blob: 9cea7de22ffbf351b8cc77eb40563543e38d59b7 [file] [log] [blame]
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -07001/*
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>
17#include <linux/slab.h>
18#include <linux/hugetlb.h>
19#include <linux/hugetlb_cgroup.h>
20
21struct hugetlb_cgroup {
22 struct cgroup_subsys_state css;
23 /*
24 * the counter to account for hugepages from hugetlb.
25 */
26 struct res_counter hugepage[HUGE_MAX_HSTATE];
27};
28
Aneesh Kumar K.Vabb82062012-07-31 16:42:24 -070029#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
30#define MEMFILE_IDX(val) (((val) >> 16) & 0xffff)
31#define MEMFILE_ATTR(val) ((val) & 0xffff)
32
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -070033struct cgroup_subsys hugetlb_subsys __read_mostly;
34static struct hugetlb_cgroup *root_h_cgroup __read_mostly;
35
36static inline
37struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s)
38{
39 return container_of(s, struct hugetlb_cgroup, css);
40}
41
42static inline
43struct hugetlb_cgroup *hugetlb_cgroup_from_cgroup(struct cgroup *cgroup)
44{
45 return hugetlb_cgroup_from_css(cgroup_subsys_state(cgroup,
46 hugetlb_subsys_id));
47}
48
49static inline
50struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task)
51{
52 return hugetlb_cgroup_from_css(task_subsys_state(task,
53 hugetlb_subsys_id));
54}
55
56static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg)
57{
58 return (h_cg == root_h_cgroup);
59}
60
61static inline struct hugetlb_cgroup *parent_hugetlb_cgroup(struct cgroup *cg)
62{
63 if (!cg->parent)
64 return NULL;
65 return hugetlb_cgroup_from_cgroup(cg->parent);
66}
67
68static inline bool hugetlb_cgroup_have_usage(struct cgroup *cg)
69{
70 int idx;
71 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cg);
72
73 for (idx = 0; idx < hugetlb_max_hstate; idx++) {
74 if ((res_counter_read_u64(&h_cg->hugepage[idx], RES_USAGE)) > 0)
75 return true;
76 }
77 return false;
78}
79
Tejun Heo92fb9742012-11-19 08:13:38 -080080static struct cgroup_subsys_state *hugetlb_cgroup_css_alloc(struct cgroup *cgroup)
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -070081{
82 int idx;
83 struct cgroup *parent_cgroup;
84 struct hugetlb_cgroup *h_cgroup, *parent_h_cgroup;
85
86 h_cgroup = kzalloc(sizeof(*h_cgroup), GFP_KERNEL);
87 if (!h_cgroup)
88 return ERR_PTR(-ENOMEM);
89
90 parent_cgroup = cgroup->parent;
91 if (parent_cgroup) {
92 parent_h_cgroup = hugetlb_cgroup_from_cgroup(parent_cgroup);
93 for (idx = 0; idx < HUGE_MAX_HSTATE; idx++)
94 res_counter_init(&h_cgroup->hugepage[idx],
95 &parent_h_cgroup->hugepage[idx]);
96 } else {
97 root_h_cgroup = h_cgroup;
98 for (idx = 0; idx < HUGE_MAX_HSTATE; idx++)
99 res_counter_init(&h_cgroup->hugepage[idx], NULL);
100 }
101 return &h_cgroup->css;
102}
103
Tejun Heo92fb9742012-11-19 08:13:38 -0800104static void hugetlb_cgroup_css_free(struct cgroup *cgroup)
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700105{
106 struct hugetlb_cgroup *h_cgroup;
107
108 h_cgroup = hugetlb_cgroup_from_cgroup(cgroup);
109 kfree(h_cgroup);
110}
111
Aneesh Kumar K.Vda1def52012-07-31 16:42:21 -0700112
113/*
114 * Should be called with hugetlb_lock held.
115 * Since we are holding hugetlb_lock, pages cannot get moved from
116 * active list or uncharged from the cgroup, So no need to get
117 * page reference and test for page active here. This function
118 * cannot fail.
119 */
120static void hugetlb_cgroup_move_parent(int idx, struct cgroup *cgroup,
121 struct page *page)
122{
123 int csize;
124 struct res_counter *counter;
125 struct res_counter *fail_res;
126 struct hugetlb_cgroup *page_hcg;
127 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup);
128 struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(cgroup);
129
130 page_hcg = hugetlb_cgroup_from_page(page);
131 /*
132 * We can have pages in active list without any cgroup
133 * ie, hugepage with less than 3 pages. We can safely
134 * ignore those pages.
135 */
136 if (!page_hcg || page_hcg != h_cg)
137 goto out;
138
139 csize = PAGE_SIZE << compound_order(page);
140 if (!parent) {
141 parent = root_h_cgroup;
142 /* root has no limit */
143 res_counter_charge_nofail(&parent->hugepage[idx],
144 csize, &fail_res);
145 }
146 counter = &h_cg->hugepage[idx];
147 res_counter_uncharge_until(counter, counter->parent, csize);
148
149 set_hugetlb_cgroup(page, parent);
150out:
151 return;
152}
153
154/*
155 * Force the hugetlb cgroup to empty the hugetlb resources by moving them to
156 * the parent cgroup.
157 */
Tejun Heo92fb9742012-11-19 08:13:38 -0800158static void hugetlb_cgroup_css_offline(struct cgroup *cgroup)
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700159{
Aneesh Kumar K.Vda1def52012-07-31 16:42:21 -0700160 struct hstate *h;
161 struct page *page;
Michal Hocko9d093cb2012-10-26 13:37:33 +0200162 int idx = 0;
Aneesh Kumar K.Vda1def52012-07-31 16:42:21 -0700163
164 do {
Aneesh Kumar K.Vda1def52012-07-31 16:42:21 -0700165 for_each_hstate(h) {
166 spin_lock(&hugetlb_lock);
167 list_for_each_entry(page, &h->hugepage_activelist, lru)
168 hugetlb_cgroup_move_parent(idx, cgroup, page);
169
170 spin_unlock(&hugetlb_lock);
171 idx++;
172 }
173 cond_resched();
174 } while (hugetlb_cgroup_have_usage(cgroup));
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700175}
176
Aneesh Kumar K.V6d76dcf2012-07-31 16:42:18 -0700177int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
178 struct hugetlb_cgroup **ptr)
179{
180 int ret = 0;
181 struct res_counter *fail_res;
182 struct hugetlb_cgroup *h_cg = NULL;
183 unsigned long csize = nr_pages * PAGE_SIZE;
184
185 if (hugetlb_cgroup_disabled())
186 goto done;
187 /*
188 * We don't charge any cgroup if the compound page have less
189 * than 3 pages.
190 */
191 if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER)
192 goto done;
193again:
194 rcu_read_lock();
195 h_cg = hugetlb_cgroup_from_task(current);
196 if (!css_tryget(&h_cg->css)) {
197 rcu_read_unlock();
198 goto again;
199 }
200 rcu_read_unlock();
201
202 ret = res_counter_charge(&h_cg->hugepage[idx], csize, &fail_res);
203 css_put(&h_cg->css);
204done:
205 *ptr = h_cg;
206 return ret;
207}
208
Aneesh Kumar K.V94ae8ba2012-07-31 16:42:35 -0700209/* Should be called with hugetlb_lock held */
Aneesh Kumar K.V6d76dcf2012-07-31 16:42:18 -0700210void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
211 struct hugetlb_cgroup *h_cg,
212 struct page *page)
213{
214 if (hugetlb_cgroup_disabled() || !h_cg)
215 return;
216
Aneesh Kumar K.V6d76dcf2012-07-31 16:42:18 -0700217 set_hugetlb_cgroup(page, h_cg);
Aneesh Kumar K.V6d76dcf2012-07-31 16:42:18 -0700218 return;
219}
220
221/*
222 * Should be called with hugetlb_lock held
223 */
224void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages,
225 struct page *page)
226{
227 struct hugetlb_cgroup *h_cg;
228 unsigned long csize = nr_pages * PAGE_SIZE;
229
230 if (hugetlb_cgroup_disabled())
231 return;
232 VM_BUG_ON(!spin_is_locked(&hugetlb_lock));
233 h_cg = hugetlb_cgroup_from_page(page);
234 if (unlikely(!h_cg))
235 return;
236 set_hugetlb_cgroup(page, NULL);
237 res_counter_uncharge(&h_cg->hugepage[idx], csize);
238 return;
239}
240
241void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
242 struct hugetlb_cgroup *h_cg)
243{
244 unsigned long csize = nr_pages * PAGE_SIZE;
245
246 if (hugetlb_cgroup_disabled() || !h_cg)
247 return;
248
249 if (huge_page_order(&hstates[idx]) < HUGETLB_CGROUP_MIN_ORDER)
250 return;
251
252 res_counter_uncharge(&h_cg->hugepage[idx], csize);
253 return;
254}
255
Aneesh Kumar K.Vabb82062012-07-31 16:42:24 -0700256static ssize_t hugetlb_cgroup_read(struct cgroup *cgroup, struct cftype *cft,
257 struct file *file, char __user *buf,
258 size_t nbytes, loff_t *ppos)
259{
260 u64 val;
261 char str[64];
262 int idx, name, len;
263 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup);
264
265 idx = MEMFILE_IDX(cft->private);
266 name = MEMFILE_ATTR(cft->private);
267
268 val = res_counter_read_u64(&h_cg->hugepage[idx], name);
269 len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val);
270 return simple_read_from_buffer(buf, nbytes, ppos, str, len);
271}
272
273static int hugetlb_cgroup_write(struct cgroup *cgroup, struct cftype *cft,
274 const char *buffer)
275{
276 int idx, name, ret;
277 unsigned long long val;
278 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup);
279
280 idx = MEMFILE_IDX(cft->private);
281 name = MEMFILE_ATTR(cft->private);
282
283 switch (name) {
284 case RES_LIMIT:
285 if (hugetlb_cgroup_is_root(h_cg)) {
286 /* Can't set limit on root */
287 ret = -EINVAL;
288 break;
289 }
290 /* This function does all necessary parse...reuse it */
291 ret = res_counter_memparse_write_strategy(buffer, &val);
292 if (ret)
293 break;
294 ret = res_counter_set_limit(&h_cg->hugepage[idx], val);
295 break;
296 default:
297 ret = -EINVAL;
298 break;
299 }
300 return ret;
301}
302
303static int hugetlb_cgroup_reset(struct cgroup *cgroup, unsigned int event)
304{
305 int idx, name, ret = 0;
306 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_cgroup(cgroup);
307
308 idx = MEMFILE_IDX(event);
309 name = MEMFILE_ATTR(event);
310
311 switch (name) {
312 case RES_MAX_USAGE:
313 res_counter_reset_max(&h_cg->hugepage[idx]);
314 break;
315 case RES_FAILCNT:
316 res_counter_reset_failcnt(&h_cg->hugepage[idx]);
317 break;
318 default:
319 ret = -EINVAL;
320 break;
321 }
322 return ret;
323}
324
325static 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
Jianguo Wu7179e7b2012-12-18 14:23:19 -0800336static void __init __hugetlb_cgroup_file_init(int idx)
Aneesh Kumar K.Vabb82062012-07-31 16:42:24 -0700337{
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);
349 cft->read = hugetlb_cgroup_read;
350 cft->write_string = hugetlb_cgroup_write;
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);
356 cft->read = hugetlb_cgroup_read;
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);
362 cft->trigger = hugetlb_cgroup_reset;
363 cft->read = hugetlb_cgroup_read;
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);
369 cft->trigger = hugetlb_cgroup_reset;
370 cft->read = hugetlb_cgroup_read;
371
372 /* NULL terminate the last cft */
373 cft = &h->cgroup_files[4];
374 memset(cft, 0, sizeof(*cft));
375
376 WARN_ON(cgroup_add_cftypes(&hugetlb_subsys, h->cgroup_files));
377
Jianguo Wu7179e7b2012-12-18 14:23:19 -0800378 return;
379}
380
381void __init hugetlb_cgroup_file_init(void)
382{
383 struct hstate *h;
384
385 for_each_hstate(h) {
386 /*
387 * Add cgroup control files only if the huge page consists
388 * of more than two normal pages. This is because we use
389 * page[2].lru.next for storing cgroup details.
390 */
391 if (huge_page_order(h) >= HUGETLB_CGROUP_MIN_ORDER)
392 __hugetlb_cgroup_file_init(hstate_index(h));
393 }
Aneesh Kumar K.Vabb82062012-07-31 16:42:24 -0700394}
395
Aneesh Kumar K.V75754682012-07-31 16:42:36 -0700396/*
397 * hugetlb_lock will make sure a parallel cgroup rmdir won't happen
398 * when we migrate hugepages
399 */
Aneesh Kumar K.V8e6ac7f2012-07-31 16:42:27 -0700400void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage)
401{
402 struct hugetlb_cgroup *h_cg;
Aneesh Kumar K.V94ae8ba2012-07-31 16:42:35 -0700403 struct hstate *h = page_hstate(oldhpage);
Aneesh Kumar K.V8e6ac7f2012-07-31 16:42:27 -0700404
405 if (hugetlb_cgroup_disabled())
406 return;
407
408 VM_BUG_ON(!PageHuge(oldhpage));
409 spin_lock(&hugetlb_lock);
410 h_cg = hugetlb_cgroup_from_page(oldhpage);
411 set_hugetlb_cgroup(oldhpage, NULL);
Aneesh Kumar K.V8e6ac7f2012-07-31 16:42:27 -0700412
413 /* move the h_cg details to new cgroup */
414 set_hugetlb_cgroup(newhpage, h_cg);
Aneesh Kumar K.V94ae8ba2012-07-31 16:42:35 -0700415 list_move(&newhpage->lru, &h->hugepage_activelist);
Aneesh Kumar K.V8e6ac7f2012-07-31 16:42:27 -0700416 spin_unlock(&hugetlb_lock);
Aneesh Kumar K.V8e6ac7f2012-07-31 16:42:27 -0700417 return;
418}
419
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700420struct cgroup_subsys hugetlb_subsys = {
421 .name = "hugetlb",
Tejun Heo92fb9742012-11-19 08:13:38 -0800422 .css_alloc = hugetlb_cgroup_css_alloc,
423 .css_offline = hugetlb_cgroup_css_offline,
424 .css_free = hugetlb_cgroup_css_free,
425 .subsys_id = hugetlb_subsys_id,
Aneesh Kumar K.V2bc64a22012-07-31 16:42:12 -0700426};