1/*
2 *
3 * Copyright IBM Corporation, 2012
4 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
5 *
6 * Cgroup v2
7 * Copyright (C) 2019 Red Hat, Inc.
8 * Author: Giuseppe Scrivano <gscrivan@redhat.com>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of version 2.1 of the GNU Lesser General Public License
12 * as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it would be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
17 *
18 */
19
20#include <linux/cgroup.h>
21#include <linux/page_counter.h>
22#include <linux/slab.h>
23#include <linux/hugetlb.h>
24#include <linux/hugetlb_cgroup.h>
25
26#define MEMFILE_PRIVATE(x, val) (((x) << 16) | (val))
27#define MEMFILE_IDX(val) (((val) >> 16) & 0xffff)
28#define MEMFILE_ATTR(val) ((val) & 0xffff)
29
30static struct hugetlb_cgroup *root_h_cgroup __read_mostly;
31
32static inline struct page_counter *
33__hugetlb_cgroup_counter_from_cgroup(struct hugetlb_cgroup *h_cg, int idx,
34 bool rsvd)
35{
36 if (rsvd)
37 return &h_cg->rsvd_hugepage[idx];
38 return &h_cg->hugepage[idx];
39}
40
41static inline struct page_counter *
42hugetlb_cgroup_counter_from_cgroup(struct hugetlb_cgroup *h_cg, int idx)
43{
44 return __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd: false);
45}
46
47static inline struct page_counter *
48hugetlb_cgroup_counter_from_cgroup_rsvd(struct hugetlb_cgroup *h_cg, int idx)
49{
50 return __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd: true);
51}
52
53static inline
54struct hugetlb_cgroup *hugetlb_cgroup_from_css(struct cgroup_subsys_state *s)
55{
56 return s ? container_of(s, struct hugetlb_cgroup, css) : NULL;
57}
58
59static inline
60struct hugetlb_cgroup *hugetlb_cgroup_from_task(struct task_struct *task)
61{
62 return hugetlb_cgroup_from_css(s: task_css(task, subsys_id: hugetlb_cgrp_id));
63}
64
65static inline bool hugetlb_cgroup_is_root(struct hugetlb_cgroup *h_cg)
66{
67 return (h_cg == root_h_cgroup);
68}
69
70static inline struct hugetlb_cgroup *
71parent_hugetlb_cgroup(struct hugetlb_cgroup *h_cg)
72{
73 return hugetlb_cgroup_from_css(s: h_cg->css.parent);
74}
75
76static inline bool hugetlb_cgroup_have_usage(struct hugetlb_cgroup *h_cg)
77{
78 struct hstate *h;
79
80 for_each_hstate(h) {
81 if (page_counter_read(
82 counter: hugetlb_cgroup_counter_from_cgroup(h_cg, idx: hstate_index(h))))
83 return true;
84 }
85 return false;
86}
87
88static void hugetlb_cgroup_init(struct hugetlb_cgroup *h_cgroup,
89 struct hugetlb_cgroup *parent_h_cgroup)
90{
91 int idx;
92
93 for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) {
94 struct page_counter *fault_parent = NULL;
95 struct page_counter *rsvd_parent = NULL;
96 unsigned long limit;
97 int ret;
98
99 if (parent_h_cgroup) {
100 fault_parent = hugetlb_cgroup_counter_from_cgroup(
101 h_cg: parent_h_cgroup, idx);
102 rsvd_parent = hugetlb_cgroup_counter_from_cgroup_rsvd(
103 h_cg: parent_h_cgroup, idx);
104 }
105 page_counter_init(counter: hugetlb_cgroup_counter_from_cgroup(h_cg: h_cgroup,
106 idx),
107 parent: fault_parent);
108 page_counter_init(
109 counter: hugetlb_cgroup_counter_from_cgroup_rsvd(h_cg: h_cgroup, idx),
110 parent: rsvd_parent);
111
112 limit = round_down(PAGE_COUNTER_MAX,
113 pages_per_huge_page(&hstates[idx]));
114
115 ret = page_counter_set_max(
116 counter: hugetlb_cgroup_counter_from_cgroup(h_cg: h_cgroup, idx),
117 nr_pages: limit);
118 VM_BUG_ON(ret);
119 ret = page_counter_set_max(
120 counter: hugetlb_cgroup_counter_from_cgroup_rsvd(h_cg: h_cgroup, idx),
121 nr_pages: limit);
122 VM_BUG_ON(ret);
123 }
124}
125
126static void hugetlb_cgroup_free(struct hugetlb_cgroup *h_cgroup)
127{
128 int node;
129
130 for_each_node(node)
131 kfree(objp: h_cgroup->nodeinfo[node]);
132 kfree(objp: h_cgroup);
133}
134
135static struct cgroup_subsys_state *
136hugetlb_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
137{
138 struct hugetlb_cgroup *parent_h_cgroup = hugetlb_cgroup_from_css(s: parent_css);
139 struct hugetlb_cgroup *h_cgroup;
140 int node;
141
142 h_cgroup = kzalloc(struct_size(h_cgroup, nodeinfo, nr_node_ids),
143 GFP_KERNEL);
144
145 if (!h_cgroup)
146 return ERR_PTR(error: -ENOMEM);
147
148 if (!parent_h_cgroup)
149 root_h_cgroup = h_cgroup;
150
151 /*
152 * TODO: this routine can waste much memory for nodes which will
153 * never be onlined. It's better to use memory hotplug callback
154 * function.
155 */
156 for_each_node(node) {
157 /* Set node_to_alloc to NUMA_NO_NODE for offline nodes. */
158 int node_to_alloc =
159 node_state(node, state: N_NORMAL_MEMORY) ? node : NUMA_NO_NODE;
160 h_cgroup->nodeinfo[node] =
161 kzalloc_node(size: sizeof(struct hugetlb_cgroup_per_node),
162 GFP_KERNEL, node: node_to_alloc);
163 if (!h_cgroup->nodeinfo[node])
164 goto fail_alloc_nodeinfo;
165 }
166
167 hugetlb_cgroup_init(h_cgroup, parent_h_cgroup);
168 return &h_cgroup->css;
169
170fail_alloc_nodeinfo:
171 hugetlb_cgroup_free(h_cgroup);
172 return ERR_PTR(error: -ENOMEM);
173}
174
175static void hugetlb_cgroup_css_free(struct cgroup_subsys_state *css)
176{
177 hugetlb_cgroup_free(h_cgroup: hugetlb_cgroup_from_css(s: css));
178}
179
180/*
181 * Should be called with hugetlb_lock held.
182 * Since we are holding hugetlb_lock, pages cannot get moved from
183 * active list or uncharged from the cgroup, So no need to get
184 * page reference and test for page active here. This function
185 * cannot fail.
186 */
187static void hugetlb_cgroup_move_parent(int idx, struct hugetlb_cgroup *h_cg,
188 struct page *page)
189{
190 unsigned int nr_pages;
191 struct page_counter *counter;
192 struct hugetlb_cgroup *page_hcg;
193 struct hugetlb_cgroup *parent = parent_hugetlb_cgroup(h_cg);
194 struct folio *folio = page_folio(page);
195
196 page_hcg = hugetlb_cgroup_from_folio(folio);
197 /*
198 * We can have pages in active list without any cgroup
199 * ie, hugepage with less than 3 pages. We can safely
200 * ignore those pages.
201 */
202 if (!page_hcg || page_hcg != h_cg)
203 goto out;
204
205 nr_pages = compound_nr(page);
206 if (!parent) {
207 parent = root_h_cgroup;
208 /* root has no limit */
209 page_counter_charge(counter: &parent->hugepage[idx], nr_pages);
210 }
211 counter = &h_cg->hugepage[idx];
212 /* Take the pages off the local counter */
213 page_counter_cancel(counter, nr_pages);
214
215 set_hugetlb_cgroup(folio, h_cg: parent);
216out:
217 return;
218}
219
220/*
221 * Force the hugetlb cgroup to empty the hugetlb resources by moving them to
222 * the parent cgroup.
223 */
224static void hugetlb_cgroup_css_offline(struct cgroup_subsys_state *css)
225{
226 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(s: css);
227 struct hstate *h;
228 struct page *page;
229
230 do {
231 for_each_hstate(h) {
232 spin_lock_irq(lock: &hugetlb_lock);
233 list_for_each_entry(page, &h->hugepage_activelist, lru)
234 hugetlb_cgroup_move_parent(idx: hstate_index(h), h_cg, page);
235
236 spin_unlock_irq(lock: &hugetlb_lock);
237 }
238 cond_resched();
239 } while (hugetlb_cgroup_have_usage(h_cg));
240}
241
242static inline void hugetlb_event(struct hugetlb_cgroup *hugetlb, int idx,
243 enum hugetlb_memory_event event)
244{
245 atomic_long_inc(v: &hugetlb->events_local[idx][event]);
246 cgroup_file_notify(cfile: &hugetlb->events_local_file[idx]);
247
248 do {
249 atomic_long_inc(v: &hugetlb->events[idx][event]);
250 cgroup_file_notify(cfile: &hugetlb->events_file[idx]);
251 } while ((hugetlb = parent_hugetlb_cgroup(h_cg: hugetlb)) &&
252 !hugetlb_cgroup_is_root(h_cg: hugetlb));
253}
254
255static int __hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
256 struct hugetlb_cgroup **ptr,
257 bool rsvd)
258{
259 int ret = 0;
260 struct page_counter *counter;
261 struct hugetlb_cgroup *h_cg = NULL;
262
263 if (hugetlb_cgroup_disabled())
264 goto done;
265again:
266 rcu_read_lock();
267 h_cg = hugetlb_cgroup_from_task(current);
268 if (!css_tryget(css: &h_cg->css)) {
269 rcu_read_unlock();
270 goto again;
271 }
272 rcu_read_unlock();
273
274 if (!page_counter_try_charge(
275 counter: __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd),
276 nr_pages, fail: &counter)) {
277 ret = -ENOMEM;
278 hugetlb_event(hugetlb: h_cg, idx, event: HUGETLB_MAX);
279 css_put(css: &h_cg->css);
280 goto done;
281 }
282 /* Reservations take a reference to the css because they do not get
283 * reparented.
284 */
285 if (!rsvd)
286 css_put(css: &h_cg->css);
287done:
288 *ptr = h_cg;
289 return ret;
290}
291
292int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
293 struct hugetlb_cgroup **ptr)
294{
295 return __hugetlb_cgroup_charge_cgroup(idx, nr_pages, ptr, rsvd: false);
296}
297
298int hugetlb_cgroup_charge_cgroup_rsvd(int idx, unsigned long nr_pages,
299 struct hugetlb_cgroup **ptr)
300{
301 return __hugetlb_cgroup_charge_cgroup(idx, nr_pages, ptr, rsvd: true);
302}
303
304/* Should be called with hugetlb_lock held */
305static void __hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
306 struct hugetlb_cgroup *h_cg,
307 struct folio *folio, bool rsvd)
308{
309 if (hugetlb_cgroup_disabled() || !h_cg)
310 return;
311
312 __set_hugetlb_cgroup(folio, h_cg, rsvd);
313 if (!rsvd) {
314 unsigned long usage =
315 h_cg->nodeinfo[folio_nid(folio)]->usage[idx];
316 /*
317 * This write is not atomic due to fetching usage and writing
318 * to it, but that's fine because we call this with
319 * hugetlb_lock held anyway.
320 */
321 WRITE_ONCE(h_cg->nodeinfo[folio_nid(folio)]->usage[idx],
322 usage + nr_pages);
323 }
324}
325
326void hugetlb_cgroup_commit_charge(int idx, unsigned long nr_pages,
327 struct hugetlb_cgroup *h_cg,
328 struct folio *folio)
329{
330 __hugetlb_cgroup_commit_charge(idx, nr_pages, h_cg, folio, rsvd: false);
331}
332
333void hugetlb_cgroup_commit_charge_rsvd(int idx, unsigned long nr_pages,
334 struct hugetlb_cgroup *h_cg,
335 struct folio *folio)
336{
337 __hugetlb_cgroup_commit_charge(idx, nr_pages, h_cg, folio, rsvd: true);
338}
339
340/*
341 * Should be called with hugetlb_lock held
342 */
343static void __hugetlb_cgroup_uncharge_folio(int idx, unsigned long nr_pages,
344 struct folio *folio, bool rsvd)
345{
346 struct hugetlb_cgroup *h_cg;
347
348 if (hugetlb_cgroup_disabled())
349 return;
350 lockdep_assert_held(&hugetlb_lock);
351 h_cg = __hugetlb_cgroup_from_folio(folio, rsvd);
352 if (unlikely(!h_cg))
353 return;
354 __set_hugetlb_cgroup(folio, NULL, rsvd);
355
356 page_counter_uncharge(counter: __hugetlb_cgroup_counter_from_cgroup(h_cg, idx,
357 rsvd),
358 nr_pages);
359
360 if (rsvd)
361 css_put(css: &h_cg->css);
362 else {
363 unsigned long usage =
364 h_cg->nodeinfo[folio_nid(folio)]->usage[idx];
365 /*
366 * This write is not atomic due to fetching usage and writing
367 * to it, but that's fine because we call this with
368 * hugetlb_lock held anyway.
369 */
370 WRITE_ONCE(h_cg->nodeinfo[folio_nid(folio)]->usage[idx],
371 usage - nr_pages);
372 }
373}
374
375void hugetlb_cgroup_uncharge_folio(int idx, unsigned long nr_pages,
376 struct folio *folio)
377{
378 __hugetlb_cgroup_uncharge_folio(idx, nr_pages, folio, rsvd: false);
379}
380
381void hugetlb_cgroup_uncharge_folio_rsvd(int idx, unsigned long nr_pages,
382 struct folio *folio)
383{
384 __hugetlb_cgroup_uncharge_folio(idx, nr_pages, folio, rsvd: true);
385}
386
387static void __hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
388 struct hugetlb_cgroup *h_cg,
389 bool rsvd)
390{
391 if (hugetlb_cgroup_disabled() || !h_cg)
392 return;
393
394 page_counter_uncharge(counter: __hugetlb_cgroup_counter_from_cgroup(h_cg, idx,
395 rsvd),
396 nr_pages);
397
398 if (rsvd)
399 css_put(css: &h_cg->css);
400}
401
402void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
403 struct hugetlb_cgroup *h_cg)
404{
405 __hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg, rsvd: false);
406}
407
408void hugetlb_cgroup_uncharge_cgroup_rsvd(int idx, unsigned long nr_pages,
409 struct hugetlb_cgroup *h_cg)
410{
411 __hugetlb_cgroup_uncharge_cgroup(idx, nr_pages, h_cg, rsvd: true);
412}
413
414void hugetlb_cgroup_uncharge_counter(struct resv_map *resv, unsigned long start,
415 unsigned long end)
416{
417 if (hugetlb_cgroup_disabled() || !resv || !resv->reservation_counter ||
418 !resv->css)
419 return;
420
421 page_counter_uncharge(counter: resv->reservation_counter,
422 nr_pages: (end - start) * resv->pages_per_hpage);
423 css_put(css: resv->css);
424}
425
426void hugetlb_cgroup_uncharge_file_region(struct resv_map *resv,
427 struct file_region *rg,
428 unsigned long nr_pages,
429 bool region_del)
430{
431 if (hugetlb_cgroup_disabled() || !resv || !rg || !nr_pages)
432 return;
433
434 if (rg->reservation_counter && resv->pages_per_hpage &&
435 !resv->reservation_counter) {
436 page_counter_uncharge(counter: rg->reservation_counter,
437 nr_pages: nr_pages * resv->pages_per_hpage);
438 /*
439 * Only do css_put(rg->css) when we delete the entire region
440 * because one file_region must hold exactly one css reference.
441 */
442 if (region_del)
443 css_put(css: rg->css);
444 }
445}
446
447enum {
448 RES_USAGE,
449 RES_RSVD_USAGE,
450 RES_LIMIT,
451 RES_RSVD_LIMIT,
452 RES_MAX_USAGE,
453 RES_RSVD_MAX_USAGE,
454 RES_FAILCNT,
455 RES_RSVD_FAILCNT,
456};
457
458static int hugetlb_cgroup_read_numa_stat(struct seq_file *seq, void *dummy)
459{
460 int nid;
461 struct cftype *cft = seq_cft(seq);
462 int idx = MEMFILE_IDX(cft->private);
463 bool legacy = MEMFILE_ATTR(cft->private);
464 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(s: seq_css(seq));
465 struct cgroup_subsys_state *css;
466 unsigned long usage;
467
468 if (legacy) {
469 /* Add up usage across all nodes for the non-hierarchical total. */
470 usage = 0;
471 for_each_node_state(nid, N_MEMORY)
472 usage += READ_ONCE(h_cg->nodeinfo[nid]->usage[idx]);
473 seq_printf(m: seq, fmt: "total=%lu", usage * PAGE_SIZE);
474
475 /* Simply print the per-node usage for the non-hierarchical total. */
476 for_each_node_state(nid, N_MEMORY)
477 seq_printf(m: seq, fmt: " N%d=%lu", nid,
478 READ_ONCE(h_cg->nodeinfo[nid]->usage[idx]) *
479 PAGE_SIZE);
480 seq_putc(m: seq, c: '\n');
481 }
482
483 /*
484 * The hierarchical total is pretty much the value recorded by the
485 * counter, so use that.
486 */
487 seq_printf(m: seq, fmt: "%stotal=%lu", legacy ? "hierarchical_" : "",
488 page_counter_read(counter: &h_cg->hugepage[idx]) * PAGE_SIZE);
489
490 /*
491 * For each node, transverse the css tree to obtain the hierarchical
492 * node usage.
493 */
494 for_each_node_state(nid, N_MEMORY) {
495 usage = 0;
496 rcu_read_lock();
497 css_for_each_descendant_pre(css, &h_cg->css) {
498 usage += READ_ONCE(hugetlb_cgroup_from_css(css)
499 ->nodeinfo[nid]
500 ->usage[idx]);
501 }
502 rcu_read_unlock();
503 seq_printf(m: seq, fmt: " N%d=%lu", nid, usage * PAGE_SIZE);
504 }
505
506 seq_putc(m: seq, c: '\n');
507
508 return 0;
509}
510
511static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css,
512 struct cftype *cft)
513{
514 struct page_counter *counter;
515 struct page_counter *rsvd_counter;
516 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(s: css);
517
518 counter = &h_cg->hugepage[MEMFILE_IDX(cft->private)];
519 rsvd_counter = &h_cg->rsvd_hugepage[MEMFILE_IDX(cft->private)];
520
521 switch (MEMFILE_ATTR(cft->private)) {
522 case RES_USAGE:
523 return (u64)page_counter_read(counter) * PAGE_SIZE;
524 case RES_RSVD_USAGE:
525 return (u64)page_counter_read(counter: rsvd_counter) * PAGE_SIZE;
526 case RES_LIMIT:
527 return (u64)counter->max * PAGE_SIZE;
528 case RES_RSVD_LIMIT:
529 return (u64)rsvd_counter->max * PAGE_SIZE;
530 case RES_MAX_USAGE:
531 return (u64)counter->watermark * PAGE_SIZE;
532 case RES_RSVD_MAX_USAGE:
533 return (u64)rsvd_counter->watermark * PAGE_SIZE;
534 case RES_FAILCNT:
535 return counter->failcnt;
536 case RES_RSVD_FAILCNT:
537 return rsvd_counter->failcnt;
538 default:
539 BUG();
540 }
541}
542
543static int hugetlb_cgroup_read_u64_max(struct seq_file *seq, void *v)
544{
545 int idx;
546 u64 val;
547 struct cftype *cft = seq_cft(seq);
548 unsigned long limit;
549 struct page_counter *counter;
550 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(s: seq_css(seq));
551
552 idx = MEMFILE_IDX(cft->private);
553 counter = &h_cg->hugepage[idx];
554
555 limit = round_down(PAGE_COUNTER_MAX,
556 pages_per_huge_page(&hstates[idx]));
557
558 switch (MEMFILE_ATTR(cft->private)) {
559 case RES_RSVD_USAGE:
560 counter = &h_cg->rsvd_hugepage[idx];
561 fallthrough;
562 case RES_USAGE:
563 val = (u64)page_counter_read(counter);
564 seq_printf(m: seq, fmt: "%llu\n", val * PAGE_SIZE);
565 break;
566 case RES_RSVD_LIMIT:
567 counter = &h_cg->rsvd_hugepage[idx];
568 fallthrough;
569 case RES_LIMIT:
570 val = (u64)counter->max;
571 if (val == limit)
572 seq_puts(m: seq, s: "max\n");
573 else
574 seq_printf(m: seq, fmt: "%llu\n", val * PAGE_SIZE);
575 break;
576 default:
577 BUG();
578 }
579
580 return 0;
581}
582
583static DEFINE_MUTEX(hugetlb_limit_mutex);
584
585static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of,
586 char *buf, size_t nbytes, loff_t off,
587 const char *max)
588{
589 int ret, idx;
590 unsigned long nr_pages;
591 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(s: of_css(of));
592 bool rsvd = false;
593
594 if (hugetlb_cgroup_is_root(h_cg)) /* Can't set limit on root */
595 return -EINVAL;
596
597 buf = strstrip(str: buf);
598 ret = page_counter_memparse(buf, max, nr_pages: &nr_pages);
599 if (ret)
600 return ret;
601
602 idx = MEMFILE_IDX(of_cft(of)->private);
603 nr_pages = round_down(nr_pages, pages_per_huge_page(&hstates[idx]));
604
605 switch (MEMFILE_ATTR(of_cft(of)->private)) {
606 case RES_RSVD_LIMIT:
607 rsvd = true;
608 fallthrough;
609 case RES_LIMIT:
610 mutex_lock(&hugetlb_limit_mutex);
611 ret = page_counter_set_max(
612 counter: __hugetlb_cgroup_counter_from_cgroup(h_cg, idx, rsvd),
613 nr_pages);
614 mutex_unlock(lock: &hugetlb_limit_mutex);
615 break;
616 default:
617 ret = -EINVAL;
618 break;
619 }
620 return ret ?: nbytes;
621}
622
623static ssize_t hugetlb_cgroup_write_legacy(struct kernfs_open_file *of,
624 char *buf, size_t nbytes, loff_t off)
625{
626 return hugetlb_cgroup_write(of, buf, nbytes, off, max: "-1");
627}
628
629static ssize_t hugetlb_cgroup_write_dfl(struct kernfs_open_file *of,
630 char *buf, size_t nbytes, loff_t off)
631{
632 return hugetlb_cgroup_write(of, buf, nbytes, off, max: "max");
633}
634
635static ssize_t hugetlb_cgroup_reset(struct kernfs_open_file *of,
636 char *buf, size_t nbytes, loff_t off)
637{
638 int ret = 0;
639 struct page_counter *counter, *rsvd_counter;
640 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(s: of_css(of));
641
642 counter = &h_cg->hugepage[MEMFILE_IDX(of_cft(of)->private)];
643 rsvd_counter = &h_cg->rsvd_hugepage[MEMFILE_IDX(of_cft(of)->private)];
644
645 switch (MEMFILE_ATTR(of_cft(of)->private)) {
646 case RES_MAX_USAGE:
647 page_counter_reset_watermark(counter);
648 break;
649 case RES_RSVD_MAX_USAGE:
650 page_counter_reset_watermark(counter: rsvd_counter);
651 break;
652 case RES_FAILCNT:
653 counter->failcnt = 0;
654 break;
655 case RES_RSVD_FAILCNT:
656 rsvd_counter->failcnt = 0;
657 break;
658 default:
659 ret = -EINVAL;
660 break;
661 }
662 return ret ?: nbytes;
663}
664
665static char *mem_fmt(char *buf, int size, unsigned long hsize)
666{
667 if (hsize >= SZ_1G)
668 snprintf(buf, size, fmt: "%luGB", hsize / SZ_1G);
669 else if (hsize >= SZ_1M)
670 snprintf(buf, size, fmt: "%luMB", hsize / SZ_1M);
671 else
672 snprintf(buf, size, fmt: "%luKB", hsize / SZ_1K);
673 return buf;
674}
675
676static int __hugetlb_events_show(struct seq_file *seq, bool local)
677{
678 int idx;
679 long max;
680 struct cftype *cft = seq_cft(seq);
681 struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(s: seq_css(seq));
682
683 idx = MEMFILE_IDX(cft->private);
684
685 if (local)
686 max = atomic_long_read(v: &h_cg->events_local[idx][HUGETLB_MAX]);
687 else
688 max = atomic_long_read(v: &h_cg->events[idx][HUGETLB_MAX]);
689
690 seq_printf(m: seq, fmt: "max %lu\n", max);
691
692 return 0;
693}
694
695static int hugetlb_events_show(struct seq_file *seq, void *v)
696{
697 return __hugetlb_events_show(seq, local: false);
698}
699
700static int hugetlb_events_local_show(struct seq_file *seq, void *v)
701{
702 return __hugetlb_events_show(seq, local: true);
703}
704
705static void __init __hugetlb_cgroup_file_dfl_init(int idx)
706{
707 char buf[32];
708 struct cftype *cft;
709 struct hstate *h = &hstates[idx];
710
711 /* format the size */
712 mem_fmt(buf, size: sizeof(buf), hsize: huge_page_size(h));
713
714 /* Add the limit file */
715 cft = &h->cgroup_files_dfl[0];
716 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.max", buf);
717 cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
718 cft->seq_show = hugetlb_cgroup_read_u64_max;
719 cft->write = hugetlb_cgroup_write_dfl;
720 cft->flags = CFTYPE_NOT_ON_ROOT;
721
722 /* Add the reservation limit file */
723 cft = &h->cgroup_files_dfl[1];
724 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.rsvd.max", buf);
725 cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_LIMIT);
726 cft->seq_show = hugetlb_cgroup_read_u64_max;
727 cft->write = hugetlb_cgroup_write_dfl;
728 cft->flags = CFTYPE_NOT_ON_ROOT;
729
730 /* Add the current usage file */
731 cft = &h->cgroup_files_dfl[2];
732 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.current", buf);
733 cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
734 cft->seq_show = hugetlb_cgroup_read_u64_max;
735 cft->flags = CFTYPE_NOT_ON_ROOT;
736
737 /* Add the current reservation usage file */
738 cft = &h->cgroup_files_dfl[3];
739 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.rsvd.current", buf);
740 cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_USAGE);
741 cft->seq_show = hugetlb_cgroup_read_u64_max;
742 cft->flags = CFTYPE_NOT_ON_ROOT;
743
744 /* Add the events file */
745 cft = &h->cgroup_files_dfl[4];
746 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.events", buf);
747 cft->private = MEMFILE_PRIVATE(idx, 0);
748 cft->seq_show = hugetlb_events_show;
749 cft->file_offset = offsetof(struct hugetlb_cgroup, events_file[idx]);
750 cft->flags = CFTYPE_NOT_ON_ROOT;
751
752 /* Add the events.local file */
753 cft = &h->cgroup_files_dfl[5];
754 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.events.local", buf);
755 cft->private = MEMFILE_PRIVATE(idx, 0);
756 cft->seq_show = hugetlb_events_local_show;
757 cft->file_offset = offsetof(struct hugetlb_cgroup,
758 events_local_file[idx]);
759 cft->flags = CFTYPE_NOT_ON_ROOT;
760
761 /* Add the numa stat file */
762 cft = &h->cgroup_files_dfl[6];
763 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.numa_stat", buf);
764 cft->private = MEMFILE_PRIVATE(idx, 0);
765 cft->seq_show = hugetlb_cgroup_read_numa_stat;
766 cft->flags = CFTYPE_NOT_ON_ROOT;
767
768 /* NULL terminate the last cft */
769 cft = &h->cgroup_files_dfl[7];
770 memset(cft, 0, sizeof(*cft));
771
772 WARN_ON(cgroup_add_dfl_cftypes(&hugetlb_cgrp_subsys,
773 h->cgroup_files_dfl));
774}
775
776static void __init __hugetlb_cgroup_file_legacy_init(int idx)
777{
778 char buf[32];
779 struct cftype *cft;
780 struct hstate *h = &hstates[idx];
781
782 /* format the size */
783 mem_fmt(buf, size: sizeof(buf), hsize: huge_page_size(h));
784
785 /* Add the limit file */
786 cft = &h->cgroup_files_legacy[0];
787 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.limit_in_bytes", buf);
788 cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
789 cft->read_u64 = hugetlb_cgroup_read_u64;
790 cft->write = hugetlb_cgroup_write_legacy;
791
792 /* Add the reservation limit file */
793 cft = &h->cgroup_files_legacy[1];
794 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.rsvd.limit_in_bytes", buf);
795 cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_LIMIT);
796 cft->read_u64 = hugetlb_cgroup_read_u64;
797 cft->write = hugetlb_cgroup_write_legacy;
798
799 /* Add the usage file */
800 cft = &h->cgroup_files_legacy[2];
801 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.usage_in_bytes", buf);
802 cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
803 cft->read_u64 = hugetlb_cgroup_read_u64;
804
805 /* Add the reservation usage file */
806 cft = &h->cgroup_files_legacy[3];
807 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.rsvd.usage_in_bytes", buf);
808 cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_USAGE);
809 cft->read_u64 = hugetlb_cgroup_read_u64;
810
811 /* Add the MAX usage file */
812 cft = &h->cgroup_files_legacy[4];
813 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.max_usage_in_bytes", buf);
814 cft->private = MEMFILE_PRIVATE(idx, RES_MAX_USAGE);
815 cft->write = hugetlb_cgroup_reset;
816 cft->read_u64 = hugetlb_cgroup_read_u64;
817
818 /* Add the MAX reservation usage file */
819 cft = &h->cgroup_files_legacy[5];
820 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.rsvd.max_usage_in_bytes", buf);
821 cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_MAX_USAGE);
822 cft->write = hugetlb_cgroup_reset;
823 cft->read_u64 = hugetlb_cgroup_read_u64;
824
825 /* Add the failcntfile */
826 cft = &h->cgroup_files_legacy[6];
827 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.failcnt", buf);
828 cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT);
829 cft->write = hugetlb_cgroup_reset;
830 cft->read_u64 = hugetlb_cgroup_read_u64;
831
832 /* Add the reservation failcntfile */
833 cft = &h->cgroup_files_legacy[7];
834 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.rsvd.failcnt", buf);
835 cft->private = MEMFILE_PRIVATE(idx, RES_RSVD_FAILCNT);
836 cft->write = hugetlb_cgroup_reset;
837 cft->read_u64 = hugetlb_cgroup_read_u64;
838
839 /* Add the numa stat file */
840 cft = &h->cgroup_files_legacy[8];
841 snprintf(buf: cft->name, MAX_CFTYPE_NAME, fmt: "%s.numa_stat", buf);
842 cft->private = MEMFILE_PRIVATE(idx, 1);
843 cft->seq_show = hugetlb_cgroup_read_numa_stat;
844
845 /* NULL terminate the last cft */
846 cft = &h->cgroup_files_legacy[9];
847 memset(cft, 0, sizeof(*cft));
848
849 WARN_ON(cgroup_add_legacy_cftypes(&hugetlb_cgrp_subsys,
850 h->cgroup_files_legacy));
851}
852
853static void __init __hugetlb_cgroup_file_init(int idx)
854{
855 __hugetlb_cgroup_file_dfl_init(idx);
856 __hugetlb_cgroup_file_legacy_init(idx);
857}
858
859void __init hugetlb_cgroup_file_init(void)
860{
861 struct hstate *h;
862
863 for_each_hstate(h)
864 __hugetlb_cgroup_file_init(idx: hstate_index(h));
865}
866
867/*
868 * hugetlb_lock will make sure a parallel cgroup rmdir won't happen
869 * when we migrate hugepages
870 */
871void hugetlb_cgroup_migrate(struct folio *old_folio, struct folio *new_folio)
872{
873 struct hugetlb_cgroup *h_cg;
874 struct hugetlb_cgroup *h_cg_rsvd;
875 struct hstate *h = folio_hstate(folio: old_folio);
876
877 if (hugetlb_cgroup_disabled())
878 return;
879
880 spin_lock_irq(lock: &hugetlb_lock);
881 h_cg = hugetlb_cgroup_from_folio(folio: old_folio);
882 h_cg_rsvd = hugetlb_cgroup_from_folio_rsvd(folio: old_folio);
883 set_hugetlb_cgroup(folio: old_folio, NULL);
884 set_hugetlb_cgroup_rsvd(folio: old_folio, NULL);
885
886 /* move the h_cg details to new cgroup */
887 set_hugetlb_cgroup(folio: new_folio, h_cg);
888 set_hugetlb_cgroup_rsvd(folio: new_folio, h_cg: h_cg_rsvd);
889 list_move(list: &new_folio->lru, head: &h->hugepage_activelist);
890 spin_unlock_irq(lock: &hugetlb_lock);
891 return;
892}
893
894static struct cftype hugetlb_files[] = {
895 {} /* terminate */
896};
897
898struct cgroup_subsys hugetlb_cgrp_subsys = {
899 .css_alloc = hugetlb_cgroup_css_alloc,
900 .css_offline = hugetlb_cgroup_css_offline,
901 .css_free = hugetlb_cgroup_css_free,
902 .dfl_cftypes = hugetlb_files,
903 .legacy_cftypes = hugetlb_files,
904};
905

source code of linux/mm/hugetlb_cgroup.c