1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/debugfs.h>
3 #include <linux/mm.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>
15
16 #include "internal.h"
17
18 /*
19 * TODO: teach PAGE_OWNER_STACK_DEPTH (__dump_page_owner and save_stack)
20 * to use off stack temporal storage
21 */
22 #define PAGE_OWNER_STACK_DEPTH (16)
23
24 struct page_owner {
25 unsigned short order;
26 short last_migrate_reason;
27 gfp_t gfp_mask;
28 depot_stack_handle_t handle;
29 depot_stack_handle_t free_handle;
30 u64 ts_nsec;
31 u64 free_ts_nsec;
32 char comm[TASK_COMM_LEN];
33 pid_t pid;
34 pid_t tgid;
35 };
36
37 static bool page_owner_enabled __initdata;
38 DEFINE_STATIC_KEY_FALSE(page_owner_inited);
39
40 static depot_stack_handle_t dummy_handle;
41 static depot_stack_handle_t failure_handle;
42 static depot_stack_handle_t early_handle;
43
44 static void init_early_allocated_pages(void);
45
early_page_owner_param(char * buf)46 static int __init early_page_owner_param(char *buf)
47 {
48 int ret = kstrtobool(buf, &page_owner_enabled);
49
50 if (page_owner_enabled)
51 stack_depot_request_early_init();
52
53 return ret;
54 }
55 early_param("page_owner", early_page_owner_param);
56
need_page_owner(void)57 static __init bool need_page_owner(void)
58 {
59 return page_owner_enabled;
60 }
61
create_dummy_stack(void)62 static __always_inline depot_stack_handle_t create_dummy_stack(void)
63 {
64 unsigned long entries[4];
65 unsigned int nr_entries;
66
67 nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
68 return stack_depot_save(entries, nr_entries, GFP_KERNEL);
69 }
70
register_dummy_stack(void)71 static noinline void register_dummy_stack(void)
72 {
73 dummy_handle = create_dummy_stack();
74 }
75
register_failure_stack(void)76 static noinline void register_failure_stack(void)
77 {
78 failure_handle = create_dummy_stack();
79 }
80
register_early_stack(void)81 static noinline void register_early_stack(void)
82 {
83 early_handle = create_dummy_stack();
84 }
85
init_page_owner(void)86 static __init void init_page_owner(void)
87 {
88 if (!page_owner_enabled)
89 return;
90
91 register_dummy_stack();
92 register_failure_stack();
93 register_early_stack();
94 static_branch_enable(&page_owner_inited);
95 init_early_allocated_pages();
96 }
97
98 struct page_ext_operations page_owner_ops = {
99 .size = sizeof(struct page_owner),
100 .need = need_page_owner,
101 .init = init_page_owner,
102 .need_shared_flags = true,
103 };
104
get_page_owner(struct page_ext * page_ext)105 static inline struct page_owner *get_page_owner(struct page_ext *page_ext)
106 {
107 return page_ext_data(page_ext, &page_owner_ops);
108 }
109
save_stack(gfp_t flags)110 static noinline depot_stack_handle_t save_stack(gfp_t flags)
111 {
112 unsigned long entries[PAGE_OWNER_STACK_DEPTH];
113 depot_stack_handle_t handle;
114 unsigned int nr_entries;
115
116 /*
117 * Avoid recursion.
118 *
119 * Sometimes page metadata allocation tracking requires more
120 * memory to be allocated:
121 * - when new stack trace is saved to stack depot
122 * - when backtrace itself is calculated (ia64)
123 */
124 if (current->in_page_owner)
125 return dummy_handle;
126 current->in_page_owner = 1;
127
128 nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2);
129 handle = stack_depot_save(entries, nr_entries, flags);
130 if (!handle)
131 handle = failure_handle;
132
133 current->in_page_owner = 0;
134 return handle;
135 }
136
__reset_page_owner(struct page * page,unsigned short order)137 void __reset_page_owner(struct page *page, unsigned short order)
138 {
139 int i;
140 struct page_ext *page_ext;
141 depot_stack_handle_t handle;
142 struct page_owner *page_owner;
143 u64 free_ts_nsec = local_clock();
144
145 page_ext = page_ext_get(page);
146 if (unlikely(!page_ext))
147 return;
148
149 handle = save_stack(GFP_NOWAIT | __GFP_NOWARN);
150 for (i = 0; i < (1 << order); i++) {
151 __clear_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags);
152 page_owner = get_page_owner(page_ext);
153 page_owner->free_handle = handle;
154 page_owner->free_ts_nsec = free_ts_nsec;
155 page_ext = page_ext_next(page_ext);
156 }
157 page_ext_put(page_ext);
158 }
159
__set_page_owner_handle(struct page_ext * page_ext,depot_stack_handle_t handle,unsigned short order,gfp_t gfp_mask)160 static inline void __set_page_owner_handle(struct page_ext *page_ext,
161 depot_stack_handle_t handle,
162 unsigned short order, gfp_t gfp_mask)
163 {
164 struct page_owner *page_owner;
165 int i;
166 u64 ts_nsec = local_clock();
167
168 for (i = 0; i < (1 << order); i++) {
169 page_owner = get_page_owner(page_ext);
170 page_owner->handle = handle;
171 page_owner->order = order;
172 page_owner->gfp_mask = gfp_mask;
173 page_owner->last_migrate_reason = -1;
174 page_owner->pid = current->pid;
175 page_owner->tgid = current->tgid;
176 page_owner->ts_nsec = ts_nsec;
177 strscpy(page_owner->comm, current->comm,
178 sizeof(page_owner->comm));
179 __set_bit(PAGE_EXT_OWNER, &page_ext->flags);
180 __set_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags);
181
182 page_ext = page_ext_next(page_ext);
183 }
184 }
185
__set_page_owner(struct page * page,unsigned short order,gfp_t gfp_mask)186 noinline void __set_page_owner(struct page *page, unsigned short order,
187 gfp_t gfp_mask)
188 {
189 struct page_ext *page_ext;
190 depot_stack_handle_t handle;
191
192 handle = save_stack(gfp_mask);
193
194 page_ext = page_ext_get(page);
195 if (unlikely(!page_ext))
196 return;
197 __set_page_owner_handle(page_ext, handle, order, gfp_mask);
198 page_ext_put(page_ext);
199 }
200
__set_page_owner_migrate_reason(struct page * page,int reason)201 void __set_page_owner_migrate_reason(struct page *page, int reason)
202 {
203 struct page_ext *page_ext = page_ext_get(page);
204 struct page_owner *page_owner;
205
206 if (unlikely(!page_ext))
207 return;
208
209 page_owner = get_page_owner(page_ext);
210 page_owner->last_migrate_reason = reason;
211 page_ext_put(page_ext);
212 }
213
__split_page_owner(struct page * page,unsigned int nr)214 void __split_page_owner(struct page *page, unsigned int nr)
215 {
216 int i;
217 struct page_ext *page_ext = page_ext_get(page);
218 struct page_owner *page_owner;
219
220 if (unlikely(!page_ext))
221 return;
222
223 for (i = 0; i < nr; i++) {
224 page_owner = get_page_owner(page_ext);
225 page_owner->order = 0;
226 page_ext = page_ext_next(page_ext);
227 }
228 page_ext_put(page_ext);
229 }
230
__folio_copy_owner(struct folio * newfolio,struct folio * old)231 void __folio_copy_owner(struct folio *newfolio, struct folio *old)
232 {
233 struct page_ext *old_ext;
234 struct page_ext *new_ext;
235 struct page_owner *old_page_owner, *new_page_owner;
236
237 old_ext = page_ext_get(&old->page);
238 if (unlikely(!old_ext))
239 return;
240
241 new_ext = page_ext_get(&newfolio->page);
242 if (unlikely(!new_ext)) {
243 page_ext_put(old_ext);
244 return;
245 }
246
247 old_page_owner = get_page_owner(old_ext);
248 new_page_owner = get_page_owner(new_ext);
249 new_page_owner->order = old_page_owner->order;
250 new_page_owner->gfp_mask = old_page_owner->gfp_mask;
251 new_page_owner->last_migrate_reason =
252 old_page_owner->last_migrate_reason;
253 new_page_owner->handle = old_page_owner->handle;
254 new_page_owner->pid = old_page_owner->pid;
255 new_page_owner->tgid = old_page_owner->tgid;
256 new_page_owner->ts_nsec = old_page_owner->ts_nsec;
257 new_page_owner->free_ts_nsec = old_page_owner->ts_nsec;
258 strcpy(new_page_owner->comm, old_page_owner->comm);
259
260 /*
261 * We don't clear the bit on the old folio as it's going to be freed
262 * after migration. Until then, the info can be useful in case of
263 * a bug, and the overall stats will be off a bit only temporarily.
264 * Also, migrate_misplaced_transhuge_page() can still fail the
265 * migration and then we want the old folio to retain the info. But
266 * in that case we also don't need to explicitly clear the info from
267 * the new page, which will be freed.
268 */
269 __set_bit(PAGE_EXT_OWNER, &new_ext->flags);
270 __set_bit(PAGE_EXT_OWNER_ALLOCATED, &new_ext->flags);
271 page_ext_put(new_ext);
272 page_ext_put(old_ext);
273 }
274
pagetypeinfo_showmixedcount_print(struct seq_file * m,pg_data_t * pgdat,struct zone * zone)275 void pagetypeinfo_showmixedcount_print(struct seq_file *m,
276 pg_data_t *pgdat, struct zone *zone)
277 {
278 struct page *page;
279 struct page_ext *page_ext;
280 struct page_owner *page_owner;
281 unsigned long pfn, block_end_pfn;
282 unsigned long end_pfn = zone_end_pfn(zone);
283 unsigned long count[MIGRATE_TYPES] = { 0, };
284 int pageblock_mt, page_mt;
285 int i;
286
287 /* Scan block by block. First and last block may be incomplete */
288 pfn = zone->zone_start_pfn;
289
290 /*
291 * Walk the zone in pageblock_nr_pages steps. If a page block spans
292 * a zone boundary, it will be double counted between zones. This does
293 * not matter as the mixed block count will still be correct
294 */
295 for (; pfn < end_pfn; ) {
296 page = pfn_to_online_page(pfn);
297 if (!page) {
298 pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
299 continue;
300 }
301
302 block_end_pfn = pageblock_end_pfn(pfn);
303 block_end_pfn = min(block_end_pfn, end_pfn);
304
305 pageblock_mt = get_pageblock_migratetype(page);
306
307 for (; pfn < block_end_pfn; pfn++) {
308 /* The pageblock is online, no need to recheck. */
309 page = pfn_to_page(pfn);
310
311 if (page_zone(page) != zone)
312 continue;
313
314 if (PageBuddy(page)) {
315 unsigned long freepage_order;
316
317 freepage_order = buddy_order_unsafe(page);
318 if (freepage_order <= MAX_ORDER)
319 pfn += (1UL << freepage_order) - 1;
320 continue;
321 }
322
323 if (PageReserved(page))
324 continue;
325
326 page_ext = page_ext_get(page);
327 if (unlikely(!page_ext))
328 continue;
329
330 if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
331 goto ext_put_continue;
332
333 page_owner = get_page_owner(page_ext);
334 page_mt = gfp_migratetype(page_owner->gfp_mask);
335 if (pageblock_mt != page_mt) {
336 if (is_migrate_cma(pageblock_mt))
337 count[MIGRATE_MOVABLE]++;
338 else
339 count[pageblock_mt]++;
340
341 pfn = block_end_pfn;
342 page_ext_put(page_ext);
343 break;
344 }
345 pfn += (1UL << page_owner->order) - 1;
346 ext_put_continue:
347 page_ext_put(page_ext);
348 }
349 }
350
351 /* Print counts */
352 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
353 for (i = 0; i < MIGRATE_TYPES; i++)
354 seq_printf(m, "%12lu ", count[i]);
355 seq_putc(m, '\n');
356 }
357
358 /*
359 * Looking for memcg information and print it out
360 */
print_page_owner_memcg(char * kbuf,size_t count,int ret,struct page * page)361 static inline int print_page_owner_memcg(char *kbuf, size_t count, int ret,
362 struct page *page)
363 {
364 #ifdef CONFIG_MEMCG
365 unsigned long memcg_data;
366 struct mem_cgroup *memcg;
367 bool online;
368 char name[80];
369
370 rcu_read_lock();
371 memcg_data = READ_ONCE(page->memcg_data);
372 if (!memcg_data)
373 goto out_unlock;
374
375 if (memcg_data & MEMCG_DATA_OBJCGS)
376 ret += scnprintf(kbuf + ret, count - ret,
377 "Slab cache page\n");
378
379 memcg = page_memcg_check(page);
380 if (!memcg)
381 goto out_unlock;
382
383 online = (memcg->css.flags & CSS_ONLINE);
384 cgroup_name(memcg->css.cgroup, name, sizeof(name));
385 ret += scnprintf(kbuf + ret, count - ret,
386 "Charged %sto %smemcg %s\n",
387 PageMemcgKmem(page) ? "(via objcg) " : "",
388 online ? "" : "offline ",
389 name);
390 out_unlock:
391 rcu_read_unlock();
392 #endif /* CONFIG_MEMCG */
393
394 return ret;
395 }
396
397 static ssize_t
print_page_owner(char __user * buf,size_t count,unsigned long pfn,struct page * page,struct page_owner * page_owner,depot_stack_handle_t handle)398 print_page_owner(char __user *buf, size_t count, unsigned long pfn,
399 struct page *page, struct page_owner *page_owner,
400 depot_stack_handle_t handle)
401 {
402 int ret, pageblock_mt, page_mt;
403 char *kbuf;
404
405 count = min_t(size_t, count, PAGE_SIZE);
406 kbuf = kmalloc(count, GFP_KERNEL);
407 if (!kbuf)
408 return -ENOMEM;
409
410 ret = scnprintf(kbuf, count,
411 "Page allocated via order %u, mask %#x(%pGg), pid %d, tgid %d (%s), ts %llu ns, free_ts %llu ns\n",
412 page_owner->order, page_owner->gfp_mask,
413 &page_owner->gfp_mask, page_owner->pid,
414 page_owner->tgid, page_owner->comm,
415 page_owner->ts_nsec, page_owner->free_ts_nsec);
416
417 /* Print information relevant to grouping pages by mobility */
418 pageblock_mt = get_pageblock_migratetype(page);
419 page_mt = gfp_migratetype(page_owner->gfp_mask);
420 ret += scnprintf(kbuf + ret, count - ret,
421 "PFN 0x%lx type %s Block %lu type %s Flags %pGp\n",
422 pfn,
423 migratetype_names[page_mt],
424 pfn >> pageblock_order,
425 migratetype_names[pageblock_mt],
426 &page->flags);
427
428 ret += stack_depot_snprint(handle, kbuf + ret, count - ret, 0);
429 if (ret >= count)
430 goto err;
431
432 if (page_owner->last_migrate_reason != -1) {
433 ret += scnprintf(kbuf + ret, count - ret,
434 "Page has been migrated, last migrate reason: %s\n",
435 migrate_reason_names[page_owner->last_migrate_reason]);
436 }
437
438 ret = print_page_owner_memcg(kbuf, count, ret, page);
439
440 ret += snprintf(kbuf + ret, count - ret, "\n");
441 if (ret >= count)
442 goto err;
443
444 if (copy_to_user(buf, kbuf, ret))
445 ret = -EFAULT;
446
447 kfree(kbuf);
448 return ret;
449
450 err:
451 kfree(kbuf);
452 return -ENOMEM;
453 }
454
__dump_page_owner(const struct page * page)455 void __dump_page_owner(const struct page *page)
456 {
457 struct page_ext *page_ext = page_ext_get((void *)page);
458 struct page_owner *page_owner;
459 depot_stack_handle_t handle;
460 gfp_t gfp_mask;
461 int mt;
462
463 if (unlikely(!page_ext)) {
464 pr_alert("There is not page extension available.\n");
465 return;
466 }
467
468 page_owner = get_page_owner(page_ext);
469 gfp_mask = page_owner->gfp_mask;
470 mt = gfp_migratetype(gfp_mask);
471
472 if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) {
473 pr_alert("page_owner info is not present (never set?)\n");
474 page_ext_put(page_ext);
475 return;
476 }
477
478 if (test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
479 pr_alert("page_owner tracks the page as allocated\n");
480 else
481 pr_alert("page_owner tracks the page as freed\n");
482
483 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",
484 page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask,
485 page_owner->pid, page_owner->tgid, page_owner->comm,
486 page_owner->ts_nsec, page_owner->free_ts_nsec);
487
488 handle = READ_ONCE(page_owner->handle);
489 if (!handle)
490 pr_alert("page_owner allocation stack trace missing\n");
491 else
492 stack_depot_print(handle);
493
494 handle = READ_ONCE(page_owner->free_handle);
495 if (!handle) {
496 pr_alert("page_owner free stack trace missing\n");
497 } else {
498 pr_alert("page last free stack trace:\n");
499 stack_depot_print(handle);
500 }
501
502 if (page_owner->last_migrate_reason != -1)
503 pr_alert("page has been migrated, last migrate reason: %s\n",
504 migrate_reason_names[page_owner->last_migrate_reason]);
505 page_ext_put(page_ext);
506 }
507
508 static ssize_t
read_page_owner(struct file * file,char __user * buf,size_t count,loff_t * ppos)509 read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
510 {
511 unsigned long pfn;
512 struct page *page;
513 struct page_ext *page_ext;
514 struct page_owner *page_owner;
515 depot_stack_handle_t handle;
516
517 if (!static_branch_unlikely(&page_owner_inited))
518 return -EINVAL;
519
520 page = NULL;
521 if (*ppos == 0)
522 pfn = min_low_pfn;
523 else
524 pfn = *ppos;
525 /* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */
526 while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0)
527 pfn++;
528
529 /* Find an allocated page */
530 for (; pfn < max_pfn; pfn++) {
531 /*
532 * This temporary page_owner is required so
533 * that we can avoid the context switches while holding
534 * the rcu lock and copying the page owner information to
535 * user through copy_to_user() or GFP_KERNEL allocations.
536 */
537 struct page_owner page_owner_tmp;
538
539 /*
540 * If the new page is in a new MAX_ORDER_NR_PAGES area,
541 * validate the area as existing, skip it if not
542 */
543 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0 && !pfn_valid(pfn)) {
544 pfn += MAX_ORDER_NR_PAGES - 1;
545 continue;
546 }
547
548 page = pfn_to_page(pfn);
549 if (PageBuddy(page)) {
550 unsigned long freepage_order = buddy_order_unsafe(page);
551
552 if (freepage_order <= MAX_ORDER)
553 pfn += (1UL << freepage_order) - 1;
554 continue;
555 }
556
557 page_ext = page_ext_get(page);
558 if (unlikely(!page_ext))
559 continue;
560
561 /*
562 * Some pages could be missed by concurrent allocation or free,
563 * because we don't hold the zone lock.
564 */
565 if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags))
566 goto ext_put_continue;
567
568 /*
569 * Although we do have the info about past allocation of free
570 * pages, it's not relevant for current memory usage.
571 */
572 if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
573 goto ext_put_continue;
574
575 page_owner = get_page_owner(page_ext);
576
577 /*
578 * Don't print "tail" pages of high-order allocations as that
579 * would inflate the stats.
580 */
581 if (!IS_ALIGNED(pfn, 1 << page_owner->order))
582 goto ext_put_continue;
583
584 /*
585 * Access to page_ext->handle isn't synchronous so we should
586 * be careful to access it.
587 */
588 handle = READ_ONCE(page_owner->handle);
589 if (!handle)
590 goto ext_put_continue;
591
592 /* Record the next PFN to read in the file offset */
593 *ppos = pfn + 1;
594
595 page_owner_tmp = *page_owner;
596 page_ext_put(page_ext);
597 return print_page_owner(buf, count, pfn, page,
598 &page_owner_tmp, handle);
599 ext_put_continue:
600 page_ext_put(page_ext);
601 }
602
603 return 0;
604 }
605
lseek_page_owner(struct file * file,loff_t offset,int orig)606 static loff_t lseek_page_owner(struct file *file, loff_t offset, int orig)
607 {
608 switch (orig) {
609 case SEEK_SET:
610 file->f_pos = offset;
611 break;
612 case SEEK_CUR:
613 file->f_pos += offset;
614 break;
615 default:
616 return -EINVAL;
617 }
618 return file->f_pos;
619 }
620
init_pages_in_zone(pg_data_t * pgdat,struct zone * zone)621 static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
622 {
623 unsigned long pfn = zone->zone_start_pfn;
624 unsigned long end_pfn = zone_end_pfn(zone);
625 unsigned long count = 0;
626
627 /*
628 * Walk the zone in pageblock_nr_pages steps. If a page block spans
629 * a zone boundary, it will be double counted between zones. This does
630 * not matter as the mixed block count will still be correct
631 */
632 for (; pfn < end_pfn; ) {
633 unsigned long block_end_pfn;
634
635 if (!pfn_valid(pfn)) {
636 pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
637 continue;
638 }
639
640 block_end_pfn = pageblock_end_pfn(pfn);
641 block_end_pfn = min(block_end_pfn, end_pfn);
642
643 for (; pfn < block_end_pfn; pfn++) {
644 struct page *page = pfn_to_page(pfn);
645 struct page_ext *page_ext;
646
647 if (page_zone(page) != zone)
648 continue;
649
650 /*
651 * To avoid having to grab zone->lock, be a little
652 * careful when reading buddy page order. The only
653 * danger is that we skip too much and potentially miss
654 * some early allocated pages, which is better than
655 * heavy lock contention.
656 */
657 if (PageBuddy(page)) {
658 unsigned long order = buddy_order_unsafe(page);
659
660 if (order > 0 && order <= MAX_ORDER)
661 pfn += (1UL << order) - 1;
662 continue;
663 }
664
665 if (PageReserved(page))
666 continue;
667
668 page_ext = page_ext_get(page);
669 if (unlikely(!page_ext))
670 continue;
671
672 /* Maybe overlapping zone */
673 if (test_bit(PAGE_EXT_OWNER, &page_ext->flags))
674 goto ext_put_continue;
675
676 /* Found early allocated page */
677 __set_page_owner_handle(page_ext, early_handle,
678 0, 0);
679 count++;
680 ext_put_continue:
681 page_ext_put(page_ext);
682 }
683 cond_resched();
684 }
685
686 pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n",
687 pgdat->node_id, zone->name, count);
688 }
689
init_zones_in_node(pg_data_t * pgdat)690 static void init_zones_in_node(pg_data_t *pgdat)
691 {
692 struct zone *zone;
693 struct zone *node_zones = pgdat->node_zones;
694
695 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
696 if (!populated_zone(zone))
697 continue;
698
699 init_pages_in_zone(pgdat, zone);
700 }
701 }
702
init_early_allocated_pages(void)703 static void init_early_allocated_pages(void)
704 {
705 pg_data_t *pgdat;
706
707 for_each_online_pgdat(pgdat)
708 init_zones_in_node(pgdat);
709 }
710
711 static const struct file_operations proc_page_owner_operations = {
712 .read = read_page_owner,
713 .llseek = lseek_page_owner,
714 };
715
pageowner_init(void)716 static int __init pageowner_init(void)
717 {
718 if (!static_branch_unlikely(&page_owner_inited)) {
719 pr_info("page_owner is disabled\n");
720 return 0;
721 }
722
723 debugfs_create_file("page_owner", 0400, NULL, NULL,
724 &proc_page_owner_operations);
725
726 return 0;
727 }
728 late_initcall(pageowner_init)
729