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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
48c96a36 JK |
2 | #include <linux/debugfs.h> |
3 | #include <linux/mm.h> | |
4 | #include <linux/slab.h> | |
5 | #include <linux/uaccess.h> | |
57c8a661 | 6 | #include <linux/memblock.h> |
48c96a36 JK |
7 | #include <linux/stacktrace.h> |
8 | #include <linux/page_owner.h> | |
7dd80b8a | 9 | #include <linux/jump_label.h> |
7cd12b4a | 10 | #include <linux/migrate.h> |
f2ca0b55 | 11 | #include <linux/stackdepot.h> |
e2f612e6 | 12 | #include <linux/seq_file.h> |
9cc7e96a | 13 | #include <linux/sched/clock.h> |
f2ca0b55 | 14 | |
48c96a36 JK |
15 | #include "internal.h" |
16 | ||
f2ca0b55 JK |
17 | /* |
18 | * TODO: teach PAGE_OWNER_STACK_DEPTH (__dump_page_owner and save_stack) | |
19 | * to use off stack temporal storage | |
20 | */ | |
21 | #define PAGE_OWNER_STACK_DEPTH (16) | |
22 | ||
9300d8df | 23 | struct page_owner { |
6b4c54e3 AM |
24 | unsigned short order; |
25 | short last_migrate_reason; | |
9300d8df | 26 | gfp_t gfp_mask; |
9300d8df | 27 | depot_stack_handle_t handle; |
8974558f | 28 | depot_stack_handle_t free_handle; |
9cc7e96a | 29 | u64 ts_nsec; |
866b4852 | 30 | u64 free_ts_nsec; |
9cc7e96a | 31 | pid_t pid; |
9300d8df JK |
32 | }; |
33 | ||
0fe9a448 | 34 | static bool page_owner_enabled = false; |
7dd80b8a | 35 | DEFINE_STATIC_KEY_FALSE(page_owner_inited); |
48c96a36 | 36 | |
f2ca0b55 JK |
37 | static depot_stack_handle_t dummy_handle; |
38 | static depot_stack_handle_t failure_handle; | |
dab4ead1 | 39 | static depot_stack_handle_t early_handle; |
f2ca0b55 | 40 | |
61cf5feb JK |
41 | static void init_early_allocated_pages(void); |
42 | ||
1173194e | 43 | static int __init early_page_owner_param(char *buf) |
48c96a36 | 44 | { |
608b5d66 | 45 | return kstrtobool(buf, &page_owner_enabled); |
48c96a36 JK |
46 | } |
47 | early_param("page_owner", early_page_owner_param); | |
48 | ||
49 | static bool need_page_owner(void) | |
50 | { | |
0fe9a448 | 51 | return page_owner_enabled; |
48c96a36 JK |
52 | } |
53 | ||
dab4ead1 | 54 | static __always_inline depot_stack_handle_t create_dummy_stack(void) |
f2ca0b55 JK |
55 | { |
56 | unsigned long entries[4]; | |
af52bf6b | 57 | unsigned int nr_entries; |
f2ca0b55 | 58 | |
af52bf6b TG |
59 | nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); |
60 | return stack_depot_save(entries, nr_entries, GFP_KERNEL); | |
f2ca0b55 JK |
61 | } |
62 | ||
dab4ead1 | 63 | static noinline void register_dummy_stack(void) |
f2ca0b55 | 64 | { |
dab4ead1 VB |
65 | dummy_handle = create_dummy_stack(); |
66 | } | |
f2ca0b55 | 67 | |
dab4ead1 VB |
68 | static noinline void register_failure_stack(void) |
69 | { | |
70 | failure_handle = create_dummy_stack(); | |
71 | } | |
f2ca0b55 | 72 | |
dab4ead1 VB |
73 | static noinline void register_early_stack(void) |
74 | { | |
75 | early_handle = create_dummy_stack(); | |
f2ca0b55 JK |
76 | } |
77 | ||
48c96a36 JK |
78 | static void init_page_owner(void) |
79 | { | |
0fe9a448 | 80 | if (!page_owner_enabled) |
48c96a36 JK |
81 | return; |
82 | ||
f2ca0b55 JK |
83 | register_dummy_stack(); |
84 | register_failure_stack(); | |
dab4ead1 | 85 | register_early_stack(); |
7dd80b8a | 86 | static_branch_enable(&page_owner_inited); |
61cf5feb | 87 | init_early_allocated_pages(); |
48c96a36 JK |
88 | } |
89 | ||
90 | struct page_ext_operations page_owner_ops = { | |
9300d8df | 91 | .size = sizeof(struct page_owner), |
48c96a36 JK |
92 | .need = need_page_owner, |
93 | .init = init_page_owner, | |
94 | }; | |
95 | ||
9300d8df JK |
96 | static inline struct page_owner *get_page_owner(struct page_ext *page_ext) |
97 | { | |
98 | return (void *)page_ext + page_owner_ops.offset; | |
99 | } | |
100 | ||
f2ca0b55 JK |
101 | static noinline depot_stack_handle_t save_stack(gfp_t flags) |
102 | { | |
103 | unsigned long entries[PAGE_OWNER_STACK_DEPTH]; | |
f2ca0b55 | 104 | depot_stack_handle_t handle; |
af52bf6b | 105 | unsigned int nr_entries; |
f2ca0b55 | 106 | |
f2ca0b55 | 107 | /* |
8e9b16c4 ST |
108 | * Avoid recursion. |
109 | * | |
110 | * Sometimes page metadata allocation tracking requires more | |
111 | * memory to be allocated: | |
112 | * - when new stack trace is saved to stack depot | |
113 | * - when backtrace itself is calculated (ia64) | |
f2ca0b55 | 114 | */ |
8e9b16c4 | 115 | if (current->in_page_owner) |
f2ca0b55 | 116 | return dummy_handle; |
8e9b16c4 | 117 | current->in_page_owner = 1; |
f2ca0b55 | 118 | |
8e9b16c4 | 119 | nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2); |
af52bf6b | 120 | handle = stack_depot_save(entries, nr_entries, flags); |
f2ca0b55 JK |
121 | if (!handle) |
122 | handle = failure_handle; | |
123 | ||
8e9b16c4 | 124 | current->in_page_owner = 0; |
f2ca0b55 JK |
125 | return handle; |
126 | } | |
127 | ||
8974558f VB |
128 | void __reset_page_owner(struct page *page, unsigned int order) |
129 | { | |
130 | int i; | |
131 | struct page_ext *page_ext; | |
fab765c2 | 132 | depot_stack_handle_t handle; |
8974558f | 133 | struct page_owner *page_owner; |
866b4852 | 134 | u64 free_ts_nsec = local_clock(); |
8974558f | 135 | |
5556cfe8 VB |
136 | page_ext = lookup_page_ext(page); |
137 | if (unlikely(!page_ext)) | |
138 | return; | |
fab765c2 ST |
139 | |
140 | handle = save_stack(GFP_NOWAIT | __GFP_NOWARN); | |
8974558f | 141 | for (i = 0; i < (1 << order); i++) { |
fdf3bf80 | 142 | __clear_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); |
0fe9a448 VB |
143 | page_owner = get_page_owner(page_ext); |
144 | page_owner->free_handle = handle; | |
866b4852 | 145 | page_owner->free_ts_nsec = free_ts_nsec; |
5556cfe8 | 146 | page_ext = page_ext_next(page_ext); |
8974558f VB |
147 | } |
148 | } | |
149 | ||
64ea78d2 | 150 | static inline void __set_page_owner_handle(struct page_ext *page_ext, |
151 | depot_stack_handle_t handle, | |
152 | unsigned int order, gfp_t gfp_mask) | |
f2ca0b55 | 153 | { |
9300d8df | 154 | struct page_owner *page_owner; |
7e2f2a0c | 155 | int i; |
48c96a36 | 156 | |
7e2f2a0c VB |
157 | for (i = 0; i < (1 << order); i++) { |
158 | page_owner = get_page_owner(page_ext); | |
159 | page_owner->handle = handle; | |
160 | page_owner->order = order; | |
161 | page_owner->gfp_mask = gfp_mask; | |
162 | page_owner->last_migrate_reason = -1; | |
9cc7e96a LM |
163 | page_owner->pid = current->pid; |
164 | page_owner->ts_nsec = local_clock(); | |
7e2f2a0c | 165 | __set_bit(PAGE_EXT_OWNER, &page_ext->flags); |
fdf3bf80 | 166 | __set_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); |
48c96a36 | 167 | |
5556cfe8 | 168 | page_ext = page_ext_next(page_ext); |
7e2f2a0c | 169 | } |
48c96a36 JK |
170 | } |
171 | ||
dab4ead1 VB |
172 | noinline void __set_page_owner(struct page *page, unsigned int order, |
173 | gfp_t gfp_mask) | |
174 | { | |
175 | struct page_ext *page_ext = lookup_page_ext(page); | |
176 | depot_stack_handle_t handle; | |
177 | ||
178 | if (unlikely(!page_ext)) | |
179 | return; | |
180 | ||
181 | handle = save_stack(gfp_mask); | |
64ea78d2 | 182 | __set_page_owner_handle(page_ext, handle, order, gfp_mask); |
dab4ead1 VB |
183 | } |
184 | ||
7cd12b4a VB |
185 | void __set_page_owner_migrate_reason(struct page *page, int reason) |
186 | { | |
187 | struct page_ext *page_ext = lookup_page_ext(page); | |
9300d8df JK |
188 | struct page_owner *page_owner; |
189 | ||
f86e4271 YS |
190 | if (unlikely(!page_ext)) |
191 | return; | |
7cd12b4a | 192 | |
9300d8df JK |
193 | page_owner = get_page_owner(page_ext); |
194 | page_owner->last_migrate_reason = reason; | |
7cd12b4a VB |
195 | } |
196 | ||
8fb156c9 | 197 | void __split_page_owner(struct page *page, unsigned int nr) |
e2cfc911 | 198 | { |
a9627bc5 | 199 | int i; |
e2cfc911 | 200 | struct page_ext *page_ext = lookup_page_ext(page); |
9300d8df | 201 | struct page_owner *page_owner; |
a9627bc5 | 202 | |
f86e4271 | 203 | if (unlikely(!page_ext)) |
a9627bc5 | 204 | return; |
e2cfc911 | 205 | |
8fb156c9 | 206 | for (i = 0; i < nr; i++) { |
7e2f2a0c VB |
207 | page_owner = get_page_owner(page_ext); |
208 | page_owner->order = 0; | |
5556cfe8 | 209 | page_ext = page_ext_next(page_ext); |
7e2f2a0c | 210 | } |
e2cfc911 JK |
211 | } |
212 | ||
d435edca VB |
213 | void __copy_page_owner(struct page *oldpage, struct page *newpage) |
214 | { | |
215 | struct page_ext *old_ext = lookup_page_ext(oldpage); | |
216 | struct page_ext *new_ext = lookup_page_ext(newpage); | |
9300d8df | 217 | struct page_owner *old_page_owner, *new_page_owner; |
d435edca | 218 | |
f86e4271 YS |
219 | if (unlikely(!old_ext || !new_ext)) |
220 | return; | |
221 | ||
9300d8df JK |
222 | old_page_owner = get_page_owner(old_ext); |
223 | new_page_owner = get_page_owner(new_ext); | |
224 | new_page_owner->order = old_page_owner->order; | |
225 | new_page_owner->gfp_mask = old_page_owner->gfp_mask; | |
226 | new_page_owner->last_migrate_reason = | |
227 | old_page_owner->last_migrate_reason; | |
228 | new_page_owner->handle = old_page_owner->handle; | |
9cc7e96a LM |
229 | new_page_owner->pid = old_page_owner->pid; |
230 | new_page_owner->ts_nsec = old_page_owner->ts_nsec; | |
866b4852 | 231 | new_page_owner->free_ts_nsec = old_page_owner->ts_nsec; |
d435edca VB |
232 | |
233 | /* | |
234 | * We don't clear the bit on the oldpage as it's going to be freed | |
235 | * after migration. Until then, the info can be useful in case of | |
f0953a1b | 236 | * a bug, and the overall stats will be off a bit only temporarily. |
d435edca VB |
237 | * Also, migrate_misplaced_transhuge_page() can still fail the |
238 | * migration and then we want the oldpage to retain the info. But | |
239 | * in that case we also don't need to explicitly clear the info from | |
240 | * the new page, which will be freed. | |
241 | */ | |
242 | __set_bit(PAGE_EXT_OWNER, &new_ext->flags); | |
fdf3bf80 | 243 | __set_bit(PAGE_EXT_OWNER_ALLOCATED, &new_ext->flags); |
d435edca VB |
244 | } |
245 | ||
e2f612e6 JK |
246 | void pagetypeinfo_showmixedcount_print(struct seq_file *m, |
247 | pg_data_t *pgdat, struct zone *zone) | |
248 | { | |
249 | struct page *page; | |
250 | struct page_ext *page_ext; | |
9300d8df | 251 | struct page_owner *page_owner; |
1d2cae8e ML |
252 | unsigned long pfn, block_end_pfn; |
253 | unsigned long end_pfn = zone_end_pfn(zone); | |
e2f612e6 JK |
254 | unsigned long count[MIGRATE_TYPES] = { 0, }; |
255 | int pageblock_mt, page_mt; | |
256 | int i; | |
257 | ||
258 | /* Scan block by block. First and last block may be incomplete */ | |
259 | pfn = zone->zone_start_pfn; | |
260 | ||
261 | /* | |
262 | * Walk the zone in pageblock_nr_pages steps. If a page block spans | |
263 | * a zone boundary, it will be double counted between zones. This does | |
264 | * not matter as the mixed block count will still be correct | |
265 | */ | |
266 | for (; pfn < end_pfn; ) { | |
a26ee565 QC |
267 | page = pfn_to_online_page(pfn); |
268 | if (!page) { | |
e2f612e6 JK |
269 | pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); |
270 | continue; | |
271 | } | |
272 | ||
273 | block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); | |
274 | block_end_pfn = min(block_end_pfn, end_pfn); | |
275 | ||
e2f612e6 JK |
276 | pageblock_mt = get_pageblock_migratetype(page); |
277 | ||
278 | for (; pfn < block_end_pfn; pfn++) { | |
a26ee565 | 279 | /* The pageblock is online, no need to recheck. */ |
e2f612e6 JK |
280 | page = pfn_to_page(pfn); |
281 | ||
282 | if (page_zone(page) != zone) | |
283 | continue; | |
284 | ||
285 | if (PageBuddy(page)) { | |
727c080f VM |
286 | unsigned long freepage_order; |
287 | ||
ab130f91 | 288 | freepage_order = buddy_order_unsafe(page); |
727c080f VM |
289 | if (freepage_order < MAX_ORDER) |
290 | pfn += (1UL << freepage_order) - 1; | |
e2f612e6 JK |
291 | continue; |
292 | } | |
293 | ||
294 | if (PageReserved(page)) | |
295 | continue; | |
296 | ||
297 | page_ext = lookup_page_ext(page); | |
298 | if (unlikely(!page_ext)) | |
299 | continue; | |
300 | ||
fdf3bf80 | 301 | if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags)) |
e2f612e6 JK |
302 | continue; |
303 | ||
9300d8df | 304 | page_owner = get_page_owner(page_ext); |
01c0bfe0 | 305 | page_mt = gfp_migratetype(page_owner->gfp_mask); |
e2f612e6 JK |
306 | if (pageblock_mt != page_mt) { |
307 | if (is_migrate_cma(pageblock_mt)) | |
308 | count[MIGRATE_MOVABLE]++; | |
309 | else | |
310 | count[pageblock_mt]++; | |
311 | ||
312 | pfn = block_end_pfn; | |
313 | break; | |
314 | } | |
9300d8df | 315 | pfn += (1UL << page_owner->order) - 1; |
e2f612e6 JK |
316 | } |
317 | } | |
318 | ||
319 | /* Print counts */ | |
320 | seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); | |
321 | for (i = 0; i < MIGRATE_TYPES; i++) | |
322 | seq_printf(m, "%12lu ", count[i]); | |
323 | seq_putc(m, '\n'); | |
324 | } | |
325 | ||
48c96a36 JK |
326 | static ssize_t |
327 | print_page_owner(char __user *buf, size_t count, unsigned long pfn, | |
9300d8df | 328 | struct page *page, struct page_owner *page_owner, |
f2ca0b55 | 329 | depot_stack_handle_t handle) |
48c96a36 | 330 | { |
af52bf6b TG |
331 | int ret, pageblock_mt, page_mt; |
332 | unsigned long *entries; | |
333 | unsigned int nr_entries; | |
48c96a36 JK |
334 | char *kbuf; |
335 | ||
c8f61cfc | 336 | count = min_t(size_t, count, PAGE_SIZE); |
48c96a36 JK |
337 | kbuf = kmalloc(count, GFP_KERNEL); |
338 | if (!kbuf) | |
339 | return -ENOMEM; | |
340 | ||
341 | ret = snprintf(kbuf, count, | |
866b4852 | 342 | "Page allocated via order %u, mask %#x(%pGg), pid %d, ts %llu ns, free_ts %llu ns\n", |
9300d8df | 343 | page_owner->order, page_owner->gfp_mask, |
9cc7e96a | 344 | &page_owner->gfp_mask, page_owner->pid, |
866b4852 | 345 | page_owner->ts_nsec, page_owner->free_ts_nsec); |
48c96a36 JK |
346 | |
347 | if (ret >= count) | |
348 | goto err; | |
349 | ||
350 | /* Print information relevant to grouping pages by mobility */ | |
0b423ca2 | 351 | pageblock_mt = get_pageblock_migratetype(page); |
01c0bfe0 | 352 | page_mt = gfp_migratetype(page_owner->gfp_mask); |
48c96a36 | 353 | ret += snprintf(kbuf + ret, count - ret, |
60f30350 | 354 | "PFN %lu type %s Block %lu type %s Flags %#lx(%pGp)\n", |
48c96a36 | 355 | pfn, |
60f30350 | 356 | migratetype_names[page_mt], |
48c96a36 | 357 | pfn >> pageblock_order, |
60f30350 VB |
358 | migratetype_names[pageblock_mt], |
359 | page->flags, &page->flags); | |
48c96a36 JK |
360 | |
361 | if (ret >= count) | |
362 | goto err; | |
363 | ||
af52bf6b TG |
364 | nr_entries = stack_depot_fetch(handle, &entries); |
365 | ret += stack_trace_snprint(kbuf + ret, count - ret, entries, nr_entries, 0); | |
48c96a36 JK |
366 | if (ret >= count) |
367 | goto err; | |
368 | ||
9300d8df | 369 | if (page_owner->last_migrate_reason != -1) { |
7cd12b4a VB |
370 | ret += snprintf(kbuf + ret, count - ret, |
371 | "Page has been migrated, last migrate reason: %s\n", | |
9300d8df | 372 | migrate_reason_names[page_owner->last_migrate_reason]); |
7cd12b4a VB |
373 | if (ret >= count) |
374 | goto err; | |
375 | } | |
376 | ||
48c96a36 JK |
377 | ret += snprintf(kbuf + ret, count - ret, "\n"); |
378 | if (ret >= count) | |
379 | goto err; | |
380 | ||
381 | if (copy_to_user(buf, kbuf, ret)) | |
382 | ret = -EFAULT; | |
383 | ||
384 | kfree(kbuf); | |
385 | return ret; | |
386 | ||
387 | err: | |
388 | kfree(kbuf); | |
389 | return -ENOMEM; | |
390 | } | |
391 | ||
8bf6f451 | 392 | void __dump_page_owner(const struct page *page) |
4e462112 VB |
393 | { |
394 | struct page_ext *page_ext = lookup_page_ext(page); | |
9300d8df | 395 | struct page_owner *page_owner; |
f2ca0b55 | 396 | depot_stack_handle_t handle; |
af52bf6b TG |
397 | unsigned long *entries; |
398 | unsigned int nr_entries; | |
8285027f SM |
399 | gfp_t gfp_mask; |
400 | int mt; | |
4e462112 | 401 | |
f86e4271 YS |
402 | if (unlikely(!page_ext)) { |
403 | pr_alert("There is not page extension available.\n"); | |
404 | return; | |
405 | } | |
9300d8df JK |
406 | |
407 | page_owner = get_page_owner(page_ext); | |
408 | gfp_mask = page_owner->gfp_mask; | |
01c0bfe0 | 409 | mt = gfp_migratetype(gfp_mask); |
f86e4271 | 410 | |
4e462112 | 411 | if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) { |
37389167 | 412 | pr_alert("page_owner info is not present (never set?)\n"); |
4e462112 VB |
413 | return; |
414 | } | |
415 | ||
fdf3bf80 | 416 | if (test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags)) |
37389167 VB |
417 | pr_alert("page_owner tracks the page as allocated\n"); |
418 | else | |
419 | pr_alert("page_owner tracks the page as freed\n"); | |
420 | ||
866b4852 | 421 | pr_alert("page last allocated via order %u, migratetype %s, gfp_mask %#x(%pGg), pid %d, ts %llu, free_ts %llu\n", |
9cc7e96a | 422 | page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask, |
866b4852 | 423 | page_owner->pid, page_owner->ts_nsec, page_owner->free_ts_nsec); |
37389167 | 424 | |
9300d8df | 425 | handle = READ_ONCE(page_owner->handle); |
f2ca0b55 | 426 | if (!handle) { |
37389167 VB |
427 | pr_alert("page_owner allocation stack trace missing\n"); |
428 | } else { | |
429 | nr_entries = stack_depot_fetch(handle, &entries); | |
430 | stack_trace_print(entries, nr_entries, 0); | |
f2ca0b55 JK |
431 | } |
432 | ||
8974558f VB |
433 | handle = READ_ONCE(page_owner->free_handle); |
434 | if (!handle) { | |
435 | pr_alert("page_owner free stack trace missing\n"); | |
436 | } else { | |
437 | nr_entries = stack_depot_fetch(handle, &entries); | |
438 | pr_alert("page last free stack trace:\n"); | |
439 | stack_trace_print(entries, nr_entries, 0); | |
440 | } | |
8974558f | 441 | |
9300d8df | 442 | if (page_owner->last_migrate_reason != -1) |
4e462112 | 443 | pr_alert("page has been migrated, last migrate reason: %s\n", |
9300d8df | 444 | migrate_reason_names[page_owner->last_migrate_reason]); |
4e462112 VB |
445 | } |
446 | ||
48c96a36 JK |
447 | static ssize_t |
448 | read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
449 | { | |
450 | unsigned long pfn; | |
451 | struct page *page; | |
452 | struct page_ext *page_ext; | |
9300d8df | 453 | struct page_owner *page_owner; |
f2ca0b55 | 454 | depot_stack_handle_t handle; |
48c96a36 | 455 | |
7dd80b8a | 456 | if (!static_branch_unlikely(&page_owner_inited)) |
48c96a36 JK |
457 | return -EINVAL; |
458 | ||
459 | page = NULL; | |
460 | pfn = min_low_pfn + *ppos; | |
461 | ||
462 | /* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */ | |
463 | while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) | |
464 | pfn++; | |
465 | ||
466 | drain_all_pages(NULL); | |
467 | ||
468 | /* Find an allocated page */ | |
469 | for (; pfn < max_pfn; pfn++) { | |
470 | /* | |
471 | * If the new page is in a new MAX_ORDER_NR_PAGES area, | |
472 | * validate the area as existing, skip it if not | |
473 | */ | |
474 | if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0 && !pfn_valid(pfn)) { | |
475 | pfn += MAX_ORDER_NR_PAGES - 1; | |
476 | continue; | |
477 | } | |
478 | ||
48c96a36 JK |
479 | page = pfn_to_page(pfn); |
480 | if (PageBuddy(page)) { | |
ab130f91 | 481 | unsigned long freepage_order = buddy_order_unsafe(page); |
48c96a36 JK |
482 | |
483 | if (freepage_order < MAX_ORDER) | |
484 | pfn += (1UL << freepage_order) - 1; | |
485 | continue; | |
486 | } | |
487 | ||
488 | page_ext = lookup_page_ext(page); | |
f86e4271 YS |
489 | if (unlikely(!page_ext)) |
490 | continue; | |
48c96a36 JK |
491 | |
492 | /* | |
61cf5feb JK |
493 | * Some pages could be missed by concurrent allocation or free, |
494 | * because we don't hold the zone lock. | |
48c96a36 JK |
495 | */ |
496 | if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) | |
497 | continue; | |
498 | ||
37389167 VB |
499 | /* |
500 | * Although we do have the info about past allocation of free | |
501 | * pages, it's not relevant for current memory usage. | |
502 | */ | |
fdf3bf80 | 503 | if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags)) |
37389167 VB |
504 | continue; |
505 | ||
9300d8df JK |
506 | page_owner = get_page_owner(page_ext); |
507 | ||
7e2f2a0c VB |
508 | /* |
509 | * Don't print "tail" pages of high-order allocations as that | |
510 | * would inflate the stats. | |
511 | */ | |
512 | if (!IS_ALIGNED(pfn, 1 << page_owner->order)) | |
513 | continue; | |
514 | ||
f2ca0b55 JK |
515 | /* |
516 | * Access to page_ext->handle isn't synchronous so we should | |
517 | * be careful to access it. | |
518 | */ | |
9300d8df | 519 | handle = READ_ONCE(page_owner->handle); |
f2ca0b55 JK |
520 | if (!handle) |
521 | continue; | |
522 | ||
48c96a36 JK |
523 | /* Record the next PFN to read in the file offset */ |
524 | *ppos = (pfn - min_low_pfn) + 1; | |
525 | ||
f2ca0b55 | 526 | return print_page_owner(buf, count, pfn, page, |
9300d8df | 527 | page_owner, handle); |
48c96a36 JK |
528 | } |
529 | ||
530 | return 0; | |
531 | } | |
532 | ||
61cf5feb JK |
533 | static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone) |
534 | { | |
6787c1da OS |
535 | unsigned long pfn = zone->zone_start_pfn; |
536 | unsigned long end_pfn = zone_end_pfn(zone); | |
61cf5feb JK |
537 | unsigned long count = 0; |
538 | ||
61cf5feb JK |
539 | /* |
540 | * Walk the zone in pageblock_nr_pages steps. If a page block spans | |
541 | * a zone boundary, it will be double counted between zones. This does | |
542 | * not matter as the mixed block count will still be correct | |
543 | */ | |
544 | for (; pfn < end_pfn; ) { | |
6787c1da OS |
545 | unsigned long block_end_pfn; |
546 | ||
61cf5feb JK |
547 | if (!pfn_valid(pfn)) { |
548 | pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); | |
549 | continue; | |
550 | } | |
551 | ||
552 | block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); | |
553 | block_end_pfn = min(block_end_pfn, end_pfn); | |
554 | ||
61cf5feb | 555 | for (; pfn < block_end_pfn; pfn++) { |
859a85dd | 556 | struct page *page = pfn_to_page(pfn); |
6787c1da OS |
557 | struct page_ext *page_ext; |
558 | ||
9d43f5ae JK |
559 | if (page_zone(page) != zone) |
560 | continue; | |
561 | ||
61cf5feb | 562 | /* |
10903027 VB |
563 | * To avoid having to grab zone->lock, be a little |
564 | * careful when reading buddy page order. The only | |
565 | * danger is that we skip too much and potentially miss | |
566 | * some early allocated pages, which is better than | |
567 | * heavy lock contention. | |
61cf5feb JK |
568 | */ |
569 | if (PageBuddy(page)) { | |
ab130f91 | 570 | unsigned long order = buddy_order_unsafe(page); |
10903027 VB |
571 | |
572 | if (order > 0 && order < MAX_ORDER) | |
573 | pfn += (1UL << order) - 1; | |
61cf5feb JK |
574 | continue; |
575 | } | |
576 | ||
577 | if (PageReserved(page)) | |
578 | continue; | |
579 | ||
580 | page_ext = lookup_page_ext(page); | |
f86e4271 YS |
581 | if (unlikely(!page_ext)) |
582 | continue; | |
61cf5feb | 583 | |
dab4ead1 | 584 | /* Maybe overlapping zone */ |
61cf5feb JK |
585 | if (test_bit(PAGE_EXT_OWNER, &page_ext->flags)) |
586 | continue; | |
587 | ||
588 | /* Found early allocated page */ | |
64ea78d2 | 589 | __set_page_owner_handle(page_ext, early_handle, |
7e2f2a0c | 590 | 0, 0); |
61cf5feb JK |
591 | count++; |
592 | } | |
10903027 | 593 | cond_resched(); |
61cf5feb JK |
594 | } |
595 | ||
596 | pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n", | |
597 | pgdat->node_id, zone->name, count); | |
598 | } | |
599 | ||
600 | static void init_zones_in_node(pg_data_t *pgdat) | |
601 | { | |
602 | struct zone *zone; | |
603 | struct zone *node_zones = pgdat->node_zones; | |
61cf5feb JK |
604 | |
605 | for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { | |
606 | if (!populated_zone(zone)) | |
607 | continue; | |
608 | ||
61cf5feb | 609 | init_pages_in_zone(pgdat, zone); |
61cf5feb JK |
610 | } |
611 | } | |
612 | ||
613 | static void init_early_allocated_pages(void) | |
614 | { | |
615 | pg_data_t *pgdat; | |
616 | ||
61cf5feb JK |
617 | for_each_online_pgdat(pgdat) |
618 | init_zones_in_node(pgdat); | |
619 | } | |
620 | ||
48c96a36 JK |
621 | static const struct file_operations proc_page_owner_operations = { |
622 | .read = read_page_owner, | |
623 | }; | |
624 | ||
625 | static int __init pageowner_init(void) | |
626 | { | |
7dd80b8a | 627 | if (!static_branch_unlikely(&page_owner_inited)) { |
48c96a36 JK |
628 | pr_info("page_owner is disabled\n"); |
629 | return 0; | |
630 | } | |
631 | ||
d9f7979c GKH |
632 | debugfs_create_file("page_owner", 0400, NULL, NULL, |
633 | &proc_page_owner_operations); | |
48c96a36 | 634 | |
d9f7979c | 635 | return 0; |
48c96a36 | 636 | } |
44c5af96 | 637 | late_initcall(pageowner_init) |