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2bc64a20 AK |
1 | /* |
2 | * | |
3 | * Copyright IBM Corporation, 2012 | |
4 | * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of version 2.1 of the GNU Lesser General Public License | |
8 | * as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it would be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/cgroup.h> | |
71f87bee | 17 | #include <linux/page_counter.h> |
2bc64a20 AK |
18 | #include <linux/slab.h> |
19 | #include <linux/hugetlb.h> | |
20 | #include <linux/hugetlb_cgroup.h> | |
21 | ||
22 | struct hugetlb_cgroup { | |
23 | struct cgroup_subsys_state css; | |
24 | /* | |
25 | * the counter to account for hugepages from hugetlb. | |
26 | */ | |
71f87bee | 27 | struct page_counter hugepage[HUGE_MAX_HSTATE]; |
2bc64a20 AK |
28 | }; |
29 | ||
abb8206c AK |
30 | #define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val)) |
31 | #define MEMFILE_IDX(val) (((val) >> 16) & 0xffff) | |
32 | #define MEMFILE_ATTR(val) ((val) & 0xffff) | |
33 | ||
2bc64a20 AK |
34 | static struct hugetlb_cgroup *root_h_cgroup __read_mostly; |
35 | ||
36 | static inline | |
37 | struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s) | |
38 | { | |
a7c6d554 | 39 | return s ? container_of(s, struct hugetlb_cgroup, css) : NULL; |
2bc64a20 AK |
40 | } |
41 | ||
2bc64a20 AK |
42 | static inline |
43 | struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task) | |
44 | { | |
073219e9 | 45 | return hugetlb_cgroup_from_css(task_css(task, hugetlb_cgrp_id)); |
2bc64a20 AK |
46 | } |
47 | ||
48 | static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg) | |
49 | { | |
50 | return (h_cg == root_h_cgroup); | |
51 | } | |
52 | ||
3f798518 TH |
53 | static inline struct hugetlb_cgroup * |
54 | parent_hugetlb_cgroup(struct hugetlb_cgroup *h_cg) | |
2bc64a20 | 55 | { |
5c9d535b | 56 | return hugetlb_cgroup_from_css(h_cg->css.parent); |
2bc64a20 AK |
57 | } |
58 | ||
3f798518 | 59 | static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg) |
2bc64a20 AK |
60 | { |
61 | int idx; | |
2bc64a20 AK |
62 | |
63 | for (idx = 0; idx < hugetlb_max_hstate; idx++) { | |
71f87bee | 64 | if (page_counter_read(&h_cg->hugepage[idx])) |
2bc64a20 AK |
65 | return true; |
66 | } | |
67 | return false; | |
68 | } | |
69 | ||
eb95419b TH |
70 | static struct cgroup_subsys_state * |
71 | hugetlb_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
2bc64a20 | 72 | { |
eb95419b TH |
73 | struct hugetlb_cgroup *parent_h_cgroup = hugetlb_cgroup_from_css(parent_css); |
74 | struct hugetlb_cgroup *h_cgroup; | |
2bc64a20 | 75 | int idx; |
2bc64a20 AK |
76 | |
77 | h_cgroup = kzalloc(sizeof(*h_cgroup), GFP_KERNEL); | |
78 | if (!h_cgroup) | |
79 | return ERR_PTR(-ENOMEM); | |
80 | ||
eb95419b | 81 | if (parent_h_cgroup) { |
2bc64a20 | 82 | for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) |
71f87bee JW |
83 | page_counter_init(&h_cgroup->hugepage[idx], |
84 | &parent_h_cgroup->hugepage[idx]); | |
2bc64a20 AK |
85 | } else { |
86 | root_h_cgroup = h_cgroup; | |
87 | for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) | |
71f87bee | 88 | page_counter_init(&h_cgroup->hugepage[idx], NULL); |
2bc64a20 AK |
89 | } |
90 | return &h_cgroup->css; | |
91 | } | |
92 | ||
eb95419b | 93 | static void hugetlb_cgroup_css_free(struct cgroup_subsys_state *css) |
2bc64a20 AK |
94 | { |
95 | struct hugetlb_cgroup *h_cgroup; | |
96 | ||
eb95419b | 97 | h_cgroup = hugetlb_cgroup_from_css(css); |
2bc64a20 AK |
98 | kfree(h_cgroup); |
99 | } | |
100 | ||
da1def55 AK |
101 | |
102 | /* | |
103 | * Should be called with hugetlb_lock held. | |
104 | * Since we are holding hugetlb_lock, pages cannot get moved from | |
105 | * active list or uncharged from the cgroup, So no need to get | |
106 | * page reference and test for page active here. This function | |
107 | * cannot fail. | |
108 | */ | |
3f798518 | 109 | static void hugetlb_cgroup_move_parent(int idx, struct hugetlb_cgroup *h_cg, |
da1def55 AK |
110 | struct page *page) |
111 | { | |
71f87bee JW |
112 | unsigned int nr_pages; |
113 | struct page_counter *counter; | |
da1def55 | 114 | struct hugetlb_cgroup *page_hcg; |
3f798518 | 115 | struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(h_cg); |
da1def55 AK |
116 | |
117 | page_hcg = hugetlb_cgroup_from_page(page); | |
118 | /* | |
119 | * We can have pages in active list without any cgroup | |
120 | * ie, hugepage with less than 3 pages. We can safely | |
121 | * ignore those pages. | |
122 | */ | |
123 | if (!page_hcg || page_hcg != h_cg) | |
124 | goto out; | |
125 | ||
71f87bee | 126 | nr_pages = 1 << compound_order(page); |
da1def55 AK |
127 | if (!parent) { |
128 | parent = root_h_cgroup; | |
129 | /* root has no limit */ | |
71f87bee | 130 | page_counter_charge(&parent->hugepage[idx], nr_pages); |
da1def55 AK |
131 | } |
132 | counter = &h_cg->hugepage[idx]; | |
71f87bee JW |
133 | /* Take the pages off the local counter */ |
134 | page_counter_cancel(counter, nr_pages); | |
da1def55 AK |
135 | |
136 | set_hugetlb_cgroup(page, parent); | |
137 | out: | |
138 | return; | |
139 | } | |
140 | ||
141 | /* | |
142 | * Force the hugetlb cgroup to empty the hugetlb resources by moving them to | |
143 | * the parent cgroup. | |
144 | */ | |
eb95419b | 145 | static void hugetlb_cgroup_css_offline(struct cgroup_subsys_state *css) |
2bc64a20 | 146 | { |
eb95419b | 147 | struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css); |
da1def55 AK |
148 | struct hstate *h; |
149 | struct page *page; | |
9d093cb1 | 150 | int idx = 0; |
da1def55 AK |
151 | |
152 | do { | |
da1def55 AK |
153 | for_each_hstate(h) { |
154 | spin_lock(&hugetlb_lock); | |
155 | list_for_each_entry(page, &h->hugepage_activelist, lru) | |
3f798518 | 156 | hugetlb_cgroup_move_parent(idx, h_cg, page); |
da1def55 AK |
157 | |
158 | spin_unlock(&hugetlb_lock); | |
159 | idx++; | |
160 | } | |
161 | cond_resched(); | |
3f798518 | 162 | } while (hugetlb_cgroup_have_usage(h_cg)); |
2bc64a20 AK |
163 | } |
164 | ||
6d76dcf4 AK |
165 | int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, |
166 | struct hugetlb_cgroup **ptr) | |
167 | { | |
168 | int ret = 0; | |
71f87bee | 169 | struct page_counter *counter; |
6d76dcf4 | 170 | struct hugetlb_cgroup *h_cg = NULL; |
6d76dcf4 AK |
171 | |
172 | if (hugetlb_cgroup_disabled()) | |
173 | goto done; | |
174 | /* | |
175 | * We don't charge any cgroup if the compound page have less | |
176 | * than 3 pages. | |
177 | */ | |
178 | if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER) | |
179 | goto done; | |
180 | again: | |
181 | rcu_read_lock(); | |
182 | h_cg = hugetlb_cgroup_from_task(current); | |
ec903c0c | 183 | if (!css_tryget_online(&h_cg->css)) { |
6d76dcf4 AK |
184 | rcu_read_unlock(); |
185 | goto again; | |
186 | } | |
187 | rcu_read_unlock(); | |
188 | ||
6071ca52 JW |
189 | if (!page_counter_try_charge(&h_cg->hugepage[idx], nr_pages, &counter)) |
190 | ret = -ENOMEM; | |
6d76dcf4 AK |
191 | css_put(&h_cg->css); |
192 | done: | |
193 | *ptr = h_cg; | |
194 | return ret; | |
195 | } | |
196 | ||
94ae8ba7 | 197 | /* Should be called with hugetlb_lock held */ |
6d76dcf4 AK |
198 | void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages, |
199 | struct hugetlb_cgroup *h_cg, | |
200 | struct page *page) | |
201 | { | |
202 | if (hugetlb_cgroup_disabled() || !h_cg) | |
203 | return; | |
204 | ||
6d76dcf4 | 205 | set_hugetlb_cgroup(page, h_cg); |
6d76dcf4 AK |
206 | return; |
207 | } | |
208 | ||
209 | /* | |
210 | * Should be called with hugetlb_lock held | |
211 | */ | |
212 | void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, | |
213 | struct page *page) | |
214 | { | |
215 | struct hugetlb_cgroup *h_cg; | |
6d76dcf4 AK |
216 | |
217 | if (hugetlb_cgroup_disabled()) | |
218 | return; | |
7ea8574e | 219 | lockdep_assert_held(&hugetlb_lock); |
6d76dcf4 AK |
220 | h_cg = hugetlb_cgroup_from_page(page); |
221 | if (unlikely(!h_cg)) | |
222 | return; | |
223 | set_hugetlb_cgroup(page, NULL); | |
71f87bee | 224 | page_counter_uncharge(&h_cg->hugepage[idx], nr_pages); |
6d76dcf4 AK |
225 | return; |
226 | } | |
227 | ||
228 | void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages, | |
229 | struct hugetlb_cgroup *h_cg) | |
230 | { | |
6d76dcf4 AK |
231 | if (hugetlb_cgroup_disabled() || !h_cg) |
232 | return; | |
233 | ||
234 | if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER) | |
235 | return; | |
236 | ||
71f87bee | 237 | page_counter_uncharge(&h_cg->hugepage[idx], nr_pages); |
6d76dcf4 AK |
238 | return; |
239 | } | |
240 | ||
71f87bee JW |
241 | enum { |
242 | RES_USAGE, | |
243 | RES_LIMIT, | |
244 | RES_MAX_USAGE, | |
245 | RES_FAILCNT, | |
246 | }; | |
247 | ||
716f479d TH |
248 | static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css, |
249 | struct cftype *cft) | |
abb8206c | 250 | { |
71f87bee | 251 | struct page_counter *counter; |
182446d0 | 252 | struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css); |
abb8206c | 253 | |
71f87bee | 254 | counter = &h_cg->hugepage[MEMFILE_IDX(cft->private)]; |
abb8206c | 255 | |
71f87bee JW |
256 | switch (MEMFILE_ATTR(cft->private)) { |
257 | case RES_USAGE: | |
258 | return (u64)page_counter_read(counter) * PAGE_SIZE; | |
259 | case RES_LIMIT: | |
260 | return (u64)counter->limit * PAGE_SIZE; | |
261 | case RES_MAX_USAGE: | |
262 | return (u64)counter->watermark * PAGE_SIZE; | |
263 | case RES_FAILCNT: | |
264 | return counter->failcnt; | |
265 | default: | |
266 | BUG(); | |
267 | } | |
abb8206c AK |
268 | } |
269 | ||
71f87bee JW |
270 | static DEFINE_MUTEX(hugetlb_limit_mutex); |
271 | ||
451af504 TH |
272 | static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of, |
273 | char *buf, size_t nbytes, loff_t off) | |
abb8206c | 274 | { |
71f87bee JW |
275 | int ret, idx; |
276 | unsigned long nr_pages; | |
451af504 | 277 | struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); |
abb8206c | 278 | |
71f87bee JW |
279 | if (hugetlb_cgroup_is_root(h_cg)) /* Can't set limit on root */ |
280 | return -EINVAL; | |
281 | ||
451af504 | 282 | buf = strstrip(buf); |
650c5e56 | 283 | ret = page_counter_memparse(buf, "-1", &nr_pages); |
71f87bee JW |
284 | if (ret) |
285 | return ret; | |
286 | ||
451af504 | 287 | idx = MEMFILE_IDX(of_cft(of)->private); |
abb8206c | 288 | |
71f87bee | 289 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
abb8206c | 290 | case RES_LIMIT: |
71f87bee JW |
291 | mutex_lock(&hugetlb_limit_mutex); |
292 | ret = page_counter_limit(&h_cg->hugepage[idx], nr_pages); | |
293 | mutex_unlock(&hugetlb_limit_mutex); | |
abb8206c AK |
294 | break; |
295 | default: | |
296 | ret = -EINVAL; | |
297 | break; | |
298 | } | |
451af504 | 299 | return ret ?: nbytes; |
abb8206c AK |
300 | } |
301 | ||
6770c64e TH |
302 | static ssize_t hugetlb_cgroup_reset(struct kernfs_open_file *of, |
303 | char *buf, size_t nbytes, loff_t off) | |
abb8206c | 304 | { |
71f87bee JW |
305 | int ret = 0; |
306 | struct page_counter *counter; | |
6770c64e | 307 | struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); |
abb8206c | 308 | |
71f87bee | 309 | counter = &h_cg->hugepage[MEMFILE_IDX(of_cft(of)->private)]; |
abb8206c | 310 | |
71f87bee | 311 | switch (MEMFILE_ATTR(of_cft(of)->private)) { |
abb8206c | 312 | case RES_MAX_USAGE: |
71f87bee | 313 | page_counter_reset_watermark(counter); |
abb8206c AK |
314 | break; |
315 | case RES_FAILCNT: | |
71f87bee | 316 | counter->failcnt = 0; |
abb8206c AK |
317 | break; |
318 | default: | |
319 | ret = -EINVAL; | |
320 | break; | |
321 | } | |
6770c64e | 322 | return ret ?: nbytes; |
abb8206c AK |
323 | } |
324 | ||
325 | static char *mem_fmt(char *buf, int size, unsigned long hsize) | |
326 | { | |
327 | if (hsize >= (1UL << 30)) | |
328 | snprintf(buf, size, "%luGB", hsize >> 30); | |
329 | else if (hsize >= (1UL << 20)) | |
330 | snprintf(buf, size, "%luMB", hsize >> 20); | |
331 | else | |
332 | snprintf(buf, size, "%luKB", hsize >> 10); | |
333 | return buf; | |
334 | } | |
335 | ||
7179e7bf | 336 | static void __init __hugetlb_cgroup_file_init(int idx) |
abb8206c AK |
337 | { |
338 | char buf[32]; | |
339 | struct cftype *cft; | |
340 | struct hstate *h = &hstates[idx]; | |
341 | ||
342 | /* format the size */ | |
343 | mem_fmt(buf, 32, huge_page_size(h)); | |
344 | ||
345 | /* Add the limit file */ | |
346 | cft = &h->cgroup_files[0]; | |
347 | snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf); | |
348 | cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT); | |
716f479d | 349 | cft->read_u64 = hugetlb_cgroup_read_u64; |
451af504 | 350 | cft->write = hugetlb_cgroup_write; |
abb8206c AK |
351 | |
352 | /* Add the usage file */ | |
353 | cft = &h->cgroup_files[1]; | |
354 | snprintf(cft->name, MAX_CFTYPE_NAME, "%s.usage_in_bytes", buf); | |
355 | cft->private = MEMFILE_PRIVATE(idx, RES_USAGE); | |
716f479d | 356 | cft->read_u64 = hugetlb_cgroup_read_u64; |
abb8206c AK |
357 | |
358 | /* Add the MAX usage file */ | |
359 | cft = &h->cgroup_files[2]; | |
360 | snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max_usage_in_bytes", buf); | |
361 | cft->private = MEMFILE_PRIVATE(idx, RES_MAX_USAGE); | |
6770c64e | 362 | cft->write = hugetlb_cgroup_reset; |
716f479d | 363 | cft->read_u64 = hugetlb_cgroup_read_u64; |
abb8206c AK |
364 | |
365 | /* Add the failcntfile */ | |
366 | cft = &h->cgroup_files[3]; | |
367 | snprintf(cft->name, MAX_CFTYPE_NAME, "%s.failcnt", buf); | |
368 | cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT); | |
6770c64e | 369 | cft->write = hugetlb_cgroup_reset; |
716f479d | 370 | cft->read_u64 = hugetlb_cgroup_read_u64; |
abb8206c AK |
371 | |
372 | /* NULL terminate the last cft */ | |
373 | cft = &h->cgroup_files[4]; | |
374 | memset(cft, 0, sizeof(*cft)); | |
375 | ||
2cf669a5 TH |
376 | WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys, |
377 | h->cgroup_files)); | |
7179e7bf JW |
378 | } |
379 | ||
380 | void __init hugetlb_cgroup_file_init(void) | |
381 | { | |
382 | struct hstate *h; | |
383 | ||
384 | for_each_hstate(h) { | |
385 | /* | |
386 | * Add cgroup control files only if the huge page consists | |
387 | * of more than two normal pages. This is because we use | |
1d798ca3 | 388 | * page[2].private for storing cgroup details. |
7179e7bf JW |
389 | */ |
390 | if (huge_page_order(h) >= HUGETLB_CGROUP_MIN_ORDER) | |
391 | __hugetlb_cgroup_file_init(hstate_index(h)); | |
392 | } | |
abb8206c AK |
393 | } |
394 | ||
75754681 AK |
395 | /* |
396 | * hugetlb_lock will make sure a parallel cgroup rmdir won't happen | |
397 | * when we migrate hugepages | |
398 | */ | |
8e6ac7fa AK |
399 | void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage) |
400 | { | |
401 | struct hugetlb_cgroup *h_cg; | |
94ae8ba7 | 402 | struct hstate *h = page_hstate(oldhpage); |
8e6ac7fa AK |
403 | |
404 | if (hugetlb_cgroup_disabled()) | |
405 | return; | |
406 | ||
309381fe | 407 | VM_BUG_ON_PAGE(!PageHuge(oldhpage), oldhpage); |
8e6ac7fa AK |
408 | spin_lock(&hugetlb_lock); |
409 | h_cg = hugetlb_cgroup_from_page(oldhpage); | |
410 | set_hugetlb_cgroup(oldhpage, NULL); | |
8e6ac7fa AK |
411 | |
412 | /* move the h_cg details to new cgroup */ | |
413 | set_hugetlb_cgroup(newhpage, h_cg); | |
94ae8ba7 | 414 | list_move(&newhpage->lru, &h->hugepage_activelist); |
8e6ac7fa | 415 | spin_unlock(&hugetlb_lock); |
8e6ac7fa AK |
416 | return; |
417 | } | |
418 | ||
073219e9 | 419 | struct cgroup_subsys hugetlb_cgrp_subsys = { |
92fb9748 TH |
420 | .css_alloc = hugetlb_cgroup_css_alloc, |
421 | .css_offline = hugetlb_cgroup_css_offline, | |
422 | .css_free = hugetlb_cgroup_css_free, | |
2bc64a20 | 423 | }; |