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Commit | Line | Data |
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31e4c28d VG |
1 | /* |
2 | * Common Block IO controller cgroup interface | |
3 | * | |
4 | * Based on ideas and code from CFQ, CFS and BFQ: | |
5 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> | |
6 | * | |
7 | * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> | |
8 | * Paolo Valente <paolo.valente@unimore.it> | |
9 | * | |
10 | * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com> | |
11 | * Nauman Rafique <nauman@google.com> | |
12 | */ | |
13 | #include <linux/ioprio.h> | |
22084190 VG |
14 | #include <linux/seq_file.h> |
15 | #include <linux/kdev_t.h> | |
9d6a986c | 16 | #include <linux/module.h> |
accee785 | 17 | #include <linux/err.h> |
31e4c28d | 18 | #include "blk-cgroup.h" |
3e252066 VG |
19 | |
20 | static DEFINE_SPINLOCK(blkio_list_lock); | |
21 | static LIST_HEAD(blkio_list); | |
b1c35769 | 22 | |
31e4c28d | 23 | struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT }; |
9d6a986c VG |
24 | EXPORT_SYMBOL_GPL(blkio_root_cgroup); |
25 | ||
67523c48 BB |
26 | static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *, |
27 | struct cgroup *); | |
28 | static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *, | |
29 | struct task_struct *, bool); | |
30 | static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *, | |
31 | struct cgroup *, struct task_struct *, bool); | |
32 | static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *); | |
33 | static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); | |
34 | ||
35 | struct cgroup_subsys blkio_subsys = { | |
36 | .name = "blkio", | |
37 | .create = blkiocg_create, | |
38 | .can_attach = blkiocg_can_attach, | |
39 | .attach = blkiocg_attach, | |
40 | .destroy = blkiocg_destroy, | |
41 | .populate = blkiocg_populate, | |
42 | #ifdef CONFIG_BLK_CGROUP | |
43 | /* note: blkio_subsys_id is otherwise defined in blk-cgroup.h */ | |
44 | .subsys_id = blkio_subsys_id, | |
45 | #endif | |
46 | .use_id = 1, | |
47 | .module = THIS_MODULE, | |
48 | }; | |
49 | EXPORT_SYMBOL_GPL(blkio_subsys); | |
50 | ||
31e4c28d VG |
51 | struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup) |
52 | { | |
53 | return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id), | |
54 | struct blkio_cgroup, css); | |
55 | } | |
9d6a986c | 56 | EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup); |
31e4c28d | 57 | |
303a3acb | 58 | void blkiocg_update_timeslice_used(struct blkio_group *blkg, unsigned long time) |
22084190 | 59 | { |
303a3acb DS |
60 | unsigned long flags; |
61 | ||
62 | spin_lock_irqsave(&blkg->stats_lock, flags); | |
63 | blkg->stats.time += time; | |
64 | spin_unlock_irqrestore(&blkg->stats_lock, flags); | |
22084190 | 65 | } |
303a3acb | 66 | EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used); |
22084190 | 67 | |
31e4c28d | 68 | void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, |
22084190 | 69 | struct blkio_group *blkg, void *key, dev_t dev) |
31e4c28d VG |
70 | { |
71 | unsigned long flags; | |
72 | ||
73 | spin_lock_irqsave(&blkcg->lock, flags); | |
74 | rcu_assign_pointer(blkg->key, key); | |
b1c35769 | 75 | blkg->blkcg_id = css_id(&blkcg->css); |
31e4c28d VG |
76 | hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); |
77 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
2868ef7b VG |
78 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
79 | /* Need to take css reference ? */ | |
80 | cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path)); | |
81 | #endif | |
22084190 | 82 | blkg->dev = dev; |
31e4c28d | 83 | } |
9d6a986c | 84 | EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group); |
31e4c28d | 85 | |
b1c35769 VG |
86 | static void __blkiocg_del_blkio_group(struct blkio_group *blkg) |
87 | { | |
88 | hlist_del_init_rcu(&blkg->blkcg_node); | |
89 | blkg->blkcg_id = 0; | |
90 | } | |
91 | ||
92 | /* | |
93 | * returns 0 if blkio_group was still on cgroup list. Otherwise returns 1 | |
94 | * indicating that blk_group was unhashed by the time we got to it. | |
95 | */ | |
31e4c28d VG |
96 | int blkiocg_del_blkio_group(struct blkio_group *blkg) |
97 | { | |
b1c35769 VG |
98 | struct blkio_cgroup *blkcg; |
99 | unsigned long flags; | |
100 | struct cgroup_subsys_state *css; | |
101 | int ret = 1; | |
102 | ||
103 | rcu_read_lock(); | |
104 | css = css_lookup(&blkio_subsys, blkg->blkcg_id); | |
105 | if (!css) | |
106 | goto out; | |
107 | ||
108 | blkcg = container_of(css, struct blkio_cgroup, css); | |
109 | spin_lock_irqsave(&blkcg->lock, flags); | |
110 | if (!hlist_unhashed(&blkg->blkcg_node)) { | |
111 | __blkiocg_del_blkio_group(blkg); | |
112 | ret = 0; | |
113 | } | |
114 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
115 | out: | |
116 | rcu_read_unlock(); | |
117 | return ret; | |
31e4c28d | 118 | } |
9d6a986c | 119 | EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group); |
31e4c28d VG |
120 | |
121 | /* called under rcu_read_lock(). */ | |
122 | struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) | |
123 | { | |
124 | struct blkio_group *blkg; | |
125 | struct hlist_node *n; | |
126 | void *__key; | |
127 | ||
128 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
129 | __key = blkg->key; | |
130 | if (__key == key) | |
131 | return blkg; | |
132 | } | |
133 | ||
134 | return NULL; | |
135 | } | |
9d6a986c | 136 | EXPORT_SYMBOL_GPL(blkiocg_lookup_group); |
31e4c28d VG |
137 | |
138 | #define SHOW_FUNCTION(__VAR) \ | |
139 | static u64 blkiocg_##__VAR##_read(struct cgroup *cgroup, \ | |
140 | struct cftype *cftype) \ | |
141 | { \ | |
142 | struct blkio_cgroup *blkcg; \ | |
143 | \ | |
144 | blkcg = cgroup_to_blkio_cgroup(cgroup); \ | |
145 | return (u64)blkcg->__VAR; \ | |
146 | } | |
147 | ||
148 | SHOW_FUNCTION(weight); | |
149 | #undef SHOW_FUNCTION | |
150 | ||
151 | static int | |
152 | blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val) | |
153 | { | |
154 | struct blkio_cgroup *blkcg; | |
f8d461d6 VG |
155 | struct blkio_group *blkg; |
156 | struct hlist_node *n; | |
3e252066 | 157 | struct blkio_policy_type *blkiop; |
31e4c28d VG |
158 | |
159 | if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX) | |
160 | return -EINVAL; | |
161 | ||
162 | blkcg = cgroup_to_blkio_cgroup(cgroup); | |
bcf4dd43 | 163 | spin_lock(&blkio_list_lock); |
f8d461d6 | 164 | spin_lock_irq(&blkcg->lock); |
31e4c28d | 165 | blkcg->weight = (unsigned int)val; |
3e252066 | 166 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { |
3e252066 VG |
167 | list_for_each_entry(blkiop, &blkio_list, list) |
168 | blkiop->ops.blkio_update_group_weight_fn(blkg, | |
169 | blkcg->weight); | |
3e252066 | 170 | } |
f8d461d6 | 171 | spin_unlock_irq(&blkcg->lock); |
bcf4dd43 | 172 | spin_unlock(&blkio_list_lock); |
31e4c28d VG |
173 | return 0; |
174 | } | |
175 | ||
303a3acb DS |
176 | static int |
177 | blkiocg_reset_write(struct cgroup *cgroup, struct cftype *cftype, u64 val) | |
178 | { | |
179 | struct blkio_cgroup *blkcg; | |
180 | struct blkio_group *blkg; | |
181 | struct hlist_node *n; | |
182 | struct blkio_group_stats *stats; | |
183 | ||
184 | blkcg = cgroup_to_blkio_cgroup(cgroup); | |
185 | spin_lock_irq(&blkcg->lock); | |
186 | hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { | |
187 | spin_lock(&blkg->stats_lock); | |
188 | stats = &blkg->stats; | |
189 | memset(stats, 0, sizeof(struct blkio_group_stats)); | |
190 | spin_unlock(&blkg->stats_lock); | |
191 | } | |
192 | spin_unlock_irq(&blkcg->lock); | |
193 | return 0; | |
194 | } | |
195 | ||
196 | void get_key_name(int type, char *disk_id, char *str, int chars_left) | |
197 | { | |
198 | strlcpy(str, disk_id, chars_left); | |
199 | chars_left -= strlen(str); | |
200 | if (chars_left <= 0) { | |
201 | printk(KERN_WARNING | |
202 | "Possibly incorrect cgroup stat display format"); | |
203 | return; | |
204 | } | |
205 | switch (type) { | |
206 | case IO_READ: | |
207 | strlcat(str, " Read", chars_left); | |
208 | break; | |
209 | case IO_WRITE: | |
210 | strlcat(str, " Write", chars_left); | |
211 | break; | |
212 | case IO_SYNC: | |
213 | strlcat(str, " Sync", chars_left); | |
214 | break; | |
215 | case IO_ASYNC: | |
216 | strlcat(str, " Async", chars_left); | |
217 | break; | |
218 | case IO_TYPE_MAX: | |
219 | strlcat(str, " Total", chars_left); | |
220 | break; | |
221 | default: | |
222 | strlcat(str, " Invalid", chars_left); | |
223 | } | |
224 | } | |
225 | ||
226 | typedef uint64_t (get_var) (struct blkio_group *, int); | |
227 | ||
228 | #define MAX_KEY_LEN 100 | |
229 | uint64_t get_typed_stat(struct blkio_group *blkg, struct cgroup_map_cb *cb, | |
230 | get_var *getvar, char *disk_id) | |
231 | { | |
232 | uint64_t disk_total; | |
233 | char key_str[MAX_KEY_LEN]; | |
234 | int type; | |
235 | ||
236 | for (type = 0; type < IO_TYPE_MAX; type++) { | |
237 | get_key_name(type, disk_id, key_str, MAX_KEY_LEN); | |
238 | cb->fill(cb, key_str, getvar(blkg, type)); | |
239 | } | |
240 | disk_total = getvar(blkg, IO_READ) + getvar(blkg, IO_WRITE); | |
241 | get_key_name(IO_TYPE_MAX, disk_id, key_str, MAX_KEY_LEN); | |
242 | cb->fill(cb, key_str, disk_total); | |
243 | return disk_total; | |
244 | } | |
245 | ||
246 | uint64_t get_stat(struct blkio_group *blkg, struct cgroup_map_cb *cb, | |
247 | get_var *getvar, char *disk_id) | |
248 | { | |
249 | uint64_t var = getvar(blkg, 0); | |
250 | cb->fill(cb, disk_id, var); | |
251 | return var; | |
252 | } | |
253 | ||
254 | #define GET_STAT_INDEXED(__VAR) \ | |
255 | uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int type) \ | |
256 | { \ | |
257 | return blkg->stats.__VAR[type]; \ | |
258 | } \ | |
259 | ||
260 | GET_STAT_INDEXED(io_service_bytes); | |
261 | GET_STAT_INDEXED(io_serviced); | |
262 | GET_STAT_INDEXED(io_service_time); | |
263 | GET_STAT_INDEXED(io_wait_time); | |
264 | #undef GET_STAT_INDEXED | |
265 | ||
266 | #define GET_STAT(__VAR, __CONV) \ | |
267 | uint64_t get_##__VAR##_stat(struct blkio_group *blkg, int dummy) \ | |
268 | { \ | |
269 | uint64_t data = blkg->stats.__VAR; \ | |
270 | if (__CONV) \ | |
271 | data = (uint64_t)jiffies_to_msecs(data) * NSEC_PER_MSEC;\ | |
272 | return data; \ | |
273 | } | |
274 | ||
275 | GET_STAT(time, 1); | |
276 | GET_STAT(sectors, 0); | |
277 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
278 | GET_STAT(dequeue, 0); | |
279 | #endif | |
280 | #undef GET_STAT | |
281 | ||
282 | #define SHOW_FUNCTION_PER_GROUP(__VAR, get_stats, getvar, show_total) \ | |
22084190 | 283 | static int blkiocg_##__VAR##_read(struct cgroup *cgroup, \ |
303a3acb | 284 | struct cftype *cftype, struct cgroup_map_cb *cb) \ |
22084190 VG |
285 | { \ |
286 | struct blkio_cgroup *blkcg; \ | |
287 | struct blkio_group *blkg; \ | |
288 | struct hlist_node *n; \ | |
303a3acb DS |
289 | uint64_t cgroup_total = 0; \ |
290 | char disk_id[10]; \ | |
22084190 VG |
291 | \ |
292 | if (!cgroup_lock_live_group(cgroup)) \ | |
293 | return -ENODEV; \ | |
294 | \ | |
295 | blkcg = cgroup_to_blkio_cgroup(cgroup); \ | |
296 | rcu_read_lock(); \ | |
297 | hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {\ | |
303a3acb DS |
298 | if (blkg->dev) { \ |
299 | spin_lock_irq(&blkg->stats_lock); \ | |
300 | snprintf(disk_id, 10, "%u:%u", MAJOR(blkg->dev),\ | |
301 | MINOR(blkg->dev)); \ | |
302 | cgroup_total += get_stats(blkg, cb, getvar, \ | |
303 | disk_id); \ | |
304 | spin_unlock_irq(&blkg->stats_lock); \ | |
305 | } \ | |
22084190 | 306 | } \ |
303a3acb DS |
307 | if (show_total) \ |
308 | cb->fill(cb, "Total", cgroup_total); \ | |
22084190 VG |
309 | rcu_read_unlock(); \ |
310 | cgroup_unlock(); \ | |
311 | return 0; \ | |
312 | } | |
313 | ||
303a3acb DS |
314 | SHOW_FUNCTION_PER_GROUP(time, get_stat, get_time_stat, 0); |
315 | SHOW_FUNCTION_PER_GROUP(sectors, get_stat, get_sectors_stat, 0); | |
316 | SHOW_FUNCTION_PER_GROUP(io_service_bytes, get_typed_stat, | |
317 | get_io_service_bytes_stat, 1); | |
318 | SHOW_FUNCTION_PER_GROUP(io_serviced, get_typed_stat, get_io_serviced_stat, 1); | |
319 | SHOW_FUNCTION_PER_GROUP(io_service_time, get_typed_stat, | |
320 | get_io_service_time_stat, 1); | |
321 | SHOW_FUNCTION_PER_GROUP(io_wait_time, get_typed_stat, get_io_wait_time_stat, 1); | |
22084190 | 322 | #ifdef CONFIG_DEBUG_BLK_CGROUP |
303a3acb | 323 | SHOW_FUNCTION_PER_GROUP(dequeue, get_stat, get_dequeue_stat, 0); |
22084190 VG |
324 | #endif |
325 | #undef SHOW_FUNCTION_PER_GROUP | |
326 | ||
327 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
328 | void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg, | |
329 | unsigned long dequeue) | |
330 | { | |
303a3acb | 331 | blkg->stats.dequeue += dequeue; |
22084190 | 332 | } |
9d6a986c | 333 | EXPORT_SYMBOL_GPL(blkiocg_update_blkio_group_dequeue_stats); |
22084190 VG |
334 | #endif |
335 | ||
31e4c28d VG |
336 | struct cftype blkio_files[] = { |
337 | { | |
338 | .name = "weight", | |
339 | .read_u64 = blkiocg_weight_read, | |
340 | .write_u64 = blkiocg_weight_write, | |
341 | }, | |
22084190 VG |
342 | { |
343 | .name = "time", | |
303a3acb DS |
344 | .read_map = blkiocg_time_read, |
345 | .write_u64 = blkiocg_reset_write, | |
22084190 VG |
346 | }, |
347 | { | |
348 | .name = "sectors", | |
303a3acb DS |
349 | .read_map = blkiocg_sectors_read, |
350 | .write_u64 = blkiocg_reset_write, | |
351 | }, | |
352 | { | |
353 | .name = "io_service_bytes", | |
354 | .read_map = blkiocg_io_service_bytes_read, | |
355 | .write_u64 = blkiocg_reset_write, | |
356 | }, | |
357 | { | |
358 | .name = "io_serviced", | |
359 | .read_map = blkiocg_io_serviced_read, | |
360 | .write_u64 = blkiocg_reset_write, | |
361 | }, | |
362 | { | |
363 | .name = "io_service_time", | |
364 | .read_map = blkiocg_io_service_time_read, | |
365 | .write_u64 = blkiocg_reset_write, | |
366 | }, | |
367 | { | |
368 | .name = "io_wait_time", | |
369 | .read_map = blkiocg_io_wait_time_read, | |
370 | .write_u64 = blkiocg_reset_write, | |
22084190 VG |
371 | }, |
372 | #ifdef CONFIG_DEBUG_BLK_CGROUP | |
373 | { | |
374 | .name = "dequeue", | |
303a3acb | 375 | .read_map = blkiocg_dequeue_read, |
22084190 VG |
376 | }, |
377 | #endif | |
31e4c28d VG |
378 | }; |
379 | ||
380 | static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
381 | { | |
382 | return cgroup_add_files(cgroup, subsys, blkio_files, | |
383 | ARRAY_SIZE(blkio_files)); | |
384 | } | |
385 | ||
386 | static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
387 | { | |
388 | struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); | |
b1c35769 VG |
389 | unsigned long flags; |
390 | struct blkio_group *blkg; | |
391 | void *key; | |
3e252066 | 392 | struct blkio_policy_type *blkiop; |
b1c35769 VG |
393 | |
394 | rcu_read_lock(); | |
395 | remove_entry: | |
396 | spin_lock_irqsave(&blkcg->lock, flags); | |
397 | ||
398 | if (hlist_empty(&blkcg->blkg_list)) { | |
399 | spin_unlock_irqrestore(&blkcg->lock, flags); | |
400 | goto done; | |
401 | } | |
402 | ||
403 | blkg = hlist_entry(blkcg->blkg_list.first, struct blkio_group, | |
404 | blkcg_node); | |
405 | key = rcu_dereference(blkg->key); | |
406 | __blkiocg_del_blkio_group(blkg); | |
31e4c28d | 407 | |
b1c35769 VG |
408 | spin_unlock_irqrestore(&blkcg->lock, flags); |
409 | ||
410 | /* | |
411 | * This blkio_group is being unlinked as associated cgroup is going | |
412 | * away. Let all the IO controlling policies know about this event. | |
413 | * | |
414 | * Currently this is static call to one io controlling policy. Once | |
415 | * we have more policies in place, we need some dynamic registration | |
416 | * of callback function. | |
417 | */ | |
3e252066 VG |
418 | spin_lock(&blkio_list_lock); |
419 | list_for_each_entry(blkiop, &blkio_list, list) | |
420 | blkiop->ops.blkio_unlink_group_fn(key, blkg); | |
421 | spin_unlock(&blkio_list_lock); | |
b1c35769 VG |
422 | goto remove_entry; |
423 | done: | |
31e4c28d | 424 | free_css_id(&blkio_subsys, &blkcg->css); |
b1c35769 | 425 | rcu_read_unlock(); |
67523c48 BB |
426 | if (blkcg != &blkio_root_cgroup) |
427 | kfree(blkcg); | |
31e4c28d VG |
428 | } |
429 | ||
430 | static struct cgroup_subsys_state * | |
431 | blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup) | |
432 | { | |
433 | struct blkio_cgroup *blkcg, *parent_blkcg; | |
434 | ||
435 | if (!cgroup->parent) { | |
436 | blkcg = &blkio_root_cgroup; | |
437 | goto done; | |
438 | } | |
439 | ||
440 | /* Currently we do not support hierarchy deeper than two level (0,1) */ | |
441 | parent_blkcg = cgroup_to_blkio_cgroup(cgroup->parent); | |
442 | if (css_depth(&parent_blkcg->css) > 0) | |
443 | return ERR_PTR(-EINVAL); | |
444 | ||
445 | blkcg = kzalloc(sizeof(*blkcg), GFP_KERNEL); | |
446 | if (!blkcg) | |
447 | return ERR_PTR(-ENOMEM); | |
448 | ||
449 | blkcg->weight = BLKIO_WEIGHT_DEFAULT; | |
450 | done: | |
451 | spin_lock_init(&blkcg->lock); | |
452 | INIT_HLIST_HEAD(&blkcg->blkg_list); | |
453 | ||
454 | return &blkcg->css; | |
455 | } | |
456 | ||
457 | /* | |
458 | * We cannot support shared io contexts, as we have no mean to support | |
459 | * two tasks with the same ioc in two different groups without major rework | |
460 | * of the main cic data structures. For now we allow a task to change | |
461 | * its cgroup only if it's the only owner of its ioc. | |
462 | */ | |
463 | static int blkiocg_can_attach(struct cgroup_subsys *subsys, | |
464 | struct cgroup *cgroup, struct task_struct *tsk, | |
465 | bool threadgroup) | |
466 | { | |
467 | struct io_context *ioc; | |
468 | int ret = 0; | |
469 | ||
470 | /* task_lock() is needed to avoid races with exit_io_context() */ | |
471 | task_lock(tsk); | |
472 | ioc = tsk->io_context; | |
473 | if (ioc && atomic_read(&ioc->nr_tasks) > 1) | |
474 | ret = -EINVAL; | |
475 | task_unlock(tsk); | |
476 | ||
477 | return ret; | |
478 | } | |
479 | ||
480 | static void blkiocg_attach(struct cgroup_subsys *subsys, struct cgroup *cgroup, | |
481 | struct cgroup *prev, struct task_struct *tsk, | |
482 | bool threadgroup) | |
483 | { | |
484 | struct io_context *ioc; | |
485 | ||
486 | task_lock(tsk); | |
487 | ioc = tsk->io_context; | |
488 | if (ioc) | |
489 | ioc->cgroup_changed = 1; | |
490 | task_unlock(tsk); | |
491 | } | |
492 | ||
3e252066 VG |
493 | void blkio_policy_register(struct blkio_policy_type *blkiop) |
494 | { | |
495 | spin_lock(&blkio_list_lock); | |
496 | list_add_tail(&blkiop->list, &blkio_list); | |
497 | spin_unlock(&blkio_list_lock); | |
498 | } | |
499 | EXPORT_SYMBOL_GPL(blkio_policy_register); | |
500 | ||
501 | void blkio_policy_unregister(struct blkio_policy_type *blkiop) | |
502 | { | |
503 | spin_lock(&blkio_list_lock); | |
504 | list_del_init(&blkiop->list); | |
505 | spin_unlock(&blkio_list_lock); | |
506 | } | |
507 | EXPORT_SYMBOL_GPL(blkio_policy_unregister); | |
67523c48 BB |
508 | |
509 | static int __init init_cgroup_blkio(void) | |
510 | { | |
511 | return cgroup_load_subsys(&blkio_subsys); | |
512 | } | |
513 | ||
514 | static void __exit exit_cgroup_blkio(void) | |
515 | { | |
516 | cgroup_unload_subsys(&blkio_subsys); | |
517 | } | |
518 | ||
519 | module_init(init_cgroup_blkio); | |
520 | module_exit(exit_cgroup_blkio); | |
521 | MODULE_LICENSE("GPL"); |