1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/debugfs.h>
4 #include <linux/slab.h>
5 #include <linux/uaccess.h>
6 #include <linux/memblock.h>
7 #include <linux/stacktrace.h>
8 #include <linux/page_owner.h>
9 #include <linux/jump_label.h>
10 #include <linux/migrate.h>
11 #include <linux/stackdepot.h>
12 #include <linux/seq_file.h>
13 #include <linux/memcontrol.h>
14 #include <linux/sched/clock.h>
19 * TODO: teach PAGE_OWNER_STACK_DEPTH (__dump_page_owner and save_stack)
20 * to use off stack temporal storage
22 #define PAGE_OWNER_STACK_DEPTH (16)
26 short last_migrate_reason;
28 depot_stack_handle_t handle;
29 depot_stack_handle_t free_handle;
32 char comm[TASK_COMM_LEN];
40 struct stack_record *stack_record;
43 static struct stack dummy_stack;
44 static struct stack failure_stack;
45 static struct stack *stack_list;
46 static DEFINE_SPINLOCK(stack_list_lock);
48 static bool page_owner_enabled __initdata;
49 DEFINE_STATIC_KEY_FALSE(page_owner_inited);
51 static depot_stack_handle_t dummy_handle;
52 static depot_stack_handle_t failure_handle;
53 static depot_stack_handle_t early_handle;
55 static void init_early_allocated_pages(void);
57 static int __init early_page_owner_param(char *buf)
59 int ret = kstrtobool(buf, &page_owner_enabled);
61 if (page_owner_enabled)
62 stack_depot_request_early_init();
66 early_param("page_owner", early_page_owner_param);
68 static __init bool need_page_owner(void)
70 return page_owner_enabled;
73 static __always_inline depot_stack_handle_t create_dummy_stack(void)
75 unsigned long entries[4];
76 unsigned int nr_entries;
78 nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
79 return stack_depot_save(entries, nr_entries, GFP_KERNEL);
82 static noinline void register_dummy_stack(void)
84 dummy_handle = create_dummy_stack();
87 static noinline void register_failure_stack(void)
89 failure_handle = create_dummy_stack();
92 static noinline void register_early_stack(void)
94 early_handle = create_dummy_stack();
97 static __init void init_page_owner(void)
99 if (!page_owner_enabled)
102 register_dummy_stack();
103 register_failure_stack();
104 register_early_stack();
105 static_branch_enable(&page_owner_inited);
106 init_early_allocated_pages();
107 /* Initialize dummy and failure stacks and link them to stack_list */
108 dummy_stack.stack_record = __stack_depot_get_stack_record(dummy_handle);
109 failure_stack.stack_record = __stack_depot_get_stack_record(failure_handle);
110 if (dummy_stack.stack_record)
111 refcount_set(&dummy_stack.stack_record->count, 1);
112 if (failure_stack.stack_record)
113 refcount_set(&failure_stack.stack_record->count, 1);
114 dummy_stack.next = &failure_stack;
115 stack_list = &dummy_stack;
118 struct page_ext_operations page_owner_ops = {
119 .size = sizeof(struct page_owner),
120 .need = need_page_owner,
121 .init = init_page_owner,
122 .need_shared_flags = true,
125 static inline struct page_owner *get_page_owner(struct page_ext *page_ext)
127 return page_ext_data(page_ext, &page_owner_ops);
130 static noinline depot_stack_handle_t save_stack(gfp_t flags)
132 unsigned long entries[PAGE_OWNER_STACK_DEPTH];
133 depot_stack_handle_t handle;
134 unsigned int nr_entries;
139 * Sometimes page metadata allocation tracking requires more
140 * memory to be allocated:
141 * - when new stack trace is saved to stack depot
143 if (current->in_page_owner)
145 current->in_page_owner = 1;
147 nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2);
148 handle = stack_depot_save(entries, nr_entries, flags);
150 handle = failure_handle;
152 current->in_page_owner = 0;
156 static void add_stack_record_to_list(struct stack_record *stack_record,
162 /* Filter gfp_mask the same way stackdepot does, for consistency */
163 gfp_mask &= ~GFP_ZONEMASK;
164 gfp_mask &= (GFP_ATOMIC | GFP_KERNEL);
165 gfp_mask |= __GFP_NOWARN;
167 stack = kmalloc(sizeof(*stack), gfp_mask);
171 stack->stack_record = stack_record;
174 spin_lock_irqsave(&stack_list_lock, flags);
175 stack->next = stack_list;
177 * This pairs with smp_load_acquire() from function
178 * stack_start(). This guarantees that stack_start()
179 * will see an updated stack_list before starting to
182 smp_store_release(&stack_list, stack);
183 spin_unlock_irqrestore(&stack_list_lock, flags);
186 static void inc_stack_record_count(depot_stack_handle_t handle, gfp_t gfp_mask)
188 struct stack_record *stack_record = __stack_depot_get_stack_record(handle);
194 * New stack_record's that do not use STACK_DEPOT_FLAG_GET start
195 * with REFCOUNT_SATURATED to catch spurious increments of their
197 * Since we do not use STACK_DEPOT_FLAG_GET API, let us
198 * set a refcount of 1 ourselves.
200 if (refcount_read(&stack_record->count) == REFCOUNT_SATURATED) {
201 int old = REFCOUNT_SATURATED;
203 if (atomic_try_cmpxchg_relaxed(&stack_record->count.refs, &old, 1))
204 /* Add the new stack_record to our list */
205 add_stack_record_to_list(stack_record, gfp_mask);
207 refcount_inc(&stack_record->count);
210 static void dec_stack_record_count(depot_stack_handle_t handle)
212 struct stack_record *stack_record = __stack_depot_get_stack_record(handle);
215 refcount_dec(&stack_record->count);
218 void __reset_page_owner(struct page *page, unsigned short order)
221 struct page_ext *page_ext;
222 depot_stack_handle_t handle;
223 depot_stack_handle_t alloc_handle;
224 struct page_owner *page_owner;
225 u64 free_ts_nsec = local_clock();
227 page_ext = page_ext_get(page);
228 if (unlikely(!page_ext))
231 page_owner = get_page_owner(page_ext);
232 alloc_handle = page_owner->handle;
234 handle = save_stack(GFP_NOWAIT | __GFP_NOWARN);
235 for (i = 0; i < (1 << order); i++) {
236 __clear_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags);
237 page_owner->free_handle = handle;
238 page_owner->free_ts_nsec = free_ts_nsec;
239 page_owner->free_pid = current->pid;
240 page_owner->free_tgid = current->tgid;
241 page_ext = page_ext_next(page_ext);
242 page_owner = get_page_owner(page_ext);
244 page_ext_put(page_ext);
245 if (alloc_handle != early_handle)
247 * early_handle is being set as a handle for all those
248 * early allocated pages. See init_pages_in_zone().
249 * Since their refcount is not being incremented because
250 * the machinery is not ready yet, we cannot decrement
251 * their refcount either.
253 dec_stack_record_count(alloc_handle);
256 static inline void __set_page_owner_handle(struct page_ext *page_ext,
257 depot_stack_handle_t handle,
258 unsigned short order, gfp_t gfp_mask)
260 struct page_owner *page_owner;
262 u64 ts_nsec = local_clock();
264 for (i = 0; i < (1 << order); i++) {
265 page_owner = get_page_owner(page_ext);
266 page_owner->handle = handle;
267 page_owner->order = order;
268 page_owner->gfp_mask = gfp_mask;
269 page_owner->last_migrate_reason = -1;
270 page_owner->pid = current->pid;
271 page_owner->tgid = current->tgid;
272 page_owner->ts_nsec = ts_nsec;
273 strscpy(page_owner->comm, current->comm,
274 sizeof(page_owner->comm));
275 __set_bit(PAGE_EXT_OWNER, &page_ext->flags);
276 __set_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags);
278 page_ext = page_ext_next(page_ext);
282 noinline void __set_page_owner(struct page *page, unsigned short order,
285 struct page_ext *page_ext;
286 depot_stack_handle_t handle;
288 handle = save_stack(gfp_mask);
290 page_ext = page_ext_get(page);
291 if (unlikely(!page_ext))
293 __set_page_owner_handle(page_ext, handle, order, gfp_mask);
294 page_ext_put(page_ext);
295 inc_stack_record_count(handle, gfp_mask);
298 void __set_page_owner_migrate_reason(struct page *page, int reason)
300 struct page_ext *page_ext = page_ext_get(page);
301 struct page_owner *page_owner;
303 if (unlikely(!page_ext))
306 page_owner = get_page_owner(page_ext);
307 page_owner->last_migrate_reason = reason;
308 page_ext_put(page_ext);
311 void __split_page_owner(struct page *page, int old_order, int new_order)
314 struct page_ext *page_ext = page_ext_get(page);
315 struct page_owner *page_owner;
317 if (unlikely(!page_ext))
320 for (i = 0; i < (1 << old_order); i++) {
321 page_owner = get_page_owner(page_ext);
322 page_owner->order = new_order;
323 page_ext = page_ext_next(page_ext);
325 page_ext_put(page_ext);
328 void __folio_copy_owner(struct folio *newfolio, struct folio *old)
330 struct page_ext *old_ext;
331 struct page_ext *new_ext;
332 struct page_owner *old_page_owner, *new_page_owner;
334 old_ext = page_ext_get(&old->page);
335 if (unlikely(!old_ext))
338 new_ext = page_ext_get(&newfolio->page);
339 if (unlikely(!new_ext)) {
340 page_ext_put(old_ext);
344 old_page_owner = get_page_owner(old_ext);
345 new_page_owner = get_page_owner(new_ext);
346 new_page_owner->order = old_page_owner->order;
347 new_page_owner->gfp_mask = old_page_owner->gfp_mask;
348 new_page_owner->last_migrate_reason =
349 old_page_owner->last_migrate_reason;
350 new_page_owner->handle = old_page_owner->handle;
351 new_page_owner->pid = old_page_owner->pid;
352 new_page_owner->tgid = old_page_owner->tgid;
353 new_page_owner->free_pid = old_page_owner->free_pid;
354 new_page_owner->free_tgid = old_page_owner->free_tgid;
355 new_page_owner->ts_nsec = old_page_owner->ts_nsec;
356 new_page_owner->free_ts_nsec = old_page_owner->ts_nsec;
357 strcpy(new_page_owner->comm, old_page_owner->comm);
360 * We don't clear the bit on the old folio as it's going to be freed
361 * after migration. Until then, the info can be useful in case of
362 * a bug, and the overall stats will be off a bit only temporarily.
363 * Also, migrate_misplaced_transhuge_page() can still fail the
364 * migration and then we want the old folio to retain the info. But
365 * in that case we also don't need to explicitly clear the info from
366 * the new page, which will be freed.
368 __set_bit(PAGE_EXT_OWNER, &new_ext->flags);
369 __set_bit(PAGE_EXT_OWNER_ALLOCATED, &new_ext->flags);
370 page_ext_put(new_ext);
371 page_ext_put(old_ext);
374 void pagetypeinfo_showmixedcount_print(struct seq_file *m,
375 pg_data_t *pgdat, struct zone *zone)
378 struct page_ext *page_ext;
379 struct page_owner *page_owner;
380 unsigned long pfn, block_end_pfn;
381 unsigned long end_pfn = zone_end_pfn(zone);
382 unsigned long count[MIGRATE_TYPES] = { 0, };
383 int pageblock_mt, page_mt;
386 /* Scan block by block. First and last block may be incomplete */
387 pfn = zone->zone_start_pfn;
390 * Walk the zone in pageblock_nr_pages steps. If a page block spans
391 * a zone boundary, it will be double counted between zones. This does
392 * not matter as the mixed block count will still be correct
394 for (; pfn < end_pfn; ) {
395 page = pfn_to_online_page(pfn);
397 pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
401 block_end_pfn = pageblock_end_pfn(pfn);
402 block_end_pfn = min(block_end_pfn, end_pfn);
404 pageblock_mt = get_pageblock_migratetype(page);
406 for (; pfn < block_end_pfn; pfn++) {
407 /* The pageblock is online, no need to recheck. */
408 page = pfn_to_page(pfn);
410 if (page_zone(page) != zone)
413 if (PageBuddy(page)) {
414 unsigned long freepage_order;
416 freepage_order = buddy_order_unsafe(page);
417 if (freepage_order <= MAX_PAGE_ORDER)
418 pfn += (1UL << freepage_order) - 1;
422 if (PageReserved(page))
425 page_ext = page_ext_get(page);
426 if (unlikely(!page_ext))
429 if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
430 goto ext_put_continue;
432 page_owner = get_page_owner(page_ext);
433 page_mt = gfp_migratetype(page_owner->gfp_mask);
434 if (pageblock_mt != page_mt) {
435 if (is_migrate_cma(pageblock_mt))
436 count[MIGRATE_MOVABLE]++;
438 count[pageblock_mt]++;
441 page_ext_put(page_ext);
444 pfn += (1UL << page_owner->order) - 1;
446 page_ext_put(page_ext);
451 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
452 for (i = 0; i < MIGRATE_TYPES; i++)
453 seq_printf(m, "%12lu ", count[i]);
458 * Looking for memcg information and print it out
460 static inline int print_page_owner_memcg(char *kbuf, size_t count, int ret,
464 unsigned long memcg_data;
465 struct mem_cgroup *memcg;
470 memcg_data = READ_ONCE(page->memcg_data);
474 if (memcg_data & MEMCG_DATA_OBJCGS)
475 ret += scnprintf(kbuf + ret, count - ret,
476 "Slab cache page\n");
478 memcg = page_memcg_check(page);
482 online = (memcg->css.flags & CSS_ONLINE);
483 cgroup_name(memcg->css.cgroup, name, sizeof(name));
484 ret += scnprintf(kbuf + ret, count - ret,
485 "Charged %sto %smemcg %s\n",
486 PageMemcgKmem(page) ? "(via objcg) " : "",
487 online ? "" : "offline ",
491 #endif /* CONFIG_MEMCG */
497 print_page_owner(char __user *buf, size_t count, unsigned long pfn,
498 struct page *page, struct page_owner *page_owner,
499 depot_stack_handle_t handle)
501 int ret, pageblock_mt, page_mt;
504 count = min_t(size_t, count, PAGE_SIZE);
505 kbuf = kmalloc(count, GFP_KERNEL);
509 ret = scnprintf(kbuf, count,
510 "Page allocated via order %u, mask %#x(%pGg), pid %d, tgid %d (%s), ts %llu ns\n",
511 page_owner->order, page_owner->gfp_mask,
512 &page_owner->gfp_mask, page_owner->pid,
513 page_owner->tgid, page_owner->comm,
514 page_owner->ts_nsec);
516 /* Print information relevant to grouping pages by mobility */
517 pageblock_mt = get_pageblock_migratetype(page);
518 page_mt = gfp_migratetype(page_owner->gfp_mask);
519 ret += scnprintf(kbuf + ret, count - ret,
520 "PFN 0x%lx type %s Block %lu type %s Flags %pGp\n",
522 migratetype_names[page_mt],
523 pfn >> pageblock_order,
524 migratetype_names[pageblock_mt],
527 ret += stack_depot_snprint(handle, kbuf + ret, count - ret, 0);
531 if (page_owner->last_migrate_reason != -1) {
532 ret += scnprintf(kbuf + ret, count - ret,
533 "Page has been migrated, last migrate reason: %s\n",
534 migrate_reason_names[page_owner->last_migrate_reason]);
537 ret = print_page_owner_memcg(kbuf, count, ret, page);
539 ret += snprintf(kbuf + ret, count - ret, "\n");
543 if (copy_to_user(buf, kbuf, ret))
554 void __dump_page_owner(const struct page *page)
556 struct page_ext *page_ext = page_ext_get((void *)page);
557 struct page_owner *page_owner;
558 depot_stack_handle_t handle;
562 if (unlikely(!page_ext)) {
563 pr_alert("There is not page extension available.\n");
567 page_owner = get_page_owner(page_ext);
568 gfp_mask = page_owner->gfp_mask;
569 mt = gfp_migratetype(gfp_mask);
571 if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) {
572 pr_alert("page_owner info is not present (never set?)\n");
573 page_ext_put(page_ext);
577 if (test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
578 pr_alert("page_owner tracks the page as allocated\n");
580 pr_alert("page_owner tracks the page as freed\n");
582 pr_alert("page last allocated via order %u, migratetype %s, gfp_mask %#x(%pGg), pid %d, tgid %d (%s), ts %llu, free_ts %llu\n",
583 page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask,
584 page_owner->pid, page_owner->tgid, page_owner->comm,
585 page_owner->ts_nsec, page_owner->free_ts_nsec);
587 handle = READ_ONCE(page_owner->handle);
589 pr_alert("page_owner allocation stack trace missing\n");
591 stack_depot_print(handle);
593 handle = READ_ONCE(page_owner->free_handle);
595 pr_alert("page_owner free stack trace missing\n");
597 pr_alert("page last free pid %d tgid %d stack trace:\n",
598 page_owner->free_pid, page_owner->free_tgid);
599 stack_depot_print(handle);
602 if (page_owner->last_migrate_reason != -1)
603 pr_alert("page has been migrated, last migrate reason: %s\n",
604 migrate_reason_names[page_owner->last_migrate_reason]);
605 page_ext_put(page_ext);
609 read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
613 struct page_ext *page_ext;
614 struct page_owner *page_owner;
615 depot_stack_handle_t handle;
617 if (!static_branch_unlikely(&page_owner_inited))
625 /* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */
626 while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0)
629 /* Find an allocated page */
630 for (; pfn < max_pfn; pfn++) {
632 * This temporary page_owner is required so
633 * that we can avoid the context switches while holding
634 * the rcu lock and copying the page owner information to
635 * user through copy_to_user() or GFP_KERNEL allocations.
637 struct page_owner page_owner_tmp;
640 * If the new page is in a new MAX_ORDER_NR_PAGES area,
641 * validate the area as existing, skip it if not
643 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0 && !pfn_valid(pfn)) {
644 pfn += MAX_ORDER_NR_PAGES - 1;
648 page = pfn_to_page(pfn);
649 if (PageBuddy(page)) {
650 unsigned long freepage_order = buddy_order_unsafe(page);
652 if (freepage_order <= MAX_PAGE_ORDER)
653 pfn += (1UL << freepage_order) - 1;
657 page_ext = page_ext_get(page);
658 if (unlikely(!page_ext))
662 * Some pages could be missed by concurrent allocation or free,
663 * because we don't hold the zone lock.
665 if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags))
666 goto ext_put_continue;
669 * Although we do have the info about past allocation of free
670 * pages, it's not relevant for current memory usage.
672 if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
673 goto ext_put_continue;
675 page_owner = get_page_owner(page_ext);
678 * Don't print "tail" pages of high-order allocations as that
679 * would inflate the stats.
681 if (!IS_ALIGNED(pfn, 1 << page_owner->order))
682 goto ext_put_continue;
685 * Access to page_ext->handle isn't synchronous so we should
686 * be careful to access it.
688 handle = READ_ONCE(page_owner->handle);
690 goto ext_put_continue;
692 /* Record the next PFN to read in the file offset */
695 page_owner_tmp = *page_owner;
696 page_ext_put(page_ext);
697 return print_page_owner(buf, count, pfn, page,
698 &page_owner_tmp, handle);
700 page_ext_put(page_ext);
706 static loff_t lseek_page_owner(struct file *file, loff_t offset, int orig)
710 file->f_pos = offset;
713 file->f_pos += offset;
721 static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
723 unsigned long pfn = zone->zone_start_pfn;
724 unsigned long end_pfn = zone_end_pfn(zone);
725 unsigned long count = 0;
728 * Walk the zone in pageblock_nr_pages steps. If a page block spans
729 * a zone boundary, it will be double counted between zones. This does
730 * not matter as the mixed block count will still be correct
732 for (; pfn < end_pfn; ) {
733 unsigned long block_end_pfn;
735 if (!pfn_valid(pfn)) {
736 pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
740 block_end_pfn = pageblock_end_pfn(pfn);
741 block_end_pfn = min(block_end_pfn, end_pfn);
743 for (; pfn < block_end_pfn; pfn++) {
744 struct page *page = pfn_to_page(pfn);
745 struct page_ext *page_ext;
747 if (page_zone(page) != zone)
751 * To avoid having to grab zone->lock, be a little
752 * careful when reading buddy page order. The only
753 * danger is that we skip too much and potentially miss
754 * some early allocated pages, which is better than
755 * heavy lock contention.
757 if (PageBuddy(page)) {
758 unsigned long order = buddy_order_unsafe(page);
760 if (order > 0 && order <= MAX_PAGE_ORDER)
761 pfn += (1UL << order) - 1;
765 if (PageReserved(page))
768 page_ext = page_ext_get(page);
769 if (unlikely(!page_ext))
772 /* Maybe overlapping zone */
773 if (test_bit(PAGE_EXT_OWNER, &page_ext->flags))
774 goto ext_put_continue;
776 /* Found early allocated page */
777 __set_page_owner_handle(page_ext, early_handle,
781 page_ext_put(page_ext);
786 pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n",
787 pgdat->node_id, zone->name, count);
790 static void init_zones_in_node(pg_data_t *pgdat)
793 struct zone *node_zones = pgdat->node_zones;
795 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
796 if (!populated_zone(zone))
799 init_pages_in_zone(pgdat, zone);
803 static void init_early_allocated_pages(void)
807 for_each_online_pgdat(pgdat)
808 init_zones_in_node(pgdat);
811 static const struct file_operations proc_page_owner_operations = {
812 .read = read_page_owner,
813 .llseek = lseek_page_owner,
816 static void *stack_start(struct seq_file *m, loff_t *ppos)
825 * This pairs with smp_store_release() from function
826 * add_stack_record_to_list(), so we get a consistent
827 * value of stack_list.
829 stack = smp_load_acquire(&stack_list);
840 static void *stack_next(struct seq_file *m, void *v, loff_t *ppos)
842 struct stack *stack = v;
845 *ppos = stack ? *ppos + 1 : -1UL;
851 static unsigned long page_owner_stack_threshold;
853 static int stack_print(struct seq_file *m, void *v)
856 struct stack *stack = v;
857 unsigned long *entries;
858 unsigned long nr_entries;
859 struct stack_record *stack_record = stack->stack_record;
861 if (!stack->stack_record)
864 nr_entries = stack_record->size;
865 entries = stack_record->entries;
866 stack_count = refcount_read(&stack_record->count) - 1;
868 if (stack_count < 1 || stack_count < page_owner_stack_threshold)
871 for (i = 0; i < nr_entries; i++)
872 seq_printf(m, " %pS\n", (void *)entries[i]);
873 seq_printf(m, "stack_count: %d\n\n", stack_count);
878 static void stack_stop(struct seq_file *m, void *v)
882 static const struct seq_operations page_owner_stack_op = {
883 .start = stack_start,
889 static int page_owner_stack_open(struct inode *inode, struct file *file)
891 return seq_open_private(file, &page_owner_stack_op, 0);
894 static const struct file_operations page_owner_stack_operations = {
895 .open = page_owner_stack_open,
898 .release = seq_release,
901 static int page_owner_threshold_get(void *data, u64 *val)
903 *val = READ_ONCE(page_owner_stack_threshold);
907 static int page_owner_threshold_set(void *data, u64 val)
909 WRITE_ONCE(page_owner_stack_threshold, val);
913 DEFINE_SIMPLE_ATTRIBUTE(proc_page_owner_threshold, &page_owner_threshold_get,
914 &page_owner_threshold_set, "%llu");
917 static int __init pageowner_init(void)
921 if (!static_branch_unlikely(&page_owner_inited)) {
922 pr_info("page_owner is disabled\n");
926 debugfs_create_file("page_owner", 0400, NULL, NULL,
927 &proc_page_owner_operations);
928 dir = debugfs_create_dir("page_owner_stacks", NULL);
929 debugfs_create_file("show_stacks", 0400, dir, NULL,
930 &page_owner_stack_operations);
931 debugfs_create_file("count_threshold", 0600, dir, NULL,
932 &proc_page_owner_threshold);
936 late_initcall(pageowner_init)