]>
Commit | Line | Data |
---|---|---|
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/bootmem.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 | ||
14 | #include "internal.h" | |
15 | ||
16 | /* | |
17 | * TODO: teach PAGE_OWNER_STACK_DEPTH (__dump_page_owner and save_stack) | |
18 | * to use off stack temporal storage | |
19 | */ | |
20 | #define PAGE_OWNER_STACK_DEPTH (16) | |
21 | ||
22 | struct page_owner { | |
23 | unsigned short order; | |
24 | short last_migrate_reason; | |
25 | gfp_t gfp_mask; | |
26 | depot_stack_handle_t handle; | |
27 | }; | |
28 | ||
29 | static bool page_owner_disabled = true; | |
30 | DEFINE_STATIC_KEY_FALSE(page_owner_inited); | |
31 | ||
32 | static depot_stack_handle_t dummy_handle; | |
33 | static depot_stack_handle_t failure_handle; | |
34 | static depot_stack_handle_t early_handle; | |
35 | ||
36 | static void init_early_allocated_pages(void); | |
37 | ||
38 | static int early_page_owner_param(char *buf) | |
39 | { | |
40 | if (!buf) | |
41 | return -EINVAL; | |
42 | ||
43 | if (strcmp(buf, "on") == 0) | |
44 | page_owner_disabled = false; | |
45 | ||
46 | return 0; | |
47 | } | |
48 | early_param("page_owner", early_page_owner_param); | |
49 | ||
50 | static bool need_page_owner(void) | |
51 | { | |
52 | if (page_owner_disabled) | |
53 | return false; | |
54 | ||
55 | return true; | |
56 | } | |
57 | ||
58 | static __always_inline depot_stack_handle_t create_dummy_stack(void) | |
59 | { | |
60 | unsigned long entries[4]; | |
61 | struct stack_trace dummy; | |
62 | ||
63 | dummy.nr_entries = 0; | |
64 | dummy.max_entries = ARRAY_SIZE(entries); | |
65 | dummy.entries = &entries[0]; | |
66 | dummy.skip = 0; | |
67 | ||
68 | save_stack_trace(&dummy); | |
69 | return depot_save_stack(&dummy, GFP_KERNEL); | |
70 | } | |
71 | ||
72 | static noinline void register_dummy_stack(void) | |
73 | { | |
74 | dummy_handle = create_dummy_stack(); | |
75 | } | |
76 | ||
77 | static noinline void register_failure_stack(void) | |
78 | { | |
79 | failure_handle = create_dummy_stack(); | |
80 | } | |
81 | ||
82 | static noinline void register_early_stack(void) | |
83 | { | |
84 | early_handle = create_dummy_stack(); | |
85 | } | |
86 | ||
87 | static void init_page_owner(void) | |
88 | { | |
89 | if (page_owner_disabled) | |
90 | return; | |
91 | ||
92 | register_dummy_stack(); | |
93 | register_failure_stack(); | |
94 | register_early_stack(); | |
95 | static_branch_enable(&page_owner_inited); | |
96 | init_early_allocated_pages(); | |
97 | } | |
98 | ||
99 | struct page_ext_operations page_owner_ops = { | |
100 | .size = sizeof(struct page_owner), | |
101 | .need = need_page_owner, | |
102 | .init = init_page_owner, | |
103 | }; | |
104 | ||
105 | static inline struct page_owner *get_page_owner(struct page_ext *page_ext) | |
106 | { | |
107 | return (void *)page_ext + page_owner_ops.offset; | |
108 | } | |
109 | ||
110 | void __reset_page_owner(struct page *page, unsigned int order) | |
111 | { | |
112 | int i; | |
113 | struct page_ext *page_ext; | |
114 | ||
115 | for (i = 0; i < (1 << order); i++) { | |
116 | page_ext = lookup_page_ext(page + i); | |
117 | if (unlikely(!page_ext)) | |
118 | continue; | |
119 | __clear_bit(PAGE_EXT_OWNER, &page_ext->flags); | |
120 | } | |
121 | } | |
122 | ||
123 | static inline bool check_recursive_alloc(struct stack_trace *trace, | |
124 | unsigned long ip) | |
125 | { | |
126 | int i; | |
127 | ||
128 | if (!trace->nr_entries) | |
129 | return false; | |
130 | ||
131 | for (i = 0; i < trace->nr_entries; i++) { | |
132 | if (trace->entries[i] == ip) | |
133 | return true; | |
134 | } | |
135 | ||
136 | return false; | |
137 | } | |
138 | ||
139 | static noinline depot_stack_handle_t save_stack(gfp_t flags) | |
140 | { | |
141 | unsigned long entries[PAGE_OWNER_STACK_DEPTH]; | |
142 | struct stack_trace trace = { | |
143 | .nr_entries = 0, | |
144 | .entries = entries, | |
145 | .max_entries = PAGE_OWNER_STACK_DEPTH, | |
146 | .skip = 2 | |
147 | }; | |
148 | depot_stack_handle_t handle; | |
149 | ||
150 | save_stack_trace(&trace); | |
151 | if (trace.nr_entries != 0 && | |
152 | trace.entries[trace.nr_entries-1] == ULONG_MAX) | |
153 | trace.nr_entries--; | |
154 | ||
155 | /* | |
156 | * We need to check recursion here because our request to stackdepot | |
157 | * could trigger memory allocation to save new entry. New memory | |
158 | * allocation would reach here and call depot_save_stack() again | |
159 | * if we don't catch it. There is still not enough memory in stackdepot | |
160 | * so it would try to allocate memory again and loop forever. | |
161 | */ | |
162 | if (check_recursive_alloc(&trace, _RET_IP_)) | |
163 | return dummy_handle; | |
164 | ||
165 | handle = depot_save_stack(&trace, flags); | |
166 | if (!handle) | |
167 | handle = failure_handle; | |
168 | ||
169 | return handle; | |
170 | } | |
171 | ||
172 | static inline void __set_page_owner_handle(struct page_ext *page_ext, | |
173 | depot_stack_handle_t handle, unsigned int order, gfp_t gfp_mask) | |
174 | { | |
175 | struct page_owner *page_owner; | |
176 | ||
177 | page_owner = get_page_owner(page_ext); | |
178 | page_owner->handle = handle; | |
179 | page_owner->order = order; | |
180 | page_owner->gfp_mask = gfp_mask; | |
181 | page_owner->last_migrate_reason = -1; | |
182 | ||
183 | __set_bit(PAGE_EXT_OWNER, &page_ext->flags); | |
184 | } | |
185 | ||
186 | noinline void __set_page_owner(struct page *page, unsigned int order, | |
187 | gfp_t gfp_mask) | |
188 | { | |
189 | struct page_ext *page_ext = lookup_page_ext(page); | |
190 | depot_stack_handle_t handle; | |
191 | ||
192 | if (unlikely(!page_ext)) | |
193 | return; | |
194 | ||
195 | handle = save_stack(gfp_mask); | |
196 | __set_page_owner_handle(page_ext, handle, order, gfp_mask); | |
197 | } | |
198 | ||
199 | void __set_page_owner_migrate_reason(struct page *page, int reason) | |
200 | { | |
201 | struct page_ext *page_ext = lookup_page_ext(page); | |
202 | struct page_owner *page_owner; | |
203 | ||
204 | if (unlikely(!page_ext)) | |
205 | return; | |
206 | ||
207 | page_owner = get_page_owner(page_ext); | |
208 | page_owner->last_migrate_reason = reason; | |
209 | } | |
210 | ||
211 | void __split_page_owner(struct page *page, unsigned int order) | |
212 | { | |
213 | int i; | |
214 | struct page_ext *page_ext = lookup_page_ext(page); | |
215 | struct page_owner *page_owner; | |
216 | ||
217 | if (unlikely(!page_ext)) | |
218 | return; | |
219 | ||
220 | page_owner = get_page_owner(page_ext); | |
221 | page_owner->order = 0; | |
222 | for (i = 1; i < (1 << order); i++) | |
223 | __copy_page_owner(page, page + i); | |
224 | } | |
225 | ||
226 | void __copy_page_owner(struct page *oldpage, struct page *newpage) | |
227 | { | |
228 | struct page_ext *old_ext = lookup_page_ext(oldpage); | |
229 | struct page_ext *new_ext = lookup_page_ext(newpage); | |
230 | struct page_owner *old_page_owner, *new_page_owner; | |
231 | ||
232 | if (unlikely(!old_ext || !new_ext)) | |
233 | return; | |
234 | ||
235 | old_page_owner = get_page_owner(old_ext); | |
236 | new_page_owner = get_page_owner(new_ext); | |
237 | new_page_owner->order = old_page_owner->order; | |
238 | new_page_owner->gfp_mask = old_page_owner->gfp_mask; | |
239 | new_page_owner->last_migrate_reason = | |
240 | old_page_owner->last_migrate_reason; | |
241 | new_page_owner->handle = old_page_owner->handle; | |
242 | ||
243 | /* | |
244 | * We don't clear the bit on the oldpage as it's going to be freed | |
245 | * after migration. Until then, the info can be useful in case of | |
246 | * a bug, and the overal stats will be off a bit only temporarily. | |
247 | * Also, migrate_misplaced_transhuge_page() can still fail the | |
248 | * migration and then we want the oldpage to retain the info. But | |
249 | * in that case we also don't need to explicitly clear the info from | |
250 | * the new page, which will be freed. | |
251 | */ | |
252 | __set_bit(PAGE_EXT_OWNER, &new_ext->flags); | |
253 | } | |
254 | ||
255 | void pagetypeinfo_showmixedcount_print(struct seq_file *m, | |
256 | pg_data_t *pgdat, struct zone *zone) | |
257 | { | |
258 | struct page *page; | |
259 | struct page_ext *page_ext; | |
260 | struct page_owner *page_owner; | |
261 | unsigned long pfn = zone->zone_start_pfn, block_end_pfn; | |
262 | unsigned long end_pfn = pfn + zone->spanned_pages; | |
263 | unsigned long count[MIGRATE_TYPES] = { 0, }; | |
264 | int pageblock_mt, page_mt; | |
265 | int i; | |
266 | ||
267 | /* Scan block by block. First and last block may be incomplete */ | |
268 | pfn = zone->zone_start_pfn; | |
269 | ||
270 | /* | |
271 | * Walk the zone in pageblock_nr_pages steps. If a page block spans | |
272 | * a zone boundary, it will be double counted between zones. This does | |
273 | * not matter as the mixed block count will still be correct | |
274 | */ | |
275 | for (; pfn < end_pfn; ) { | |
276 | if (!pfn_valid(pfn)) { | |
277 | pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); | |
278 | continue; | |
279 | } | |
280 | ||
281 | block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); | |
282 | block_end_pfn = min(block_end_pfn, end_pfn); | |
283 | ||
284 | page = pfn_to_page(pfn); | |
285 | pageblock_mt = get_pageblock_migratetype(page); | |
286 | ||
287 | for (; pfn < block_end_pfn; pfn++) { | |
288 | if (!pfn_valid_within(pfn)) | |
289 | continue; | |
290 | ||
291 | page = pfn_to_page(pfn); | |
292 | ||
293 | if (page_zone(page) != zone) | |
294 | continue; | |
295 | ||
296 | if (PageBuddy(page)) { | |
297 | unsigned long freepage_order; | |
298 | ||
299 | freepage_order = page_order_unsafe(page); | |
300 | if (freepage_order < MAX_ORDER) | |
301 | pfn += (1UL << freepage_order) - 1; | |
302 | continue; | |
303 | } | |
304 | ||
305 | if (PageReserved(page)) | |
306 | continue; | |
307 | ||
308 | page_ext = lookup_page_ext(page); | |
309 | if (unlikely(!page_ext)) | |
310 | continue; | |
311 | ||
312 | if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) | |
313 | continue; | |
314 | ||
315 | page_owner = get_page_owner(page_ext); | |
316 | page_mt = gfpflags_to_migratetype( | |
317 | page_owner->gfp_mask); | |
318 | if (pageblock_mt != page_mt) { | |
319 | if (is_migrate_cma(pageblock_mt)) | |
320 | count[MIGRATE_MOVABLE]++; | |
321 | else | |
322 | count[pageblock_mt]++; | |
323 | ||
324 | pfn = block_end_pfn; | |
325 | break; | |
326 | } | |
327 | pfn += (1UL << page_owner->order) - 1; | |
328 | } | |
329 | } | |
330 | ||
331 | /* Print counts */ | |
332 | seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); | |
333 | for (i = 0; i < MIGRATE_TYPES; i++) | |
334 | seq_printf(m, "%12lu ", count[i]); | |
335 | seq_putc(m, '\n'); | |
336 | } | |
337 | ||
338 | static ssize_t | |
339 | print_page_owner(char __user *buf, size_t count, unsigned long pfn, | |
340 | struct page *page, struct page_owner *page_owner, | |
341 | depot_stack_handle_t handle) | |
342 | { | |
343 | int ret; | |
344 | int pageblock_mt, page_mt; | |
345 | char *kbuf; | |
346 | unsigned long entries[PAGE_OWNER_STACK_DEPTH]; | |
347 | struct stack_trace trace = { | |
348 | .nr_entries = 0, | |
349 | .entries = entries, | |
350 | .max_entries = PAGE_OWNER_STACK_DEPTH, | |
351 | .skip = 0 | |
352 | }; | |
353 | ||
354 | kbuf = kmalloc(count, GFP_KERNEL); | |
355 | if (!kbuf) | |
356 | return -ENOMEM; | |
357 | ||
358 | ret = snprintf(kbuf, count, | |
359 | "Page allocated via order %u, mask %#x(%pGg)\n", | |
360 | page_owner->order, page_owner->gfp_mask, | |
361 | &page_owner->gfp_mask); | |
362 | ||
363 | if (ret >= count) | |
364 | goto err; | |
365 | ||
366 | /* Print information relevant to grouping pages by mobility */ | |
367 | pageblock_mt = get_pageblock_migratetype(page); | |
368 | page_mt = gfpflags_to_migratetype(page_owner->gfp_mask); | |
369 | ret += snprintf(kbuf + ret, count - ret, | |
370 | "PFN %lu type %s Block %lu type %s Flags %#lx(%pGp)\n", | |
371 | pfn, | |
372 | migratetype_names[page_mt], | |
373 | pfn >> pageblock_order, | |
374 | migratetype_names[pageblock_mt], | |
375 | page->flags, &page->flags); | |
376 | ||
377 | if (ret >= count) | |
378 | goto err; | |
379 | ||
380 | depot_fetch_stack(handle, &trace); | |
381 | ret += snprint_stack_trace(kbuf + ret, count - ret, &trace, 0); | |
382 | if (ret >= count) | |
383 | goto err; | |
384 | ||
385 | if (page_owner->last_migrate_reason != -1) { | |
386 | ret += snprintf(kbuf + ret, count - ret, | |
387 | "Page has been migrated, last migrate reason: %s\n", | |
388 | migrate_reason_names[page_owner->last_migrate_reason]); | |
389 | if (ret >= count) | |
390 | goto err; | |
391 | } | |
392 | ||
393 | ret += snprintf(kbuf + ret, count - ret, "\n"); | |
394 | if (ret >= count) | |
395 | goto err; | |
396 | ||
397 | if (copy_to_user(buf, kbuf, ret)) | |
398 | ret = -EFAULT; | |
399 | ||
400 | kfree(kbuf); | |
401 | return ret; | |
402 | ||
403 | err: | |
404 | kfree(kbuf); | |
405 | return -ENOMEM; | |
406 | } | |
407 | ||
408 | void __dump_page_owner(struct page *page) | |
409 | { | |
410 | struct page_ext *page_ext = lookup_page_ext(page); | |
411 | struct page_owner *page_owner; | |
412 | unsigned long entries[PAGE_OWNER_STACK_DEPTH]; | |
413 | struct stack_trace trace = { | |
414 | .nr_entries = 0, | |
415 | .entries = entries, | |
416 | .max_entries = PAGE_OWNER_STACK_DEPTH, | |
417 | .skip = 0 | |
418 | }; | |
419 | depot_stack_handle_t handle; | |
420 | gfp_t gfp_mask; | |
421 | int mt; | |
422 | ||
423 | if (unlikely(!page_ext)) { | |
424 | pr_alert("There is not page extension available.\n"); | |
425 | return; | |
426 | } | |
427 | ||
428 | page_owner = get_page_owner(page_ext); | |
429 | gfp_mask = page_owner->gfp_mask; | |
430 | mt = gfpflags_to_migratetype(gfp_mask); | |
431 | ||
432 | if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) { | |
433 | pr_alert("page_owner info is not active (free page?)\n"); | |
434 | return; | |
435 | } | |
436 | ||
437 | handle = READ_ONCE(page_owner->handle); | |
438 | if (!handle) { | |
439 | pr_alert("page_owner info is not active (free page?)\n"); | |
440 | return; | |
441 | } | |
442 | ||
443 | depot_fetch_stack(handle, &trace); | |
444 | pr_alert("page allocated via order %u, migratetype %s, gfp_mask %#x(%pGg)\n", | |
445 | page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask); | |
446 | print_stack_trace(&trace, 0); | |
447 | ||
448 | if (page_owner->last_migrate_reason != -1) | |
449 | pr_alert("page has been migrated, last migrate reason: %s\n", | |
450 | migrate_reason_names[page_owner->last_migrate_reason]); | |
451 | } | |
452 | ||
453 | static ssize_t | |
454 | read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
455 | { | |
456 | unsigned long pfn; | |
457 | struct page *page; | |
458 | struct page_ext *page_ext; | |
459 | struct page_owner *page_owner; | |
460 | depot_stack_handle_t handle; | |
461 | ||
462 | if (!static_branch_unlikely(&page_owner_inited)) | |
463 | return -EINVAL; | |
464 | ||
465 | page = NULL; | |
466 | pfn = min_low_pfn + *ppos; | |
467 | ||
468 | /* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */ | |
469 | while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) | |
470 | pfn++; | |
471 | ||
472 | drain_all_pages(NULL); | |
473 | ||
474 | /* Find an allocated page */ | |
475 | for (; pfn < max_pfn; pfn++) { | |
476 | /* | |
477 | * If the new page is in a new MAX_ORDER_NR_PAGES area, | |
478 | * validate the area as existing, skip it if not | |
479 | */ | |
480 | if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0 && !pfn_valid(pfn)) { | |
481 | pfn += MAX_ORDER_NR_PAGES - 1; | |
482 | continue; | |
483 | } | |
484 | ||
485 | /* Check for holes within a MAX_ORDER area */ | |
486 | if (!pfn_valid_within(pfn)) | |
487 | continue; | |
488 | ||
489 | page = pfn_to_page(pfn); | |
490 | if (PageBuddy(page)) { | |
491 | unsigned long freepage_order = page_order_unsafe(page); | |
492 | ||
493 | if (freepage_order < MAX_ORDER) | |
494 | pfn += (1UL << freepage_order) - 1; | |
495 | continue; | |
496 | } | |
497 | ||
498 | page_ext = lookup_page_ext(page); | |
499 | if (unlikely(!page_ext)) | |
500 | continue; | |
501 | ||
502 | /* | |
503 | * Some pages could be missed by concurrent allocation or free, | |
504 | * because we don't hold the zone lock. | |
505 | */ | |
506 | if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) | |
507 | continue; | |
508 | ||
509 | page_owner = get_page_owner(page_ext); | |
510 | ||
511 | /* | |
512 | * Access to page_ext->handle isn't synchronous so we should | |
513 | * be careful to access it. | |
514 | */ | |
515 | handle = READ_ONCE(page_owner->handle); | |
516 | if (!handle) | |
517 | continue; | |
518 | ||
519 | /* Record the next PFN to read in the file offset */ | |
520 | *ppos = (pfn - min_low_pfn) + 1; | |
521 | ||
522 | return print_page_owner(buf, count, pfn, page, | |
523 | page_owner, handle); | |
524 | } | |
525 | ||
526 | return 0; | |
527 | } | |
528 | ||
529 | static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone) | |
530 | { | |
531 | struct page *page; | |
532 | struct page_ext *page_ext; | |
533 | unsigned long pfn = zone->zone_start_pfn, block_end_pfn; | |
534 | unsigned long end_pfn = pfn + zone->spanned_pages; | |
535 | unsigned long count = 0; | |
536 | ||
537 | /* Scan block by block. First and last block may be incomplete */ | |
538 | pfn = zone->zone_start_pfn; | |
539 | ||
540 | /* | |
541 | * Walk the zone in pageblock_nr_pages steps. If a page block spans | |
542 | * a zone boundary, it will be double counted between zones. This does | |
543 | * not matter as the mixed block count will still be correct | |
544 | */ | |
545 | for (; pfn < end_pfn; ) { | |
546 | if (!pfn_valid(pfn)) { | |
547 | pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); | |
548 | continue; | |
549 | } | |
550 | ||
551 | block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); | |
552 | block_end_pfn = min(block_end_pfn, end_pfn); | |
553 | ||
554 | page = pfn_to_page(pfn); | |
555 | ||
556 | for (; pfn < block_end_pfn; pfn++) { | |
557 | if (!pfn_valid_within(pfn)) | |
558 | continue; | |
559 | ||
560 | page = pfn_to_page(pfn); | |
561 | ||
562 | if (page_zone(page) != zone) | |
563 | continue; | |
564 | ||
565 | /* | |
566 | * To avoid having to grab zone->lock, be a little | |
567 | * careful when reading buddy page order. The only | |
568 | * danger is that we skip too much and potentially miss | |
569 | * some early allocated pages, which is better than | |
570 | * heavy lock contention. | |
571 | */ | |
572 | if (PageBuddy(page)) { | |
573 | unsigned long order = page_order_unsafe(page); | |
574 | ||
575 | if (order > 0 && order < MAX_ORDER) | |
576 | pfn += (1UL << order) - 1; | |
577 | continue; | |
578 | } | |
579 | ||
580 | if (PageReserved(page)) | |
581 | continue; | |
582 | ||
583 | page_ext = lookup_page_ext(page); | |
584 | if (unlikely(!page_ext)) | |
585 | continue; | |
586 | ||
587 | /* Maybe overlapping zone */ | |
588 | if (test_bit(PAGE_EXT_OWNER, &page_ext->flags)) | |
589 | continue; | |
590 | ||
591 | /* Found early allocated page */ | |
592 | __set_page_owner_handle(page_ext, early_handle, 0, 0); | |
593 | count++; | |
594 | } | |
595 | cond_resched(); | |
596 | } | |
597 | ||
598 | pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n", | |
599 | pgdat->node_id, zone->name, count); | |
600 | } | |
601 | ||
602 | static void init_zones_in_node(pg_data_t *pgdat) | |
603 | { | |
604 | struct zone *zone; | |
605 | struct zone *node_zones = pgdat->node_zones; | |
606 | ||
607 | for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { | |
608 | if (!populated_zone(zone)) | |
609 | continue; | |
610 | ||
611 | init_pages_in_zone(pgdat, zone); | |
612 | } | |
613 | } | |
614 | ||
615 | static void init_early_allocated_pages(void) | |
616 | { | |
617 | pg_data_t *pgdat; | |
618 | ||
619 | for_each_online_pgdat(pgdat) | |
620 | init_zones_in_node(pgdat); | |
621 | } | |
622 | ||
623 | static const struct file_operations proc_page_owner_operations = { | |
624 | .read = read_page_owner, | |
625 | }; | |
626 | ||
627 | static int __init pageowner_init(void) | |
628 | { | |
629 | struct dentry *dentry; | |
630 | ||
631 | if (!static_branch_unlikely(&page_owner_inited)) { | |
632 | pr_info("page_owner is disabled\n"); | |
633 | return 0; | |
634 | } | |
635 | ||
636 | dentry = debugfs_create_file("page_owner", S_IRUSR, NULL, | |
637 | NULL, &proc_page_owner_operations); | |
638 | if (IS_ERR(dentry)) | |
639 | return PTR_ERR(dentry); | |
640 | ||
641 | return 0; | |
642 | } | |
643 | late_initcall(pageowner_init) |