Commit | Line | Data |
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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> |
fcf89358 | 13 | #include <linux/memcontrol.h> |
9cc7e96a | 14 | #include <linux/sched/clock.h> |
f2ca0b55 | 15 | |
48c96a36 JK |
16 | #include "internal.h" |
17 | ||
f2ca0b55 JK |
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 | ||
9300d8df | 24 | struct page_owner { |
6b4c54e3 AM |
25 | unsigned short order; |
26 | short last_migrate_reason; | |
9300d8df | 27 | gfp_t gfp_mask; |
9300d8df | 28 | depot_stack_handle_t handle; |
8974558f | 29 | depot_stack_handle_t free_handle; |
9cc7e96a | 30 | u64 ts_nsec; |
866b4852 | 31 | u64 free_ts_nsec; |
865ed6a3 | 32 | char comm[TASK_COMM_LEN]; |
9cc7e96a | 33 | pid_t pid; |
bf215eab | 34 | pid_t tgid; |
9300d8df JK |
35 | }; |
36 | ||
0fe9a448 | 37 | static bool page_owner_enabled = false; |
7dd80b8a | 38 | DEFINE_STATIC_KEY_FALSE(page_owner_inited); |
48c96a36 | 39 | |
f2ca0b55 JK |
40 | static depot_stack_handle_t dummy_handle; |
41 | static depot_stack_handle_t failure_handle; | |
dab4ead1 | 42 | static depot_stack_handle_t early_handle; |
f2ca0b55 | 43 | |
61cf5feb JK |
44 | static void init_early_allocated_pages(void); |
45 | ||
1173194e | 46 | static int __init early_page_owner_param(char *buf) |
48c96a36 | 47 | { |
608b5d66 | 48 | return kstrtobool(buf, &page_owner_enabled); |
48c96a36 JK |
49 | } |
50 | early_param("page_owner", early_page_owner_param); | |
51 | ||
cab0a7c1 | 52 | static __init bool need_page_owner(void) |
48c96a36 | 53 | { |
0fe9a448 | 54 | return page_owner_enabled; |
48c96a36 JK |
55 | } |
56 | ||
dab4ead1 | 57 | static __always_inline depot_stack_handle_t create_dummy_stack(void) |
f2ca0b55 JK |
58 | { |
59 | unsigned long entries[4]; | |
af52bf6b | 60 | unsigned int nr_entries; |
f2ca0b55 | 61 | |
af52bf6b TG |
62 | nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0); |
63 | return stack_depot_save(entries, nr_entries, GFP_KERNEL); | |
f2ca0b55 JK |
64 | } |
65 | ||
dab4ead1 | 66 | static noinline void register_dummy_stack(void) |
f2ca0b55 | 67 | { |
dab4ead1 VB |
68 | dummy_handle = create_dummy_stack(); |
69 | } | |
f2ca0b55 | 70 | |
dab4ead1 VB |
71 | static noinline void register_failure_stack(void) |
72 | { | |
73 | failure_handle = create_dummy_stack(); | |
74 | } | |
f2ca0b55 | 75 | |
dab4ead1 VB |
76 | static noinline void register_early_stack(void) |
77 | { | |
78 | early_handle = create_dummy_stack(); | |
f2ca0b55 JK |
79 | } |
80 | ||
cab0a7c1 | 81 | static __init void init_page_owner(void) |
48c96a36 | 82 | { |
0fe9a448 | 83 | if (!page_owner_enabled) |
48c96a36 JK |
84 | return; |
85 | ||
2dba5eb1 VB |
86 | stack_depot_init(); |
87 | ||
f2ca0b55 JK |
88 | register_dummy_stack(); |
89 | register_failure_stack(); | |
dab4ead1 | 90 | register_early_stack(); |
7dd80b8a | 91 | static_branch_enable(&page_owner_inited); |
61cf5feb | 92 | init_early_allocated_pages(); |
48c96a36 JK |
93 | } |
94 | ||
95 | struct page_ext_operations page_owner_ops = { | |
9300d8df | 96 | .size = sizeof(struct page_owner), |
48c96a36 JK |
97 | .need = need_page_owner, |
98 | .init = init_page_owner, | |
99 | }; | |
100 | ||
9300d8df JK |
101 | static inline struct page_owner *get_page_owner(struct page_ext *page_ext) |
102 | { | |
103 | return (void *)page_ext + page_owner_ops.offset; | |
104 | } | |
105 | ||
f2ca0b55 JK |
106 | static noinline depot_stack_handle_t save_stack(gfp_t flags) |
107 | { | |
108 | unsigned long entries[PAGE_OWNER_STACK_DEPTH]; | |
f2ca0b55 | 109 | depot_stack_handle_t handle; |
af52bf6b | 110 | unsigned int nr_entries; |
f2ca0b55 | 111 | |
f2ca0b55 | 112 | /* |
8e9b16c4 ST |
113 | * Avoid recursion. |
114 | * | |
115 | * Sometimes page metadata allocation tracking requires more | |
116 | * memory to be allocated: | |
117 | * - when new stack trace is saved to stack depot | |
118 | * - when backtrace itself is calculated (ia64) | |
f2ca0b55 | 119 | */ |
8e9b16c4 | 120 | if (current->in_page_owner) |
f2ca0b55 | 121 | return dummy_handle; |
8e9b16c4 | 122 | current->in_page_owner = 1; |
f2ca0b55 | 123 | |
8e9b16c4 | 124 | nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 2); |
af52bf6b | 125 | handle = stack_depot_save(entries, nr_entries, flags); |
f2ca0b55 JK |
126 | if (!handle) |
127 | handle = failure_handle; | |
128 | ||
8e9b16c4 | 129 | current->in_page_owner = 0; |
f2ca0b55 JK |
130 | return handle; |
131 | } | |
132 | ||
0093de69 | 133 | void __reset_page_owner(struct page *page, unsigned short order) |
8974558f VB |
134 | { |
135 | int i; | |
136 | struct page_ext *page_ext; | |
fab765c2 | 137 | depot_stack_handle_t handle; |
8974558f | 138 | struct page_owner *page_owner; |
866b4852 | 139 | u64 free_ts_nsec = local_clock(); |
8974558f | 140 | |
5556cfe8 VB |
141 | page_ext = lookup_page_ext(page); |
142 | if (unlikely(!page_ext)) | |
143 | return; | |
fab765c2 ST |
144 | |
145 | handle = save_stack(GFP_NOWAIT | __GFP_NOWARN); | |
8974558f | 146 | for (i = 0; i < (1 << order); i++) { |
fdf3bf80 | 147 | __clear_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); |
0fe9a448 VB |
148 | page_owner = get_page_owner(page_ext); |
149 | page_owner->free_handle = handle; | |
866b4852 | 150 | page_owner->free_ts_nsec = free_ts_nsec; |
5556cfe8 | 151 | page_ext = page_ext_next(page_ext); |
8974558f VB |
152 | } |
153 | } | |
154 | ||
64ea78d2 | 155 | static inline void __set_page_owner_handle(struct page_ext *page_ext, |
156 | depot_stack_handle_t handle, | |
0093de69 | 157 | unsigned short order, gfp_t gfp_mask) |
f2ca0b55 | 158 | { |
9300d8df | 159 | struct page_owner *page_owner; |
7e2f2a0c | 160 | int i; |
48c96a36 | 161 | |
7e2f2a0c VB |
162 | for (i = 0; i < (1 << order); i++) { |
163 | page_owner = get_page_owner(page_ext); | |
164 | page_owner->handle = handle; | |
165 | page_owner->order = order; | |
166 | page_owner->gfp_mask = gfp_mask; | |
167 | page_owner->last_migrate_reason = -1; | |
9cc7e96a | 168 | page_owner->pid = current->pid; |
bf215eab | 169 | page_owner->tgid = current->tgid; |
9cc7e96a | 170 | page_owner->ts_nsec = local_clock(); |
865ed6a3 WL |
171 | strlcpy(page_owner->comm, current->comm, |
172 | sizeof(page_owner->comm)); | |
7e2f2a0c | 173 | __set_bit(PAGE_EXT_OWNER, &page_ext->flags); |
fdf3bf80 | 174 | __set_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags); |
48c96a36 | 175 | |
5556cfe8 | 176 | page_ext = page_ext_next(page_ext); |
7e2f2a0c | 177 | } |
48c96a36 JK |
178 | } |
179 | ||
0093de69 | 180 | noinline void __set_page_owner(struct page *page, unsigned short order, |
dab4ead1 VB |
181 | gfp_t gfp_mask) |
182 | { | |
183 | struct page_ext *page_ext = lookup_page_ext(page); | |
184 | depot_stack_handle_t handle; | |
185 | ||
186 | if (unlikely(!page_ext)) | |
187 | return; | |
188 | ||
189 | handle = save_stack(gfp_mask); | |
64ea78d2 | 190 | __set_page_owner_handle(page_ext, handle, order, gfp_mask); |
dab4ead1 VB |
191 | } |
192 | ||
7cd12b4a VB |
193 | void __set_page_owner_migrate_reason(struct page *page, int reason) |
194 | { | |
195 | struct page_ext *page_ext = lookup_page_ext(page); | |
9300d8df JK |
196 | struct page_owner *page_owner; |
197 | ||
f86e4271 YS |
198 | if (unlikely(!page_ext)) |
199 | return; | |
7cd12b4a | 200 | |
9300d8df JK |
201 | page_owner = get_page_owner(page_ext); |
202 | page_owner->last_migrate_reason = reason; | |
7cd12b4a VB |
203 | } |
204 | ||
8fb156c9 | 205 | void __split_page_owner(struct page *page, unsigned int nr) |
e2cfc911 | 206 | { |
a9627bc5 | 207 | int i; |
e2cfc911 | 208 | struct page_ext *page_ext = lookup_page_ext(page); |
9300d8df | 209 | struct page_owner *page_owner; |
a9627bc5 | 210 | |
f86e4271 | 211 | if (unlikely(!page_ext)) |
a9627bc5 | 212 | return; |
e2cfc911 | 213 | |
8fb156c9 | 214 | for (i = 0; i < nr; i++) { |
7e2f2a0c VB |
215 | page_owner = get_page_owner(page_ext); |
216 | page_owner->order = 0; | |
5556cfe8 | 217 | page_ext = page_ext_next(page_ext); |
7e2f2a0c | 218 | } |
e2cfc911 JK |
219 | } |
220 | ||
19138349 | 221 | void __folio_copy_owner(struct folio *newfolio, struct folio *old) |
d435edca | 222 | { |
19138349 MWO |
223 | struct page_ext *old_ext = lookup_page_ext(&old->page); |
224 | struct page_ext *new_ext = lookup_page_ext(&newfolio->page); | |
9300d8df | 225 | struct page_owner *old_page_owner, *new_page_owner; |
d435edca | 226 | |
f86e4271 YS |
227 | if (unlikely(!old_ext || !new_ext)) |
228 | return; | |
229 | ||
9300d8df JK |
230 | old_page_owner = get_page_owner(old_ext); |
231 | new_page_owner = get_page_owner(new_ext); | |
232 | new_page_owner->order = old_page_owner->order; | |
233 | new_page_owner->gfp_mask = old_page_owner->gfp_mask; | |
234 | new_page_owner->last_migrate_reason = | |
235 | old_page_owner->last_migrate_reason; | |
236 | new_page_owner->handle = old_page_owner->handle; | |
9cc7e96a | 237 | new_page_owner->pid = old_page_owner->pid; |
bf215eab | 238 | new_page_owner->tgid = old_page_owner->tgid; |
9cc7e96a | 239 | new_page_owner->ts_nsec = old_page_owner->ts_nsec; |
866b4852 | 240 | new_page_owner->free_ts_nsec = old_page_owner->ts_nsec; |
865ed6a3 | 241 | strcpy(new_page_owner->comm, old_page_owner->comm); |
d435edca VB |
242 | |
243 | /* | |
19138349 | 244 | * We don't clear the bit on the old folio as it's going to be freed |
d435edca | 245 | * after migration. Until then, the info can be useful in case of |
f0953a1b | 246 | * a bug, and the overall stats will be off a bit only temporarily. |
d435edca | 247 | * Also, migrate_misplaced_transhuge_page() can still fail the |
19138349 | 248 | * migration and then we want the old folio to retain the info. But |
d435edca VB |
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); | |
fdf3bf80 | 253 | __set_bit(PAGE_EXT_OWNER_ALLOCATED, &new_ext->flags); |
d435edca VB |
254 | } |
255 | ||
e2f612e6 JK |
256 | void pagetypeinfo_showmixedcount_print(struct seq_file *m, |
257 | pg_data_t *pgdat, struct zone *zone) | |
258 | { | |
259 | struct page *page; | |
260 | struct page_ext *page_ext; | |
9300d8df | 261 | struct page_owner *page_owner; |
1d2cae8e ML |
262 | unsigned long pfn, block_end_pfn; |
263 | unsigned long end_pfn = zone_end_pfn(zone); | |
e2f612e6 JK |
264 | unsigned long count[MIGRATE_TYPES] = { 0, }; |
265 | int pageblock_mt, page_mt; | |
266 | int i; | |
267 | ||
268 | /* Scan block by block. First and last block may be incomplete */ | |
269 | pfn = zone->zone_start_pfn; | |
270 | ||
271 | /* | |
272 | * Walk the zone in pageblock_nr_pages steps. If a page block spans | |
273 | * a zone boundary, it will be double counted between zones. This does | |
274 | * not matter as the mixed block count will still be correct | |
275 | */ | |
276 | for (; pfn < end_pfn; ) { | |
a26ee565 QC |
277 | page = pfn_to_online_page(pfn); |
278 | if (!page) { | |
e2f612e6 JK |
279 | pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); |
280 | continue; | |
281 | } | |
282 | ||
283 | block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); | |
284 | block_end_pfn = min(block_end_pfn, end_pfn); | |
285 | ||
e2f612e6 JK |
286 | pageblock_mt = get_pageblock_migratetype(page); |
287 | ||
288 | for (; pfn < block_end_pfn; pfn++) { | |
a26ee565 | 289 | /* The pageblock is online, no need to recheck. */ |
e2f612e6 JK |
290 | page = pfn_to_page(pfn); |
291 | ||
292 | if (page_zone(page) != zone) | |
293 | continue; | |
294 | ||
295 | if (PageBuddy(page)) { | |
727c080f VM |
296 | unsigned long freepage_order; |
297 | ||
ab130f91 | 298 | freepage_order = buddy_order_unsafe(page); |
727c080f VM |
299 | if (freepage_order < MAX_ORDER) |
300 | pfn += (1UL << freepage_order) - 1; | |
e2f612e6 JK |
301 | continue; |
302 | } | |
303 | ||
304 | if (PageReserved(page)) | |
305 | continue; | |
306 | ||
307 | page_ext = lookup_page_ext(page); | |
308 | if (unlikely(!page_ext)) | |
309 | continue; | |
310 | ||
fdf3bf80 | 311 | if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags)) |
e2f612e6 JK |
312 | continue; |
313 | ||
9300d8df | 314 | page_owner = get_page_owner(page_ext); |
01c0bfe0 | 315 | page_mt = gfp_migratetype(page_owner->gfp_mask); |
e2f612e6 JK |
316 | if (pageblock_mt != page_mt) { |
317 | if (is_migrate_cma(pageblock_mt)) | |
318 | count[MIGRATE_MOVABLE]++; | |
319 | else | |
320 | count[pageblock_mt]++; | |
321 | ||
322 | pfn = block_end_pfn; | |
323 | break; | |
324 | } | |
9300d8df | 325 | pfn += (1UL << page_owner->order) - 1; |
e2f612e6 JK |
326 | } |
327 | } | |
328 | ||
329 | /* Print counts */ | |
330 | seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name); | |
331 | for (i = 0; i < MIGRATE_TYPES; i++) | |
332 | seq_printf(m, "%12lu ", count[i]); | |
333 | seq_putc(m, '\n'); | |
334 | } | |
335 | ||
fcf89358 WL |
336 | /* |
337 | * Looking for memcg information and print it out | |
338 | */ | |
339 | static inline int print_page_owner_memcg(char *kbuf, size_t count, int ret, | |
340 | struct page *page) | |
341 | { | |
342 | #ifdef CONFIG_MEMCG | |
343 | unsigned long memcg_data; | |
344 | struct mem_cgroup *memcg; | |
345 | bool online; | |
346 | char name[80]; | |
347 | ||
348 | rcu_read_lock(); | |
349 | memcg_data = READ_ONCE(page->memcg_data); | |
350 | if (!memcg_data) | |
351 | goto out_unlock; | |
352 | ||
353 | if (memcg_data & MEMCG_DATA_OBJCGS) | |
354 | ret += scnprintf(kbuf + ret, count - ret, | |
355 | "Slab cache page\n"); | |
356 | ||
357 | memcg = page_memcg_check(page); | |
358 | if (!memcg) | |
359 | goto out_unlock; | |
360 | ||
361 | online = (memcg->css.flags & CSS_ONLINE); | |
362 | cgroup_name(memcg->css.cgroup, name, sizeof(name)); | |
363 | ret += scnprintf(kbuf + ret, count - ret, | |
364 | "Charged %sto %smemcg %s\n", | |
365 | PageMemcgKmem(page) ? "(via objcg) " : "", | |
366 | online ? "" : "offline ", | |
367 | name); | |
368 | out_unlock: | |
369 | rcu_read_unlock(); | |
370 | #endif /* CONFIG_MEMCG */ | |
371 | ||
372 | return ret; | |
373 | } | |
374 | ||
48c96a36 JK |
375 | static ssize_t |
376 | print_page_owner(char __user *buf, size_t count, unsigned long pfn, | |
9300d8df | 377 | struct page *page, struct page_owner *page_owner, |
f2ca0b55 | 378 | depot_stack_handle_t handle) |
48c96a36 | 379 | { |
af52bf6b | 380 | int ret, pageblock_mt, page_mt; |
48c96a36 JK |
381 | char *kbuf; |
382 | ||
c8f61cfc | 383 | count = min_t(size_t, count, PAGE_SIZE); |
48c96a36 JK |
384 | kbuf = kmalloc(count, GFP_KERNEL); |
385 | if (!kbuf) | |
386 | return -ENOMEM; | |
387 | ||
3ebc4397 | 388 | ret = scnprintf(kbuf, count, |
bf215eab | 389 | "Page allocated via order %u, mask %#x(%pGg), pid %d, tgid %d (%s), ts %llu ns, free_ts %llu ns\n", |
9300d8df | 390 | page_owner->order, page_owner->gfp_mask, |
9cc7e96a | 391 | &page_owner->gfp_mask, page_owner->pid, |
bf215eab YC |
392 | page_owner->tgid, page_owner->comm, |
393 | page_owner->ts_nsec, page_owner->free_ts_nsec); | |
48c96a36 | 394 | |
48c96a36 | 395 | /* Print information relevant to grouping pages by mobility */ |
0b423ca2 | 396 | pageblock_mt = get_pageblock_migratetype(page); |
01c0bfe0 | 397 | page_mt = gfp_migratetype(page_owner->gfp_mask); |
3ebc4397 | 398 | ret += scnprintf(kbuf + ret, count - ret, |
23efd080 | 399 | "PFN %lu type %s Block %lu type %s Flags %pGp\n", |
48c96a36 | 400 | pfn, |
60f30350 | 401 | migratetype_names[page_mt], |
48c96a36 | 402 | pfn >> pageblock_order, |
60f30350 | 403 | migratetype_names[pageblock_mt], |
23efd080 | 404 | &page->flags); |
48c96a36 | 405 | |
0f68d45e | 406 | ret += stack_depot_snprint(handle, kbuf + ret, count - ret, 0); |
48c96a36 JK |
407 | if (ret >= count) |
408 | goto err; | |
409 | ||
9300d8df | 410 | if (page_owner->last_migrate_reason != -1) { |
3ebc4397 | 411 | ret += scnprintf(kbuf + ret, count - ret, |
7cd12b4a | 412 | "Page has been migrated, last migrate reason: %s\n", |
9300d8df | 413 | migrate_reason_names[page_owner->last_migrate_reason]); |
7cd12b4a VB |
414 | } |
415 | ||
fcf89358 WL |
416 | ret = print_page_owner_memcg(kbuf, count, ret, page); |
417 | ||
48c96a36 JK |
418 | ret += snprintf(kbuf + ret, count - ret, "\n"); |
419 | if (ret >= count) | |
420 | goto err; | |
421 | ||
422 | if (copy_to_user(buf, kbuf, ret)) | |
423 | ret = -EFAULT; | |
424 | ||
425 | kfree(kbuf); | |
426 | return ret; | |
427 | ||
428 | err: | |
429 | kfree(kbuf); | |
430 | return -ENOMEM; | |
431 | } | |
432 | ||
8bf6f451 | 433 | void __dump_page_owner(const struct page *page) |
4e462112 VB |
434 | { |
435 | struct page_ext *page_ext = lookup_page_ext(page); | |
9300d8df | 436 | struct page_owner *page_owner; |
f2ca0b55 | 437 | depot_stack_handle_t handle; |
8285027f SM |
438 | gfp_t gfp_mask; |
439 | int mt; | |
4e462112 | 440 | |
f86e4271 YS |
441 | if (unlikely(!page_ext)) { |
442 | pr_alert("There is not page extension available.\n"); | |
443 | return; | |
444 | } | |
9300d8df JK |
445 | |
446 | page_owner = get_page_owner(page_ext); | |
447 | gfp_mask = page_owner->gfp_mask; | |
01c0bfe0 | 448 | mt = gfp_migratetype(gfp_mask); |
f86e4271 | 449 | |
4e462112 | 450 | if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) { |
37389167 | 451 | pr_alert("page_owner info is not present (never set?)\n"); |
4e462112 VB |
452 | return; |
453 | } | |
454 | ||
fdf3bf80 | 455 | if (test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags)) |
37389167 VB |
456 | pr_alert("page_owner tracks the page as allocated\n"); |
457 | else | |
458 | pr_alert("page_owner tracks the page as freed\n"); | |
459 | ||
bf215eab | 460 | 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", |
9cc7e96a | 461 | page_owner->order, migratetype_names[mt], gfp_mask, &gfp_mask, |
bf215eab YC |
462 | page_owner->pid, page_owner->tgid, page_owner->comm, |
463 | page_owner->ts_nsec, page_owner->free_ts_nsec); | |
37389167 | 464 | |
9300d8df | 465 | handle = READ_ONCE(page_owner->handle); |
505be481 | 466 | if (!handle) |
37389167 | 467 | pr_alert("page_owner allocation stack trace missing\n"); |
505be481 IK |
468 | else |
469 | stack_depot_print(handle); | |
f2ca0b55 | 470 | |
8974558f VB |
471 | handle = READ_ONCE(page_owner->free_handle); |
472 | if (!handle) { | |
473 | pr_alert("page_owner free stack trace missing\n"); | |
474 | } else { | |
8974558f | 475 | pr_alert("page last free stack trace:\n"); |
505be481 | 476 | stack_depot_print(handle); |
8974558f | 477 | } |
8974558f | 478 | |
9300d8df | 479 | if (page_owner->last_migrate_reason != -1) |
4e462112 | 480 | pr_alert("page has been migrated, last migrate reason: %s\n", |
9300d8df | 481 | migrate_reason_names[page_owner->last_migrate_reason]); |
4e462112 VB |
482 | } |
483 | ||
48c96a36 JK |
484 | static ssize_t |
485 | read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
486 | { | |
487 | unsigned long pfn; | |
488 | struct page *page; | |
489 | struct page_ext *page_ext; | |
9300d8df | 490 | struct page_owner *page_owner; |
f2ca0b55 | 491 | depot_stack_handle_t handle; |
48c96a36 | 492 | |
7dd80b8a | 493 | if (!static_branch_unlikely(&page_owner_inited)) |
48c96a36 JK |
494 | return -EINVAL; |
495 | ||
496 | page = NULL; | |
497 | pfn = min_low_pfn + *ppos; | |
498 | ||
499 | /* Find a valid PFN or the start of a MAX_ORDER_NR_PAGES area */ | |
500 | while (!pfn_valid(pfn) && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) | |
501 | pfn++; | |
502 | ||
503 | drain_all_pages(NULL); | |
504 | ||
505 | /* Find an allocated page */ | |
506 | for (; pfn < max_pfn; pfn++) { | |
507 | /* | |
508 | * If the new page is in a new MAX_ORDER_NR_PAGES area, | |
509 | * validate the area as existing, skip it if not | |
510 | */ | |
511 | if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0 && !pfn_valid(pfn)) { | |
512 | pfn += MAX_ORDER_NR_PAGES - 1; | |
513 | continue; | |
514 | } | |
515 | ||
48c96a36 JK |
516 | page = pfn_to_page(pfn); |
517 | if (PageBuddy(page)) { | |
ab130f91 | 518 | unsigned long freepage_order = buddy_order_unsafe(page); |
48c96a36 JK |
519 | |
520 | if (freepage_order < MAX_ORDER) | |
521 | pfn += (1UL << freepage_order) - 1; | |
522 | continue; | |
523 | } | |
524 | ||
525 | page_ext = lookup_page_ext(page); | |
f86e4271 YS |
526 | if (unlikely(!page_ext)) |
527 | continue; | |
48c96a36 JK |
528 | |
529 | /* | |
61cf5feb JK |
530 | * Some pages could be missed by concurrent allocation or free, |
531 | * because we don't hold the zone lock. | |
48c96a36 JK |
532 | */ |
533 | if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) | |
534 | continue; | |
535 | ||
37389167 VB |
536 | /* |
537 | * Although we do have the info about past allocation of free | |
538 | * pages, it's not relevant for current memory usage. | |
539 | */ | |
fdf3bf80 | 540 | if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags)) |
37389167 VB |
541 | continue; |
542 | ||
9300d8df JK |
543 | page_owner = get_page_owner(page_ext); |
544 | ||
7e2f2a0c VB |
545 | /* |
546 | * Don't print "tail" pages of high-order allocations as that | |
547 | * would inflate the stats. | |
548 | */ | |
549 | if (!IS_ALIGNED(pfn, 1 << page_owner->order)) | |
550 | continue; | |
551 | ||
f2ca0b55 JK |
552 | /* |
553 | * Access to page_ext->handle isn't synchronous so we should | |
554 | * be careful to access it. | |
555 | */ | |
9300d8df | 556 | handle = READ_ONCE(page_owner->handle); |
f2ca0b55 JK |
557 | if (!handle) |
558 | continue; | |
559 | ||
48c96a36 JK |
560 | /* Record the next PFN to read in the file offset */ |
561 | *ppos = (pfn - min_low_pfn) + 1; | |
562 | ||
f2ca0b55 | 563 | return print_page_owner(buf, count, pfn, page, |
9300d8df | 564 | page_owner, handle); |
48c96a36 JK |
565 | } |
566 | ||
567 | return 0; | |
568 | } | |
569 | ||
61cf5feb JK |
570 | static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone) |
571 | { | |
6787c1da OS |
572 | unsigned long pfn = zone->zone_start_pfn; |
573 | unsigned long end_pfn = zone_end_pfn(zone); | |
61cf5feb JK |
574 | unsigned long count = 0; |
575 | ||
61cf5feb JK |
576 | /* |
577 | * Walk the zone in pageblock_nr_pages steps. If a page block spans | |
578 | * a zone boundary, it will be double counted between zones. This does | |
579 | * not matter as the mixed block count will still be correct | |
580 | */ | |
581 | for (; pfn < end_pfn; ) { | |
6787c1da OS |
582 | unsigned long block_end_pfn; |
583 | ||
61cf5feb JK |
584 | if (!pfn_valid(pfn)) { |
585 | pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES); | |
586 | continue; | |
587 | } | |
588 | ||
589 | block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages); | |
590 | block_end_pfn = min(block_end_pfn, end_pfn); | |
591 | ||
61cf5feb | 592 | for (; pfn < block_end_pfn; pfn++) { |
859a85dd | 593 | struct page *page = pfn_to_page(pfn); |
6787c1da OS |
594 | struct page_ext *page_ext; |
595 | ||
9d43f5ae JK |
596 | if (page_zone(page) != zone) |
597 | continue; | |
598 | ||
61cf5feb | 599 | /* |
10903027 VB |
600 | * To avoid having to grab zone->lock, be a little |
601 | * careful when reading buddy page order. The only | |
602 | * danger is that we skip too much and potentially miss | |
603 | * some early allocated pages, which is better than | |
604 | * heavy lock contention. | |
61cf5feb JK |
605 | */ |
606 | if (PageBuddy(page)) { | |
ab130f91 | 607 | unsigned long order = buddy_order_unsafe(page); |
10903027 VB |
608 | |
609 | if (order > 0 && order < MAX_ORDER) | |
610 | pfn += (1UL << order) - 1; | |
61cf5feb JK |
611 | continue; |
612 | } | |
613 | ||
614 | if (PageReserved(page)) | |
615 | continue; | |
616 | ||
617 | page_ext = lookup_page_ext(page); | |
f86e4271 YS |
618 | if (unlikely(!page_ext)) |
619 | continue; | |
61cf5feb | 620 | |
dab4ead1 | 621 | /* Maybe overlapping zone */ |
61cf5feb JK |
622 | if (test_bit(PAGE_EXT_OWNER, &page_ext->flags)) |
623 | continue; | |
624 | ||
625 | /* Found early allocated page */ | |
64ea78d2 | 626 | __set_page_owner_handle(page_ext, early_handle, |
7e2f2a0c | 627 | 0, 0); |
61cf5feb JK |
628 | count++; |
629 | } | |
10903027 | 630 | cond_resched(); |
61cf5feb JK |
631 | } |
632 | ||
633 | pr_info("Node %d, zone %8s: page owner found early allocated %lu pages\n", | |
634 | pgdat->node_id, zone->name, count); | |
635 | } | |
636 | ||
637 | static void init_zones_in_node(pg_data_t *pgdat) | |
638 | { | |
639 | struct zone *zone; | |
640 | struct zone *node_zones = pgdat->node_zones; | |
61cf5feb JK |
641 | |
642 | for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { | |
643 | if (!populated_zone(zone)) | |
644 | continue; | |
645 | ||
61cf5feb | 646 | init_pages_in_zone(pgdat, zone); |
61cf5feb JK |
647 | } |
648 | } | |
649 | ||
650 | static void init_early_allocated_pages(void) | |
651 | { | |
652 | pg_data_t *pgdat; | |
653 | ||
61cf5feb JK |
654 | for_each_online_pgdat(pgdat) |
655 | init_zones_in_node(pgdat); | |
656 | } | |
657 | ||
48c96a36 JK |
658 | static const struct file_operations proc_page_owner_operations = { |
659 | .read = read_page_owner, | |
660 | }; | |
661 | ||
662 | static int __init pageowner_init(void) | |
663 | { | |
7dd80b8a | 664 | if (!static_branch_unlikely(&page_owner_inited)) { |
48c96a36 JK |
665 | pr_info("page_owner is disabled\n"); |
666 | return 0; | |
667 | } | |
668 | ||
d9f7979c GKH |
669 | debugfs_create_file("page_owner", 0400, NULL, NULL, |
670 | &proc_page_owner_operations); | |
48c96a36 | 671 | |
d9f7979c | 672 | return 0; |
48c96a36 | 673 | } |
44c5af96 | 674 | late_initcall(pageowner_init) |