594 | * all requests of this queue are merged to other queues, delete it | |
2595 | * from the service tree. If it's the active_queue, | |
2596 | * cfq_dispatch_requests() will choose to expire it or do idle | |
2597 | */ | |
2598 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list) && | |
2599 | cfqq != cfqd->active_queue) | |
2600 | cfq_del_cfqq_rr(cfqd, cfqq); | |
22e2c507 JA |
2601 | } |
2602 | ||
165125e1 | 2603 | static int cfq_allow_merge(struct request_queue *q, struct request *rq, |
da775265 JA |
2604 | struct bio *bio) |
2605 | { | |
2606 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
c5869807 | 2607 | struct cfq_io_cq *cic; |
da775265 | 2608 | struct cfq_queue *cfqq; |
da775265 JA |
2609 | |
2610 | /* | |
ec8acb69 | 2611 | * Disallow merge of a sync bio into an async request. |
da775265 | 2612 | */ |
91fac317 | 2613 | if (cfq_bio_sync(bio) && !rq_is_sync(rq)) |
a6151c3a | 2614 | return false; |
da775265 JA |
2615 | |
2616 | /* | |
f1a4f4d3 | 2617 | * Lookup the cfqq that this bio will be queued with and allow |
07c2bd37 | 2618 | * merge only if rq is queued there. |
f1a4f4d3 | 2619 | */ |
07c2bd37 TH |
2620 | cic = cfq_cic_lookup(cfqd, current->io_context); |
2621 | if (!cic) | |
2622 | return false; | |
719d3402 | 2623 | |
91fac317 | 2624 | cfqq = cic_to_cfqq(cic, cfq_bio_sync(bio)); |
a6151c3a | 2625 | return cfqq == RQ_CFQQ(rq); |
da775265 JA |
2626 | } |
2627 | ||
812df48d DS |
2628 | static inline void cfq_del_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
2629 | { | |
91148325 | 2630 | hrtimer_try_to_cancel(&cfqd->idle_slice_timer); |
155fead9 | 2631 | cfqg_stats_update_idle_time(cfqq->cfqg); |
812df48d DS |
2632 | } |
2633 | ||
febffd61 JA |
2634 | static void __cfq_set_active_queue(struct cfq_data *cfqd, |
2635 | struct cfq_queue *cfqq) | |
22e2c507 JA |
2636 | { |
2637 | if (cfqq) { | |
3bf10fea | 2638 | cfq_log_cfqq(cfqd, cfqq, "set_active wl_class:%d wl_type:%d", |
4d2ceea4 | 2639 | cfqd->serving_wl_class, cfqd->serving_wl_type); |
155fead9 | 2640 | cfqg_stats_update_avg_queue_size(cfqq->cfqg); |
62a37f6b | 2641 | cfqq->slice_start = 0; |
9a7f38c4 | 2642 | cfqq->dispatch_start = ktime_get_ns(); |
62a37f6b JT |
2643 | cfqq->allocated_slice = 0; |
2644 | cfqq->slice_end = 0; | |
2645 | cfqq->slice_dispatch = 0; | |
2646 | cfqq->nr_sectors = 0; | |
2647 | ||
2648 | cfq_clear_cfqq_wait_request(cfqq); | |
2649 | cfq_clear_cfqq_must_dispatch(cfqq); | |
2650 | cfq_clear_cfqq_must_alloc_slice(cfqq); | |
2651 | cfq_clear_cfqq_fifo_expire(cfqq); | |
2652 | cfq_mark_cfqq_slice_new(cfqq); | |
2653 | ||
2654 | cfq_del_timer(cfqd, cfqq); | |
22e2c507 JA |
2655 | } |
2656 | ||
2657 | cfqd->active_queue = cfqq; | |
2658 | } | |
2659 | ||
7b14e3b5 JA |
2660 | /* |
2661 | * current cfqq expired its slice (or was too idle), select new one | |
2662 | */ | |
2663 | static void | |
2664 | __cfq_slice_expired(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
e5ff082e | 2665 | bool timed_out) |
7b14e3b5 | 2666 | { |
7b679138 JA |
2667 | cfq_log_cfqq(cfqd, cfqq, "slice expired t=%d", timed_out); |
2668 | ||
7b14e3b5 | 2669 | if (cfq_cfqq_wait_request(cfqq)) |
812df48d | 2670 | cfq_del_timer(cfqd, cfqq); |
7b14e3b5 | 2671 | |
7b14e3b5 | 2672 | cfq_clear_cfqq_wait_request(cfqq); |
f75edf2d | 2673 | cfq_clear_cfqq_wait_busy(cfqq); |
7b14e3b5 | 2674 | |
ae54abed SL |
2675 | /* |
2676 | * If this cfqq is shared between multiple processes, check to | |
2677 | * make sure that those processes are still issuing I/Os within | |
2678 | * the mean seek distance. If not, it may be time to break the | |
2679 | * queues apart again. | |
2680 | */ | |
2681 | if (cfq_cfqq_coop(cfqq) && CFQQ_SEEKY(cfqq)) | |
2682 | cfq_mark_cfqq_split_coop(cfqq); | |
2683 | ||
7b14e3b5 | 2684 | /* |
6084cdda | 2685 | * store what was left of this slice, if the queue idled/timed out |
7b14e3b5 | 2686 | */ |
c553f8e3 SL |
2687 | if (timed_out) { |
2688 | if (cfq_cfqq_slice_new(cfqq)) | |
ba5bd520 | 2689 | cfqq->slice_resid = cfq_scaled_cfqq_slice(cfqd, cfqq); |
c553f8e3 | 2690 | else |
9a7f38c4 | 2691 | cfqq->slice_resid = cfqq->slice_end - ktime_get_ns(); |
93fdf147 | 2692 | cfq_log_cfqq(cfqd, cfqq, "resid=%lld", cfqq->slice_resid); |
7b679138 | 2693 | } |
7b14e3b5 | 2694 | |
e5ff082e | 2695 | cfq_group_served(cfqd, cfqq->cfqg, cfqq); |
dae739eb | 2696 | |
f04a6424 VG |
2697 | if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list)) |
2698 | cfq_del_cfqq_rr(cfqd, cfqq); | |
2699 | ||
edd75ffd | 2700 | cfq_resort_rr_list(cfqd, cfqq); |
7b14e3b5 JA |
2701 | |
2702 | if (cfqq == cfqd->active_queue) | |
2703 | cfqd->active_queue = NULL; | |
2704 | ||
2705 | if (cfqd->active_cic) { | |
11a3122f | 2706 | put_io_context(cfqd->active_cic->icq.ioc); |
7b14e3b5 JA |
2707 | cfqd->active_cic = NULL; |
2708 | } | |
7b14e3b5 JA |
2709 | } |
2710 | ||
e5ff082e | 2711 | static inline void cfq_slice_expired(struct cfq_data *cfqd, bool timed_out) |
7b14e3b5 JA |
2712 | { |
2713 | struct cfq_queue *cfqq = cfqd->active_queue; | |
2714 | ||
2715 | if (cfqq) | |
e5ff082e | 2716 | __cfq_slice_expired(cfqd, cfqq, timed_out); |
7b14e3b5 JA |
2717 | } |
2718 | ||
498d3aa2 JA |
2719 | /* |
2720 | * Get next queue for service. Unless we have a queue preemption, | |
2721 | * we'll simply select the first cfqq in the service tree. | |
2722 | */ | |
6d048f53 | 2723 | static struct cfq_queue *cfq_get_next_queue(struct cfq_data *cfqd) |
22e2c507 | 2724 | { |
34b98d03 VG |
2725 | struct cfq_rb_root *st = st_for(cfqd->serving_group, |
2726 | cfqd->serving_wl_class, cfqd->serving_wl_type); | |
d9e7620e | 2727 | |
f04a6424 VG |
2728 | if (!cfqd->rq_queued) |
2729 | return NULL; | |
2730 | ||
1fa8f6d6 | 2731 | /* There is nothing to dispatch */ |
34b98d03 | 2732 | if (!st) |
1fa8f6d6 | 2733 | return NULL; |
34b98d03 | 2734 | if (RB_EMPTY_ROOT(&st->rb)) |
c0324a02 | 2735 | return NULL; |
34b98d03 | 2736 | return cfq_rb_first(st); |
6d048f53 JA |
2737 | } |
2738 | ||
f04a6424 VG |
2739 | static struct cfq_queue *cfq_get_next_queue_forced(struct cfq_data *cfqd) |
2740 | { | |
25fb5169 | 2741 | struct cfq_group *cfqg; |
f04a6424 VG |
2742 | struct cfq_queue *cfqq; |
2743 | int i, j; | |
2744 | struct cfq_rb_root *st; | |
2745 | ||
2746 | if (!cfqd->rq_queued) | |
2747 | return NULL; | |
2748 | ||
25fb5169 VG |
2749 | cfqg = cfq_get_next_cfqg(cfqd); |
2750 | if (!cfqg) | |
2751 | return NULL; | |
2752 | ||
f04a6424 VG |
2753 | for_each_cfqg_st(cfqg, i, j, st) |
2754 | if ((cfqq = cfq_rb_first(st)) != NULL) | |
2755 | return cfqq; | |
2756 | return NULL; | |
2757 | } | |
2758 | ||
498d3aa2 JA |
2759 | /* |
2760 | * Get and set a new active queue for service. | |
2761 | */ | |
a36e71f9 JA |
2762 | static struct cfq_queue *cfq_set_active_queue(struct cfq_data *cfqd, |
2763 | struct cfq_queue *cfqq) | |
6d048f53 | 2764 | { |
e00ef799 | 2765 | if (!cfqq) |
a36e71f9 | 2766 | cfqq = cfq_get_next_queue(cfqd); |
6d048f53 | 2767 | |
22e2c507 | 2768 | __cfq_set_active_queue(cfqd, cfqq); |
3b18152c | 2769 | return cfqq; |
22e2c507 JA |
2770 | } |
2771 | ||
d9e7620e JA |
2772 | static inline sector_t cfq_dist_from_last(struct cfq_data *cfqd, |
2773 | struct request *rq) | |
2774 | { | |
83096ebf TH |
2775 | if (blk_rq_pos(rq) >= cfqd->last_position) |
2776 | return blk_rq_pos(rq) - cfqd->last_position; | |
d9e7620e | 2777 | else |
83096ebf | 2778 | return cfqd->last_position - blk_rq_pos(rq); |
d9e7620e JA |
2779 | } |
2780 | ||
b2c18e1e | 2781 | static inline int cfq_rq_close(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
e9ce335d | 2782 | struct request *rq) |
6d048f53 | 2783 | { |
e9ce335d | 2784 | return cfq_dist_from_last(cfqd, rq) <= CFQQ_CLOSE_THR; |
6d048f53 JA |
2785 | } |
2786 | ||
a36e71f9 JA |
2787 | static struct cfq_queue *cfqq_close(struct cfq_data *cfqd, |
2788 | struct cfq_queue *cur_cfqq) | |
2789 | { | |
f2d1f0ae | 2790 | struct rb_root *root = &cfqd->prio_trees[cur_cfqq->org_ioprio]; |
a36e71f9 JA |
2791 | struct rb_node *parent, *node; |
2792 | struct cfq_queue *__cfqq; | |
2793 | sector_t sector = cfqd->last_position; | |
2794 | ||
2795 | if (RB_EMPTY_ROOT(root)) | |
2796 | return NULL; | |
2797 | ||
2798 | /* | |
2799 | * First, if we find a request starting at the end of the last | |
2800 | * request, choose it. | |
2801 | */ | |
f2d1f0ae | 2802 | __cfqq = cfq_prio_tree_lookup(cfqd, root, sector, &parent, NULL); |
a36e71f9 JA |
2803 | if (__cfqq) |
2804 | return __cfqq; | |
2805 | ||
2806 | /* | |
2807 | * If the exact sector wasn't found, the parent of the NULL leaf | |
2808 | * will contain the closest sector. | |
2809 | */ | |
2810 | __cfqq = rb_entry(parent, struct cfq_queue, p_node); | |
e9ce335d | 2811 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
a36e71f9 JA |
2812 | return __cfqq; |
2813 | ||
2e46e8b2 | 2814 | if (blk_rq_pos(__cfqq->next_rq) < sector) |
a36e71f9 JA |
2815 | node = rb_next(&__cfqq->p_node); |
2816 | else | |
2817 | node = rb_prev(&__cfqq->p_node); | |
2818 | if (!node) | |
2819 | return NULL; | |
2820 | ||
2821 | __cfqq = rb_entry(node, struct cfq_queue, p_node); | |
e9ce335d | 2822 | if (cfq_rq_close(cfqd, cur_cfqq, __cfqq->next_rq)) |
a36e71f9 JA |
2823 | return __cfqq; |
2824 | ||
2825 | return NULL; | |
2826 | } | |
2827 | ||
2828 | /* | |
2829 | * cfqd - obvious | |
2830 | * cur_cfqq - passed in so that we don't decide that the current queue is | |
2831 | * closely cooperating with itself. | |
2832 | * | |
2833 | * So, basically we're assuming that that cur_cfqq has dispatched at least | |
2834 | * one request, and that cfqd->last_position reflects a position on the disk | |
2835 | * associated with the I/O issued by cur_cfqq. I'm not sure this is a valid | |
2836 | * assumption. | |
2837 | */ | |
2838 | static struct cfq_queue *cfq_close_cooperator(struct cfq_data *cfqd, | |
b3b6d040 | 2839 | struct cfq_queue *cur_cfqq) |
6d048f53 | 2840 | { |
a36e71f9 JA |
2841 | struct cfq_queue *cfqq; |
2842 | ||
39c01b21 DS |
2843 | if (cfq_class_idle(cur_cfqq)) |
2844 | return NULL; | |
e6c5bc73 JM |
2845 | if (!cfq_cfqq_sync(cur_cfqq)) |
2846 | return NULL; | |
2847 | if (CFQQ_SEEKY(cur_cfqq)) | |
2848 | return NULL; | |
2849 | ||
b9d8f4c7 GJ |
2850 | /* |
2851 | * Don't search priority tree if it's the only queue in the group. | |
2852 | */ | |
2853 | if (cur_cfqq->cfqg->nr_cfqq == 1) | |
2854 | return NULL; | |
2855 | ||
6d048f53 | 2856 | /* |
d9e7620e JA |
2857 | * We should notice if some of the queues are cooperating, eg |
2858 | * working closely on the same area of the disk. In that case, | |
2859 | * we can group them together and don't waste time idling. | |
6d048f53 | 2860 | */ |
a36e71f9 JA |
2861 | cfqq = cfqq_close(cfqd, cur_cfqq); |
2862 | if (!cfqq) | |
2863 | return NULL; | |
2864 | ||
8682e1f1 VG |
2865 | /* If new queue belongs to different cfq_group, don't choose it */ |
2866 | if (cur_cfqq->cfqg != cfqq->cfqg) | |
2867 | return NULL; | |
2868 | ||
df5fe3e8 JM |
2869 | /* |
2870 | * It only makes sense to merge sync queues. | |
2871 | */ | |
2872 | if (!cfq_cfqq_sync(cfqq)) | |
2873 | return NULL; | |
e6c5bc73 JM |
2874 | if (CFQQ_SEEKY(cfqq)) |
2875 | return NULL; | |
df5fe3e8 | 2876 | |
c0324a02 CZ |
2877 | /* |
2878 | * Do not merge queues of different priority classes | |
2879 | */ | |
2880 | if (cfq_class_rt(cfqq) != cfq_class_rt(cur_cfqq)) | |
2881 | return NULL; | |
2882 | ||
a36e71f9 | 2883 | return cfqq; |
6d048f53 JA |
2884 | } |
2885 | ||
a6d44e98 CZ |
2886 | /* |
2887 | * Determine whether we should enforce idle window for this queue. | |
2888 | */ | |
2889 | ||
2890 | static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
2891 | { | |
3bf10fea | 2892 | enum wl_class_t wl_class = cfqq_class(cfqq); |
34b98d03 | 2893 | struct cfq_rb_root *st = cfqq->service_tree; |
a6d44e98 | 2894 | |
34b98d03 VG |
2895 | BUG_ON(!st); |
2896 | BUG_ON(!st->count); | |
f04a6424 | 2897 | |
b6508c16 VG |
2898 | if (!cfqd->cfq_slice_idle) |
2899 | return false; | |
2900 | ||
a6d44e98 | 2901 | /* We never do for idle class queues. */ |
3bf10fea | 2902 | if (wl_class == IDLE_WORKLOAD) |
a6d44e98 CZ |
2903 | return false; |
2904 | ||
2905 | /* We do for queues that were marked with idle window flag. */ | |
3c764b7a SL |
2906 | if (cfq_cfqq_idle_window(cfqq) && |
2907 | !(blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)) | |
a6d44e98 CZ |
2908 | return true; |
2909 | ||
2910 | /* | |
2911 | * Otherwise, we do only if they are the last ones | |
2912 | * in their service tree. | |
2913 | */ | |
34b98d03 VG |
2914 | if (st->count == 1 && cfq_cfqq_sync(cfqq) && |
2915 | !cfq_io_thinktime_big(cfqd, &st->ttime, false)) | |
c1e44756 | 2916 | return true; |
34b98d03 | 2917 | cfq_log_cfqq(cfqd, cfqq, "Not idling. st->count:%d", st->count); |
c1e44756 | 2918 | return false; |
a6d44e98 CZ |
2919 | } |
2920 | ||
6d048f53 | 2921 | static void cfq_arm_slice_timer(struct cfq_data *cfqd) |
22e2c507 | 2922 | { |
1792669c | 2923 | struct cfq_queue *cfqq = cfqd->active_queue; |
e795421e | 2924 | struct cfq_rb_root *st = cfqq->service_tree; |
c5869807 | 2925 | struct cfq_io_cq *cic; |
9a7f38c4 JM |
2926 | u64 sl, group_idle = 0; |
2927 | u64 now = ktime_get_ns(); | |
7b14e3b5 | 2928 | |
a68bbddb | 2929 | /* |
f7d7b7a7 JA |
2930 | * SSD device without seek penalty, disable idling. But only do so |
2931 | * for devices that support queuing, otherwise we still have a problem | |
2932 | * with sync vs async workloads. | |
a68bbddb | 2933 | */ |
f7d7b7a7 | 2934 | if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag) |
a68bbddb JA |
2935 | return; |
2936 | ||
dd67d051 | 2937 | WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list)); |
6d048f53 | 2938 | WARN_ON(cfq_cfqq_slice_new(cfqq)); |
22e2c507 JA |
2939 | |
2940 | /* | |
2941 | * idle is disabled, either manually or by past process history | |
2942 | */ | |
80bdf0c7 VG |
2943 | if (!cfq_should_idle(cfqd, cfqq)) { |
2944 | /* no queue idling. Check for group idling */ | |
2945 | if (cfqd->cfq_group_idle) | |
2946 | group_idle = cfqd->cfq_group_idle; | |
2947 | else | |
2948 | return; | |
2949 | } | |
6d048f53 | 2950 | |
7b679138 | 2951 | /* |
8e550632 | 2952 | * still active requests from this queue, don't idle |
7b679138 | 2953 | */ |
8e550632 | 2954 | if (cfqq->dispatched) |
7b679138 JA |
2955 | return; |
2956 | ||
22e2c507 JA |
2957 | /* |
2958 | * task has exited, don't wait | |
2959 | */ | |
206dc69b | 2960 | cic = cfqd->active_cic; |
f6e8d01b | 2961 | if (!cic || !atomic_read(&cic->icq.ioc->active_ref)) |
6d048f53 JA |
2962 | return; |
2963 | ||
355b659c CZ |
2964 | /* |
2965 | * If our average think time is larger than the remaining time | |
2966 | * slice, then don't idle. This avoids overrunning the allotted | |
2967 | * time slice. | |
2968 | */ | |
383cd721 | 2969 | if (sample_valid(cic->ttime.ttime_samples) && |
9a7f38c4 JM |
2970 | (cfqq->slice_end - now < cic->ttime.ttime_mean)) { |
2971 | cfq_log_cfqq(cfqd, cfqq, "Not idling. think_time:%llu", | |
383cd721 | 2972 | cic->ttime.ttime_mean); |
355b659c | 2973 | return; |
b1ffe737 | 2974 | } |
355b659c | 2975 | |
e795421e JK |
2976 | /* |
2977 | * There are other queues in the group or this is the only group and | |
2978 | * it has too big thinktime, don't do group idle. | |
2979 | */ | |
2980 | if (group_idle && | |
2981 | (cfqq->cfqg->nr_cfqq > 1 || | |
2982 | cfq_io_thinktime_big(cfqd, &st->ttime, true))) | |
80bdf0c7 VG |
2983 | return; |
2984 | ||
3b18152c | 2985 | cfq_mark_cfqq_wait_request(cfqq); |
22e2c507 | 2986 | |
80bdf0c7 VG |
2987 | if (group_idle) |
2988 | sl = cfqd->cfq_group_idle; | |
2989 | else | |
2990 | sl = cfqd->cfq_slice_idle; | |
206dc69b | 2991 | |
91148325 JK |
2992 | hrtimer_start(&cfqd->idle_slice_timer, ns_to_ktime(sl), |
2993 | HRTIMER_MODE_REL); | |
155fead9 | 2994 | cfqg_stats_set_start_idle_time(cfqq->cfqg); |
9a7f38c4 | 2995 | cfq_log_cfqq(cfqd, cfqq, "arm_idle: %llu group_idle: %d", sl, |
80bdf0c7 | 2996 | group_idle ? 1 : 0); |
1da177e4 LT |
2997 | } |
2998 | ||
498d3aa2 JA |
2999 | /* |
3000 | * Move request from internal lists to the request queue dispatch list. | |
3001 | */ | |
165125e1 | 3002 | static void cfq_dispatch_insert(struct request_queue *q, struct request *rq) |
1da177e4 | 3003 | { |
3ed9a296 | 3004 | struct cfq_data *cfqd = q->elevator->elevator_data; |
5e705374 | 3005 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
22e2c507 | 3006 | |
7b679138 JA |
3007 | cfq_log_cfqq(cfqd, cfqq, "dispatch_insert"); |
3008 | ||
06d21886 | 3009 | cfqq->next_rq = cfq_find_next_rq(cfqd, cfqq, rq); |
5380a101 | 3010 | cfq_remove_request(rq); |
6d048f53 | 3011 | cfqq->dispatched++; |
80bdf0c7 | 3012 | (RQ_CFQG(rq))->dispatched++; |
5380a101 | 3013 | elv_dispatch_sort(q, rq); |
3ed9a296 | 3014 | |
53c583d2 | 3015 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++; |
c4e7893e | 3016 | cfqq->nr_sectors += blk_rq_sectors(rq); |
1da177e4 LT |
3017 | } |
3018 | ||
3019 | /* | |
3020 | * return expired entry, or NULL to just start from scratch in rbtree | |
3021 | */ | |
febffd61 | 3022 | static struct request *cfq_check_fifo(struct cfq_queue *cfqq) |
1da177e4 | 3023 | { |
30996f40 | 3024 | struct request *rq = NULL; |
1da177e4 | 3025 | |
3b18152c | 3026 | if (cfq_cfqq_fifo_expire(cfqq)) |
1da177e4 | 3027 | return NULL; |
cb887411 JA |
3028 | |
3029 | cfq_mark_cfqq_fifo_expire(cfqq); | |
3030 | ||
89850f7e JA |
3031 | if (list_empty(&cfqq->fifo)) |
3032 | return NULL; | |
1da177e4 | 3033 | |
89850f7e | 3034 | rq = rq_entry_fifo(cfqq->fifo.next); |
9a7f38c4 | 3035 | if (ktime_get_ns() < rq->fifo_time) |
7b679138 | 3036 | rq = NULL; |
1da177e4 | 3037 | |
30996f40 | 3038 | cfq_log_cfqq(cfqq->cfqd, cfqq, "fifo=%p", rq); |
6d048f53 | 3039 | return rq; |
1da177e4 LT |
3040 | } |
3041 | ||
22e2c507 JA |
3042 | static inline int |
3043 | cfq_prio_to_maxrq(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3044 | { | |
3045 | const int base_rq = cfqd->cfq_slice_async_rq; | |
1da177e4 | 3046 | |
22e2c507 | 3047 | WARN_ON(cfqq->ioprio >= IOPRIO_BE_NR); |
1da177e4 | 3048 | |
b9f8ce05 | 3049 | return 2 * base_rq * (IOPRIO_BE_NR - cfqq->ioprio); |
1da177e4 LT |
3050 | } |
3051 | ||
df5fe3e8 JM |
3052 | /* |
3053 | * Must be called with the queue_lock held. | |
3054 | */ | |
3055 | static int cfqq_process_refs(struct cfq_queue *cfqq) | |
3056 | { | |
3057 | int process_refs, io_refs; | |
3058 | ||
3059 | io_refs = cfqq->allocated[READ] + cfqq->allocated[WRITE]; | |
30d7b944 | 3060 | process_refs = cfqq->ref - io_refs; |
df5fe3e8 JM |
3061 | BUG_ON(process_refs < 0); |
3062 | return process_refs; | |
3063 | } | |
3064 | ||
3065 | static void cfq_setup_merge(struct cfq_queue *cfqq, struct cfq_queue *new_cfqq) | |
3066 | { | |
e6c5bc73 | 3067 | int process_refs, new_process_refs; |
df5fe3e8 JM |
3068 | struct cfq_queue *__cfqq; |
3069 | ||
c10b61f0 JM |
3070 | /* |
3071 | * If there are no process references on the new_cfqq, then it is | |
3072 | * unsafe to follow the ->new_cfqq chain as other cfqq's in the | |
3073 | * chain may have dropped their last reference (not just their | |
3074 | * last process reference). | |
3075 | */ | |
3076 | if (!cfqq_process_refs(new_cfqq)) | |
3077 | return; | |
3078 | ||
df5fe3e8 JM |
3079 | /* Avoid a circular list and skip interim queue merges */ |
3080 | while ((__cfqq = new_cfqq->new_cfqq)) { | |
3081 | if (__cfqq == cfqq) | |
3082 | return; | |
3083 | new_cfqq = __cfqq; | |
3084 | } | |
3085 | ||
3086 | process_refs = cfqq_process_refs(cfqq); | |
c10b61f0 | 3087 | new_process_refs = cfqq_process_refs(new_cfqq); |
df5fe3e8 JM |
3088 | /* |
3089 | * If the process for the cfqq has gone away, there is no | |
3090 | * sense in merging the queues. | |
3091 | */ | |
c10b61f0 | 3092 | if (process_refs == 0 || new_process_refs == 0) |
df5fe3e8 JM |
3093 | return; |
3094 | ||
e6c5bc73 JM |
3095 | /* |
3096 | * Merge in the direction of the lesser amount of work. | |
3097 | */ | |
e6c5bc73 JM |
3098 | if (new_process_refs >= process_refs) { |
3099 | cfqq->new_cfqq = new_cfqq; | |
30d7b944 | 3100 | new_cfqq->ref += process_refs; |
e6c5bc73 JM |
3101 | } else { |
3102 | new_cfqq->new_cfqq = cfqq; | |
30d7b944 | 3103 | cfqq->ref += new_process_refs; |
e6c5bc73 | 3104 | } |
df5fe3e8 JM |
3105 | } |
3106 | ||
6d816ec7 | 3107 | static enum wl_type_t cfq_choose_wl_type(struct cfq_data *cfqd, |
3bf10fea | 3108 | struct cfq_group *cfqg, enum wl_class_t wl_class) |
718eee05 CZ |
3109 | { |
3110 | struct cfq_queue *queue; | |
3111 | int i; | |
3112 | bool key_valid = false; | |
9a7f38c4 | 3113 | u64 lowest_key = 0; |
718eee05 CZ |
3114 | enum wl_type_t cur_best = SYNC_NOIDLE_WORKLOAD; |
3115 | ||
65b32a57 VG |
3116 | for (i = 0; i <= SYNC_WORKLOAD; ++i) { |
3117 | /* select the one with lowest rb_key */ | |
34b98d03 | 3118 | queue = cfq_rb_first(st_for(cfqg, wl_class, i)); |
718eee05 | 3119 | if (queue && |
9a7f38c4 | 3120 | (!key_valid || queue->rb_key < lowest_key)) { |
718eee05 CZ |
3121 | lowest_key = queue->rb_key; |
3122 | cur_best = i; | |
3123 | key_valid = true; | |
3124 | } | |
3125 | } | |
3126 | ||
3127 | return cur_best; | |
3128 | } | |
3129 | ||
6d816ec7 VG |
3130 | static void |
3131 | choose_wl_class_and_type(struct cfq_data *cfqd, struct cfq_group *cfqg) | |
718eee05 | 3132 | { |
9a7f38c4 | 3133 | u64 slice; |
718eee05 | 3134 | unsigned count; |
cdb16e8f | 3135 | struct cfq_rb_root *st; |
9a7f38c4 | 3136 | u64 group_slice; |
4d2ceea4 | 3137 | enum wl_class_t original_class = cfqd->serving_wl_class; |
9a7f38c4 | 3138 | u64 now = ktime_get_ns(); |
1fa8f6d6 | 3139 | |
718eee05 | 3140 | /* Choose next priority. RT > BE > IDLE */ |
58ff82f3 | 3141 | if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg)) |
4d2ceea4 | 3142 | cfqd->serving_wl_class = RT_WORKLOAD; |
58ff82f3 | 3143 | else if (cfq_group_busy_queues_wl(BE_WORKLOAD, cfqd, cfqg)) |
4d2ceea4 | 3144 | cfqd->serving_wl_class = BE_WORKLOAD; |
718eee05 | 3145 | else { |
4d2ceea4 | 3146 | cfqd->serving_wl_class = IDLE_WORKLOAD; |
9a7f38c4 | 3147 | cfqd->workload_expires = now + jiffies_to_nsecs(1); |
718eee05 CZ |
3148 | return; |
3149 | } | |
3150 | ||
4d2ceea4 | 3151 | if (original_class != cfqd->serving_wl_class) |
e4ea0c16 SL |
3152 | goto new_workload; |
3153 | ||
718eee05 CZ |
3154 | /* |
3155 | * For RT and BE, we have to choose also the type | |
3156 | * (SYNC, SYNC_NOIDLE, ASYNC), and to compute a workload | |
3157 | * expiration time | |
3158 | */ | |
34b98d03 | 3159 | st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type); |
cdb16e8f | 3160 | count = st->count; |
718eee05 CZ |
3161 | |
3162 | /* | |
65b32a57 | 3163 | * check workload expiration, and that we still have other queues ready |
718eee05 | 3164 | */ |
9a7f38c4 | 3165 | if (count && !(now > cfqd->workload_expires)) |
718eee05 CZ |
3166 | return; |
3167 | ||
e4ea0c16 | 3168 | new_workload: |
718eee05 | 3169 | /* otherwise select new workload type */ |
6d816ec7 | 3170 | cfqd->serving_wl_type = cfq_choose_wl_type(cfqd, cfqg, |
4d2ceea4 | 3171 | cfqd->serving_wl_class); |
34b98d03 | 3172 | st = st_for(cfqg, cfqd->serving_wl_class, cfqd->serving_wl_type); |
cdb16e8f | 3173 | count = st->count; |
718eee05 CZ |
3174 | |
3175 | /* | |
3176 | * the workload slice is computed as a fraction of target latency | |
3177 | * proportional to the number of queues in that workload, over | |
3178 | * all the queues in the same priority class | |
3179 | */ | |
58ff82f3 VG |
3180 | group_slice = cfq_group_slice(cfqd, cfqg); |
3181 | ||
9a7f38c4 | 3182 | slice = div_u64(group_slice * count, |
4d2ceea4 VG |
3183 | max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_wl_class], |
3184 | cfq_group_busy_queues_wl(cfqd->serving_wl_class, cfqd, | |
9a7f38c4 | 3185 | cfqg))); |
718eee05 | 3186 | |
4d2ceea4 | 3187 | if (cfqd->serving_wl_type == ASYNC_WORKLOAD) { |
9a7f38c4 | 3188 | u64 tmp; |
f26bd1f0 VG |
3189 | |
3190 | /* | |
3191 | * Async queues are currently system wide. Just taking | |
3192 | * proportion of queues with-in same group will lead to higher | |
3193 | * async ratio system wide as generally root group is going | |
3194 | * to have higher weight. A more accurate thing would be to | |
3195 | * calculate system wide asnc/sync ratio. | |
3196 | */ | |
5bf14c07 TM |
3197 | tmp = cfqd->cfq_target_latency * |
3198 | cfqg_busy_async_queues(cfqd, cfqg); | |
9a7f38c4 JM |
3199 | tmp = div_u64(tmp, cfqd->busy_queues); |
3200 | slice = min_t(u64, slice, tmp); | |
f26bd1f0 | 3201 | |
718eee05 CZ |
3202 | /* async workload slice is scaled down according to |
3203 | * the sync/async slice ratio. */ | |
9a7f38c4 | 3204 | slice = div64_u64(slice*cfqd->cfq_slice[0], cfqd->cfq_slice[1]); |
f26bd1f0 | 3205 | } else |
718eee05 CZ |
3206 | /* sync workload slice is at least 2 * cfq_slice_idle */ |
3207 | slice = max(slice, 2 * cfqd->cfq_slice_idle); | |
3208 | ||
9a7f38c4 JM |
3209 | slice = max_t(u64, slice, CFQ_MIN_TT); |
3210 | cfq_log(cfqd, "workload slice:%llu", slice); | |
3211 | cfqd->workload_expires = now + slice; | |
718eee05 CZ |
3212 | } |
3213 | ||
1fa8f6d6 VG |
3214 | static struct cfq_group *cfq_get_next_cfqg(struct cfq_data *cfqd) |
3215 | { | |
3216 | struct cfq_rb_root *st = &cfqd->grp_service_tree; | |
25bc6b07 | 3217 | struct cfq_group *cfqg; |
1fa8f6d6 VG |
3218 | |
3219 | if (RB_EMPTY_ROOT(&st->rb)) | |
3220 | return NULL; | |
25bc6b07 | 3221 | cfqg = cfq_rb_first_group(st); |
25bc6b07 VG |
3222 | update_min_vdisktime(st); |
3223 | return cfqg; | |
1fa8f6d6 VG |
3224 | } |
3225 | ||
cdb16e8f VG |
3226 | static void cfq_choose_cfqg(struct cfq_data *cfqd) |
3227 | { | |
1fa8f6d6 | 3228 | struct cfq_group *cfqg = cfq_get_next_cfqg(cfqd); |
9a7f38c4 | 3229 | u64 now = ktime_get_ns(); |
1fa8f6d6 VG |
3230 | |
3231 | cfqd->serving_group = cfqg; | |
dae739eb VG |
3232 | |
3233 | /* Restore the workload type data */ | |
4d2ceea4 | 3234 | if (cfqg->saved_wl_slice) { |
9a7f38c4 | 3235 | cfqd->workload_expires = now + cfqg->saved_wl_slice; |
4d2ceea4 VG |
3236 | cfqd->serving_wl_type = cfqg->saved_wl_type; |
3237 | cfqd->serving_wl_class = cfqg->saved_wl_class; | |
66ae2919 | 3238 | } else |
9a7f38c4 | 3239 | cfqd->workload_expires = now - 1; |
66ae2919 | 3240 | |
6d816ec7 | 3241 | choose_wl_class_and_type(cfqd, cfqg); |
cdb16e8f VG |
3242 | } |
3243 | ||
22e2c507 | 3244 | /* |
498d3aa2 JA |
3245 | * Select a queue for service. If we have a current active queue, |
3246 | * check whether to continue servicing it, or retrieve and set a new one. | |
22e2c507 | 3247 | */ |
1b5ed5e1 | 3248 | static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) |
1da177e4 | 3249 | { |
a36e71f9 | 3250 | struct cfq_queue *cfqq, *new_cfqq = NULL; |
9a7f38c4 | 3251 | u64 now = ktime_get_ns(); |
1da177e4 | 3252 | |
22e2c507 JA |
3253 | cfqq = cfqd->active_queue; |
3254 | if (!cfqq) | |
3255 | goto new_queue; | |
1da177e4 | 3256 | |
f04a6424 VG |
3257 | if (!cfqd->rq_queued) |
3258 | return NULL; | |
c244bb50 VG |
3259 | |
3260 | /* | |
3261 | * We were waiting for group to get backlogged. Expire the queue | |
3262 | */ | |
3263 | if (cfq_cfqq_wait_busy(cfqq) && !RB_EMPTY_ROOT(&cfqq->sort_list)) | |
3264 | goto expire; | |
3265 | ||
22e2c507 | 3266 | /* |
6d048f53 | 3267 | * The active queue has run out of time, expire it and select new. |
22e2c507 | 3268 | */ |
7667aa06 VG |
3269 | if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) { |
3270 | /* | |
3271 | * If slice had not expired at the completion of last request | |
3272 | * we might not have turned on wait_busy flag. Don't expire | |
3273 | * the queue yet. Allow the group to get backlogged. | |
3274 | * | |
3275 | * The very fact that we have used the slice, that means we | |
3276 | * have been idling all along on this queue and it should be | |
3277 | * ok to wait for this request to complete. | |
3278 | */ | |
82bbbf28 VG |
3279 | if (cfqq->cfqg->nr_cfqq == 1 && RB_EMPTY_ROOT(&cfqq->sort_list) |
3280 | && cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { | |
3281 | cfqq = NULL; | |
7667aa06 | 3282 | goto keep_queue; |
82bbbf28 | 3283 | } else |
80bdf0c7 | 3284 | goto check_group_idle; |
7667aa06 | 3285 | } |
1da177e4 | 3286 | |
22e2c507 | 3287 | /* |
6d048f53 JA |
3288 | * The active queue has requests and isn't expired, allow it to |
3289 | * dispatch. | |
22e2c507 | 3290 | */ |
dd67d051 | 3291 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
22e2c507 | 3292 | goto keep_queue; |
6d048f53 | 3293 | |
a36e71f9 JA |
3294 | /* |
3295 | * If another queue has a request waiting within our mean seek | |
3296 | * distance, let it run. The expire code will check for close | |
3297 | * cooperators and put the close queue at the front of the service | |
df5fe3e8 | 3298 | * tree. If possible, merge the expiring queue with the new cfqq. |
a36e71f9 | 3299 | */ |
b3b6d040 | 3300 | new_cfqq = cfq_close_cooperator(cfqd, cfqq); |
df5fe3e8 JM |
3301 | if (new_cfqq) { |
3302 | if (!cfqq->new_cfqq) | |
3303 | cfq_setup_merge(cfqq, new_cfqq); | |
a36e71f9 | 3304 | goto expire; |
df5fe3e8 | 3305 | } |
a36e71f9 | 3306 | |
6d048f53 JA |
3307 | /* |
3308 | * No requests pending. If the active queue still has requests in | |
3309 | * flight or is idling for a new request, allow either of these | |
3310 | * conditions to happen (or time out) before selecting a new queue. | |
3311 | */ | |
91148325 | 3312 | if (hrtimer_active(&cfqd->idle_slice_timer)) { |
80bdf0c7 VG |
3313 | cfqq = NULL; |
3314 | goto keep_queue; | |
3315 | } | |
3316 | ||
8e1ac665 SL |
3317 | /* |
3318 | * This is a deep seek queue, but the device is much faster than | |
3319 | * the queue can deliver, don't idle | |
3320 | **/ | |
3321 | if (CFQQ_SEEKY(cfqq) && cfq_cfqq_idle_window(cfqq) && | |
3322 | (cfq_cfqq_slice_new(cfqq) || | |
9a7f38c4 | 3323 | (cfqq->slice_end - now > now - cfqq->slice_start))) { |
8e1ac665 SL |
3324 | cfq_clear_cfqq_deep(cfqq); |
3325 | cfq_clear_cfqq_idle_window(cfqq); | |
3326 | } | |
3327 | ||
80bdf0c7 VG |
3328 | if (cfqq->dispatched && cfq_should_idle(cfqd, cfqq)) { |
3329 | cfqq = NULL; | |
3330 | goto keep_queue; | |
3331 | } | |
3332 | ||
3333 | /* | |
3334 | * If group idle is enabled and there are requests dispatched from | |
3335 | * this group, wait for requests to complete. | |
3336 | */ | |
3337 | check_group_idle: | |
7700fc4f SL |
3338 | if (cfqd->cfq_group_idle && cfqq->cfqg->nr_cfqq == 1 && |
3339 | cfqq->cfqg->dispatched && | |
3340 | !cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) { | |
caaa5f9f JA |
3341 | cfqq = NULL; |
3342 | goto keep_queue; | |
22e2c507 JA |
3343 | } |
3344 | ||
3b18152c | 3345 | expire: |
e5ff082e | 3346 | cfq_slice_expired(cfqd, 0); |
3b18152c | 3347 | new_queue: |
718eee05 CZ |
3348 | /* |
3349 | * Current queue expired. Check if we have to switch to a new | |
3350 | * service tree | |
3351 | */ | |
3352 | if (!new_cfqq) | |
cdb16e8f | 3353 | cfq_choose_cfqg(cfqd); |
718eee05 | 3354 | |
a36e71f9 | 3355 | cfqq = cfq_set_active_queue(cfqd, new_cfqq); |
22e2c507 | 3356 | keep_queue: |
3b18152c | 3357 | return cfqq; |
22e2c507 JA |
3358 | } |
3359 | ||
febffd61 | 3360 | static int __cfq_forced_dispatch_cfqq(struct cfq_queue *cfqq) |
d9e7620e JA |
3361 | { |
3362 | int dispatched = 0; | |
3363 | ||
3364 | while (cfqq->next_rq) { | |
3365 | cfq_dispatch_insert(cfqq->cfqd->queue, cfqq->next_rq); | |
3366 | dispatched++; | |
3367 | } | |
3368 | ||
3369 | BUG_ON(!list_empty(&cfqq->fifo)); | |
f04a6424 VG |
3370 | |
3371 | /* By default cfqq is not expired if it is empty. Do it explicitly */ | |
e5ff082e | 3372 | __cfq_slice_expired(cfqq->cfqd, cfqq, 0); |
d9e7620e JA |
3373 | return dispatched; |
3374 | } | |
3375 | ||
498d3aa2 JA |
3376 | /* |
3377 | * Drain our current requests. Used for barriers and when switching | |
3378 | * io schedulers on-the-fly. | |
3379 | */ | |
d9e7620e | 3380 | static int cfq_forced_dispatch(struct cfq_data *cfqd) |
1b5ed5e1 | 3381 | { |
0871714e | 3382 | struct cfq_queue *cfqq; |
d9e7620e | 3383 | int dispatched = 0; |
cdb16e8f | 3384 | |
3440c49f | 3385 | /* Expire the timeslice of the current active queue first */ |
e5ff082e | 3386 | cfq_slice_expired(cfqd, 0); |
3440c49f DS |
3387 | while ((cfqq = cfq_get_next_queue_forced(cfqd)) != NULL) { |
3388 | __cfq_set_active_queue(cfqd, cfqq); | |
f04a6424 | 3389 | dispatched += __cfq_forced_dispatch_cfqq(cfqq); |
3440c49f | 3390 | } |
1b5ed5e1 | 3391 | |
1b5ed5e1 TH |
3392 | BUG_ON(cfqd->busy_queues); |
3393 | ||
6923715a | 3394 | cfq_log(cfqd, "forced_dispatch=%d", dispatched); |
1b5ed5e1 TH |
3395 | return dispatched; |
3396 | } | |
3397 | ||
abc3c744 SL |
3398 | static inline bool cfq_slice_used_soon(struct cfq_data *cfqd, |
3399 | struct cfq_queue *cfqq) | |
3400 | { | |
9a7f38c4 JM |
3401 | u64 now = ktime_get_ns(); |
3402 | ||
abc3c744 SL |
3403 | /* the queue hasn't finished any request, can't estimate */ |
3404 | if (cfq_cfqq_slice_new(cfqq)) | |
c1e44756 | 3405 | return true; |
9a7f38c4 | 3406 | if (now + cfqd->cfq_slice_idle * cfqq->dispatched > cfqq->slice_end) |
c1e44756 | 3407 | return true; |
abc3c744 | 3408 | |
c1e44756 | 3409 | return false; |
abc3c744 SL |
3410 | } |
3411 | ||
0b182d61 | 3412 | static bool cfq_may_dispatch(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
2f5cb738 | 3413 | { |
2f5cb738 | 3414 | unsigned int max_dispatch; |
22e2c507 | 3415 | |
5ad531db JA |
3416 | /* |
3417 | * Drain async requests before we start sync IO | |
3418 | */ | |
53c583d2 | 3419 | if (cfq_should_idle(cfqd, cfqq) && cfqd->rq_in_flight[BLK_RW_ASYNC]) |
0b182d61 | 3420 | return false; |
5ad531db | 3421 | |
2f5cb738 JA |
3422 | /* |
3423 | * If this is an async queue and we have sync IO in flight, let it wait | |
3424 | */ | |
53c583d2 | 3425 | if (cfqd->rq_in_flight[BLK_RW_SYNC] && !cfq_cfqq_sync(cfqq)) |
0b182d61 | 3426 | return false; |
2f5cb738 | 3427 | |
abc3c744 | 3428 | max_dispatch = max_t(unsigned int, cfqd->cfq_quantum / 2, 1); |
2f5cb738 JA |
3429 | if (cfq_class_idle(cfqq)) |
3430 | max_dispatch = 1; | |
b4878f24 | 3431 | |
2f5cb738 JA |
3432 | /* |
3433 | * Does this cfqq already have too much IO in flight? | |
3434 | */ | |
3435 | if (cfqq->dispatched >= max_dispatch) { | |
ef8a41df | 3436 | bool promote_sync = false; |
2f5cb738 JA |
3437 | /* |
3438 | * idle queue must always only have a single IO in flight | |
3439 | */ | |
3ed9a296 | 3440 | if (cfq_class_idle(cfqq)) |
0b182d61 | 3441 | return false; |
3ed9a296 | 3442 | |
ef8a41df | 3443 | /* |
c4ade94f LS |
3444 | * If there is only one sync queue |
3445 | * we can ignore async queue here and give the sync | |
ef8a41df SL |
3446 | * queue no dispatch limit. The reason is a sync queue can |
3447 | * preempt async queue, limiting the sync queue doesn't make | |
3448 | * sense. This is useful for aiostress test. | |
3449 | */ | |
c4ade94f LS |
3450 | if (cfq_cfqq_sync(cfqq) && cfqd->busy_sync_queues == 1) |
3451 | promote_sync = true; | |
ef8a41df | 3452 | |
2f5cb738 JA |
3453 | /* |
3454 | * We have other queues, don't allow more IO from this one | |
3455 | */ | |
ef8a41df SL |
3456 | if (cfqd->busy_queues > 1 && cfq_slice_used_soon(cfqd, cfqq) && |
3457 | !promote_sync) | |
0b182d61 | 3458 | return false; |
9ede209e | 3459 | |
365722bb | 3460 | /* |
474b18cc | 3461 | * Sole queue user, no limit |
365722bb | 3462 | */ |
ef8a41df | 3463 | if (cfqd->busy_queues == 1 || promote_sync) |
abc3c744 SL |
3464 | max_dispatch = -1; |
3465 | else | |
3466 | /* | |
3467 | * Normally we start throttling cfqq when cfq_quantum/2 | |
3468 | * requests have been dispatched. But we can drive | |
3469 | * deeper queue depths at the beginning of slice | |
3470 | * subjected to upper limit of cfq_quantum. | |
3471 | * */ | |
3472 | max_dispatch = cfqd->cfq_quantum; | |
8e296755 JA |
3473 | } |
3474 | ||
3475 | /* | |
3476 | * Async queues must wait a bit before being allowed dispatch. | |
3477 | * We also ramp up the dispatch depth gradually for async IO, | |
3478 | * based on the last sync IO we serviced | |
3479 | */ | |
963b72fc | 3480 | if (!cfq_cfqq_sync(cfqq) && cfqd->cfq_latency) { |
9a7f38c4 | 3481 | u64 last_sync = ktime_get_ns() - cfqd->last_delayed_sync; |
8e296755 | 3482 | unsigned int depth; |
365722bb | 3483 | |
9a7f38c4 | 3484 | depth = div64_u64(last_sync, cfqd->cfq_slice[1]); |
e00c54c3 JA |
3485 | if (!depth && !cfqq->dispatched) |
3486 | depth = 1; | |
8e296755 JA |
3487 | if (depth < max_dispatch) |
3488 | max_dispatch = depth; | |
2f5cb738 | 3489 | } |
3ed9a296 | 3490 | |
0b182d61 JA |
3491 | /* |
3492 | * If we're below the current max, allow a dispatch | |
3493 | */ | |
3494 | return cfqq->dispatched < max_dispatch; | |
3495 | } | |
3496 | ||
3497 | /* | |
3498 | * Dispatch a request from cfqq, moving them to the request queue | |
3499 | * dispatch list. | |
3500 | */ | |
3501 | static bool cfq_dispatch_request(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3502 | { | |
3503 | struct request *rq; | |
3504 | ||
3505 | BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list)); | |
3506 | ||
3507 | if (!cfq_may_dispatch(cfqd, cfqq)) | |
3508 | return false; | |
3509 | ||
3510 | /* | |
3511 | * follow expired path, else get first next available | |
3512 | */ | |
3513 | rq = cfq_check_fifo(cfqq); | |
3514 | if (!rq) | |
3515 | rq = cfqq->next_rq; | |
3516 | ||
3517 | /* | |
3518 | * insert request into driver dispatch list | |
3519 | */ | |
3520 | cfq_dispatch_insert(cfqd->queue, rq); | |
3521 | ||
3522 | if (!cfqd->active_cic) { | |
c5869807 | 3523 | struct cfq_io_cq *cic = RQ_CIC(rq); |
0b182d61 | 3524 | |
c5869807 | 3525 | atomic_long_inc(&cic->icq.ioc->refcount); |
0b182d61 JA |
3526 | cfqd->active_cic = cic; |
3527 | } | |
3528 | ||
3529 | return true; | |
3530 | } | |
3531 | ||
3532 | /* | |
3533 | * Find the cfqq that we need to service and move a request from that to the | |
3534 | * dispatch list | |
3535 | */ | |
3536 | static int cfq_dispatch_requests(struct request_queue *q, int force) | |
3537 | { | |
3538 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
3539 | struct cfq_queue *cfqq; | |
3540 | ||
3541 | if (!cfqd->busy_queues) | |
3542 | return 0; | |
3543 | ||
3544 | if (unlikely(force)) | |
3545 | return cfq_forced_dispatch(cfqd); | |
3546 | ||
3547 | cfqq = cfq_select_queue(cfqd); | |
3548 | if (!cfqq) | |
8e296755 JA |
3549 | return 0; |
3550 | ||
2f5cb738 | 3551 | /* |
0b182d61 | 3552 | * Dispatch a request from this cfqq, if it is allowed |
2f5cb738 | 3553 | */ |
0b182d61 JA |
3554 | if (!cfq_dispatch_request(cfqd, cfqq)) |
3555 | return 0; | |
3556 | ||
2f5cb738 | 3557 | cfqq->slice_dispatch++; |
b029195d | 3558 | cfq_clear_cfqq_must_dispatch(cfqq); |
22e2c507 | 3559 | |
2f5cb738 JA |
3560 | /* |
3561 | * expire an async queue immediately if it has used up its slice. idle | |
3562 | * queue always expire after 1 dispatch round. | |
3563 | */ | |
3564 | if (cfqd->busy_queues > 1 && ((!cfq_cfqq_sync(cfqq) && | |
3565 | cfqq->slice_dispatch >= cfq_prio_to_maxrq(cfqd, cfqq)) || | |
3566 | cfq_class_idle(cfqq))) { | |
9a7f38c4 | 3567 | cfqq->slice_end = ktime_get_ns() + 1; |
e5ff082e | 3568 | cfq_slice_expired(cfqd, 0); |
1da177e4 LT |
3569 | } |
3570 | ||
b217a903 | 3571 | cfq_log_cfqq(cfqd, cfqq, "dispatched a request"); |
2f5cb738 | 3572 | return 1; |
1da177e4 LT |
3573 | } |
3574 | ||
1da177e4 | 3575 | /* |
5e705374 JA |
3576 | * task holds one reference to the queue, dropped when task exits. each rq |
3577 | * in-flight on this queue also holds a reference, dropped when rq is freed. | |
1da177e4 | 3578 | * |
b1c35769 | 3579 | * Each cfq queue took a reference on the parent group. Drop it now. |
1da177e4 LT |
3580 | * queue lock must be held here. |
3581 | */ | |
3582 | static void cfq_put_queue(struct cfq_queue *cfqq) | |
3583 | { | |
22e2c507 | 3584 | struct cfq_data *cfqd = cfqq->cfqd; |
0bbfeb83 | 3585 | struct cfq_group *cfqg; |
22e2c507 | 3586 | |
30d7b944 | 3587 | BUG_ON(cfqq->ref <= 0); |
1da177e4 | 3588 | |
30d7b944 SL |
3589 | cfqq->ref--; |
3590 | if (cfqq->ref) | |
1da177e4 LT |
3591 | return; |
3592 | ||
7b679138 | 3593 | cfq_log_cfqq(cfqd, cfqq, "put_queue"); |
1da177e4 | 3594 | BUG_ON(rb_first(&cfqq->sort_list)); |
22e2c507 | 3595 | BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); |
b1c35769 | 3596 | cfqg = cfqq->cfqg; |
1da177e4 | 3597 | |
28f95cbc | 3598 | if (unlikely(cfqd->active_queue == cfqq)) { |
e5ff082e | 3599 | __cfq_slice_expired(cfqd, cfqq, 0); |
23e018a1 | 3600 | cfq_schedule_dispatch(cfqd); |
28f95cbc | 3601 | } |
22e2c507 | 3602 | |
f04a6424 | 3603 | BUG_ON(cfq_cfqq_on_rr(cfqq)); |
1da177e4 | 3604 | kmem_cache_free(cfq_pool, cfqq); |
eb7d8c07 | 3605 | cfqg_put(cfqg); |
1da177e4 LT |
3606 | } |
3607 | ||
d02a2c07 | 3608 | static void cfq_put_cooperator(struct cfq_queue *cfqq) |
1da177e4 | 3609 | { |
df5fe3e8 JM |
3610 | struct cfq_queue *__cfqq, *next; |
3611 | ||
df5fe3e8 JM |
3612 | /* |
3613 | * If this queue was scheduled to merge with another queue, be | |
3614 | * sure to drop the reference taken on that queue (and others in | |
3615 | * the merge chain). See cfq_setup_merge and cfq_merge_cfqqs. | |
3616 | */ | |
3617 | __cfqq = cfqq->new_cfqq; | |
3618 | while (__cfqq) { | |
3619 | if (__cfqq == cfqq) { | |
3620 | WARN(1, "cfqq->new_cfqq loop detected\n"); | |
3621 | break; | |
3622 | } | |
3623 | next = __cfqq->new_cfqq; | |
3624 | cfq_put_queue(__cfqq); | |
3625 | __cfqq = next; | |
3626 | } | |
d02a2c07 SL |
3627 | } |
3628 | ||
3629 | static void cfq_exit_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
3630 | { | |
3631 | if (unlikely(cfqq == cfqd->active_queue)) { | |
3632 | __cfq_slice_expired(cfqd, cfqq, 0); | |
3633 | cfq_schedule_dispatch(cfqd); | |
3634 | } | |
3635 | ||
3636 | cfq_put_cooperator(cfqq); | |
df5fe3e8 | 3637 | |
89850f7e JA |
3638 | cfq_put_queue(cfqq); |
3639 | } | |
22e2c507 | 3640 | |
9b84cacd TH |
3641 | static void cfq_init_icq(struct io_cq *icq) |
3642 | { | |
3643 | struct cfq_io_cq *cic = icq_to_cic(icq); | |
3644 | ||
9a7f38c4 | 3645 | cic->ttime.last_end_request = ktime_get_ns(); |
9b84cacd TH |
3646 | } |
3647 | ||
c5869807 | 3648 | static void cfq_exit_icq(struct io_cq *icq) |
89850f7e | 3649 | { |
c5869807 | 3650 | struct cfq_io_cq *cic = icq_to_cic(icq); |
283287a5 | 3651 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
4faa3c81 | 3652 | |
563180a4 TH |
3653 | if (cic_to_cfqq(cic, false)) { |
3654 | cfq_exit_cfqq(cfqd, cic_to_cfqq(cic, false)); | |
3655 | cic_set_cfqq(cic, NULL, false); | |
12a05732 AV |
3656 | } |
3657 | ||
563180a4 TH |
3658 | if (cic_to_cfqq(cic, true)) { |
3659 | cfq_exit_cfqq(cfqd, cic_to_cfqq(cic, true)); | |
3660 | cic_set_cfqq(cic, NULL, true); | |
12a05732 | 3661 | } |
89850f7e JA |
3662 | } |
3663 | ||
abede6da | 3664 | static void cfq_init_prio_data(struct cfq_queue *cfqq, struct cfq_io_cq *cic) |
22e2c507 JA |
3665 | { |
3666 | struct task_struct *tsk = current; | |
3667 | int ioprio_class; | |
3668 | ||
3b18152c | 3669 | if (!cfq_cfqq_prio_changed(cfqq)) |
22e2c507 JA |
3670 | return; |
3671 | ||
598971bf | 3672 | ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio); |
22e2c507 | 3673 | switch (ioprio_class) { |
fe094d98 JA |
3674 | default: |
3675 | printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class); | |
3676 | case IOPRIO_CLASS_NONE: | |
3677 | /* | |
6d63c275 | 3678 | * no prio set, inherit CPU scheduling settings |
fe094d98 JA |
3679 | */ |
3680 | cfqq->ioprio = task_nice_ioprio(tsk); | |
6d63c275 | 3681 | cfqq->ioprio_class = task_nice_ioclass(tsk); |
fe094d98 JA |
3682 | break; |
3683 | case IOPRIO_CLASS_RT: | |
598971bf | 3684 | cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio); |
fe094d98 JA |
3685 | cfqq->ioprio_class = IOPRIO_CLASS_RT; |
3686 | break; | |
3687 | case IOPRIO_CLASS_BE: | |
598971bf | 3688 | cfqq->ioprio = IOPRIO_PRIO_DATA(cic->ioprio); |
fe094d98 JA |
3689 | cfqq->ioprio_class = IOPRIO_CLASS_BE; |
3690 | break; | |
3691 | case IOPRIO_CLASS_IDLE: | |
3692 | cfqq->ioprio_class = IOPRIO_CLASS_IDLE; | |
3693 | cfqq->ioprio = 7; | |
3694 | cfq_clear_cfqq_idle_window(cfqq); | |
3695 | break; | |
22e2c507 JA |
3696 | } |
3697 | ||
3698 | /* | |
3699 | * keep track of original prio settings in case we have to temporarily | |
3700 | * elevate the priority of this queue | |
3701 | */ | |
3702 | cfqq->org_ioprio = cfqq->ioprio; | |
b8269db4 | 3703 | cfqq->org_ioprio_class = cfqq->ioprio_class; |
3b18152c | 3704 | cfq_clear_cfqq_prio_changed(cfqq); |
22e2c507 JA |
3705 | } |
3706 | ||
598971bf | 3707 | static void check_ioprio_changed(struct cfq_io_cq *cic, struct bio *bio) |
22e2c507 | 3708 | { |
598971bf | 3709 | int ioprio = cic->icq.ioc->ioprio; |
bca4b914 | 3710 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
478a82b0 | 3711 | struct cfq_queue *cfqq; |
35e6077c | 3712 | |
598971bf TH |
3713 | /* |
3714 | * Check whether ioprio has changed. The condition may trigger | |
3715 | * spuriously on a newly created cic but there's no harm. | |
3716 | */ | |
3717 | if (unlikely(!cfqd) || likely(cic->ioprio == ioprio)) | |
caaa5f9f JA |
3718 | return; |
3719 | ||
563180a4 | 3720 | cfqq = cic_to_cfqq(cic, false); |
caaa5f9f | 3721 | if (cfqq) { |
563180a4 | 3722 | cfq_put_queue(cfqq); |
2da8de0b | 3723 | cfqq = cfq_get_queue(cfqd, BLK_RW_ASYNC, cic, bio); |
563180a4 | 3724 | cic_set_cfqq(cic, cfqq, false); |
22e2c507 | 3725 | } |
caaa5f9f | 3726 | |
563180a4 | 3727 | cfqq = cic_to_cfqq(cic, true); |
caaa5f9f JA |
3728 | if (cfqq) |
3729 | cfq_mark_cfqq_prio_changed(cfqq); | |
598971bf TH |
3730 | |
3731 | cic->ioprio = ioprio; | |
22e2c507 JA |
3732 | } |
3733 | ||
d5036d77 | 3734 | static void cfq_init_cfqq(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
a6151c3a | 3735 | pid_t pid, bool is_sync) |
d5036d77 JA |
3736 | { |
3737 | RB_CLEAR_NODE(&cfqq->rb_node); | |
3738 | RB_CLEAR_NODE(&cfqq->p_node); | |
3739 | INIT_LIST_HEAD(&cfqq->fifo); | |
3740 | ||
30d7b944 | 3741 | cfqq->ref = 0; |
d5036d77 JA |
3742 | cfqq->cfqd = cfqd; |
3743 | ||
3744 | cfq_mark_cfqq_prio_changed(cfqq); | |
3745 | ||
3746 | if (is_sync) { | |
3747 | if (!cfq_class_idle(cfqq)) | |
3748 | cfq_mark_cfqq_idle_window(cfqq); | |
3749 | cfq_mark_cfqq_sync(cfqq); | |
3750 | } | |
3751 | cfqq->pid = pid; | |
3752 | } | |
3753 | ||
24610333 | 3754 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
598971bf | 3755 | static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) |
24610333 | 3756 | { |
bca4b914 | 3757 | struct cfq_data *cfqd = cic_to_cfqd(cic); |
60a83707 | 3758 | struct cfq_queue *cfqq; |
f4da8072 | 3759 | uint64_t serial_nr; |
24610333 | 3760 | |
598971bf | 3761 | rcu_read_lock(); |
f4da8072 | 3762 | serial_nr = bio_blkcg(bio)->css.serial_nr; |
598971bf | 3763 | rcu_read_unlock(); |
24610333 | 3764 | |
598971bf TH |
3765 | /* |
3766 | * Check whether blkcg has changed. The condition may trigger | |
3767 | * spuriously on a newly created cic but there's no harm. | |
3768 | */ | |
f4da8072 | 3769 | if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr)) |
598971bf | 3770 | return; |
24610333 | 3771 | |
60a83707 TH |
3772 | /* |
3773 | * Drop reference to queues. New queues will be assigned in new | |
3774 | * group upon arrival of fresh requests. | |
3775 | */ | |
3776 | cfqq = cic_to_cfqq(cic, false); | |
3777 | if (cfqq) { | |
3778 | cfq_log_cfqq(cfqd, cfqq, "changed cgroup"); | |
3779 | cic_set_cfqq(cic, NULL, false); | |
3780 | cfq_put_queue(cfqq); | |
3781 | } | |
3782 | ||
3783 | cfqq = cic_to_cfqq(cic, true); | |
3784 | if (cfqq) { | |
3785 | cfq_log_cfqq(cfqd, cfqq, "changed cgroup"); | |
3786 | cic_set_cfqq(cic, NULL, true); | |
3787 | cfq_put_queue(cfqq); | |
24610333 | 3788 | } |
598971bf | 3789 | |
f4da8072 | 3790 | cic->blkcg_serial_nr = serial_nr; |
24610333 | 3791 | } |
598971bf TH |
3792 | #else |
3793 | static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { } | |
24610333 VG |
3794 | #endif /* CONFIG_CFQ_GROUP_IOSCHED */ |
3795 | ||
c2dea2d1 | 3796 | static struct cfq_queue ** |
60a83707 | 3797 | cfq_async_queue_prio(struct cfq_group *cfqg, int ioprio_class, int ioprio) |
c2dea2d1 | 3798 | { |
fe094d98 | 3799 | switch (ioprio_class) { |
c2dea2d1 | 3800 | case IOPRIO_CLASS_RT: |
60a83707 | 3801 | return &cfqg->async_cfqq[0][ioprio]; |
598971bf TH |
3802 | case IOPRIO_CLASS_NONE: |
3803 | ioprio = IOPRIO_NORM; | |
3804 | /* fall through */ | |
c2dea2d1 | 3805 | case IOPRIO_CLASS_BE: |
60a83707 | 3806 | return &cfqg->async_cfqq[1][ioprio]; |
c2dea2d1 | 3807 | case IOPRIO_CLASS_IDLE: |
60a83707 | 3808 | return &cfqg->async_idle_cfqq; |
c2dea2d1 VT |
3809 | default: |
3810 | BUG(); | |
3811 | } | |
3812 | } | |
3813 | ||
15c31be4 | 3814 | static struct cfq_queue * |
abede6da | 3815 | cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic, |
2da8de0b | 3816 | struct bio *bio) |
15c31be4 | 3817 | { |
c6ce1943 JM |
3818 | int ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio); |
3819 | int ioprio = IOPRIO_PRIO_DATA(cic->ioprio); | |
d4aad7ff | 3820 | struct cfq_queue **async_cfqq = NULL; |
4ebc1c61 | 3821 | struct cfq_queue *cfqq; |
322731ed TH |
3822 | struct cfq_group *cfqg; |
3823 | ||
3824 | rcu_read_lock(); | |
ae118896 | 3825 | cfqg = cfq_lookup_cfqg(cfqd, bio_blkcg(bio)); |
322731ed TH |
3826 | if (!cfqg) { |
3827 | cfqq = &cfqd->oom_cfqq; | |
3828 | goto out; | |
3829 | } | |
15c31be4 | 3830 | |
c2dea2d1 | 3831 | if (!is_sync) { |
c6ce1943 JM |
3832 | if (!ioprio_valid(cic->ioprio)) { |
3833 | struct task_struct *tsk = current; | |
3834 | ioprio = task_nice_ioprio(tsk); | |
3835 | ioprio_class = task_nice_ioclass(tsk); | |
3836 | } | |
60a83707 | 3837 | async_cfqq = cfq_async_queue_prio(cfqg, ioprio_class, ioprio); |
c2dea2d1 | 3838 | cfqq = *async_cfqq; |
4ebc1c61 TH |
3839 | if (cfqq) |
3840 | goto out; | |
c2dea2d1 VT |
3841 | } |
3842 | ||
d4aad7ff TH |
3843 | cfqq = kmem_cache_alloc_node(cfq_pool, GFP_NOWAIT | __GFP_ZERO, |
3844 | cfqd->queue->node); | |
3845 | if (!cfqq) { | |
3846 | cfqq = &cfqd->oom_cfqq; | |
3847 | goto out; | |
3848 | } | |
3849 | ||
3850 | cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync); | |
3851 | cfq_init_prio_data(cfqq, cic); | |
3852 | cfq_link_cfqq_cfqg(cfqq, cfqg); | |
3853 | cfq_log_cfqq(cfqd, cfqq, "alloced"); | |
15c31be4 | 3854 | |
d4aad7ff TH |
3855 | if (async_cfqq) { |
3856 | /* a new async queue is created, pin and remember */ | |
30d7b944 | 3857 | cfqq->ref++; |
c2dea2d1 | 3858 | *async_cfqq = cfqq; |
15c31be4 | 3859 | } |
4ebc1c61 | 3860 | out: |
30d7b944 | 3861 | cfqq->ref++; |
322731ed | 3862 | rcu_read_unlock(); |
15c31be4 JA |
3863 | return cfqq; |
3864 | } | |
3865 | ||
22e2c507 | 3866 | static void |
9a7f38c4 | 3867 | __cfq_update_io_thinktime(struct cfq_ttime *ttime, u64 slice_idle) |
1da177e4 | 3868 | { |
9a7f38c4 | 3869 | u64 elapsed = ktime_get_ns() - ttime->last_end_request; |
383cd721 | 3870 | elapsed = min(elapsed, 2UL * slice_idle); |
db3b5848 | 3871 | |
383cd721 | 3872 | ttime->ttime_samples = (7*ttime->ttime_samples + 256) / 8; |
9a7f38c4 JM |
3873 | ttime->ttime_total = div_u64(7*ttime->ttime_total + 256*elapsed, 8); |
3874 | ttime->ttime_mean = div64_ul(ttime->ttime_total + 128, | |
3875 | ttime->ttime_samples); | |
383cd721 SL |
3876 | } |
3877 | ||
3878 | static void | |
3879 | cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
c5869807 | 3880 | struct cfq_io_cq *cic) |
383cd721 | 3881 | { |
f5f2b6ce | 3882 | if (cfq_cfqq_sync(cfqq)) { |
383cd721 | 3883 | __cfq_update_io_thinktime(&cic->ttime, cfqd->cfq_slice_idle); |
f5f2b6ce SL |
3884 | __cfq_update_io_thinktime(&cfqq->service_tree->ttime, |
3885 | cfqd->cfq_slice_idle); | |
3886 | } | |
7700fc4f SL |
3887 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3888 | __cfq_update_io_thinktime(&cfqq->cfqg->ttime, cfqd->cfq_group_idle); | |
3889 | #endif | |
22e2c507 | 3890 | } |
1da177e4 | 3891 | |
206dc69b | 3892 | static void |
b2c18e1e | 3893 | cfq_update_io_seektime(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
6d048f53 | 3894 | struct request *rq) |
206dc69b | 3895 | { |
3dde36dd | 3896 | sector_t sdist = 0; |
41647e7a | 3897 | sector_t n_sec = blk_rq_sectors(rq); |
3dde36dd CZ |
3898 | if (cfqq->last_request_pos) { |
3899 | if (cfqq->last_request_pos < blk_rq_pos(rq)) | |
3900 | sdist = blk_rq_pos(rq) - cfqq->last_request_pos; | |
3901 | else | |
3902 | sdist = cfqq->last_request_pos - blk_rq_pos(rq); | |
3903 | } | |
206dc69b | 3904 | |
3dde36dd | 3905 | cfqq->seek_history <<= 1; |
41647e7a CZ |
3906 | if (blk_queue_nonrot(cfqd->queue)) |
3907 | cfqq->seek_history |= (n_sec < CFQQ_SECT_THR_NONROT); | |
3908 | else | |
3909 | cfqq->seek_history |= (sdist > CFQQ_SEEK_THR); | |
206dc69b | 3910 | } |
1da177e4 | 3911 | |
22e2c507 JA |
3912 | /* |
3913 | * Disable idle window if the process thinks too long or seeks so much that | |
3914 | * it doesn't matter | |
3915 | */ | |
3916 | static void | |
3917 | cfq_update_idle_window(struct cfq_data *cfqd, struct cfq_queue *cfqq, | |
c5869807 | 3918 | struct cfq_io_cq *cic) |
22e2c507 | 3919 | { |
7b679138 | 3920 | int old_idle, enable_idle; |
1be92f2f | 3921 | |
0871714e JA |
3922 | /* |
3923 | * Don't idle for async or idle io prio class | |
3924 | */ | |
3925 | if (!cfq_cfqq_sync(cfqq) || cfq_class_idle(cfqq)) | |
1be92f2f JA |
3926 | return; |
3927 | ||
c265a7f4 | 3928 | enable_idle = old_idle = cfq_cfqq_idle_window(cfqq); |
1da177e4 | 3929 | |
76280aff CZ |
3930 | if (cfqq->queued[0] + cfqq->queued[1] >= 4) |
3931 | cfq_mark_cfqq_deep(cfqq); | |
3932 | ||
749ef9f8 CZ |
3933 | if (cfqq->next_rq && (cfqq->next_rq->cmd_flags & REQ_NOIDLE)) |
3934 | enable_idle = 0; | |
f6e8d01b | 3935 | else if (!atomic_read(&cic->icq.ioc->active_ref) || |
c5869807 TH |
3936 | !cfqd->cfq_slice_idle || |
3937 | (!cfq_cfqq_deep(cfqq) && CFQQ_SEEKY(cfqq))) | |
22e2c507 | 3938 | enable_idle = 0; |
383cd721 SL |
3939 | else if (sample_valid(cic->ttime.ttime_samples)) { |
3940 | if (cic->ttime.ttime_mean > cfqd->cfq_slice_idle) | |
22e2c507 JA |
3941 | enable_idle = 0; |
3942 | else | |
3943 | enable_idle = 1; | |
1da177e4 LT |
3944 | } |
3945 | ||
7b679138 JA |
3946 | if (old_idle != enable_idle) { |
3947 | cfq_log_cfqq(cfqd, cfqq, "idle=%d", enable_idle); | |
3948 | if (enable_idle) | |
3949 | cfq_mark_cfqq_idle_window(cfqq); | |
3950 | else | |
3951 | cfq_clear_cfqq_idle_window(cfqq); | |
3952 | } | |
22e2c507 | 3953 | } |
1da177e4 | 3954 | |
22e2c507 JA |
3955 | /* |
3956 | * Check if new_cfqq should preempt the currently active queue. Return 0 for | |
3957 | * no or if we aren't sure, a 1 will cause a preempt. | |
3958 | */ | |
a6151c3a | 3959 | static bool |
22e2c507 | 3960 | cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq, |
5e705374 | 3961 | struct request *rq) |
22e2c507 | 3962 | { |
6d048f53 | 3963 | struct cfq_queue *cfqq; |
22e2c507 | 3964 | |
6d048f53 JA |
3965 | cfqq = cfqd->active_queue; |
3966 | if (!cfqq) | |
a6151c3a | 3967 | return false; |
22e2c507 | 3968 | |
6d048f53 | 3969 | if (cfq_class_idle(new_cfqq)) |
a6151c3a | 3970 | return false; |
22e2c507 JA |
3971 | |
3972 | if (cfq_class_idle(cfqq)) | |
a6151c3a | 3973 | return true; |
1e3335de | 3974 | |
875feb63 DS |
3975 | /* |
3976 | * Don't allow a non-RT request to preempt an ongoing RT cfqq timeslice. | |
3977 | */ | |
3978 | if (cfq_class_rt(cfqq) && !cfq_class_rt(new_cfqq)) | |
3979 | return false; | |
3980 | ||
374f84ac JA |
3981 | /* |
3982 | * if the new request is sync, but the currently running queue is | |
3983 | * not, let the sync request have priority. | |
3984 | */ | |
5e705374 | 3985 | if (rq_is_sync(rq) && !cfq_cfqq_sync(cfqq)) |
a6151c3a | 3986 | return true; |
1e3335de | 3987 | |
3984aa55 JK |
3988 | /* |
3989 | * Treat ancestors of current cgroup the same way as current cgroup. | |
3990 | * For anybody else we disallow preemption to guarantee service | |
3991 | * fairness among cgroups. | |
3992 | */ | |
3993 | if (!cfqg_is_descendant(cfqq->cfqg, new_cfqq->cfqg)) | |
8682e1f1 VG |
3994 | return false; |
3995 | ||
3996 | if (cfq_slice_used(cfqq)) | |
3997 | return true; | |
3998 | ||
6c80731c JK |
3999 | /* |
4000 | * Allow an RT request to pre-empt an ongoing non-RT cfqq timeslice. | |
4001 | */ | |
4002 | if (cfq_class_rt(new_cfqq) && !cfq_class_rt(cfqq)) | |
4003 | return true; | |
4004 | ||
4005 | WARN_ON_ONCE(cfqq->ioprio_class != new_cfqq->ioprio_class); | |
8682e1f1 | 4006 | /* Allow preemption only if we are idling on sync-noidle tree */ |
4d2ceea4 | 4007 | if (cfqd->serving_wl_type == SYNC_NOIDLE_WORKLOAD && |
8682e1f1 | 4008 | cfqq_type(new_cfqq) == SYNC_NOIDLE_WORKLOAD && |
8682e1f1 VG |
4009 | RB_EMPTY_ROOT(&cfqq->sort_list)) |
4010 | return true; | |
4011 | ||
b53d1ed7 JA |
4012 | /* |
4013 | * So both queues are sync. Let the new request get disk time if | |
4014 | * it's a metadata request and the current queue is doing regular IO. | |
4015 | */ | |
65299a3b | 4016 | if ((rq->cmd_flags & REQ_PRIO) && !cfqq->prio_pending) |
b53d1ed7 JA |
4017 | return true; |
4018 | ||
d2d59e18 SL |
4019 | /* An idle queue should not be idle now for some reason */ |
4020 | if (RB_EMPTY_ROOT(&cfqq->sort_list) && !cfq_should_idle(cfqd, cfqq)) | |
4021 | return true; | |
4022 | ||
1e3335de | 4023 | if (!cfqd->active_cic || !cfq_cfqq_wait_request(cfqq)) |
a6151c3a | 4024 | return false; |
1e3335de JA |
4025 | |
4026 | /* | |
4027 | * if this request is as-good as one we would expect from the | |
4028 | * current cfqq, let it preempt | |
4029 | */ | |
e9ce335d | 4030 | if (cfq_rq_close(cfqd, cfqq, rq)) |
a6151c3a | 4031 | return true; |
1e3335de | 4032 | |
a6151c3a | 4033 | return false; |
22e2c507 JA |
4034 | } |
4035 | ||
4036 | /* | |
4037 | * cfqq preempts the active queue. if we allowed preempt with no slice left, | |
4038 | * let it have half of its nominal slice. | |
4039 | */ | |
4040 | static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq) | |
4041 | { | |
df0793ab SL |
4042 | enum wl_type_t old_type = cfqq_type(cfqd->active_queue); |
4043 | ||
7b679138 | 4044 | cfq_log_cfqq(cfqd, cfqq, "preempt"); |
df0793ab | 4045 | cfq_slice_expired(cfqd, 1); |
22e2c507 | 4046 | |
f8ae6e3e SL |
4047 | /* |
4048 | * workload type is changed, don't save slice, otherwise preempt | |
4049 | * doesn't happen | |
4050 | */ | |
df0793ab | 4051 | if (old_type != cfqq_type(cfqq)) |
4d2ceea4 | 4052 | cfqq->cfqg->saved_wl_slice = 0; |
f8ae6e3e | 4053 | |
bf572256 JA |
4054 | /* |
4055 | * Put the new queue at the front of the of the current list, | |
4056 | * so we know that it will be selected next. | |
4057 | */ | |
4058 | BUG_ON(!cfq_cfqq_on_rr(cfqq)); | |
edd75ffd JA |
4059 | |
4060 | cfq_service_tree_add(cfqd, cfqq, 1); | |
eda5e0c9 | 4061 | |
62a37f6b JT |
4062 | cfqq->slice_end = 0; |
4063 | cfq_mark_cfqq_slice_new(cfqq); | |
22e2c507 JA |
4064 | } |
4065 | ||
22e2c507 | 4066 | /* |
5e705374 | 4067 | * Called when a new fs request (rq) is added (to cfqq). Check if there's |
22e2c507 JA |
4068 | * something we should do about it |
4069 | */ | |
4070 | static void | |
5e705374 JA |
4071 | cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, |
4072 | struct request *rq) | |
22e2c507 | 4073 | { |
c5869807 | 4074 | struct cfq_io_cq *cic = RQ_CIC(rq); |
12e9fddd | 4075 | |
45333d5a | 4076 | cfqd->rq_queued++; |
65299a3b CH |
4077 | if (rq->cmd_flags & REQ_PRIO) |
4078 | cfqq->prio_pending++; | |
374f84ac | 4079 | |
383cd721 | 4080 | cfq_update_io_thinktime(cfqd, cfqq, cic); |
b2c18e1e | 4081 | cfq_update_io_seektime(cfqd, cfqq, rq); |
9c2c38a1 JA |
4082 | cfq_update_idle_window(cfqd, cfqq, cic); |
4083 | ||
b2c18e1e | 4084 | cfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq); |
22e2c507 JA |
4085 | |
4086 | if (cfqq == cfqd->active_queue) { | |
4087 | /* | |
b029195d JA |
4088 | * Remember that we saw a request from this process, but |
4089 | * don't start queuing just yet. Otherwise we risk seeing lots | |
4090 | * of tiny requests, because we disrupt the normal plugging | |
d6ceb25e JA |
4091 | * and merging. If the request is already larger than a single |
4092 | * page, let it rip immediately. For that case we assume that | |
2d870722 JA |
4093 | * merging is already done. Ditto for a busy system that |
4094 | * has other work pending, don't risk delaying until the | |
4095 | * idle timer unplug to continue working. | |
22e2c507 | 4096 | */ |
d6ceb25e | 4097 | if (cfq_cfqq_wait_request(cfqq)) { |
09cbfeaf | 4098 | if (blk_rq_bytes(rq) > PAGE_SIZE || |
2d870722 | 4099 | cfqd->busy_queues > 1) { |
812df48d | 4100 | cfq_del_timer(cfqd, cfqq); |
554554f6 | 4101 | cfq_clear_cfqq_wait_request(cfqq); |
24ecfbe2 | 4102 | __blk_run_queue(cfqd->queue); |
a11cdaa7 | 4103 | } else { |
155fead9 | 4104 | cfqg_stats_update_idle_time(cfqq->cfqg); |
bf791937 | 4105 | cfq_mark_cfqq_must_dispatch(cfqq); |
a11cdaa7 | 4106 | } |
d6ceb25e | 4107 | } |
5e705374 | 4108 | } else if (cfq_should_preempt(cfqd, cfqq, rq)) { |
22e2c507 JA |
4109 | /* |
4110 | * not the active queue - expire current slice if it is | |
4111 | * idle and has expired it's mean thinktime or this new queue | |
3a9a3f6c DS |
4112 | * has some old slice time left and is of higher priority or |
4113 | * this new queue is RT and the current one is BE | |
22e2c507 JA |
4114 | */ |
4115 | cfq_preempt_queue(cfqd, cfqq); | |
24ecfbe2 | 4116 | __blk_run_queue(cfqd->queue); |
22e2c507 | 4117 | } |
1da177e4 LT |
4118 | } |
4119 | ||
165125e1 | 4120 | static void cfq_insert_request(struct request_queue *q, struct request *rq) |
1da177e4 | 4121 | { |
b4878f24 | 4122 | struct cfq_data *cfqd = q->elevator->elevator_data; |
5e705374 | 4123 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
22e2c507 | 4124 | |
7b679138 | 4125 | cfq_log_cfqq(cfqd, cfqq, "insert_request"); |
abede6da | 4126 | cfq_init_prio_data(cfqq, RQ_CIC(rq)); |
1da177e4 | 4127 | |
9a7f38c4 | 4128 | rq->fifo_time = ktime_get_ns() + cfqd->cfq_fifo_expire[rq_is_sync(rq)]; |
22e2c507 | 4129 | list_add_tail(&rq->queuelist, &cfqq->fifo); |
aa6f6a3d | 4130 | cfq_add_rq_rb(rq); |
63a4cc24 | 4131 | cfqg_stats_update_io_add(RQ_CFQG(rq), cfqd->serving_group, req_op(rq), |
155fead9 | 4132 | rq->cmd_flags); |
5e705374 | 4133 | cfq_rq_enqueued(cfqd, cfqq, rq); |
1da177e4 LT |
4134 | } |
4135 | ||
45333d5a AC |
4136 | /* |
4137 | * Update hw_tag based on peak queue depth over 50 samples under | |
4138 | * sufficient load. | |
4139 | */ | |
4140 | static void cfq_update_hw_tag(struct cfq_data *cfqd) | |
4141 | { | |
1a1238a7 SL |
4142 | struct cfq_queue *cfqq = cfqd->active_queue; |
4143 | ||
53c583d2 CZ |
4144 | if (cfqd->rq_in_driver > cfqd->hw_tag_est_depth) |
4145 | cfqd->hw_tag_est_depth = cfqd->rq_in_driver; | |
e459dd08 CZ |
4146 | |
4147 | if (cfqd->hw_tag == 1) | |
4148 | return; | |
45333d5a AC |
4149 | |
4150 | if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN && | |
53c583d2 | 4151 | cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN) |
45333d5a AC |
4152 | return; |
4153 | ||
1a1238a7 SL |
4154 | /* |
4155 | * If active queue hasn't enough requests and can idle, cfq might not | |
4156 | * dispatch sufficient requests to hardware. Don't zero hw_tag in this | |
4157 | * case | |
4158 | */ | |
4159 | if (cfqq && cfq_cfqq_idle_window(cfqq) && | |
4160 | cfqq->dispatched + cfqq->queued[0] + cfqq->queued[1] < | |
53c583d2 | 4161 | CFQ_HW_QUEUE_MIN && cfqd->rq_in_driver < CFQ_HW_QUEUE_MIN) |
1a1238a7 SL |
4162 | return; |
4163 | ||
45333d5a AC |
4164 | if (cfqd->hw_tag_samples++ < 50) |
4165 | return; | |
4166 | ||
e459dd08 | 4167 | if (cfqd->hw_tag_est_depth >= CFQ_HW_QUEUE_MIN) |
45333d5a AC |
4168 | cfqd->hw_tag = 1; |
4169 | else | |
4170 | cfqd->hw_tag = 0; | |
45333d5a AC |
4171 | } |
4172 | ||
7667aa06 VG |
4173 | static bool cfq_should_wait_busy(struct cfq_data *cfqd, struct cfq_queue *cfqq) |
4174 | { | |
c5869807 | 4175 | struct cfq_io_cq *cic = cfqd->active_cic; |
9a7f38c4 | 4176 | u64 now = ktime_get_ns(); |
7667aa06 | 4177 | |
02a8f01b JT |
4178 | /* If the queue already has requests, don't wait */ |
4179 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) | |
4180 | return false; | |
4181 | ||
7667aa06 VG |
4182 | /* If there are other queues in the group, don't wait */ |
4183 | if (cfqq->cfqg->nr_cfqq > 1) | |
4184 | return false; | |
4185 | ||
7700fc4f SL |
4186 | /* the only queue in the group, but think time is big */ |
4187 | if (cfq_io_thinktime_big(cfqd, &cfqq->cfqg->ttime, true)) | |
4188 | return false; | |
4189 | ||
7667aa06 VG |
4190 | if (cfq_slice_used(cfqq)) |
4191 | return true; | |
4192 | ||
4193 | /* if slice left is less than think time, wait busy */ | |
383cd721 | 4194 | if (cic && sample_valid(cic->ttime.ttime_samples) |
9a7f38c4 | 4195 | && (cfqq->slice_end - now < cic->ttime.ttime_mean)) |
7667aa06 VG |
4196 | return true; |
4197 | ||
4198 | /* | |
4199 | * If think times is less than a jiffy than ttime_mean=0 and above | |
4200 | * will not be true. It might happen that slice has not expired yet | |
4201 | * but will expire soon (4-5 ns) during select_queue(). To cover the | |
4202 | * case where think time is less than a jiffy, mark the queue wait | |
4203 | * busy if only 1 jiffy is left in the slice. | |
4204 | */ | |
9a7f38c4 | 4205 | if (cfqq->slice_end - now <= jiffies_to_nsecs(1)) |
7667aa06 VG |
4206 | return true; |
4207 | ||
4208 | return false; | |
4209 | } | |
4210 | ||
165125e1 | 4211 | static void cfq_completed_request(struct request_queue *q, struct request *rq) |
1da177e4 | 4212 | { |
5e705374 | 4213 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
b4878f24 | 4214 | struct cfq_data *cfqd = cfqq->cfqd; |
5380a101 | 4215 | const int sync = rq_is_sync(rq); |
9a7f38c4 | 4216 | u64 now = ktime_get_ns(); |
1da177e4 | 4217 | |
33659ebb CH |
4218 | cfq_log_cfqq(cfqd, cfqq, "complete rqnoidle %d", |
4219 | !!(rq->cmd_flags & REQ_NOIDLE)); | |
1da177e4 | 4220 | |
45333d5a AC |
4221 | cfq_update_hw_tag(cfqd); |
4222 | ||
53c583d2 | 4223 | WARN_ON(!cfqd->rq_in_driver); |
6d048f53 | 4224 | WARN_ON(!cfqq->dispatched); |
53c583d2 | 4225 | cfqd->rq_in_driver--; |
6d048f53 | 4226 | cfqq->dispatched--; |
80bdf0c7 | 4227 | (RQ_CFQG(rq))->dispatched--; |
155fead9 | 4228 | cfqg_stats_update_completion(cfqq->cfqg, rq_start_time_ns(rq), |
63a4cc24 MC |
4229 | rq_io_start_time_ns(rq), req_op(rq), |
4230 | rq->cmd_flags); | |
1da177e4 | 4231 | |
53c583d2 | 4232 | cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--; |
3ed9a296 | 4233 | |
365722bb | 4234 | if (sync) { |
34b98d03 | 4235 | struct cfq_rb_root *st; |
f5f2b6ce | 4236 | |
383cd721 | 4237 | RQ_CIC(rq)->ttime.last_end_request = now; |
f5f2b6ce SL |
4238 | |
4239 | if (cfq_cfqq_on_rr(cfqq)) | |
34b98d03 | 4240 | st = cfqq->service_tree; |
f5f2b6ce | 4241 | else |
34b98d03 VG |
4242 | st = st_for(cfqq->cfqg, cfqq_class(cfqq), |
4243 | cfqq_type(cfqq)); | |
4244 | ||
4245 | st->ttime.last_end_request = now; | |
149321a6 JK |
4246 | /* |
4247 | * We have to do this check in jiffies since start_time is in | |
4248 | * jiffies and it is not trivial to convert to ns. If | |
4249 | * cfq_fifo_expire[1] ever comes close to 1 jiffie, this test | |
4250 | * will become problematic but so far we are fine (the default | |
4251 | * is 128 ms). | |
4252 | */ | |
4253 | if (!time_after(rq->start_time + | |
4254 | nsecs_to_jiffies(cfqd->cfq_fifo_expire[1]), | |
4255 | jiffies)) | |
573412b2 | 4256 | cfqd->last_delayed_sync = now; |
365722bb | 4257 | } |
caaa5f9f | 4258 | |
7700fc4f SL |
4259 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
4260 | cfqq->cfqg->ttime.last_end_request = now; | |
4261 | #endif | |
4262 | ||
caaa5f9f JA |
4263 | /* |
4264 | * If this is the active queue, check if it needs to be expired, | |
4265 | * or if we want to idle in case it has no pending requests. | |
4266 | */ | |
4267 | if (cfqd->active_queue == cfqq) { | |
a36e71f9 JA |
4268 | const bool cfqq_empty = RB_EMPTY_ROOT(&cfqq->sort_list); |
4269 | ||
44f7c160 JA |
4270 | if (cfq_cfqq_slice_new(cfqq)) { |
4271 | cfq_set_prio_slice(cfqd, cfqq); | |
4272 | cfq_clear_cfqq_slice_new(cfqq); | |
4273 | } | |
f75edf2d VG |
4274 | |
4275 | /* | |
7667aa06 VG |
4276 | * Should we wait for next request to come in before we expire |
4277 | * the queue. | |
f75edf2d | 4278 | */ |
7667aa06 | 4279 | if (cfq_should_wait_busy(cfqd, cfqq)) { |
9a7f38c4 | 4280 | u64 extend_sl = cfqd->cfq_slice_idle; |
80bdf0c7 VG |
4281 | if (!cfqd->cfq_slice_idle) |
4282 | extend_sl = cfqd->cfq_group_idle; | |
9a7f38c4 | 4283 | cfqq->slice_end = now + extend_sl; |
f75edf2d | 4284 | cfq_mark_cfqq_wait_busy(cfqq); |
b1ffe737 | 4285 | cfq_log_cfqq(cfqd, cfqq, "will busy wait"); |
f75edf2d VG |
4286 | } |
4287 | ||
a36e71f9 | 4288 | /* |
8e550632 CZ |
4289 | * Idling is not enabled on: |
4290 | * - expired queues | |
4291 | * - idle-priority queues | |
4292 | * - async queues | |
4293 | * - queues with still some requests queued | |
4294 | * - when there is a close cooperator | |
a36e71f9 | 4295 | */ |
0871714e | 4296 | if (cfq_slice_used(cfqq) || cfq_class_idle(cfqq)) |
e5ff082e | 4297 | cfq_slice_expired(cfqd, 1); |
8e550632 CZ |
4298 | else if (sync && cfqq_empty && |
4299 | !cfq_close_cooperator(cfqd, cfqq)) { | |
749ef9f8 | 4300 | cfq_arm_slice_timer(cfqd); |
8e550632 | 4301 | } |
caaa5f9f | 4302 | } |
6d048f53 | 4303 | |
53c583d2 | 4304 | if (!cfqd->rq_in_driver) |
23e018a1 | 4305 | cfq_schedule_dispatch(cfqd); |
1da177e4 LT |
4306 | } |
4307 | ||
b8269db4 JA |
4308 | static void cfqq_boost_on_prio(struct cfq_queue *cfqq, int op_flags) |
4309 | { | |
4310 | /* | |
4311 | * If REQ_PRIO is set, boost class and prio level, if it's below | |
4312 | * BE/NORM. If prio is not set, restore the potentially boosted | |
4313 | * class/prio level. | |
4314 | */ | |
4315 | if (!(op_flags & REQ_PRIO)) { | |
4316 | cfqq->ioprio_class = cfqq->org_ioprio_class; | |
4317 | cfqq->ioprio = cfqq->org_ioprio; | |
4318 | } else { | |
4319 | if (cfq_class_idle(cfqq)) | |
4320 | cfqq->ioprio_class = IOPRIO_CLASS_BE; | |
4321 | if (cfqq->ioprio > IOPRIO_NORM) | |
4322 | cfqq->ioprio = IOPRIO_NORM; | |
4323 | } | |
4324 | } | |
4325 | ||
89850f7e | 4326 | static inline int __cfq_may_queue(struct cfq_queue *cfqq) |
22e2c507 | 4327 | { |
1b379d8d | 4328 | if (cfq_cfqq_wait_request(cfqq) && !cfq_cfqq_must_alloc_slice(cfqq)) { |
3b18152c | 4329 | cfq_mark_cfqq_must_alloc_slice(cfqq); |
22e2c507 | 4330 | return ELV_MQUEUE_MUST; |
3b18152c | 4331 | } |
1da177e4 | 4332 | |
22e2c507 | 4333 | return ELV_MQUEUE_MAY; |
22e2c507 JA |
4334 | } |
4335 | ||
ba568ea0 | 4336 | static int cfq_may_queue(struct request_queue *q, int op, int op_flags) |
22e2c507 JA |
4337 | { |
4338 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
4339 | struct task_struct *tsk = current; | |
c5869807 | 4340 | struct cfq_io_cq *cic; |
22e2c507 JA |
4341 | struct cfq_queue *cfqq; |
4342 | ||
4343 | /* | |
4344 | * don't force setup of a queue from here, as a call to may_queue | |
4345 | * does not necessarily imply that a request actually will be queued. | |
4346 | * so just lookup a possibly existing queue, or return 'may queue' | |
4347 | * if that fails | |
4348 | */ | |
4ac845a2 | 4349 | cic = cfq_cic_lookup(cfqd, tsk->io_context); |
91fac317 VT |
4350 | if (!cic) |
4351 | return ELV_MQUEUE_MAY; | |
4352 | ||
d9d8c5c4 | 4353 | cfqq = cic_to_cfqq(cic, rw_is_sync(op, op_flags)); |
22e2c507 | 4354 | if (cfqq) { |
abede6da | 4355 | cfq_init_prio_data(cfqq, cic); |
b8269db4 | 4356 | cfqq_boost_on_prio(cfqq, op_flags); |
22e2c507 | 4357 | |
89850f7e | 4358 | return __cfq_may_queue(cfqq); |
22e2c507 JA |
4359 | } |
4360 | ||
4361 | return ELV_MQUEUE_MAY; | |
1da177e4 LT |
4362 | } |
4363 | ||
1da177e4 LT |
4364 | /* |
4365 | * queue lock held here | |
4366 | */ | |
bb37b94c | 4367 | static void cfq_put_request(struct request *rq) |
1da177e4 | 4368 | { |
5e705374 | 4369 | struct cfq_queue *cfqq = RQ_CFQQ(rq); |
1da177e4 | 4370 | |
5e705374 | 4371 | if (cfqq) { |
22e2c507 | 4372 | const int rw = rq_data_dir(rq); |
1da177e4 | 4373 | |
22e2c507 JA |
4374 | BUG_ON(!cfqq->allocated[rw]); |
4375 | cfqq->allocated[rw]--; | |
1da177e4 | 4376 | |
7f1dc8a2 | 4377 | /* Put down rq reference on cfqg */ |
eb7d8c07 | 4378 | cfqg_put(RQ_CFQG(rq)); |
a612fddf TH |
4379 | rq->elv.priv[0] = NULL; |
4380 | rq->elv.priv[1] = NULL; | |
7f1dc8a2 | 4381 | |
1da177e4 LT |
4382 | cfq_put_queue(cfqq); |
4383 | } | |
4384 | } | |
4385 | ||
df5fe3e8 | 4386 | static struct cfq_queue * |
c5869807 | 4387 | cfq_merge_cfqqs(struct cfq_data *cfqd, struct cfq_io_cq *cic, |
df5fe3e8 JM |
4388 | struct cfq_queue *cfqq) |
4389 | { | |
4390 | cfq_log_cfqq(cfqd, cfqq, "merging with queue %p", cfqq->new_cfqq); | |
4391 | cic_set_cfqq(cic, cfqq->new_cfqq, 1); | |
b3b6d040 | 4392 | cfq_mark_cfqq_coop(cfqq->new_cfqq); |
df5fe3e8 JM |
4393 | cfq_put_queue(cfqq); |
4394 | return cic_to_cfqq(cic, 1); | |
4395 | } | |
4396 | ||
e6c5bc73 JM |
4397 | /* |
4398 | * Returns NULL if a new cfqq should be allocated, or the old cfqq if this | |
4399 | * was the last process referring to said cfqq. | |
4400 | */ | |
4401 | static struct cfq_queue * | |
c5869807 | 4402 | split_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq) |
e6c5bc73 JM |
4403 | { |
4404 | if (cfqq_process_refs(cfqq) == 1) { | |
e6c5bc73 JM |
4405 | cfqq->pid = current->pid; |
4406 | cfq_clear_cfqq_coop(cfqq); | |
ae54abed | 4407 | cfq_clear_cfqq_split_coop(cfqq); |
e6c5bc73 JM |
4408 | return cfqq; |
4409 | } | |
4410 | ||
4411 | cic_set_cfqq(cic, NULL, 1); | |
d02a2c07 SL |
4412 | |
4413 | cfq_put_cooperator(cfqq); | |
4414 | ||
e6c5bc73 JM |
4415 | cfq_put_queue(cfqq); |
4416 | return NULL; | |
4417 | } | |
1da177e4 | 4418 | /* |
22e2c507 | 4419 | * Allocate cfq data structures associated with this request. |
1da177e4 | 4420 | */ |
22e2c507 | 4421 | static int |
852c788f TH |
4422 | cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio, |
4423 | gfp_t gfp_mask) | |
1da177e4 LT |
4424 | { |
4425 | struct cfq_data *cfqd = q->elevator->elevator_data; | |
f1f8cc94 | 4426 | struct cfq_io_cq *cic = icq_to_cic(rq->elv.icq); |
1da177e4 | 4427 | const int rw = rq_data_dir(rq); |
a6151c3a | 4428 | const bool is_sync = rq_is_sync(rq); |
22e2c507 | 4429 | struct cfq_queue *cfqq; |
1da177e4 | 4430 | |
216284c3 | 4431 | spin_lock_irq(q->queue_lock); |
f1f8cc94 | 4432 | |
598971bf TH |
4433 | check_ioprio_changed(cic, bio); |
4434 | check_blkcg_changed(cic, bio); | |
e6c5bc73 | 4435 | new_queue: |
91fac317 | 4436 | cfqq = cic_to_cfqq(cic, is_sync); |
32f2e807 | 4437 | if (!cfqq || cfqq == &cfqd->oom_cfqq) { |
bce6133b TH |
4438 | if (cfqq) |
4439 | cfq_put_queue(cfqq); | |
2da8de0b | 4440 | cfqq = cfq_get_queue(cfqd, is_sync, cic, bio); |
91fac317 | 4441 | cic_set_cfqq(cic, cfqq, is_sync); |
df5fe3e8 | 4442 | } else { |
e6c5bc73 JM |
4443 | /* |
4444 | * If the queue was seeky for too long, break it apart. | |
4445 | */ | |
ae54abed | 4446 | if (cfq_cfqq_coop(cfqq) && cfq_cfqq_split_coop(cfqq)) { |
e6c5bc73 JM |
4447 | cfq_log_cfqq(cfqd, cfqq, "breaking apart cfqq"); |
4448 | cfqq = split_cfqq(cic, cfqq); | |
4449 | if (!cfqq) | |
4450 | goto new_queue; | |
4451 | } | |
4452 | ||
df5fe3e8 JM |
4453 | /* |
4454 | * Check to see if this queue is scheduled to merge with | |
4455 | * another, closely cooperating queue. The merging of | |
4456 | * queues happens here as it must be done in process context. | |
4457 | * The reference on new_cfqq was taken in merge_cfqqs. | |
4458 | */ | |
4459 | if (cfqq->new_cfqq) | |
4460 | cfqq = cfq_merge_cfqqs(cfqd, cic, cfqq); | |
91fac317 | 4461 | } |
1da177e4 LT |
4462 | |
4463 | cfqq->allocated[rw]++; | |
1da177e4 | 4464 | |
6fae9c25 | 4465 | cfqq->ref++; |
eb7d8c07 | 4466 | cfqg_get(cfqq->cfqg); |
a612fddf | 4467 | rq->elv.priv[0] = cfqq; |
1adaf3dd | 4468 | rq->elv.priv[1] = cfqq->cfqg; |
216284c3 | 4469 | spin_unlock_irq(q->queue_lock); |
5e705374 | 4470 | return 0; |
1da177e4 LT |
4471 | } |
4472 | ||
65f27f38 | 4473 | static void cfq_kick_queue(struct work_struct *work) |
22e2c507 | 4474 | { |
65f27f38 | 4475 | struct cfq_data *cfqd = |
23e018a1 | 4476 | container_of(work, struct cfq_data, unplug_work); |
165125e1 | 4477 | struct request_queue *q = cfqd->queue; |
22e2c507 | 4478 | |
40bb54d1 | 4479 | spin_lock_irq(q->queue_lock); |
24ecfbe2 | 4480 | __blk_run_queue(cfqd->queue); |
40bb54d1 | 4481 | spin_unlock_irq(q->queue_lock); |
22e2c507 JA |
4482 | } |
4483 | ||
4484 | /* | |
4485 | * Timer running if the active_queue is currently idling inside its time slice | |
4486 | */ | |
91148325 | 4487 | static enum hrtimer_restart cfq_idle_slice_timer(struct hrtimer *timer) |
22e2c507 | 4488 | { |
91148325 JK |
4489 | struct cfq_data *cfqd = container_of(timer, struct cfq_data, |
4490 | idle_slice_timer); | |
22e2c507 JA |
4491 | struct cfq_queue *cfqq; |
4492 | unsigned long flags; | |
3c6bd2f8 | 4493 | int timed_out = 1; |
22e2c507 | 4494 | |
7b679138 JA |
4495 | cfq_log(cfqd, "idle timer fired"); |
4496 | ||
22e2c507 JA |
4497 | spin_lock_irqsave(cfqd->queue->queue_lock, flags); |
4498 | ||
fe094d98 JA |
4499 | cfqq = cfqd->active_queue; |
4500 | if (cfqq) { | |
3c6bd2f8 JA |
4501 | timed_out = 0; |
4502 | ||
b029195d JA |
4503 | /* |
4504 | * We saw a request before the queue expired, let it through | |
4505 | */ | |
4506 | if (cfq_cfqq_must_dispatch(cfqq)) | |
4507 | goto out_kick; | |
4508 | ||
22e2c507 JA |
4509 | /* |
4510 | * expired | |
4511 | */ | |
44f7c160 | 4512 | if (cfq_slice_used(cfqq)) |
22e2c507 JA |
4513 | goto expire; |
4514 | ||
4515 | /* | |
4516 | * only expire and reinvoke request handler, if there are | |
4517 | * other queues with pending requests | |
4518 | */ | |
caaa5f9f | 4519 | if (!cfqd->busy_queues) |
22e2c507 | 4520 | goto out_cont; |
22e2c507 JA |
4521 | |
4522 | /* | |
4523 | * not expired and it has a request pending, let it dispatch | |
4524 | */ | |
75e50984 | 4525 | if (!RB_EMPTY_ROOT(&cfqq->sort_list)) |
22e2c507 | 4526 | goto out_kick; |
76280aff CZ |
4527 | |
4528 | /* | |
4529 | * Queue depth flag is reset only when the idle didn't succeed | |
4530 | */ | |
4531 | cfq_clear_cfqq_deep(cfqq); | |
22e2c507 JA |
4532 | } |
4533 | expire: | |
e5ff082e | 4534 | cfq_slice_expired(cfqd, timed_out); |
22e2c507 | 4535 | out_kick: |
23e018a1 | 4536 | cfq_schedule_dispatch(cfqd); |
22e2c507 JA |
4537 | out_cont: |
4538 | spin_unlock_irqrestore(cfqd->queue->queue_lock, flags); | |
91148325 | 4539 | return HRTIMER_NORESTART; |
22e2c507 JA |
4540 | } |
4541 | ||
3b18152c JA |
4542 | static void cfq_shutdown_timer_wq(struct cfq_data *cfqd) |
4543 | { | |
91148325 | 4544 | hrtimer_cancel(&cfqd->idle_slice_timer); |
23e018a1 | 4545 | cancel_work_sync(&cfqd->unplug_work); |
3b18152c | 4546 | } |
22e2c507 | 4547 | |
b374d18a | 4548 | static void cfq_exit_queue(struct elevator_queue *e) |
1da177e4 | 4549 | { |
22e2c507 | 4550 | struct cfq_data *cfqd = e->elevator_data; |
165125e1 | 4551 | struct request_queue *q = cfqd->queue; |
22e2c507 | 4552 | |
3b18152c | 4553 | cfq_shutdown_timer_wq(cfqd); |
e2d74ac0 | 4554 | |
d9ff4187 | 4555 | spin_lock_irq(q->queue_lock); |
e2d74ac0 | 4556 | |
d9ff4187 | 4557 | if (cfqd->active_queue) |
e5ff082e | 4558 | __cfq_slice_expired(cfqd, cfqd->active_queue, 0); |
e2d74ac0 | 4559 | |
03aa264a TH |
4560 | spin_unlock_irq(q->queue_lock); |
4561 | ||
a90d742e AV |
4562 | cfq_shutdown_timer_wq(cfqd); |
4563 | ||
ffea73fc TH |
4564 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
4565 | blkcg_deactivate_policy(q, &blkcg_policy_cfq); | |
4566 | #else | |
f51b802c | 4567 | kfree(cfqd->root_group); |
2abae55f | 4568 | #endif |
56edf7d7 | 4569 | kfree(cfqd); |
1da177e4 LT |
4570 | } |
4571 | ||
d50235b7 | 4572 | static int cfq_init_queue(struct request_queue *q, struct elevator_type *e) |
1da177e4 LT |
4573 | { |
4574 | struct cfq_data *cfqd; | |
3c798398 | 4575 | struct blkcg_gq *blkg __maybe_unused; |
a2b1693b | 4576 | int i, ret; |
d50235b7 JM |
4577 | struct elevator_queue *eq; |
4578 | ||
4579 | eq = elevator_alloc(q, e); | |
4580 | if (!eq) | |
4581 | return -ENOMEM; | |
1da177e4 | 4582 | |
c1b511eb | 4583 | cfqd = kzalloc_node(sizeof(*cfqd), GFP_KERNEL, q->node); |
d50235b7 JM |
4584 | if (!cfqd) { |
4585 | kobject_put(&eq->kobj); | |
b2fab5ac | 4586 | return -ENOMEM; |
d50235b7 JM |
4587 | } |
4588 | eq->elevator_data = cfqd; | |
80b15c73 | 4589 | |
f51b802c | 4590 | cfqd->queue = q; |
d50235b7 JM |
4591 | spin_lock_irq(q->queue_lock); |
4592 | q->elevator = eq; | |
4593 | spin_unlock_irq(q->queue_lock); | |
f51b802c | 4594 | |
1fa8f6d6 VG |
4595 | /* Init root service tree */ |
4596 | cfqd->grp_service_tree = CFQ_RB_ROOT; | |
4597 | ||
f51b802c | 4598 | /* Init root group and prefer root group over other groups by default */ |
25fb5169 | 4599 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4600 | ret = blkcg_activate_policy(q, &blkcg_policy_cfq); |
a2b1693b TH |
4601 | if (ret) |
4602 | goto out_free; | |
f51b802c | 4603 | |
a2b1693b | 4604 | cfqd->root_group = blkg_to_cfqg(q->root_blkg); |
f51b802c | 4605 | #else |
a2b1693b | 4606 | ret = -ENOMEM; |
f51b802c TH |
4607 | cfqd->root_group = kzalloc_node(sizeof(*cfqd->root_group), |
4608 | GFP_KERNEL, cfqd->queue->node); | |
a2b1693b TH |
4609 | if (!cfqd->root_group) |
4610 | goto out_free; | |
5624a4e4 | 4611 | |
a2b1693b | 4612 | cfq_init_cfqg_base(cfqd->root_group); |
3ecca629 TH |
4613 | cfqd->root_group->weight = 2 * CFQ_WEIGHT_LEGACY_DFL; |
4614 | cfqd->root_group->leaf_weight = 2 * CFQ_WEIGHT_LEGACY_DFL; | |
69d7fde5 | 4615 | #endif |
5624a4e4 | 4616 | |
26a2ac00 JA |
4617 | /* |
4618 | * Not strictly needed (since RB_ROOT just clears the node and we | |
4619 | * zeroed cfqd on alloc), but better be safe in case someone decides | |
4620 | * to add magic to the rb code | |
4621 | */ | |
4622 | for (i = 0; i < CFQ_PRIO_LISTS; i++) | |
4623 | cfqd->prio_trees[i] = RB_ROOT; | |
4624 | ||
6118b70b | 4625 | /* |
d4aad7ff | 4626 | * Our fallback cfqq if cfq_get_queue() runs into OOM issues. |
6118b70b | 4627 | * Grab a permanent reference to it, so that the normal code flow |
f51b802c TH |
4628 | * will not attempt to free it. oom_cfqq is linked to root_group |
4629 | * but shouldn't hold a reference as it'll never be unlinked. Lose | |
4630 | * the reference from linking right away. | |
6118b70b JA |
4631 | */ |
4632 | cfq_init_cfqq(cfqd, &cfqd->oom_cfqq, 1, 0); | |
30d7b944 | 4633 | cfqd->oom_cfqq.ref++; |
1adaf3dd TH |
4634 | |
4635 | spin_lock_irq(q->queue_lock); | |
f51b802c | 4636 | cfq_link_cfqq_cfqg(&cfqd->oom_cfqq, cfqd->root_group); |
eb7d8c07 | 4637 | cfqg_put(cfqd->root_group); |
1adaf3dd | 4638 | spin_unlock_irq(q->queue_lock); |
1da177e4 | 4639 | |
91148325 JK |
4640 | hrtimer_init(&cfqd->idle_slice_timer, CLOCK_MONOTONIC, |
4641 | HRTIMER_MODE_REL); | |
22e2c507 | 4642 | cfqd->idle_slice_timer.function = cfq_idle_slice_timer; |
22e2c507 | 4643 | |
23e018a1 | 4644 | INIT_WORK(&cfqd->unplug_work, cfq_kick_queue); |
22e2c507 | 4645 | |
1da177e4 | 4646 | cfqd->cfq_quantum = cfq_quantum; |
22e2c507 JA |
4647 | cfqd->cfq_fifo_expire[0] = cfq_fifo_expire[0]; |
4648 | cfqd->cfq_fifo_expire[1] = cfq_fifo_expire[1]; | |
1da177e4 LT |
4649 | cfqd->cfq_back_max = cfq_back_max; |
4650 | cfqd->cfq_back_penalty = cfq_back_penalty; | |
22e2c507 JA |
4651 | cfqd->cfq_slice[0] = cfq_slice_async; |
4652 | cfqd->cfq_slice[1] = cfq_slice_sync; | |
5bf14c07 | 4653 | cfqd->cfq_target_latency = cfq_target_latency; |
22e2c507 | 4654 | cfqd->cfq_slice_async_rq = cfq_slice_async_rq; |
0bb97947 | 4655 | cfqd->cfq_slice_idle = cfq_slice_idle; |
80bdf0c7 | 4656 | cfqd->cfq_group_idle = cfq_group_idle; |
963b72fc | 4657 | cfqd->cfq_latency = 1; |
e459dd08 | 4658 | cfqd->hw_tag = -1; |
edc71131 CZ |
4659 | /* |
4660 | * we optimistically start assuming sync ops weren't delayed in last | |
4661 | * second, in order to have larger depth for async operations. | |
4662 | */ | |
9a7f38c4 | 4663 | cfqd->last_delayed_sync = ktime_get_ns() - NSEC_PER_SEC; |
b2fab5ac | 4664 | return 0; |
a2b1693b TH |
4665 | |
4666 | out_free: | |
4667 | kfree(cfqd); | |
d50235b7 | 4668 | kobject_put(&eq->kobj); |
a2b1693b | 4669 | return ret; |
1da177e4 LT |
4670 | } |
4671 | ||
0bb97947 JA |
4672 | static void cfq_registered_queue(struct request_queue *q) |
4673 | { | |
4674 | struct elevator_queue *e = q->elevator; | |
4675 | struct cfq_data *cfqd = e->elevator_data; | |
4676 | ||
4677 | /* | |
4678 | * Default to IOPS mode with no idling for SSDs | |
4679 | */ | |
4680 | if (blk_queue_nonrot(q)) | |
4681 | cfqd->cfq_slice_idle = 0; | |
4682 | } | |
4683 | ||
1da177e4 LT |
4684 | /* |
4685 | * sysfs parts below --> | |
4686 | */ | |
1da177e4 LT |
4687 | static ssize_t |
4688 | cfq_var_show(unsigned int var, char *page) | |
4689 | { | |
176167ad | 4690 | return sprintf(page, "%u\n", var); |
1da177e4 LT |
4691 | } |
4692 | ||
4693 | static ssize_t | |
4694 | cfq_var_store(unsigned int *var, const char *page, size_t count) | |
4695 | { | |
4696 | char *p = (char *) page; | |
4697 | ||
4698 | *var = simple_strtoul(p, &p, 10); | |
4699 | return count; | |
4700 | } | |
4701 | ||
1da177e4 | 4702 | #define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \ |
b374d18a | 4703 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ |
1da177e4 | 4704 | { \ |
3d1ab40f | 4705 | struct cfq_data *cfqd = e->elevator_data; \ |
9a7f38c4 | 4706 | u64 __data = __VAR; \ |
1da177e4 | 4707 | if (__CONV) \ |
9a7f38c4 | 4708 | __data = div_u64(__data, NSEC_PER_MSEC); \ |
1da177e4 LT |
4709 | return cfq_var_show(__data, (page)); \ |
4710 | } | |
4711 | SHOW_FUNCTION(cfq_quantum_show, cfqd->cfq_quantum, 0); | |
22e2c507 JA |
4712 | SHOW_FUNCTION(cfq_fifo_expire_sync_show, cfqd->cfq_fifo_expire[1], 1); |
4713 | SHOW_FUNCTION(cfq_fifo_expire_async_show, cfqd->cfq_fifo_expire[0], 1); | |
e572ec7e AV |
4714 | SHOW_FUNCTION(cfq_back_seek_max_show, cfqd->cfq_back_max, 0); |
4715 | SHOW_FUNCTION(cfq_back_seek_penalty_show, cfqd->cfq_back_penalty, 0); | |
22e2c507 | 4716 | SHOW_FUNCTION(cfq_slice_idle_show, cfqd->cfq_slice_idle, 1); |
80bdf0c7 | 4717 | SHOW_FUNCTION(cfq_group_idle_show, cfqd->cfq_group_idle, 1); |
22e2c507 JA |
4718 | SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1], 1); |
4719 | SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1); | |
4720 | SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0); | |
963b72fc | 4721 | SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0); |
5bf14c07 | 4722 | SHOW_FUNCTION(cfq_target_latency_show, cfqd->cfq_target_latency, 1); |
1da177e4 LT |
4723 | #undef SHOW_FUNCTION |
4724 | ||
d2d481d0 JM |
4725 | #define USEC_SHOW_FUNCTION(__FUNC, __VAR) \ |
4726 | static ssize_t __FUNC(struct elevator_queue *e, char *page) \ | |
4727 | { \ | |
4728 | struct cfq_data *cfqd = e->elevator_data; \ | |
4729 | u64 __data = __VAR; \ | |
4730 | __data = div_u64(__data, NSEC_PER_USEC); \ | |
4731 | return cfq_var_show(__data, (page)); \ | |
4732 | } | |
4733 | USEC_SHOW_FUNCTION(cfq_slice_idle_us_show, cfqd->cfq_slice_idle); | |
4734 | USEC_SHOW_FUNCTION(cfq_group_idle_us_show, cfqd->cfq_group_idle); | |
4735 | USEC_SHOW_FUNCTION(cfq_slice_sync_us_show, cfqd->cfq_slice[1]); | |
4736 | USEC_SHOW_FUNCTION(cfq_slice_async_us_show, cfqd->cfq_slice[0]); | |
4737 | USEC_SHOW_FUNCTION(cfq_target_latency_us_show, cfqd->cfq_target_latency); | |
4738 | #undef USEC_SHOW_FUNCTION | |
4739 | ||
1da177e4 | 4740 | #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \ |
b374d18a | 4741 | static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ |
1da177e4 | 4742 | { \ |
3d1ab40f | 4743 | struct cfq_data *cfqd = e->elevator_data; \ |
1da177e4 LT |
4744 | unsigned int __data; \ |
4745 | int ret = cfq_var_store(&__data, (page), count); \ | |
4746 | if (__data < (MIN)) \ | |
4747 | __data = (MIN); \ | |
4748 | else if (__data > (MAX)) \ | |
4749 | __data = (MAX); \ | |
4750 | if (__CONV) \ | |
9a7f38c4 | 4751 | *(__PTR) = (u64)__data * NSEC_PER_MSEC; \ |
1da177e4 LT |
4752 | else \ |
4753 | *(__PTR) = __data; \ | |
4754 | return ret; \ | |
4755 | } | |
4756 | STORE_FUNCTION(cfq_quantum_store, &cfqd->cfq_quantum, 1, UINT_MAX, 0); | |
fe094d98 JA |
4757 | STORE_FUNCTION(cfq_fifo_expire_sync_store, &cfqd->cfq_fifo_expire[1], 1, |
4758 | UINT_MAX, 1); | |
4759 | STORE_FUNCTION(cfq_fifo_expire_async_store, &cfqd->cfq_fifo_expire[0], 1, | |
4760 | UINT_MAX, 1); | |
e572ec7e | 4761 | STORE_FUNCTION(cfq_back_seek_max_store, &cfqd->cfq_back_max, 0, UINT_MAX, 0); |
fe094d98 JA |
4762 | STORE_FUNCTION(cfq_back_seek_penalty_store, &cfqd->cfq_back_penalty, 1, |
4763 | UINT_MAX, 0); | |
22e2c507 | 4764 | STORE_FUNCTION(cfq_slice_idle_store, &cfqd->cfq_slice_idle, 0, UINT_MAX, 1); |
80bdf0c7 | 4765 | STORE_FUNCTION(cfq_group_idle_store, &cfqd->cfq_group_idle, 0, UINT_MAX, 1); |
22e2c507 JA |
4766 | STORE_FUNCTION(cfq_slice_sync_store, &cfqd->cfq_slice[1], 1, UINT_MAX, 1); |
4767 | STORE_FUNCTION(cfq_slice_async_store, &cfqd->cfq_slice[0], 1, UINT_MAX, 1); | |
fe094d98 JA |
4768 | STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1, |
4769 | UINT_MAX, 0); | |
963b72fc | 4770 | STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0); |
5bf14c07 | 4771 | STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1, UINT_MAX, 1); |
1da177e4 LT |
4772 | #undef STORE_FUNCTION |
4773 | ||
d2d481d0 JM |
4774 | #define USEC_STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \ |
4775 | static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \ | |
4776 | { \ | |
4777 | struct cfq_data *cfqd = e->elevator_data; \ | |
4778 | unsigned int __data; \ | |
4779 | int ret = cfq_var_store(&__data, (page), count); \ | |
4780 | if (__data < (MIN)) \ | |
4781 | __data = (MIN); \ | |
4782 | else if (__data > (MAX)) \ | |
4783 | __data = (MAX); \ | |
4784 | *(__PTR) = (u64)__data * NSEC_PER_USEC; \ | |
4785 | return ret; \ | |
4786 | } | |
4787 | USEC_STORE_FUNCTION(cfq_slice_idle_us_store, &cfqd->cfq_slice_idle, 0, UINT_MAX); | |
4788 | USEC_STORE_FUNCTION(cfq_group_idle_us_store, &cfqd->cfq_group_idle, 0, UINT_MAX); | |
4789 | USEC_STORE_FUNCTION(cfq_slice_sync_us_store, &cfqd->cfq_slice[1], 1, UINT_MAX); | |
4790 | USEC_STORE_FUNCTION(cfq_slice_async_us_store, &cfqd->cfq_slice[0], 1, UINT_MAX); | |
4791 | USEC_STORE_FUNCTION(cfq_target_latency_us_store, &cfqd->cfq_target_latency, 1, UINT_MAX); | |
4792 | #undef USEC_STORE_FUNCTION | |
4793 | ||
e572ec7e AV |
4794 | #define CFQ_ATTR(name) \ |
4795 | __ATTR(name, S_IRUGO|S_IWUSR, cfq_##name##_show, cfq_##name##_store) | |
4796 | ||
4797 | static struct elv_fs_entry cfq_attrs[] = { | |
4798 | CFQ_ATTR(quantum), | |
e572ec7e AV |
4799 | CFQ_ATTR(fifo_expire_sync), |
4800 | CFQ_ATTR(fifo_expire_async), | |
4801 | CFQ_ATTR(back_seek_max), | |
4802 | CFQ_ATTR(back_seek_penalty), | |
4803 | CFQ_ATTR(slice_sync), | |
d2d481d0 | 4804 | CFQ_ATTR(slice_sync_us), |
e572ec7e | 4805 | CFQ_ATTR(slice_async), |
d2d481d0 | 4806 | CFQ_ATTR(slice_async_us), |
e572ec7e AV |
4807 | CFQ_ATTR(slice_async_rq), |
4808 | CFQ_ATTR(slice_idle), | |
d2d481d0 | 4809 | CFQ_ATTR(slice_idle_us), |
80bdf0c7 | 4810 | CFQ_ATTR(group_idle), |
d2d481d0 | 4811 | CFQ_ATTR(group_idle_us), |
963b72fc | 4812 | CFQ_ATTR(low_latency), |
5bf14c07 | 4813 | CFQ_ATTR(target_latency), |
d2d481d0 | 4814 | CFQ_ATTR(target_latency_us), |
e572ec7e | 4815 | __ATTR_NULL |
1da177e4 LT |
4816 | }; |
4817 | ||
1da177e4 LT |
4818 | static struct elevator_type iosched_cfq = { |
4819 | .ops = { | |
4820 | .elevator_merge_fn = cfq_merge, | |
4821 | .elevator_merged_fn = cfq_merged_request, | |
4822 | .elevator_merge_req_fn = cfq_merged_requests, | |
da775265 | 4823 | .elevator_allow_merge_fn = cfq_allow_merge, |
812d4026 | 4824 | .elevator_bio_merged_fn = cfq_bio_merged, |
b4878f24 | 4825 | .elevator_dispatch_fn = cfq_dispatch_requests, |
1da177e4 | 4826 | .elevator_add_req_fn = cfq_insert_request, |
b4878f24 | 4827 | .elevator_activate_req_fn = cfq_activate_request, |
1da177e4 | 4828 | .elevator_deactivate_req_fn = cfq_deactivate_request, |
1da177e4 | 4829 | .elevator_completed_req_fn = cfq_completed_request, |
21183b07 JA |
4830 | .elevator_former_req_fn = elv_rb_former_request, |
4831 | .elevator_latter_req_fn = elv_rb_latter_request, | |
9b84cacd | 4832 | .elevator_init_icq_fn = cfq_init_icq, |
7e5a8794 | 4833 | .elevator_exit_icq_fn = cfq_exit_icq, |
1da177e4 LT |
4834 | .elevator_set_req_fn = cfq_set_request, |
4835 | .elevator_put_req_fn = cfq_put_request, | |
4836 | .elevator_may_queue_fn = cfq_may_queue, | |
4837 | .elevator_init_fn = cfq_init_queue, | |
4838 | .elevator_exit_fn = cfq_exit_queue, | |
0bb97947 | 4839 | .elevator_registered_fn = cfq_registered_queue, |
1da177e4 | 4840 | }, |
3d3c2379 TH |
4841 | .icq_size = sizeof(struct cfq_io_cq), |
4842 | .icq_align = __alignof__(struct cfq_io_cq), | |
3d1ab40f | 4843 | .elevator_attrs = cfq_attrs, |
3d3c2379 | 4844 | .elevator_name = "cfq", |
1da177e4 LT |
4845 | .elevator_owner = THIS_MODULE, |
4846 | }; | |
4847 | ||
3e252066 | 4848 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4849 | static struct blkcg_policy blkcg_policy_cfq = { |
2ee867dc | 4850 | .dfl_cftypes = cfq_blkcg_files, |
880f50e2 | 4851 | .legacy_cftypes = cfq_blkcg_legacy_files, |
f9fcc2d3 | 4852 | |
e4a9bde9 | 4853 | .cpd_alloc_fn = cfq_cpd_alloc, |
e48453c3 | 4854 | .cpd_init_fn = cfq_cpd_init, |
e4a9bde9 | 4855 | .cpd_free_fn = cfq_cpd_free, |
69d7fde5 | 4856 | .cpd_bind_fn = cfq_cpd_bind, |
e4a9bde9 | 4857 | |
001bea73 | 4858 | .pd_alloc_fn = cfq_pd_alloc, |
f9fcc2d3 | 4859 | .pd_init_fn = cfq_pd_init, |
0b39920b | 4860 | .pd_offline_fn = cfq_pd_offline, |
001bea73 | 4861 | .pd_free_fn = cfq_pd_free, |
f9fcc2d3 | 4862 | .pd_reset_stats_fn = cfq_pd_reset_stats, |
3e252066 | 4863 | }; |
3e252066 VG |
4864 | #endif |
4865 | ||
1da177e4 LT |
4866 | static int __init cfq_init(void) |
4867 | { | |
3d3c2379 TH |
4868 | int ret; |
4869 | ||
80bdf0c7 | 4870 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4871 | ret = blkcg_policy_register(&blkcg_policy_cfq); |
8bd435b3 TH |
4872 | if (ret) |
4873 | return ret; | |
ffea73fc TH |
4874 | #else |
4875 | cfq_group_idle = 0; | |
4876 | #endif | |
8bd435b3 | 4877 | |
fd794956 | 4878 | ret = -ENOMEM; |
3d3c2379 TH |
4879 | cfq_pool = KMEM_CACHE(cfq_queue, 0); |
4880 | if (!cfq_pool) | |
8bd435b3 | 4881 | goto err_pol_unreg; |
1da177e4 | 4882 | |
3d3c2379 | 4883 | ret = elv_register(&iosched_cfq); |
8bd435b3 TH |
4884 | if (ret) |
4885 | goto err_free_pool; | |
3d3c2379 | 4886 | |
2fdd82bd | 4887 | return 0; |
8bd435b3 TH |
4888 | |
4889 | err_free_pool: | |
4890 | kmem_cache_destroy(cfq_pool); | |
4891 | err_pol_unreg: | |
ffea73fc | 4892 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4893 | blkcg_policy_unregister(&blkcg_policy_cfq); |
ffea73fc | 4894 | #endif |
8bd435b3 | 4895 | return ret; |
1da177e4 LT |
4896 | } |
4897 | ||
4898 | static void __exit cfq_exit(void) | |
4899 | { | |
ffea73fc | 4900 | #ifdef CONFIG_CFQ_GROUP_IOSCHED |
3c798398 | 4901 | blkcg_policy_unregister(&blkcg_policy_cfq); |
ffea73fc | 4902 | #endif |
1da177e4 | 4903 | elv_unregister(&iosched_cfq); |
3d3c2379 | 4904 | kmem_cache_destroy(cfq_pool); |
1da177e4 LT |
4905 | } |
4906 | ||
4907 | module_init(cfq_init); | |
4908 | module_exit(cfq_exit); | |
4909 | ||
4910 | MODULE_AUTHOR("Jens Axboe"); | |
4911 | MODULE_LICENSE("GPL"); | |
4912 | MODULE_DESCRIPTION("Completely Fair Queueing IO scheduler"); |