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 pid_t free_pid;
36 pid_t free_tgid;
37 };
38
39 static bool page_owner_enabled __initdata;
40 DEFINE_STATIC_KEY_FALSE(page_owner_inited);
41
42 static depot_stack_handle_t dummy_handle;
43 static depot_stack_handle_t failure_handle;
44 static depot_stack_handle_t early_handle;
45
46 static void init_early_allocated_pages(void);
47
early_page_owner_param(char * buf)48 static int __init early_page_owner_param(char *buf)
49 {
50 int ret = kstrtobool(buf, &page_owner_enabled);
51
52 if (page_owner_enabled)
53 stack_depot_request_early_init();
54
55 return ret;
56 }
57 early_param("page_owner", early_page_owner_param);
58
need_page_owner(void)59 static __init bool need_page_owner(void)
60 {
61 return page_owner_enabled;
62 }
63
create_dummy_stack(void)64 static __always_inline depot_stack_handle_t create_dummy_stack(void)
65 {
66 unsigned long entries[4];
67 unsigned int nr_entries;
68
69 nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
70 return stack_depot_save(entries, nr_entries, GFP_KERNEL);
71 }
72
register_dummy_stack(void)73 static noinline void register_dummy_stack(void)
74 {
75 dummy_handle = create_dummy_stack();
76 }
77
register_failure_stack(void)78 static noinline void register_failure_stack(void)
79 {
80 failure_handle = create_dummy_stack();
81 }
82
register_early_stack(void)83 static noinline void register_early_stack(void)
84 {
85 early_handle = create_dummy_stack();
86 }
87
init_page_owner(void)88 static __init void init_page_owner(void)
89 {
90 if (!page_owner_enabled)
91 return;
92
93 register_dummy_stack();
94 register_failure_stack();
95 register_early_stack();
96 static_branch_enable(&page_owner_inited);
97 init_early_allocated_pages();
98 }
99
100 struct page_ext_operations page_owner_ops = {
101 .size = sizeof(struct page_owner),
102 .need = need_page_owner,
103 .init = init_page_owner,
104 .need_shared_flags = true,
105 };
106
get_page_owner(struct page_ext * page_ext)107 static inline struct page_owner *get_page_owner(struct page_ext *page_ext)
108 {
109 return page_ext_data(page_ext, &page_owner_ops);
110 }
111
get_page_owner_handle(struct page_ext * page_ext,unsigned long pfn)112 depot_stack_handle_t get_page_owner_handle(struct page_ext *page_ext, unsigned long pfn)
113 {
114 struct page_owner *page_owner;
115 depot_stack_handle_t handle;
116
117 if (!static_branch_unlikely(&page_owner_inited))
118 return 0;
119
120 page_owner = get_page_owner(page_ext);
121
122 /* skip handle for tail pages of higher order allocations */
123 if (!IS_ALIGNED(pfn, 1 << page_owner->order))
124 return 0;
125
126 handle = READ_ONCE(page_owner->handle);
127 return handle;
128 }
129 EXPORT_SYMBOL_NS_GPL(get_page_owner_handle, MINIDUMP);
130
save_stack(gfp_t flags)131 static noinline depot_stack_handle_t save_stack(gfp_t flags)
132 {
133 unsigned long entries[PAGE_OWNER_STACK_DEPTH];
134 depot_stack_handle_t handle;
135 unsigned int nr_entries;
136
137 /*
138 * Avoid recursion.
139 *
140 * Sometimes page metadata allocation tracking requires more
141 * memory to be allocated:
142 * - when new stack trace is saved to stack depot
143 * - when backtrace itself is calculated (ia64)
144 */
145 if (current->in_page_owner)
146 return dummy_handle;
147 current->in_page_owner = 1;
148
149 nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2);
150 handle = stack_depot_save(entries, nr_entries, flags);
151 if (!handle)
152 handle = failure_handle;
153
154 current->in_page_owner = 0;
155 return handle;
156 }
157
__reset_page_owner(struct page * page,unsigned short order)158 void __reset_page_owner(struct page *page, unsigned short order)
159 {
160 int i;
161 struct page_ext *page_ext;
162 depot_stack_handle_t handle;
163 struct page_owner *page_owner;
164 u64 free_ts_nsec = local_clock();
165
166 page_ext = page_ext_get(page);
167 if (unlikely(!page_ext))
168 return;
169
170 handle = save_stack(GFP_NOWAIT | __GFP_NOWARN);
171 for (i = 0; i < (1 << order); i++) {
172 __clear_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags);
173 page_owner = get_page_owner(page_ext);
174 page_owner->free_handle = handle;
175 page_owner->free_ts_nsec = free_ts_nsec;
176 page_owner->free_pid = current->pid;
177 page_owner->free_tgid = current->tgid;
178 page_ext = page_ext_next(page_ext);
179 }
180 page_ext_put(page_ext);
181 }
182
__set_page_owner_handle(struct page_ext * page_ext,depot_stack_handle_t handle,unsigned short order,gfp_t gfp_mask)183 static inline void __set_page_owner_handle(struct page_ext *page_ext,
184 depot_stack_handle_t handle,
185 unsigned short order, gfp_t gfp_mask)
186 {
187 struct page_owner *page_owner;
188 int i;
189 u64 ts_nsec = local_clock();
190
191 for (i = 0; i < (1 << order); i++) {
192 page_owner = get_page_owner(page_ext);
193 page_owner->handle = handle;
194 page_owner->order = order;
195 page_owner->gfp_mask = gfp_mask;
196 page_owner->last_migrate_reason = -1;
197 page_owner->pid = current->pid;
198 page_owner->tgid = current->tgid;
199 page_owner->ts_nsec = ts_nsec;
200 strscpy(page_owner->comm, current->comm,
201 sizeof(page_owner->comm));
202 __set_bit(PAGE_EXT_OWNER, &page_ext->flags);
203 __set_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags);
204
205 page_ext = page_ext_next(page_ext);
206 }
207 }
208
__set_page_owner(struct page * page,unsigned short order,gfp_t gfp_mask)209 noinline void __set_page_owner(struct page *page, unsigned short order,
210 gfp_t gfp_mask)
211 {
212 struct page_ext *page_ext;
213 depot_stack_handle_t handle;
214
215 handle = save_stack(gfp_mask);
216
217 page_ext = page_ext_get(page);
218 if (unlikely(!page_ext))
219 return;
220 __set_page_owner_handle(page_ext, handle, order, gfp_mask);
221 page_ext_put(page_ext);
222 }
223
__set_page_owner_migrate_reason(struct page * page,int reason)224 void __set_page_owner_migrate_reason(struct page *page, int reason)
225 {
226 struct page_ext *page_ext = page_ext_get(page);
227 struct page_owner *page_owner;
228
229 if (unlikely(!page_ext))
230 return;
231
232 page_owner = get_page_owner(page_ext);
233 page_owner->last_migrate_reason = reason;
234 page_ext_put(page_ext);
235 }
236
__split_page_owner(struct page * page,unsigned int nr)237 void __split_page_owner(struct page *page, unsigned int nr)
238 {
239 int i;
240 struct page_ext *page_ext = page_ext_get(page);
241 struct page_owner *page_owner;
242
243 if (unlikely(!page_ext))
244 return;
245
246 for (i = 0; i < nr; i++) {
247 page_owner = get_page_owner(page_ext);
248 page_owner->order = 0;
249 page_ext = page_ext_next(page_ext);
250 }
251 page_ext_put(page_ext);
252 }
253
__folio_copy_owner(struct folio * newfolio,struct folio * old)254 void __folio_copy_owner(struct folio *newfolio, struct folio *old)
255 {
256 struct page_ext *old_ext;
257 struct page_ext *new_ext;
258 struct page_owner *old_page_owner, *new_page_owner;
259
260 old_ext = page_ext_get(&old->page);
261 if (unlikely(!old_ext))
262 return;
263
264 new_ext = page_ext_get(&newfolio->page);
265 if (unlikely(!new_ext)) {
266 page_ext_put(old_ext);
267 return;
268 }
269
270 old_page_owner = get_page_owner(old_ext);
271 new_page_owner = get_page_owner(new_ext);
272 new_page_owner->order = old_page_owner->order;
273 new_page_owner->gfp_mask = old_page_owner->gfp_mask;
274 new_page_owner->last_migrate_reason =
275 old_page_owner->last_migrate_reason;
276 new_page_owner->handle = old_page_owner->handle;
277 new_page_owner->pid = old_page_owner->pid;
278 new_page_owner->tgid = old_page_owner->tgid;
279 new_page_owner->free_pid = old_page_owner->free_pid;
280 new_page_owner->free_tgid = old_page_owner->free_tgid;
281 new_page_owner->ts_nsec = old_page_owner->ts_nsec;
282 new_page_owner->free_ts_nsec = old_page_owner->ts_nsec;
283 strcpy(new_page_owner->comm, old_page_owner->comm);
284
285 /*
286 * We don't clear the bit on the old folio as it's going to be freed
287 * after migration. Until then, the info can be useful in case of
288 * a bug, and the overall stats will be off a bit only temporarily.
289 * Also, migrate_misplaced_transhuge_page() can still fail the
290 * migration and then we want the old folio to retain the info. But
291 * in that case we also don't need to explicitly clear the info from
292 * the new page, which will be freed.
293 */
294 __set_bit(PAGE_EXT_OWNER, &new_ext->flags);
295 __set_bit(PAGE_EXT_OWNER_ALLOCATED, &new_ext->flags);
296 page_ext_put(new_ext);
297 page_ext_put(old_ext);
298 }
299
pagetypeinfo_showmixedcount_print(struct seq_file * m,pg_data_t * pgdat,struct zone * zone)300 void pagetypeinfo_showmixedcount_print(struct seq_file *m,
301 pg_data_t *pgdat, struct zone *zone)
302 {
303 struct page *page;
304 struct page_ext *page_ext;
305 struct page_owner *page_owner;
306 unsigned long pfn, block_end_pfn;
307 unsigned long end_pfn = zone_end_pfn(zone);
308 unsigned long count[MIGRATE_TYPES] = { 0, };
309 int pageblock_mt, page_mt;
310 int i;
311
312 /* Scan block by block. First and last block may be incomplete */
313 pfn = zone->zone_start_pfn;
314
315 /*
316 * Walk the zone in pageblock_nr_pages steps. If a page block spans
317 * a zone boundary, it will be double counted between zones. This does
318 * not matter as the mixed block count will still be correct
319 */
320 for (; pfn < end_pfn; ) {
321 page = pfn_to_online_page(pfn);
322 if (!page) {
323 pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
324 continue;
325 }
326
327 block_end_pfn = pageblock_end_pfn(pfn);
328 block_end_pfn = min(block_end_pfn, end_pfn);
329
330 pageblock_mt = get_pageblock_migratetype(page);
331
332 for (; pfn < block_end_pfn; pfn++) {
333 /* The pageblock is online, no need to recheck. */
334 page = pfn_to_page(pfn);
335
336 if (page_zone(page) != zone)
337 continue;
338
339 if (PageBuddy(page)) {
340 unsigned long freepage_order;
341
342 freepage_order = buddy_order_unsafe(page);
343 if (freepage_order <= MAX_ORDER)
344 pfn += (1UL << freepage_order) - 1;
345 continue;
346 }
347
348 if (PageReserved(page))
349 continue;
350
351 page_ext = page_ext_get(page);
352 if (unlikely(!page_ext))
353 continue;
354
355 if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
356 goto ext_put_continue;
357
358 page_owner = get_page_owner(page_ext);
359 page_mt = gfp_migratetype(page_owner->gfp_mask);
360 if (pageblock_mt != page_mt) {
361 if (is_migrate_cma(pageblock_mt))
362 count[MIGRATE_MOVABLE]++;
363 else
364 count[pageblock_mt]++;
365
366 pfn = block_end_pfn;
367 page_ext_put(page_ext);
368 break;
369 }
370 pfn += (1UL << page_owner->order) - 1;
371 ext_put_continue:
372 page_ext_put(page_ext);
373 }
374 }
375
376 /* Print counts */
377 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
378 for (i = 0; i < MIGRATE_TYPES; i++)
379 seq_printf(m, "%12lu ", count[i]);
380 seq_putc(m, '\n');
381 }
382
383 /*
384 * Looking for memcg information and print it out
385 */
print_page_owner_memcg(char * kbuf,size_t count,int ret,struct page * page)386 static inline int print_page_owner_memcg(char *kbuf, size_t count, int ret,
387 struct page *page)
388 {
389 #ifdef CONFIG_MEMCG
390 unsigned long memcg_data;
391 struct mem_cgroup *memcg;
392 bool online;
393 char name[80];
394
395 rcu_read_lock();
396 memcg_data = READ_ONCE(page->memcg_data);
397 if (!memcg_data)
398 goto out_unlock;
399
400 if (memcg_data & MEMCG_DATA_OBJCGS)
401 ret += scnprintf(kbuf + ret, count - ret,
402 "Slab cache page\n");
403
404 memcg = page_memcg_check(page);
405 if (!memcg)
406 goto out_unlock;
407
408 online = (memcg->css.flags & CSS_ONLINE);
409 cgroup_name(memcg->css.cgroup, name, sizeof(name));
410 ret += scnprintf(kbuf + ret, count - ret,
411 "Charged %sto %smemcg %s\n",
412 PageMemcgKmem(page) ? "(via objcg) " : "",
413 online ? "" : "offline ",
414 name);
415 out_unlock:
416 rcu_read_unlock();
417 #endif /* CONFIG_MEMCG */
418
419 return ret;
420 }
421
422 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)423 print_page_owner(char __user *buf, size_t count, unsigned long pfn,
424 struct page *page, struct page_owner *page_owner,
425 depot_stack_handle_t handle)
426 {
427 int ret, pageblock_mt, page_mt;
428 char *kbuf;
429
430 count = min_t(size_t, count, PAGE_SIZE);
431 kbuf = kmalloc(count, GFP_KERNEL);
432 if (!kbuf)
433 return -ENOMEM;
434
435 ret = scnprintf(kbuf, count,
436 "Page allocated via order %u, mask %#x(%pGg), pid %d, tgid %d (%s), ts %llu ns, free_ts %llu ns\n",
437 page_owner->order, page_owner->gfp_mask,
438 &page_owner->gfp_mask, page_owner->pid,
439 page_owner->tgid, page_owner->comm,
440 page_owner->ts_nsec, page_owner->free_ts_nsec);
441
442 /* Print information relevant to grouping pages by mobility */
443 pageblock_mt = get_pageblock_migratetype(page);
444 page_mt = gfp_migratetype(page_owner->gfp_mask);
445 ret += scnprintf(kbuf + ret, count - ret,
446 "PFN 0x%lx type %s Block %lu type %s Flags %pGp\n",
447 pfn,
448 migratetype_names[page_mt],
449 pfn >> pageblock_order,
450 migratetype_names[pageblock_mt],
451 &page->flags);
452
453 ret += stack_depot_snprint(handle, kbuf + ret, count - ret, 0);
454 if (ret >= count)
455 goto err;
456
457 if (page_owner->last_migrate_reason != -1) {
458 ret += scnprintf(kbuf + ret, count - ret,
459 "Page has been migrated, last migrate reason: %s\n",
460 migrate_reason_names[page_owner->last_migrate_reason]);
461 }
462
463 ret = print_page_owner_memcg(kbuf, count, ret, page);
464
465 ret += snprintf(kbuf + ret, count - ret, "\n");
466 if (ret >= count)
467 goto err;
468
469 if (copy_to_user(buf, kbuf, ret))
470 ret = -EFAULT;
471
472 kfree(kbuf);
473 return ret;
474
475 err:
476 kfree(kbuf);
477 return -ENOMEM;
478 }
479
__dump_page_owner(const struct page * page)480 void __dump_page_owner(const struct page *page)
481 {
482 struct page_ext *page_ext = page_ext_get((void *)page);
483 struct page_owner *page_owner;
484 depot_stack_handle_t handle;
485 gfp_t gfp_mask;
486 int mt;
487
488 if (unlikely(!page_ext)) {
489 pr_alert("There is not page extension available.\n");
490 return;
491 }
492
493 page_owner = get_page_owner(page_ext);
494 gfp_mask = page_owner->gfp_mask;
495 mt = gfp_migratetype(gfp_mask);
496
497 if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) {
498 pr_alert("page_owner info is not present (never set?)\n");
499 page_ext_put(page_ext);
500 return;
501 }
502
503 if (test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
504 pr_alert("page_owner tracks the page as allocated\n");
505 else
506 pr_alert("page_owner tracks the page as freed\n");
507
508 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",
509 page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask,
510 page_owner->pid, page_owner->tgid, page_owner->comm,
511 page_owner->ts_nsec, page_owner->free_ts_nsec);
512
513 handle = READ_ONCE(page_owner->handle);
514 if (!handle)
515 pr_alert("page_owner allocation stack trace missing\n");
516 else
517 stack_depot_print(handle);
518
519 handle = READ_ONCE(page_owner->free_handle);
520 if (!handle) {
521 pr_alert("page_owner free stack trace missing\n");
522 } else {
523 pr_alert("page last free pid %d tgid %d stack trace:\n",
524 page_owner->free_pid, page_owner->free_tgid);
525 stack_depot_print(handle);
526 }
527
528 if (page_owner->last_migrate_reason != -1)
529 pr_alert("page has been migrated, last migrate reason: %s\n",
530 migrate_reason_names[page_owner->last_migrate_reason]);
531 page_ext_put(page_ext);
532 }
533
534 static ssize_t
read_page_owner(struct file * file,char __user * buf,size_t count,loff_t * ppos)535 read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
536 {
537 unsigned long pfn;
538 struct page *page;
539 struct page_ext *page_ext;
540 struct page_owner *page_owner;
541 depot_stack_handle_t handle;
542
543 if (!static_branch_unlikely(&page_owner_inited))
544 return -EINVAL;
545
546 page = NULL;
547 if (*ppos == 0)
548 pfn = min_low_pfn;
549 else
550 pfn = *ppos;
551 /* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */
552 while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0)
553 pfn++;
554
555 /* Find an allocated page */
556 for (; pfn < max_pfn; pfn++) {
557 /*
558 * This temporary page_owner is required so
559 * that we can avoid the context switches while holding
560 * the rcu lock and copying the page owner information to
561 * user through copy_to_user() or GFP_KERNEL allocations.
562 */
563 struct page_owner page_owner_tmp;
564
565 /*
566 * If the new page is in a new MAX_ORDER_NR_PAGES area,
567 * validate the area as existing, skip it if not
568 */
569 if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0 && !pfn_valid(pfn)) {
570 pfn += MAX_ORDER_NR_PAGES - 1;
571 continue;
572 }
573
574 page = pfn_to_page(pfn);
575 if (PageBuddy(page)) {
576 unsigned long freepage_order = buddy_order_unsafe(page);
577
578 if (freepage_order <= MAX_ORDER)
579 pfn += (1UL << freepage_order) - 1;
580 continue;
581 }
582
583 page_ext = page_ext_get(page);
584 if (unlikely(!page_ext))
585 continue;
586
587 /*
588 * Some pages could be missed by concurrent allocation or free,
589 * because we don't hold the zone lock.
590 */
591 if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags))
592 goto ext_put_continue;
593
594 /*
595 * Although we do have the info about past allocation of free
596 * pages, it's not relevant for current memory usage.
597 */
598 if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags))
599 goto ext_put_continue;
600
601 page_owner = get_page_owner(page_ext);
602
603 /*
604 * Don't print "tail" pages of high-order allocations as that
605 * would inflate the stats.
606 */
607 if (!IS_ALIGNED(pfn, 1 << page_owner->order))
608 goto ext_put_continue;
609
610 /*
611 * Access to page_ext->handle isn't synchronous so we should
612 * be careful to access it.
613 */
614 handle = READ_ONCE(page_owner->handle);
615 if (!handle)
616 goto ext_put_continue;
617
618 /* Record the next PFN to read in the file offset */
619 *ppos = pfn + 1;
620
621 page_owner_tmp = *page_owner;
622 page_ext_put(page_ext);
623 return print_page_owner(buf, count, pfn, page,
624 &page_owner_tmp, handle);
625 ext_put_continue:
626 page_ext_put(page_ext);
627 }
628
629 return 0;
630 }
631
lseek_page_owner(struct file * file,loff_t offset,int orig)632 static loff_t lseek_page_owner(struct file *file, loff_t offset, int orig)
633 {
634 switch (orig) {
635 case SEEK_SET:
636 file->f_pos = offset;
637 break;
638 case SEEK_CUR:
639 file->f_pos += offset;
640 break;
641 default:
642 return -EINVAL;
643 }
644 return file->f_pos;
645 }
646
init_pages_in_zone(pg_data_t * pgdat,struct zone * zone)647 static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
648 {
649 unsigned long pfn = zone->zone_start_pfn;
650 unsigned long end_pfn = zone_end_pfn(zone);
651 unsigned long count = 0;
652
653 /*
654 * Walk the zone in pageblock_nr_pages steps. If a page block spans
655 * a zone boundary, it will be double counted between zones. This does
656 * not matter as the mixed block count will still be correct
657 */
658 for (; pfn < end_pfn; ) {
659 unsigned long block_end_pfn;
660
661 if (!pfn_valid(pfn)) {
662 pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
663 continue;
664 }
665
666 block_end_pfn = pageblock_end_pfn(pfn);
667 block_end_pfn = min(block_end_pfn, end_pfn);
668
669 for (; pfn < block_end_pfn; pfn++) {
670 struct page *page = pfn_to_page(pfn);
671 struct page_ext *page_ext;
672
673 if (page_zone(page) != zone)
674 continue;
675
676 /*
677 * To avoid having to grab zone->lock, be a little
678 * careful when reading buddy page order. The only
679 * danger is that we skip too much and potentially miss
680 * some early allocated pages, which is better than
681 * heavy lock contention.
682 */
683 if (PageBuddy(page)) {
684 unsigned long order = buddy_order_unsafe(page);
685
686 if (order > 0 && order <= MAX_ORDER)
687 pfn += (1UL << order) - 1;
688 continue;
689 }
690
691 if (PageReserved(page))
692 continue;
693
694 page_ext = page_ext_get(page);
695 if (unlikely(!page_ext))
696 continue;
697
698 /* Maybe overlapping zone */
699 if (test_bit(PAGE_EXT_OWNER, &page_ext->flags))
700 goto ext_put_continue;
701
702 /* Found early allocated page */
703 __set_page_owner_handle(page_ext, early_handle,
704 0, 0);
705 count++;
706 ext_put_continue:
707 page_ext_put(page_ext);
708 }
709 cond_resched();
710 }
711
712 pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n",
713 pgdat->node_id, zone->name, count);
714 }
715
init_zones_in_node(pg_data_t * pgdat)716 static void init_zones_in_node(pg_data_t *pgdat)
717 {
718 struct zone *zone;
719 struct zone *node_zones = pgdat->node_zones;
720
721 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
722 if (!populated_zone(zone))
723 continue;
724
725 init_pages_in_zone(pgdat, zone);
726 }
727 }
728
init_early_allocated_pages(void)729 static void init_early_allocated_pages(void)
730 {
731 pg_data_t *pgdat;
732
733 for_each_online_pgdat(pgdat)
734 init_zones_in_node(pgdat);
735 }
736
737 static const struct file_operations proc_page_owner_operations = {
738 .read = read_page_owner,
739 .llseek = lseek_page_owner,
740 };
741
pageowner_init(void)742 static int __init pageowner_init(void)
743 {
744 if (!static_branch_unlikely(&page_owner_inited)) {
745 pr_info("page_owner is disabled\n");
746 return 0;
747 }
748
749 debugfs_create_file("page_owner", 0400, NULL, NULL,
750 &proc_page_owner_operations);
751
752 return 0;
753 }
754 late_initcall(pageowner_init)
755