1 | /* |
2 | * linux/mm/vmstat.c |
3 | * |
4 | * Manages VM statistics |
5 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
6 | * |
7 | * zoned VM statistics |
8 | * Copyright (C) 2006 Silicon Graphics, Inc., |
9 | * Christoph Lameter <christoph@lameter.com> |
10 | * Copyright (C) 2008-2014 Christoph Lameter |
11 | */ |
12 | #include <linux/fs.h> |
13 | #include <linux/mm.h> |
14 | #include <linux/err.h> |
15 | #include <linux/module.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/cpu.h> |
18 | #include <linux/cpumask.h> |
19 | #include <linux/vmstat.h> |
20 | #include <linux/proc_fs.h> |
21 | #include <linux/seq_file.h> |
22 | #include <linux/debugfs.h> |
23 | #include <linux/sched.h> |
24 | #include <linux/math64.h> |
25 | #include <linux/writeback.h> |
26 | #include <linux/compaction.h> |
27 | #include <linux/mm_inline.h> |
28 | #include <linux/page_ext.h> |
29 | #include <linux/page_owner.h> |
30 | |
31 | #include "internal.h" |
32 | |
33 | #define NUMA_STATS_THRESHOLD (U16_MAX - 2) |
34 | |
35 | #ifdef CONFIG_NUMA |
36 | int sysctl_vm_numa_stat = ENABLE_NUMA_STAT; |
37 | |
38 | /* zero numa counters within a zone */ |
39 | static void zero_zone_numa_counters(struct zone *zone) |
40 | { |
41 | int item, cpu; |
42 | |
43 | for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++) { |
44 | atomic_long_set(&zone->vm_numa_stat[item], 0); |
45 | for_each_online_cpu(cpu) |
46 | per_cpu_ptr(zone->pageset, cpu)->vm_numa_stat_diff[item] |
47 | = 0; |
48 | } |
49 | } |
50 | |
51 | /* zero numa counters of all the populated zones */ |
52 | static void zero_zones_numa_counters(void) |
53 | { |
54 | struct zone *zone; |
55 | |
56 | for_each_populated_zone(zone) |
57 | zero_zone_numa_counters(zone); |
58 | } |
59 | |
60 | /* zero global numa counters */ |
61 | static void zero_global_numa_counters(void) |
62 | { |
63 | int item; |
64 | |
65 | for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++) |
66 | atomic_long_set(&vm_numa_stat[item], 0); |
67 | } |
68 | |
69 | static void invalid_numa_statistics(void) |
70 | { |
71 | zero_zones_numa_counters(); |
72 | zero_global_numa_counters(); |
73 | } |
74 | |
75 | static DEFINE_MUTEX(vm_numa_stat_lock); |
76 | |
77 | int sysctl_vm_numa_stat_handler(struct ctl_table *table, int write, |
78 | void __user *buffer, size_t *length, loff_t *ppos) |
79 | { |
80 | int ret, oldval; |
81 | |
82 | mutex_lock(&vm_numa_stat_lock); |
83 | if (write) |
84 | oldval = sysctl_vm_numa_stat; |
85 | ret = proc_dointvec_minmax(table, write, buffer, length, ppos); |
86 | if (ret || !write) |
87 | goto out; |
88 | |
89 | if (oldval == sysctl_vm_numa_stat) |
90 | goto out; |
91 | else if (sysctl_vm_numa_stat == ENABLE_NUMA_STAT) { |
92 | static_branch_enable(&vm_numa_stat_key); |
93 | pr_info("enable numa statistics\n" ); |
94 | } else { |
95 | static_branch_disable(&vm_numa_stat_key); |
96 | invalid_numa_statistics(); |
97 | pr_info("disable numa statistics, and clear numa counters\n" ); |
98 | } |
99 | |
100 | out: |
101 | mutex_unlock(&vm_numa_stat_lock); |
102 | return ret; |
103 | } |
104 | #endif |
105 | |
106 | #ifdef CONFIG_VM_EVENT_COUNTERS |
107 | DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}}; |
108 | EXPORT_PER_CPU_SYMBOL(vm_event_states); |
109 | |
110 | static void sum_vm_events(unsigned long *ret) |
111 | { |
112 | int cpu; |
113 | int i; |
114 | |
115 | memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long)); |
116 | |
117 | for_each_online_cpu(cpu) { |
118 | struct vm_event_state *this = &per_cpu(vm_event_states, cpu); |
119 | |
120 | for (i = 0; i < NR_VM_EVENT_ITEMS; i++) |
121 | ret[i] += this->event[i]; |
122 | } |
123 | } |
124 | |
125 | /* |
126 | * Accumulate the vm event counters across all CPUs. |
127 | * The result is unavoidably approximate - it can change |
128 | * during and after execution of this function. |
129 | */ |
130 | void all_vm_events(unsigned long *ret) |
131 | { |
132 | get_online_cpus(); |
133 | sum_vm_events(ret); |
134 | put_online_cpus(); |
135 | } |
136 | EXPORT_SYMBOL_GPL(all_vm_events); |
137 | |
138 | /* |
139 | * Fold the foreign cpu events into our own. |
140 | * |
141 | * This is adding to the events on one processor |
142 | * but keeps the global counts constant. |
143 | */ |
144 | void vm_events_fold_cpu(int cpu) |
145 | { |
146 | struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu); |
147 | int i; |
148 | |
149 | for (i = 0; i < NR_VM_EVENT_ITEMS; i++) { |
150 | count_vm_events(i, fold_state->event[i]); |
151 | fold_state->event[i] = 0; |
152 | } |
153 | } |
154 | |
155 | #endif /* CONFIG_VM_EVENT_COUNTERS */ |
156 | |
157 | /* |
158 | * Manage combined zone based / global counters |
159 | * |
160 | * vm_stat contains the global counters |
161 | */ |
162 | atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp; |
163 | atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS] __cacheline_aligned_in_smp; |
164 | atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS] __cacheline_aligned_in_smp; |
165 | EXPORT_SYMBOL(vm_zone_stat); |
166 | EXPORT_SYMBOL(vm_numa_stat); |
167 | EXPORT_SYMBOL(vm_node_stat); |
168 | |
169 | #ifdef CONFIG_SMP |
170 | |
171 | int calculate_pressure_threshold(struct zone *zone) |
172 | { |
173 | int threshold; |
174 | int watermark_distance; |
175 | |
176 | /* |
177 | * As vmstats are not up to date, there is drift between the estimated |
178 | * and real values. For high thresholds and a high number of CPUs, it |
179 | * is possible for the min watermark to be breached while the estimated |
180 | * value looks fine. The pressure threshold is a reduced value such |
181 | * that even the maximum amount of drift will not accidentally breach |
182 | * the min watermark |
183 | */ |
184 | watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone); |
185 | threshold = max(1, (int)(watermark_distance / num_online_cpus())); |
186 | |
187 | /* |
188 | * Maximum threshold is 125 |
189 | */ |
190 | threshold = min(125, threshold); |
191 | |
192 | return threshold; |
193 | } |
194 | |
195 | int calculate_normal_threshold(struct zone *zone) |
196 | { |
197 | int threshold; |
198 | int mem; /* memory in 128 MB units */ |
199 | |
200 | /* |
201 | * The threshold scales with the number of processors and the amount |
202 | * of memory per zone. More memory means that we can defer updates for |
203 | * longer, more processors could lead to more contention. |
204 | * fls() is used to have a cheap way of logarithmic scaling. |
205 | * |
206 | * Some sample thresholds: |
207 | * |
208 | * Threshold Processors (fls) Zonesize fls(mem+1) |
209 | * ------------------------------------------------------------------ |
210 | * 8 1 1 0.9-1 GB 4 |
211 | * 16 2 2 0.9-1 GB 4 |
212 | * 20 2 2 1-2 GB 5 |
213 | * 24 2 2 2-4 GB 6 |
214 | * 28 2 2 4-8 GB 7 |
215 | * 32 2 2 8-16 GB 8 |
216 | * 4 2 2 <128M 1 |
217 | * 30 4 3 2-4 GB 5 |
218 | * 48 4 3 8-16 GB 8 |
219 | * 32 8 4 1-2 GB 4 |
220 | * 32 8 4 0.9-1GB 4 |
221 | * 10 16 5 <128M 1 |
222 | * 40 16 5 900M 4 |
223 | * 70 64 7 2-4 GB 5 |
224 | * 84 64 7 4-8 GB 6 |
225 | * 108 512 9 4-8 GB 6 |
226 | * 125 1024 10 8-16 GB 8 |
227 | * 125 1024 10 16-32 GB 9 |
228 | */ |
229 | |
230 | mem = zone_managed_pages(zone) >> (27 - PAGE_SHIFT); |
231 | |
232 | threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem)); |
233 | |
234 | /* |
235 | * Maximum threshold is 125 |
236 | */ |
237 | threshold = min(125, threshold); |
238 | |
239 | return threshold; |
240 | } |
241 | |
242 | /* |
243 | * Refresh the thresholds for each zone. |
244 | */ |
245 | void refresh_zone_stat_thresholds(void) |
246 | { |
247 | struct pglist_data *pgdat; |
248 | struct zone *zone; |
249 | int cpu; |
250 | int threshold; |
251 | |
252 | /* Zero current pgdat thresholds */ |
253 | for_each_online_pgdat(pgdat) { |
254 | for_each_online_cpu(cpu) { |
255 | per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold = 0; |
256 | } |
257 | } |
258 | |
259 | for_each_populated_zone(zone) { |
260 | struct pglist_data *pgdat = zone->zone_pgdat; |
261 | unsigned long max_drift, tolerate_drift; |
262 | |
263 | threshold = calculate_normal_threshold(zone); |
264 | |
265 | for_each_online_cpu(cpu) { |
266 | int pgdat_threshold; |
267 | |
268 | per_cpu_ptr(zone->pageset, cpu)->stat_threshold |
269 | = threshold; |
270 | |
271 | /* Base nodestat threshold on the largest populated zone. */ |
272 | pgdat_threshold = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold; |
273 | per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold |
274 | = max(threshold, pgdat_threshold); |
275 | } |
276 | |
277 | /* |
278 | * Only set percpu_drift_mark if there is a danger that |
279 | * NR_FREE_PAGES reports the low watermark is ok when in fact |
280 | * the min watermark could be breached by an allocation |
281 | */ |
282 | tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone); |
283 | max_drift = num_online_cpus() * threshold; |
284 | if (max_drift > tolerate_drift) |
285 | zone->percpu_drift_mark = high_wmark_pages(zone) + |
286 | max_drift; |
287 | } |
288 | } |
289 | |
290 | void set_pgdat_percpu_threshold(pg_data_t *pgdat, |
291 | int (*calculate_pressure)(struct zone *)) |
292 | { |
293 | struct zone *zone; |
294 | int cpu; |
295 | int threshold; |
296 | int i; |
297 | |
298 | for (i = 0; i < pgdat->nr_zones; i++) { |
299 | zone = &pgdat->node_zones[i]; |
300 | if (!zone->percpu_drift_mark) |
301 | continue; |
302 | |
303 | threshold = (*calculate_pressure)(zone); |
304 | for_each_online_cpu(cpu) |
305 | per_cpu_ptr(zone->pageset, cpu)->stat_threshold |
306 | = threshold; |
307 | } |
308 | } |
309 | |
310 | /* |
311 | * For use when we know that interrupts are disabled, |
312 | * or when we know that preemption is disabled and that |
313 | * particular counter cannot be updated from interrupt context. |
314 | */ |
315 | void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item, |
316 | long delta) |
317 | { |
318 | struct per_cpu_pageset __percpu *pcp = zone->pageset; |
319 | s8 __percpu *p = pcp->vm_stat_diff + item; |
320 | long x; |
321 | long t; |
322 | |
323 | x = delta + __this_cpu_read(*p); |
324 | |
325 | t = __this_cpu_read(pcp->stat_threshold); |
326 | |
327 | if (unlikely(x > t || x < -t)) { |
328 | zone_page_state_add(x, zone, item); |
329 | x = 0; |
330 | } |
331 | __this_cpu_write(*p, x); |
332 | } |
333 | EXPORT_SYMBOL(__mod_zone_page_state); |
334 | |
335 | void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item, |
336 | long delta) |
337 | { |
338 | struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats; |
339 | s8 __percpu *p = pcp->vm_node_stat_diff + item; |
340 | long x; |
341 | long t; |
342 | |
343 | x = delta + __this_cpu_read(*p); |
344 | |
345 | t = __this_cpu_read(pcp->stat_threshold); |
346 | |
347 | if (unlikely(x > t || x < -t)) { |
348 | node_page_state_add(x, pgdat, item); |
349 | x = 0; |
350 | } |
351 | __this_cpu_write(*p, x); |
352 | } |
353 | EXPORT_SYMBOL(__mod_node_page_state); |
354 | |
355 | /* |
356 | * Optimized increment and decrement functions. |
357 | * |
358 | * These are only for a single page and therefore can take a struct page * |
359 | * argument instead of struct zone *. This allows the inclusion of the code |
360 | * generated for page_zone(page) into the optimized functions. |
361 | * |
362 | * No overflow check is necessary and therefore the differential can be |
363 | * incremented or decremented in place which may allow the compilers to |
364 | * generate better code. |
365 | * The increment or decrement is known and therefore one boundary check can |
366 | * be omitted. |
367 | * |
368 | * NOTE: These functions are very performance sensitive. Change only |
369 | * with care. |
370 | * |
371 | * Some processors have inc/dec instructions that are atomic vs an interrupt. |
372 | * However, the code must first determine the differential location in a zone |
373 | * based on the processor number and then inc/dec the counter. There is no |
374 | * guarantee without disabling preemption that the processor will not change |
375 | * in between and therefore the atomicity vs. interrupt cannot be exploited |
376 | * in a useful way here. |
377 | */ |
378 | void __inc_zone_state(struct zone *zone, enum zone_stat_item item) |
379 | { |
380 | struct per_cpu_pageset __percpu *pcp = zone->pageset; |
381 | s8 __percpu *p = pcp->vm_stat_diff + item; |
382 | s8 v, t; |
383 | |
384 | v = __this_cpu_inc_return(*p); |
385 | t = __this_cpu_read(pcp->stat_threshold); |
386 | if (unlikely(v > t)) { |
387 | s8 overstep = t >> 1; |
388 | |
389 | zone_page_state_add(v + overstep, zone, item); |
390 | __this_cpu_write(*p, -overstep); |
391 | } |
392 | } |
393 | |
394 | void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item) |
395 | { |
396 | struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats; |
397 | s8 __percpu *p = pcp->vm_node_stat_diff + item; |
398 | s8 v, t; |
399 | |
400 | v = __this_cpu_inc_return(*p); |
401 | t = __this_cpu_read(pcp->stat_threshold); |
402 | if (unlikely(v > t)) { |
403 | s8 overstep = t >> 1; |
404 | |
405 | node_page_state_add(v + overstep, pgdat, item); |
406 | __this_cpu_write(*p, -overstep); |
407 | } |
408 | } |
409 | |
410 | void __inc_zone_page_state(struct page *page, enum zone_stat_item item) |
411 | { |
412 | __inc_zone_state(page_zone(page), item); |
413 | } |
414 | EXPORT_SYMBOL(__inc_zone_page_state); |
415 | |
416 | void __inc_node_page_state(struct page *page, enum node_stat_item item) |
417 | { |
418 | __inc_node_state(page_pgdat(page), item); |
419 | } |
420 | EXPORT_SYMBOL(__inc_node_page_state); |
421 | |
422 | void __dec_zone_state(struct zone *zone, enum zone_stat_item item) |
423 | { |
424 | struct per_cpu_pageset __percpu *pcp = zone->pageset; |
425 | s8 __percpu *p = pcp->vm_stat_diff + item; |
426 | s8 v, t; |
427 | |
428 | v = __this_cpu_dec_return(*p); |
429 | t = __this_cpu_read(pcp->stat_threshold); |
430 | if (unlikely(v < - t)) { |
431 | s8 overstep = t >> 1; |
432 | |
433 | zone_page_state_add(v - overstep, zone, item); |
434 | __this_cpu_write(*p, overstep); |
435 | } |
436 | } |
437 | |
438 | void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item) |
439 | { |
440 | struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats; |
441 | s8 __percpu *p = pcp->vm_node_stat_diff + item; |
442 | s8 v, t; |
443 | |
444 | v = __this_cpu_dec_return(*p); |
445 | t = __this_cpu_read(pcp->stat_threshold); |
446 | if (unlikely(v < - t)) { |
447 | s8 overstep = t >> 1; |
448 | |
449 | node_page_state_add(v - overstep, pgdat, item); |
450 | __this_cpu_write(*p, overstep); |
451 | } |
452 | } |
453 | |
454 | void __dec_zone_page_state(struct page *page, enum zone_stat_item item) |
455 | { |
456 | __dec_zone_state(page_zone(page), item); |
457 | } |
458 | EXPORT_SYMBOL(__dec_zone_page_state); |
459 | |
460 | void __dec_node_page_state(struct page *page, enum node_stat_item item) |
461 | { |
462 | __dec_node_state(page_pgdat(page), item); |
463 | } |
464 | EXPORT_SYMBOL(__dec_node_page_state); |
465 | |
466 | #ifdef CONFIG_HAVE_CMPXCHG_LOCAL |
467 | /* |
468 | * If we have cmpxchg_local support then we do not need to incur the overhead |
469 | * that comes with local_irq_save/restore if we use this_cpu_cmpxchg. |
470 | * |
471 | * mod_state() modifies the zone counter state through atomic per cpu |
472 | * operations. |
473 | * |
474 | * Overstep mode specifies how overstep should handled: |
475 | * 0 No overstepping |
476 | * 1 Overstepping half of threshold |
477 | * -1 Overstepping minus half of threshold |
478 | */ |
479 | static inline void mod_zone_state(struct zone *zone, |
480 | enum zone_stat_item item, long delta, int overstep_mode) |
481 | { |
482 | struct per_cpu_pageset __percpu *pcp = zone->pageset; |
483 | s8 __percpu *p = pcp->vm_stat_diff + item; |
484 | long o, n, t, z; |
485 | |
486 | do { |
487 | z = 0; /* overflow to zone counters */ |
488 | |
489 | /* |
490 | * The fetching of the stat_threshold is racy. We may apply |
491 | * a counter threshold to the wrong the cpu if we get |
492 | * rescheduled while executing here. However, the next |
493 | * counter update will apply the threshold again and |
494 | * therefore bring the counter under the threshold again. |
495 | * |
496 | * Most of the time the thresholds are the same anyways |
497 | * for all cpus in a zone. |
498 | */ |
499 | t = this_cpu_read(pcp->stat_threshold); |
500 | |
501 | o = this_cpu_read(*p); |
502 | n = delta + o; |
503 | |
504 | if (n > t || n < -t) { |
505 | int os = overstep_mode * (t >> 1) ; |
506 | |
507 | /* Overflow must be added to zone counters */ |
508 | z = n + os; |
509 | n = -os; |
510 | } |
511 | } while (this_cpu_cmpxchg(*p, o, n) != o); |
512 | |
513 | if (z) |
514 | zone_page_state_add(z, zone, item); |
515 | } |
516 | |
517 | void mod_zone_page_state(struct zone *zone, enum zone_stat_item item, |
518 | long delta) |
519 | { |
520 | mod_zone_state(zone, item, delta, 0); |
521 | } |
522 | EXPORT_SYMBOL(mod_zone_page_state); |
523 | |
524 | void inc_zone_page_state(struct page *page, enum zone_stat_item item) |
525 | { |
526 | mod_zone_state(page_zone(page), item, 1, 1); |
527 | } |
528 | EXPORT_SYMBOL(inc_zone_page_state); |
529 | |
530 | void dec_zone_page_state(struct page *page, enum zone_stat_item item) |
531 | { |
532 | mod_zone_state(page_zone(page), item, -1, -1); |
533 | } |
534 | EXPORT_SYMBOL(dec_zone_page_state); |
535 | |
536 | static inline void mod_node_state(struct pglist_data *pgdat, |
537 | enum node_stat_item item, int delta, int overstep_mode) |
538 | { |
539 | struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats; |
540 | s8 __percpu *p = pcp->vm_node_stat_diff + item; |
541 | long o, n, t, z; |
542 | |
543 | do { |
544 | z = 0; /* overflow to node counters */ |
545 | |
546 | /* |
547 | * The fetching of the stat_threshold is racy. We may apply |
548 | * a counter threshold to the wrong the cpu if we get |
549 | * rescheduled while executing here. However, the next |
550 | * counter update will apply the threshold again and |
551 | * therefore bring the counter under the threshold again. |
552 | * |
553 | * Most of the time the thresholds are the same anyways |
554 | * for all cpus in a node. |
555 | */ |
556 | t = this_cpu_read(pcp->stat_threshold); |
557 | |
558 | o = this_cpu_read(*p); |
559 | n = delta + o; |
560 | |
561 | if (n > t || n < -t) { |
562 | int os = overstep_mode * (t >> 1) ; |
563 | |
564 | /* Overflow must be added to node counters */ |
565 | z = n + os; |
566 | n = -os; |
567 | } |
568 | } while (this_cpu_cmpxchg(*p, o, n) != o); |
569 | |
570 | if (z) |
571 | node_page_state_add(z, pgdat, item); |
572 | } |
573 | |
574 | void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item, |
575 | long delta) |
576 | { |
577 | mod_node_state(pgdat, item, delta, 0); |
578 | } |
579 | EXPORT_SYMBOL(mod_node_page_state); |
580 | |
581 | void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item) |
582 | { |
583 | mod_node_state(pgdat, item, 1, 1); |
584 | } |
585 | |
586 | void inc_node_page_state(struct page *page, enum node_stat_item item) |
587 | { |
588 | mod_node_state(page_pgdat(page), item, 1, 1); |
589 | } |
590 | EXPORT_SYMBOL(inc_node_page_state); |
591 | |
592 | void dec_node_page_state(struct page *page, enum node_stat_item item) |
593 | { |
594 | mod_node_state(page_pgdat(page), item, -1, -1); |
595 | } |
596 | EXPORT_SYMBOL(dec_node_page_state); |
597 | #else |
598 | /* |
599 | * Use interrupt disable to serialize counter updates |
600 | */ |
601 | void mod_zone_page_state(struct zone *zone, enum zone_stat_item item, |
602 | long delta) |
603 | { |
604 | unsigned long flags; |
605 | |
606 | local_irq_save(flags); |
607 | __mod_zone_page_state(zone, item, delta); |
608 | local_irq_restore(flags); |
609 | } |
610 | EXPORT_SYMBOL(mod_zone_page_state); |
611 | |
612 | void inc_zone_page_state(struct page *page, enum zone_stat_item item) |
613 | { |
614 | unsigned long flags; |
615 | struct zone *zone; |
616 | |
617 | zone = page_zone(page); |
618 | local_irq_save(flags); |
619 | __inc_zone_state(zone, item); |
620 | local_irq_restore(flags); |
621 | } |
622 | EXPORT_SYMBOL(inc_zone_page_state); |
623 | |
624 | void dec_zone_page_state(struct page *page, enum zone_stat_item item) |
625 | { |
626 | unsigned long flags; |
627 | |
628 | local_irq_save(flags); |
629 | __dec_zone_page_state(page, item); |
630 | local_irq_restore(flags); |
631 | } |
632 | EXPORT_SYMBOL(dec_zone_page_state); |
633 | |
634 | void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item) |
635 | { |
636 | unsigned long flags; |
637 | |
638 | local_irq_save(flags); |
639 | __inc_node_state(pgdat, item); |
640 | local_irq_restore(flags); |
641 | } |
642 | EXPORT_SYMBOL(inc_node_state); |
643 | |
644 | void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item, |
645 | long delta) |
646 | { |
647 | unsigned long flags; |
648 | |
649 | local_irq_save(flags); |
650 | __mod_node_page_state(pgdat, item, delta); |
651 | local_irq_restore(flags); |
652 | } |
653 | EXPORT_SYMBOL(mod_node_page_state); |
654 | |
655 | void inc_node_page_state(struct page *page, enum node_stat_item item) |
656 | { |
657 | unsigned long flags; |
658 | struct pglist_data *pgdat; |
659 | |
660 | pgdat = page_pgdat(page); |
661 | local_irq_save(flags); |
662 | __inc_node_state(pgdat, item); |
663 | local_irq_restore(flags); |
664 | } |
665 | EXPORT_SYMBOL(inc_node_page_state); |
666 | |
667 | void dec_node_page_state(struct page *page, enum node_stat_item item) |
668 | { |
669 | unsigned long flags; |
670 | |
671 | local_irq_save(flags); |
672 | __dec_node_page_state(page, item); |
673 | local_irq_restore(flags); |
674 | } |
675 | EXPORT_SYMBOL(dec_node_page_state); |
676 | #endif |
677 | |
678 | /* |
679 | * Fold a differential into the global counters. |
680 | * Returns the number of counters updated. |
681 | */ |
682 | #ifdef CONFIG_NUMA |
683 | static int fold_diff(int *zone_diff, int *numa_diff, int *node_diff) |
684 | { |
685 | int i; |
686 | int changes = 0; |
687 | |
688 | for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) |
689 | if (zone_diff[i]) { |
690 | atomic_long_add(zone_diff[i], &vm_zone_stat[i]); |
691 | changes++; |
692 | } |
693 | |
694 | for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) |
695 | if (numa_diff[i]) { |
696 | atomic_long_add(numa_diff[i], &vm_numa_stat[i]); |
697 | changes++; |
698 | } |
699 | |
700 | for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) |
701 | if (node_diff[i]) { |
702 | atomic_long_add(node_diff[i], &vm_node_stat[i]); |
703 | changes++; |
704 | } |
705 | return changes; |
706 | } |
707 | #else |
708 | static int fold_diff(int *zone_diff, int *node_diff) |
709 | { |
710 | int i; |
711 | int changes = 0; |
712 | |
713 | for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) |
714 | if (zone_diff[i]) { |
715 | atomic_long_add(zone_diff[i], &vm_zone_stat[i]); |
716 | changes++; |
717 | } |
718 | |
719 | for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) |
720 | if (node_diff[i]) { |
721 | atomic_long_add(node_diff[i], &vm_node_stat[i]); |
722 | changes++; |
723 | } |
724 | return changes; |
725 | } |
726 | #endif /* CONFIG_NUMA */ |
727 | |
728 | /* |
729 | * Update the zone counters for the current cpu. |
730 | * |
731 | * Note that refresh_cpu_vm_stats strives to only access |
732 | * node local memory. The per cpu pagesets on remote zones are placed |
733 | * in the memory local to the processor using that pageset. So the |
734 | * loop over all zones will access a series of cachelines local to |
735 | * the processor. |
736 | * |
737 | * The call to zone_page_state_add updates the cachelines with the |
738 | * statistics in the remote zone struct as well as the global cachelines |
739 | * with the global counters. These could cause remote node cache line |
740 | * bouncing and will have to be only done when necessary. |
741 | * |
742 | * The function returns the number of global counters updated. |
743 | */ |
744 | static int refresh_cpu_vm_stats(bool do_pagesets) |
745 | { |
746 | struct pglist_data *pgdat; |
747 | struct zone *zone; |
748 | int i; |
749 | int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, }; |
750 | #ifdef CONFIG_NUMA |
751 | int global_numa_diff[NR_VM_NUMA_STAT_ITEMS] = { 0, }; |
752 | #endif |
753 | int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, }; |
754 | int changes = 0; |
755 | |
756 | for_each_populated_zone(zone) { |
757 | struct per_cpu_pageset __percpu *p = zone->pageset; |
758 | |
759 | for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) { |
760 | int v; |
761 | |
762 | v = this_cpu_xchg(p->vm_stat_diff[i], 0); |
763 | if (v) { |
764 | |
765 | atomic_long_add(v, &zone->vm_stat[i]); |
766 | global_zone_diff[i] += v; |
767 | #ifdef CONFIG_NUMA |
768 | /* 3 seconds idle till flush */ |
769 | __this_cpu_write(p->expire, 3); |
770 | #endif |
771 | } |
772 | } |
773 | #ifdef CONFIG_NUMA |
774 | for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) { |
775 | int v; |
776 | |
777 | v = this_cpu_xchg(p->vm_numa_stat_diff[i], 0); |
778 | if (v) { |
779 | |
780 | atomic_long_add(v, &zone->vm_numa_stat[i]); |
781 | global_numa_diff[i] += v; |
782 | __this_cpu_write(p->expire, 3); |
783 | } |
784 | } |
785 | |
786 | if (do_pagesets) { |
787 | cond_resched(); |
788 | /* |
789 | * Deal with draining the remote pageset of this |
790 | * processor |
791 | * |
792 | * Check if there are pages remaining in this pageset |
793 | * if not then there is nothing to expire. |
794 | */ |
795 | if (!__this_cpu_read(p->expire) || |
796 | !__this_cpu_read(p->pcp.count)) |
797 | continue; |
798 | |
799 | /* |
800 | * We never drain zones local to this processor. |
801 | */ |
802 | if (zone_to_nid(zone) == numa_node_id()) { |
803 | __this_cpu_write(p->expire, 0); |
804 | continue; |
805 | } |
806 | |
807 | if (__this_cpu_dec_return(p->expire)) |
808 | continue; |
809 | |
810 | if (__this_cpu_read(p->pcp.count)) { |
811 | drain_zone_pages(zone, this_cpu_ptr(&p->pcp)); |
812 | changes++; |
813 | } |
814 | } |
815 | #endif |
816 | } |
817 | |
818 | for_each_online_pgdat(pgdat) { |
819 | struct per_cpu_nodestat __percpu *p = pgdat->per_cpu_nodestats; |
820 | |
821 | for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { |
822 | int v; |
823 | |
824 | v = this_cpu_xchg(p->vm_node_stat_diff[i], 0); |
825 | if (v) { |
826 | atomic_long_add(v, &pgdat->vm_stat[i]); |
827 | global_node_diff[i] += v; |
828 | } |
829 | } |
830 | } |
831 | |
832 | #ifdef CONFIG_NUMA |
833 | changes += fold_diff(global_zone_diff, global_numa_diff, |
834 | global_node_diff); |
835 | #else |
836 | changes += fold_diff(global_zone_diff, global_node_diff); |
837 | #endif |
838 | return changes; |
839 | } |
840 | |
841 | /* |
842 | * Fold the data for an offline cpu into the global array. |
843 | * There cannot be any access by the offline cpu and therefore |
844 | * synchronization is simplified. |
845 | */ |
846 | void cpu_vm_stats_fold(int cpu) |
847 | { |
848 | struct pglist_data *pgdat; |
849 | struct zone *zone; |
850 | int i; |
851 | int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, }; |
852 | #ifdef CONFIG_NUMA |
853 | int global_numa_diff[NR_VM_NUMA_STAT_ITEMS] = { 0, }; |
854 | #endif |
855 | int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, }; |
856 | |
857 | for_each_populated_zone(zone) { |
858 | struct per_cpu_pageset *p; |
859 | |
860 | p = per_cpu_ptr(zone->pageset, cpu); |
861 | |
862 | for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) |
863 | if (p->vm_stat_diff[i]) { |
864 | int v; |
865 | |
866 | v = p->vm_stat_diff[i]; |
867 | p->vm_stat_diff[i] = 0; |
868 | atomic_long_add(v, &zone->vm_stat[i]); |
869 | global_zone_diff[i] += v; |
870 | } |
871 | |
872 | #ifdef CONFIG_NUMA |
873 | for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) |
874 | if (p->vm_numa_stat_diff[i]) { |
875 | int v; |
876 | |
877 | v = p->vm_numa_stat_diff[i]; |
878 | p->vm_numa_stat_diff[i] = 0; |
879 | atomic_long_add(v, &zone->vm_numa_stat[i]); |
880 | global_numa_diff[i] += v; |
881 | } |
882 | #endif |
883 | } |
884 | |
885 | for_each_online_pgdat(pgdat) { |
886 | struct per_cpu_nodestat *p; |
887 | |
888 | p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu); |
889 | |
890 | for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) |
891 | if (p->vm_node_stat_diff[i]) { |
892 | int v; |
893 | |
894 | v = p->vm_node_stat_diff[i]; |
895 | p->vm_node_stat_diff[i] = 0; |
896 | atomic_long_add(v, &pgdat->vm_stat[i]); |
897 | global_node_diff[i] += v; |
898 | } |
899 | } |
900 | |
901 | #ifdef CONFIG_NUMA |
902 | fold_diff(global_zone_diff, global_numa_diff, global_node_diff); |
903 | #else |
904 | fold_diff(global_zone_diff, global_node_diff); |
905 | #endif |
906 | } |
907 | |
908 | /* |
909 | * this is only called if !populated_zone(zone), which implies no other users of |
910 | * pset->vm_stat_diff[] exsist. |
911 | */ |
912 | void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset) |
913 | { |
914 | int i; |
915 | |
916 | for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) |
917 | if (pset->vm_stat_diff[i]) { |
918 | int v = pset->vm_stat_diff[i]; |
919 | pset->vm_stat_diff[i] = 0; |
920 | atomic_long_add(v, &zone->vm_stat[i]); |
921 | atomic_long_add(v, &vm_zone_stat[i]); |
922 | } |
923 | |
924 | #ifdef CONFIG_NUMA |
925 | for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) |
926 | if (pset->vm_numa_stat_diff[i]) { |
927 | int v = pset->vm_numa_stat_diff[i]; |
928 | |
929 | pset->vm_numa_stat_diff[i] = 0; |
930 | atomic_long_add(v, &zone->vm_numa_stat[i]); |
931 | atomic_long_add(v, &vm_numa_stat[i]); |
932 | } |
933 | #endif |
934 | } |
935 | #endif |
936 | |
937 | #ifdef CONFIG_NUMA |
938 | void __inc_numa_state(struct zone *zone, |
939 | enum numa_stat_item item) |
940 | { |
941 | struct per_cpu_pageset __percpu *pcp = zone->pageset; |
942 | u16 __percpu *p = pcp->vm_numa_stat_diff + item; |
943 | u16 v; |
944 | |
945 | v = __this_cpu_inc_return(*p); |
946 | |
947 | if (unlikely(v > NUMA_STATS_THRESHOLD)) { |
948 | zone_numa_state_add(v, zone, item); |
949 | __this_cpu_write(*p, 0); |
950 | } |
951 | } |
952 | |
953 | /* |
954 | * Determine the per node value of a stat item. This function |
955 | * is called frequently in a NUMA machine, so try to be as |
956 | * frugal as possible. |
957 | */ |
958 | unsigned long sum_zone_node_page_state(int node, |
959 | enum zone_stat_item item) |
960 | { |
961 | struct zone *zones = NODE_DATA(node)->node_zones; |
962 | int i; |
963 | unsigned long count = 0; |
964 | |
965 | for (i = 0; i < MAX_NR_ZONES; i++) |
966 | count += zone_page_state(zones + i, item); |
967 | |
968 | return count; |
969 | } |
970 | |
971 | /* |
972 | * Determine the per node value of a numa stat item. To avoid deviation, |
973 | * the per cpu stat number in vm_numa_stat_diff[] is also included. |
974 | */ |
975 | unsigned long sum_zone_numa_state(int node, |
976 | enum numa_stat_item item) |
977 | { |
978 | struct zone *zones = NODE_DATA(node)->node_zones; |
979 | int i; |
980 | unsigned long count = 0; |
981 | |
982 | for (i = 0; i < MAX_NR_ZONES; i++) |
983 | count += zone_numa_state_snapshot(zones + i, item); |
984 | |
985 | return count; |
986 | } |
987 | |
988 | /* |
989 | * Determine the per node value of a stat item. |
990 | */ |
991 | unsigned long node_page_state(struct pglist_data *pgdat, |
992 | enum node_stat_item item) |
993 | { |
994 | long x = atomic_long_read(&pgdat->vm_stat[item]); |
995 | #ifdef CONFIG_SMP |
996 | if (x < 0) |
997 | x = 0; |
998 | #endif |
999 | return x; |
1000 | } |
1001 | #endif |
1002 | |
1003 | #ifdef CONFIG_COMPACTION |
1004 | |
1005 | struct contig_page_info { |
1006 | unsigned long free_pages; |
1007 | unsigned long free_blocks_total; |
1008 | unsigned long free_blocks_suitable; |
1009 | }; |
1010 | |
1011 | /* |
1012 | * Calculate the number of free pages in a zone, how many contiguous |
1013 | * pages are free and how many are large enough to satisfy an allocation of |
1014 | * the target size. Note that this function makes no attempt to estimate |
1015 | * how many suitable free blocks there *might* be if MOVABLE pages were |
1016 | * migrated. Calculating that is possible, but expensive and can be |
1017 | * figured out from userspace |
1018 | */ |
1019 | static void fill_contig_page_info(struct zone *zone, |
1020 | unsigned int suitable_order, |
1021 | struct contig_page_info *info) |
1022 | { |
1023 | unsigned int order; |
1024 | |
1025 | info->free_pages = 0; |
1026 | info->free_blocks_total = 0; |
1027 | info->free_blocks_suitable = 0; |
1028 | |
1029 | for (order = 0; order < MAX_ORDER; order++) { |
1030 | unsigned long blocks; |
1031 | |
1032 | /* Count number of free blocks */ |
1033 | blocks = zone->free_area[order].nr_free; |
1034 | info->free_blocks_total += blocks; |
1035 | |
1036 | /* Count free base pages */ |
1037 | info->free_pages += blocks << order; |
1038 | |
1039 | /* Count the suitable free blocks */ |
1040 | if (order >= suitable_order) |
1041 | info->free_blocks_suitable += blocks << |
1042 | (order - suitable_order); |
1043 | } |
1044 | } |
1045 | |
1046 | /* |
1047 | * A fragmentation index only makes sense if an allocation of a requested |
1048 | * size would fail. If that is true, the fragmentation index indicates |
1049 | * whether external fragmentation or a lack of memory was the problem. |
1050 | * The value can be used to determine if page reclaim or compaction |
1051 | * should be used |
1052 | */ |
1053 | static int __fragmentation_index(unsigned int order, struct contig_page_info *info) |
1054 | { |
1055 | unsigned long requested = 1UL << order; |
1056 | |
1057 | if (WARN_ON_ONCE(order >= MAX_ORDER)) |
1058 | return 0; |
1059 | |
1060 | if (!info->free_blocks_total) |
1061 | return 0; |
1062 | |
1063 | /* Fragmentation index only makes sense when a request would fail */ |
1064 | if (info->free_blocks_suitable) |
1065 | return -1000; |
1066 | |
1067 | /* |
1068 | * Index is between 0 and 1 so return within 3 decimal places |
1069 | * |
1070 | * 0 => allocation would fail due to lack of memory |
1071 | * 1 => allocation would fail due to fragmentation |
1072 | */ |
1073 | return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total); |
1074 | } |
1075 | |
1076 | /* Same as __fragmentation index but allocs contig_page_info on stack */ |
1077 | int fragmentation_index(struct zone *zone, unsigned int order) |
1078 | { |
1079 | struct contig_page_info info; |
1080 | |
1081 | fill_contig_page_info(zone, order, &info); |
1082 | return __fragmentation_index(order, &info); |
1083 | } |
1084 | #endif |
1085 | |
1086 | #if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA) |
1087 | #ifdef CONFIG_ZONE_DMA |
1088 | #define TEXT_FOR_DMA(xx) xx "_dma", |
1089 | #else |
1090 | #define TEXT_FOR_DMA(xx) |
1091 | #endif |
1092 | |
1093 | #ifdef CONFIG_ZONE_DMA32 |
1094 | #define TEXT_FOR_DMA32(xx) xx "_dma32", |
1095 | #else |
1096 | #define TEXT_FOR_DMA32(xx) |
1097 | #endif |
1098 | |
1099 | #ifdef CONFIG_HIGHMEM |
1100 | #define TEXT_FOR_HIGHMEM(xx) xx "_high", |
1101 | #else |
1102 | #define TEXT_FOR_HIGHMEM(xx) |
1103 | #endif |
1104 | |
1105 | #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \ |
1106 | TEXT_FOR_HIGHMEM(xx) xx "_movable", |
1107 | |
1108 | const char * const vmstat_text[] = { |
1109 | /* enum zone_stat_item countes */ |
1110 | "nr_free_pages" , |
1111 | "nr_zone_inactive_anon" , |
1112 | "nr_zone_active_anon" , |
1113 | "nr_zone_inactive_file" , |
1114 | "nr_zone_active_file" , |
1115 | "nr_zone_unevictable" , |
1116 | "nr_zone_write_pending" , |
1117 | "nr_mlock" , |
1118 | "nr_page_table_pages" , |
1119 | "nr_kernel_stack" , |
1120 | "nr_bounce" , |
1121 | #if IS_ENABLED(CONFIG_ZSMALLOC) |
1122 | "nr_zspages" , |
1123 | #endif |
1124 | "nr_free_cma" , |
1125 | |
1126 | /* enum numa_stat_item counters */ |
1127 | #ifdef CONFIG_NUMA |
1128 | "numa_hit" , |
1129 | "numa_miss" , |
1130 | "numa_foreign" , |
1131 | "numa_interleave" , |
1132 | "numa_local" , |
1133 | "numa_other" , |
1134 | #endif |
1135 | |
1136 | /* Node-based counters */ |
1137 | "nr_inactive_anon" , |
1138 | "nr_active_anon" , |
1139 | "nr_inactive_file" , |
1140 | "nr_active_file" , |
1141 | "nr_unevictable" , |
1142 | "nr_slab_reclaimable" , |
1143 | "nr_slab_unreclaimable" , |
1144 | "nr_isolated_anon" , |
1145 | "nr_isolated_file" , |
1146 | "workingset_nodes" , |
1147 | "workingset_refault" , |
1148 | "workingset_activate" , |
1149 | "workingset_restore" , |
1150 | "workingset_nodereclaim" , |
1151 | "nr_anon_pages" , |
1152 | "nr_mapped" , |
1153 | "nr_file_pages" , |
1154 | "nr_dirty" , |
1155 | "nr_writeback" , |
1156 | "nr_writeback_temp" , |
1157 | "nr_shmem" , |
1158 | "nr_shmem_hugepages" , |
1159 | "nr_shmem_pmdmapped" , |
1160 | "nr_anon_transparent_hugepages" , |
1161 | "nr_unstable" , |
1162 | "nr_vmscan_write" , |
1163 | "nr_vmscan_immediate_reclaim" , |
1164 | "nr_dirtied" , |
1165 | "nr_written" , |
1166 | "nr_kernel_misc_reclaimable" , |
1167 | |
1168 | /* enum writeback_stat_item counters */ |
1169 | "nr_dirty_threshold" , |
1170 | "nr_dirty_background_threshold" , |
1171 | |
1172 | #ifdef CONFIG_VM_EVENT_COUNTERS |
1173 | /* enum vm_event_item counters */ |
1174 | "pgpgin" , |
1175 | "pgpgout" , |
1176 | "pswpin" , |
1177 | "pswpout" , |
1178 | |
1179 | TEXTS_FOR_ZONES("pgalloc" ) |
1180 | TEXTS_FOR_ZONES("allocstall" ) |
1181 | TEXTS_FOR_ZONES("pgskip" ) |
1182 | |
1183 | "pgfree" , |
1184 | "pgactivate" , |
1185 | "pgdeactivate" , |
1186 | "pglazyfree" , |
1187 | |
1188 | "pgfault" , |
1189 | "pgmajfault" , |
1190 | "pglazyfreed" , |
1191 | |
1192 | "pgrefill" , |
1193 | "pgsteal_kswapd" , |
1194 | "pgsteal_direct" , |
1195 | "pgscan_kswapd" , |
1196 | "pgscan_direct" , |
1197 | "pgscan_direct_throttle" , |
1198 | |
1199 | #ifdef CONFIG_NUMA |
1200 | "zone_reclaim_failed" , |
1201 | #endif |
1202 | "pginodesteal" , |
1203 | "slabs_scanned" , |
1204 | "kswapd_inodesteal" , |
1205 | "kswapd_low_wmark_hit_quickly" , |
1206 | "kswapd_high_wmark_hit_quickly" , |
1207 | "pageoutrun" , |
1208 | |
1209 | "pgrotated" , |
1210 | |
1211 | "drop_pagecache" , |
1212 | "drop_slab" , |
1213 | "oom_kill" , |
1214 | |
1215 | #ifdef CONFIG_NUMA_BALANCING |
1216 | "numa_pte_updates" , |
1217 | "numa_huge_pte_updates" , |
1218 | "numa_hint_faults" , |
1219 | "numa_hint_faults_local" , |
1220 | "numa_pages_migrated" , |
1221 | #endif |
1222 | #ifdef CONFIG_MIGRATION |
1223 | "pgmigrate_success" , |
1224 | "pgmigrate_fail" , |
1225 | #endif |
1226 | #ifdef CONFIG_COMPACTION |
1227 | "compact_migrate_scanned" , |
1228 | "compact_free_scanned" , |
1229 | "compact_isolated" , |
1230 | "compact_stall" , |
1231 | "compact_fail" , |
1232 | "compact_success" , |
1233 | "compact_daemon_wake" , |
1234 | "compact_daemon_migrate_scanned" , |
1235 | "compact_daemon_free_scanned" , |
1236 | #endif |
1237 | |
1238 | #ifdef CONFIG_HUGETLB_PAGE |
1239 | "htlb_buddy_alloc_success" , |
1240 | "htlb_buddy_alloc_fail" , |
1241 | #endif |
1242 | "unevictable_pgs_culled" , |
1243 | "unevictable_pgs_scanned" , |
1244 | "unevictable_pgs_rescued" , |
1245 | "unevictable_pgs_mlocked" , |
1246 | "unevictable_pgs_munlocked" , |
1247 | "unevictable_pgs_cleared" , |
1248 | "unevictable_pgs_stranded" , |
1249 | |
1250 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
1251 | "thp_fault_alloc" , |
1252 | "thp_fault_fallback" , |
1253 | "thp_collapse_alloc" , |
1254 | "thp_collapse_alloc_failed" , |
1255 | "thp_file_alloc" , |
1256 | "thp_file_mapped" , |
1257 | "thp_split_page" , |
1258 | "thp_split_page_failed" , |
1259 | "thp_deferred_split_page" , |
1260 | "thp_split_pmd" , |
1261 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
1262 | "thp_split_pud" , |
1263 | #endif |
1264 | "thp_zero_page_alloc" , |
1265 | "thp_zero_page_alloc_failed" , |
1266 | "thp_swpout" , |
1267 | "thp_swpout_fallback" , |
1268 | #endif |
1269 | #ifdef CONFIG_MEMORY_BALLOON |
1270 | "balloon_inflate" , |
1271 | "balloon_deflate" , |
1272 | #ifdef CONFIG_BALLOON_COMPACTION |
1273 | "balloon_migrate" , |
1274 | #endif |
1275 | #endif /* CONFIG_MEMORY_BALLOON */ |
1276 | #ifdef CONFIG_DEBUG_TLBFLUSH |
1277 | #ifdef CONFIG_SMP |
1278 | "nr_tlb_remote_flush" , |
1279 | "nr_tlb_remote_flush_received" , |
1280 | #else |
1281 | "" , /* nr_tlb_remote_flush */ |
1282 | "" , /* nr_tlb_remote_flush_received */ |
1283 | #endif /* CONFIG_SMP */ |
1284 | "nr_tlb_local_flush_all" , |
1285 | "nr_tlb_local_flush_one" , |
1286 | #endif /* CONFIG_DEBUG_TLBFLUSH */ |
1287 | |
1288 | #ifdef CONFIG_DEBUG_VM_VMACACHE |
1289 | "vmacache_find_calls" , |
1290 | "vmacache_find_hits" , |
1291 | #endif |
1292 | #ifdef CONFIG_SWAP |
1293 | "swap_ra" , |
1294 | "swap_ra_hit" , |
1295 | #endif |
1296 | #endif /* CONFIG_VM_EVENTS_COUNTERS */ |
1297 | }; |
1298 | #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */ |
1299 | |
1300 | #if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \ |
1301 | defined(CONFIG_PROC_FS) |
1302 | static void *frag_start(struct seq_file *m, loff_t *pos) |
1303 | { |
1304 | pg_data_t *pgdat; |
1305 | loff_t node = *pos; |
1306 | |
1307 | for (pgdat = first_online_pgdat(); |
1308 | pgdat && node; |
1309 | pgdat = next_online_pgdat(pgdat)) |
1310 | --node; |
1311 | |
1312 | return pgdat; |
1313 | } |
1314 | |
1315 | static void *frag_next(struct seq_file *m, void *arg, loff_t *pos) |
1316 | { |
1317 | pg_data_t *pgdat = (pg_data_t *)arg; |
1318 | |
1319 | (*pos)++; |
1320 | return next_online_pgdat(pgdat); |
1321 | } |
1322 | |
1323 | static void frag_stop(struct seq_file *m, void *arg) |
1324 | { |
1325 | } |
1326 | |
1327 | /* |
1328 | * Walk zones in a node and print using a callback. |
1329 | * If @assert_populated is true, only use callback for zones that are populated. |
1330 | */ |
1331 | static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat, |
1332 | bool assert_populated, bool nolock, |
1333 | void (*print)(struct seq_file *m, pg_data_t *, struct zone *)) |
1334 | { |
1335 | struct zone *zone; |
1336 | struct zone *node_zones = pgdat->node_zones; |
1337 | unsigned long flags; |
1338 | |
1339 | for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) { |
1340 | if (assert_populated && !populated_zone(zone)) |
1341 | continue; |
1342 | |
1343 | if (!nolock) |
1344 | spin_lock_irqsave(&zone->lock, flags); |
1345 | print(m, pgdat, zone); |
1346 | if (!nolock) |
1347 | spin_unlock_irqrestore(&zone->lock, flags); |
1348 | } |
1349 | } |
1350 | #endif |
1351 | |
1352 | #ifdef CONFIG_PROC_FS |
1353 | static void frag_show_print(struct seq_file *m, pg_data_t *pgdat, |
1354 | struct zone *zone) |
1355 | { |
1356 | int order; |
1357 | |
1358 | seq_printf(m, "Node %d, zone %8s " , pgdat->node_id, zone->name); |
1359 | for (order = 0; order < MAX_ORDER; ++order) |
1360 | seq_printf(m, "%6lu " , zone->free_area[order].nr_free); |
1361 | seq_putc(m, '\n'); |
1362 | } |
1363 | |
1364 | /* |
1365 | * This walks the free areas for each zone. |
1366 | */ |
1367 | static int frag_show(struct seq_file *m, void *arg) |
1368 | { |
1369 | pg_data_t *pgdat = (pg_data_t *)arg; |
1370 | walk_zones_in_node(m, pgdat, true, false, frag_show_print); |
1371 | return 0; |
1372 | } |
1373 | |
1374 | static void pagetypeinfo_showfree_print(struct seq_file *m, |
1375 | pg_data_t *pgdat, struct zone *zone) |
1376 | { |
1377 | int order, mtype; |
1378 | |
1379 | for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) { |
1380 | seq_printf(m, "Node %4d, zone %8s, type %12s " , |
1381 | pgdat->node_id, |
1382 | zone->name, |
1383 | migratetype_names[mtype]); |
1384 | for (order = 0; order < MAX_ORDER; ++order) { |
1385 | unsigned long freecount = 0; |
1386 | struct free_area *area; |
1387 | struct list_head *curr; |
1388 | |
1389 | area = &(zone->free_area[order]); |
1390 | |
1391 | list_for_each(curr, &area->free_list[mtype]) |
1392 | freecount++; |
1393 | seq_printf(m, "%6lu " , freecount); |
1394 | } |
1395 | seq_putc(m, '\n'); |
1396 | } |
1397 | } |
1398 | |
1399 | /* Print out the free pages at each order for each migatetype */ |
1400 | static int pagetypeinfo_showfree(struct seq_file *m, void *arg) |
1401 | { |
1402 | int order; |
1403 | pg_data_t *pgdat = (pg_data_t *)arg; |
1404 | |
1405 | /* Print header */ |
1406 | seq_printf(m, "%-43s " , "Free pages count per migrate type at order" ); |
1407 | for (order = 0; order < MAX_ORDER; ++order) |
1408 | seq_printf(m, "%6d " , order); |
1409 | seq_putc(m, '\n'); |
1410 | |
1411 | walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print); |
1412 | |
1413 | return 0; |
1414 | } |
1415 | |
1416 | static void pagetypeinfo_showblockcount_print(struct seq_file *m, |
1417 | pg_data_t *pgdat, struct zone *zone) |
1418 | { |
1419 | int mtype; |
1420 | unsigned long pfn; |
1421 | unsigned long start_pfn = zone->zone_start_pfn; |
1422 | unsigned long end_pfn = zone_end_pfn(zone); |
1423 | unsigned long count[MIGRATE_TYPES] = { 0, }; |
1424 | |
1425 | for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { |
1426 | struct page *page; |
1427 | |
1428 | page = pfn_to_online_page(pfn); |
1429 | if (!page) |
1430 | continue; |
1431 | |
1432 | /* Watch for unexpected holes punched in the memmap */ |
1433 | if (!memmap_valid_within(pfn, page, zone)) |
1434 | continue; |
1435 | |
1436 | if (page_zone(page) != zone) |
1437 | continue; |
1438 | |
1439 | mtype = get_pageblock_migratetype(page); |
1440 | |
1441 | if (mtype < MIGRATE_TYPES) |
1442 | count[mtype]++; |
1443 | } |
1444 | |
1445 | /* Print counts */ |
1446 | seq_printf(m, "Node %d, zone %8s " , pgdat->node_id, zone->name); |
1447 | for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) |
1448 | seq_printf(m, "%12lu " , count[mtype]); |
1449 | seq_putc(m, '\n'); |
1450 | } |
1451 | |
1452 | /* Print out the number of pageblocks for each migratetype */ |
1453 | static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg) |
1454 | { |
1455 | int mtype; |
1456 | pg_data_t *pgdat = (pg_data_t *)arg; |
1457 | |
1458 | seq_printf(m, "\n%-23s" , "Number of blocks type " ); |
1459 | for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) |
1460 | seq_printf(m, "%12s " , migratetype_names[mtype]); |
1461 | seq_putc(m, '\n'); |
1462 | walk_zones_in_node(m, pgdat, true, false, |
1463 | pagetypeinfo_showblockcount_print); |
1464 | |
1465 | return 0; |
1466 | } |
1467 | |
1468 | /* |
1469 | * Print out the number of pageblocks for each migratetype that contain pages |
1470 | * of other types. This gives an indication of how well fallbacks are being |
1471 | * contained by rmqueue_fallback(). It requires information from PAGE_OWNER |
1472 | * to determine what is going on |
1473 | */ |
1474 | static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat) |
1475 | { |
1476 | #ifdef CONFIG_PAGE_OWNER |
1477 | int mtype; |
1478 | |
1479 | if (!static_branch_unlikely(&page_owner_inited)) |
1480 | return; |
1481 | |
1482 | drain_all_pages(NULL); |
1483 | |
1484 | seq_printf(m, "\n%-23s" , "Number of mixed blocks " ); |
1485 | for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) |
1486 | seq_printf(m, "%12s " , migratetype_names[mtype]); |
1487 | seq_putc(m, '\n'); |
1488 | |
1489 | walk_zones_in_node(m, pgdat, true, true, |
1490 | pagetypeinfo_showmixedcount_print); |
1491 | #endif /* CONFIG_PAGE_OWNER */ |
1492 | } |
1493 | |
1494 | /* |
1495 | * This prints out statistics in relation to grouping pages by mobility. |
1496 | * It is expensive to collect so do not constantly read the file. |
1497 | */ |
1498 | static int pagetypeinfo_show(struct seq_file *m, void *arg) |
1499 | { |
1500 | pg_data_t *pgdat = (pg_data_t *)arg; |
1501 | |
1502 | /* check memoryless node */ |
1503 | if (!node_state(pgdat->node_id, N_MEMORY)) |
1504 | return 0; |
1505 | |
1506 | seq_printf(m, "Page block order: %d\n" , pageblock_order); |
1507 | seq_printf(m, "Pages per block: %lu\n" , pageblock_nr_pages); |
1508 | seq_putc(m, '\n'); |
1509 | pagetypeinfo_showfree(m, pgdat); |
1510 | pagetypeinfo_showblockcount(m, pgdat); |
1511 | pagetypeinfo_showmixedcount(m, pgdat); |
1512 | |
1513 | return 0; |
1514 | } |
1515 | |
1516 | static const struct seq_operations fragmentation_op = { |
1517 | .start = frag_start, |
1518 | .next = frag_next, |
1519 | .stop = frag_stop, |
1520 | .show = frag_show, |
1521 | }; |
1522 | |
1523 | static const struct seq_operations pagetypeinfo_op = { |
1524 | .start = frag_start, |
1525 | .next = frag_next, |
1526 | .stop = frag_stop, |
1527 | .show = pagetypeinfo_show, |
1528 | }; |
1529 | |
1530 | static bool is_zone_first_populated(pg_data_t *pgdat, struct zone *zone) |
1531 | { |
1532 | int zid; |
1533 | |
1534 | for (zid = 0; zid < MAX_NR_ZONES; zid++) { |
1535 | struct zone *compare = &pgdat->node_zones[zid]; |
1536 | |
1537 | if (populated_zone(compare)) |
1538 | return zone == compare; |
1539 | } |
1540 | |
1541 | return false; |
1542 | } |
1543 | |
1544 | static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat, |
1545 | struct zone *zone) |
1546 | { |
1547 | int i; |
1548 | seq_printf(m, "Node %d, zone %8s" , pgdat->node_id, zone->name); |
1549 | if (is_zone_first_populated(pgdat, zone)) { |
1550 | seq_printf(m, "\n per-node stats" ); |
1551 | for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) { |
1552 | seq_printf(m, "\n %-12s %lu" , |
1553 | vmstat_text[i + NR_VM_ZONE_STAT_ITEMS + |
1554 | NR_VM_NUMA_STAT_ITEMS], |
1555 | node_page_state(pgdat, i)); |
1556 | } |
1557 | } |
1558 | seq_printf(m, |
1559 | "\n pages free %lu" |
1560 | "\n min %lu" |
1561 | "\n low %lu" |
1562 | "\n high %lu" |
1563 | "\n spanned %lu" |
1564 | "\n present %lu" |
1565 | "\n managed %lu" , |
1566 | zone_page_state(zone, NR_FREE_PAGES), |
1567 | min_wmark_pages(zone), |
1568 | low_wmark_pages(zone), |
1569 | high_wmark_pages(zone), |
1570 | zone->spanned_pages, |
1571 | zone->present_pages, |
1572 | zone_managed_pages(zone)); |
1573 | |
1574 | seq_printf(m, |
1575 | "\n protection: (%ld" , |
1576 | zone->lowmem_reserve[0]); |
1577 | for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++) |
1578 | seq_printf(m, ", %ld" , zone->lowmem_reserve[i]); |
1579 | seq_putc(m, ')'); |
1580 | |
1581 | /* If unpopulated, no other information is useful */ |
1582 | if (!populated_zone(zone)) { |
1583 | seq_putc(m, '\n'); |
1584 | return; |
1585 | } |
1586 | |
1587 | for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) |
1588 | seq_printf(m, "\n %-12s %lu" , vmstat_text[i], |
1589 | zone_page_state(zone, i)); |
1590 | |
1591 | #ifdef CONFIG_NUMA |
1592 | for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) |
1593 | seq_printf(m, "\n %-12s %lu" , |
1594 | vmstat_text[i + NR_VM_ZONE_STAT_ITEMS], |
1595 | zone_numa_state_snapshot(zone, i)); |
1596 | #endif |
1597 | |
1598 | seq_printf(m, "\n pagesets" ); |
1599 | for_each_online_cpu(i) { |
1600 | struct per_cpu_pageset *pageset; |
1601 | |
1602 | pageset = per_cpu_ptr(zone->pageset, i); |
1603 | seq_printf(m, |
1604 | "\n cpu: %i" |
1605 | "\n count: %i" |
1606 | "\n high: %i" |
1607 | "\n batch: %i" , |
1608 | i, |
1609 | pageset->pcp.count, |
1610 | pageset->pcp.high, |
1611 | pageset->pcp.batch); |
1612 | #ifdef CONFIG_SMP |
1613 | seq_printf(m, "\n vm stats threshold: %d" , |
1614 | pageset->stat_threshold); |
1615 | #endif |
1616 | } |
1617 | seq_printf(m, |
1618 | "\n node_unreclaimable: %u" |
1619 | "\n start_pfn: %lu" , |
1620 | pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES, |
1621 | zone->zone_start_pfn); |
1622 | seq_putc(m, '\n'); |
1623 | } |
1624 | |
1625 | /* |
1626 | * Output information about zones in @pgdat. All zones are printed regardless |
1627 | * of whether they are populated or not: lowmem_reserve_ratio operates on the |
1628 | * set of all zones and userspace would not be aware of such zones if they are |
1629 | * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio). |
1630 | */ |
1631 | static int zoneinfo_show(struct seq_file *m, void *arg) |
1632 | { |
1633 | pg_data_t *pgdat = (pg_data_t *)arg; |
1634 | walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print); |
1635 | return 0; |
1636 | } |
1637 | |
1638 | static const struct seq_operations zoneinfo_op = { |
1639 | .start = frag_start, /* iterate over all zones. The same as in |
1640 | * fragmentation. */ |
1641 | .next = frag_next, |
1642 | .stop = frag_stop, |
1643 | .show = zoneinfo_show, |
1644 | }; |
1645 | |
1646 | enum writeback_stat_item { |
1647 | NR_DIRTY_THRESHOLD, |
1648 | NR_DIRTY_BG_THRESHOLD, |
1649 | NR_VM_WRITEBACK_STAT_ITEMS, |
1650 | }; |
1651 | |
1652 | static void *vmstat_start(struct seq_file *m, loff_t *pos) |
1653 | { |
1654 | unsigned long *v; |
1655 | int i, stat_items_size; |
1656 | |
1657 | if (*pos >= ARRAY_SIZE(vmstat_text)) |
1658 | return NULL; |
1659 | stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) + |
1660 | NR_VM_NUMA_STAT_ITEMS * sizeof(unsigned long) + |
1661 | NR_VM_NODE_STAT_ITEMS * sizeof(unsigned long) + |
1662 | NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long); |
1663 | |
1664 | #ifdef CONFIG_VM_EVENT_COUNTERS |
1665 | stat_items_size += sizeof(struct vm_event_state); |
1666 | #endif |
1667 | |
1668 | BUILD_BUG_ON(stat_items_size != |
1669 | ARRAY_SIZE(vmstat_text) * sizeof(unsigned long)); |
1670 | v = kmalloc(stat_items_size, GFP_KERNEL); |
1671 | m->private = v; |
1672 | if (!v) |
1673 | return ERR_PTR(-ENOMEM); |
1674 | for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) |
1675 | v[i] = global_zone_page_state(i); |
1676 | v += NR_VM_ZONE_STAT_ITEMS; |
1677 | |
1678 | #ifdef CONFIG_NUMA |
1679 | for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) |
1680 | v[i] = global_numa_state(i); |
1681 | v += NR_VM_NUMA_STAT_ITEMS; |
1682 | #endif |
1683 | |
1684 | for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) |
1685 | v[i] = global_node_page_state(i); |
1686 | v += NR_VM_NODE_STAT_ITEMS; |
1687 | |
1688 | global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD, |
1689 | v + NR_DIRTY_THRESHOLD); |
1690 | v += NR_VM_WRITEBACK_STAT_ITEMS; |
1691 | |
1692 | #ifdef CONFIG_VM_EVENT_COUNTERS |
1693 | all_vm_events(v); |
1694 | v[PGPGIN] /= 2; /* sectors -> kbytes */ |
1695 | v[PGPGOUT] /= 2; |
1696 | #endif |
1697 | return (unsigned long *)m->private + *pos; |
1698 | } |
1699 | |
1700 | static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos) |
1701 | { |
1702 | (*pos)++; |
1703 | if (*pos >= ARRAY_SIZE(vmstat_text)) |
1704 | return NULL; |
1705 | return (unsigned long *)m->private + *pos; |
1706 | } |
1707 | |
1708 | static int vmstat_show(struct seq_file *m, void *arg) |
1709 | { |
1710 | unsigned long *l = arg; |
1711 | unsigned long off = l - (unsigned long *)m->private; |
1712 | |
1713 | seq_puts(m, vmstat_text[off]); |
1714 | seq_put_decimal_ull(m, " " , *l); |
1715 | seq_putc(m, '\n'); |
1716 | return 0; |
1717 | } |
1718 | |
1719 | static void vmstat_stop(struct seq_file *m, void *arg) |
1720 | { |
1721 | kfree(m->private); |
1722 | m->private = NULL; |
1723 | } |
1724 | |
1725 | static const struct seq_operations vmstat_op = { |
1726 | .start = vmstat_start, |
1727 | .next = vmstat_next, |
1728 | .stop = vmstat_stop, |
1729 | .show = vmstat_show, |
1730 | }; |
1731 | #endif /* CONFIG_PROC_FS */ |
1732 | |
1733 | #ifdef CONFIG_SMP |
1734 | static DEFINE_PER_CPU(struct delayed_work, vmstat_work); |
1735 | int sysctl_stat_interval __read_mostly = HZ; |
1736 | |
1737 | #ifdef CONFIG_PROC_FS |
1738 | static void refresh_vm_stats(struct work_struct *work) |
1739 | { |
1740 | refresh_cpu_vm_stats(true); |
1741 | } |
1742 | |
1743 | int vmstat_refresh(struct ctl_table *table, int write, |
1744 | void __user *buffer, size_t *lenp, loff_t *ppos) |
1745 | { |
1746 | long val; |
1747 | int err; |
1748 | int i; |
1749 | |
1750 | /* |
1751 | * The regular update, every sysctl_stat_interval, may come later |
1752 | * than expected: leaving a significant amount in per_cpu buckets. |
1753 | * This is particularly misleading when checking a quantity of HUGE |
1754 | * pages, immediately after running a test. /proc/sys/vm/stat_refresh, |
1755 | * which can equally be echo'ed to or cat'ted from (by root), |
1756 | * can be used to update the stats just before reading them. |
1757 | * |
1758 | * Oh, and since global_zone_page_state() etc. are so careful to hide |
1759 | * transiently negative values, report an error here if any of |
1760 | * the stats is negative, so we know to go looking for imbalance. |
1761 | */ |
1762 | err = schedule_on_each_cpu(refresh_vm_stats); |
1763 | if (err) |
1764 | return err; |
1765 | for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) { |
1766 | val = atomic_long_read(&vm_zone_stat[i]); |
1767 | if (val < 0) { |
1768 | pr_warn("%s: %s %ld\n" , |
1769 | __func__, vmstat_text[i], val); |
1770 | err = -EINVAL; |
1771 | } |
1772 | } |
1773 | #ifdef CONFIG_NUMA |
1774 | for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) { |
1775 | val = atomic_long_read(&vm_numa_stat[i]); |
1776 | if (val < 0) { |
1777 | pr_warn("%s: %s %ld\n" , |
1778 | __func__, vmstat_text[i + NR_VM_ZONE_STAT_ITEMS], val); |
1779 | err = -EINVAL; |
1780 | } |
1781 | } |
1782 | #endif |
1783 | if (err) |
1784 | return err; |
1785 | if (write) |
1786 | *ppos += *lenp; |
1787 | else |
1788 | *lenp = 0; |
1789 | return 0; |
1790 | } |
1791 | #endif /* CONFIG_PROC_FS */ |
1792 | |
1793 | static void vmstat_update(struct work_struct *w) |
1794 | { |
1795 | if (refresh_cpu_vm_stats(true)) { |
1796 | /* |
1797 | * Counters were updated so we expect more updates |
1798 | * to occur in the future. Keep on running the |
1799 | * update worker thread. |
1800 | */ |
1801 | queue_delayed_work_on(smp_processor_id(), mm_percpu_wq, |
1802 | this_cpu_ptr(&vmstat_work), |
1803 | round_jiffies_relative(sysctl_stat_interval)); |
1804 | } |
1805 | } |
1806 | |
1807 | /* |
1808 | * Switch off vmstat processing and then fold all the remaining differentials |
1809 | * until the diffs stay at zero. The function is used by NOHZ and can only be |
1810 | * invoked when tick processing is not active. |
1811 | */ |
1812 | /* |
1813 | * Check if the diffs for a certain cpu indicate that |
1814 | * an update is needed. |
1815 | */ |
1816 | static bool need_update(int cpu) |
1817 | { |
1818 | struct zone *zone; |
1819 | |
1820 | for_each_populated_zone(zone) { |
1821 | struct per_cpu_pageset *p = per_cpu_ptr(zone->pageset, cpu); |
1822 | |
1823 | BUILD_BUG_ON(sizeof(p->vm_stat_diff[0]) != 1); |
1824 | #ifdef CONFIG_NUMA |
1825 | BUILD_BUG_ON(sizeof(p->vm_numa_stat_diff[0]) != 2); |
1826 | #endif |
1827 | |
1828 | /* |
1829 | * The fast way of checking if there are any vmstat diffs. |
1830 | */ |
1831 | if (memchr_inv(p->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS * |
1832 | sizeof(p->vm_stat_diff[0]))) |
1833 | return true; |
1834 | #ifdef CONFIG_NUMA |
1835 | if (memchr_inv(p->vm_numa_stat_diff, 0, NR_VM_NUMA_STAT_ITEMS * |
1836 | sizeof(p->vm_numa_stat_diff[0]))) |
1837 | return true; |
1838 | #endif |
1839 | } |
1840 | return false; |
1841 | } |
1842 | |
1843 | /* |
1844 | * Switch off vmstat processing and then fold all the remaining differentials |
1845 | * until the diffs stay at zero. The function is used by NOHZ and can only be |
1846 | * invoked when tick processing is not active. |
1847 | */ |
1848 | void quiet_vmstat(void) |
1849 | { |
1850 | if (system_state != SYSTEM_RUNNING) |
1851 | return; |
1852 | |
1853 | if (!delayed_work_pending(this_cpu_ptr(&vmstat_work))) |
1854 | return; |
1855 | |
1856 | if (!need_update(smp_processor_id())) |
1857 | return; |
1858 | |
1859 | /* |
1860 | * Just refresh counters and do not care about the pending delayed |
1861 | * vmstat_update. It doesn't fire that often to matter and canceling |
1862 | * it would be too expensive from this path. |
1863 | * vmstat_shepherd will take care about that for us. |
1864 | */ |
1865 | refresh_cpu_vm_stats(false); |
1866 | } |
1867 | |
1868 | /* |
1869 | * Shepherd worker thread that checks the |
1870 | * differentials of processors that have their worker |
1871 | * threads for vm statistics updates disabled because of |
1872 | * inactivity. |
1873 | */ |
1874 | static void vmstat_shepherd(struct work_struct *w); |
1875 | |
1876 | static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd); |
1877 | |
1878 | static void vmstat_shepherd(struct work_struct *w) |
1879 | { |
1880 | int cpu; |
1881 | |
1882 | get_online_cpus(); |
1883 | /* Check processors whose vmstat worker threads have been disabled */ |
1884 | for_each_online_cpu(cpu) { |
1885 | struct delayed_work *dw = &per_cpu(vmstat_work, cpu); |
1886 | |
1887 | if (!delayed_work_pending(dw) && need_update(cpu)) |
1888 | queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0); |
1889 | } |
1890 | put_online_cpus(); |
1891 | |
1892 | schedule_delayed_work(&shepherd, |
1893 | round_jiffies_relative(sysctl_stat_interval)); |
1894 | } |
1895 | |
1896 | static void __init start_shepherd_timer(void) |
1897 | { |
1898 | int cpu; |
1899 | |
1900 | for_each_possible_cpu(cpu) |
1901 | INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu), |
1902 | vmstat_update); |
1903 | |
1904 | schedule_delayed_work(&shepherd, |
1905 | round_jiffies_relative(sysctl_stat_interval)); |
1906 | } |
1907 | |
1908 | static void __init init_cpu_node_state(void) |
1909 | { |
1910 | int node; |
1911 | |
1912 | for_each_online_node(node) { |
1913 | if (cpumask_weight(cpumask_of_node(node)) > 0) |
1914 | node_set_state(node, N_CPU); |
1915 | } |
1916 | } |
1917 | |
1918 | static int vmstat_cpu_online(unsigned int cpu) |
1919 | { |
1920 | refresh_zone_stat_thresholds(); |
1921 | node_set_state(cpu_to_node(cpu), N_CPU); |
1922 | return 0; |
1923 | } |
1924 | |
1925 | static int vmstat_cpu_down_prep(unsigned int cpu) |
1926 | { |
1927 | cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu)); |
1928 | return 0; |
1929 | } |
1930 | |
1931 | static int vmstat_cpu_dead(unsigned int cpu) |
1932 | { |
1933 | const struct cpumask *node_cpus; |
1934 | int node; |
1935 | |
1936 | node = cpu_to_node(cpu); |
1937 | |
1938 | refresh_zone_stat_thresholds(); |
1939 | node_cpus = cpumask_of_node(node); |
1940 | if (cpumask_weight(node_cpus) > 0) |
1941 | return 0; |
1942 | |
1943 | node_clear_state(node, N_CPU); |
1944 | return 0; |
1945 | } |
1946 | |
1947 | #endif |
1948 | |
1949 | struct workqueue_struct *mm_percpu_wq; |
1950 | |
1951 | void __init init_mm_internals(void) |
1952 | { |
1953 | int ret __maybe_unused; |
1954 | |
1955 | mm_percpu_wq = alloc_workqueue("mm_percpu_wq" , WQ_MEM_RECLAIM, 0); |
1956 | |
1957 | #ifdef CONFIG_SMP |
1958 | ret = cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD, "mm/vmstat:dead" , |
1959 | NULL, vmstat_cpu_dead); |
1960 | if (ret < 0) |
1961 | pr_err("vmstat: failed to register 'dead' hotplug state\n" ); |
1962 | |
1963 | ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "mm/vmstat:online" , |
1964 | vmstat_cpu_online, |
1965 | vmstat_cpu_down_prep); |
1966 | if (ret < 0) |
1967 | pr_err("vmstat: failed to register 'online' hotplug state\n" ); |
1968 | |
1969 | get_online_cpus(); |
1970 | init_cpu_node_state(); |
1971 | put_online_cpus(); |
1972 | |
1973 | start_shepherd_timer(); |
1974 | #endif |
1975 | #ifdef CONFIG_PROC_FS |
1976 | proc_create_seq("buddyinfo" , 0444, NULL, &fragmentation_op); |
1977 | proc_create_seq("pagetypeinfo" , 0444, NULL, &pagetypeinfo_op); |
1978 | proc_create_seq("vmstat" , 0444, NULL, &vmstat_op); |
1979 | proc_create_seq("zoneinfo" , 0444, NULL, &zoneinfo_op); |
1980 | #endif |
1981 | } |
1982 | |
1983 | #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION) |
1984 | |
1985 | /* |
1986 | * Return an index indicating how much of the available free memory is |
1987 | * unusable for an allocation of the requested size. |
1988 | */ |
1989 | static int unusable_free_index(unsigned int order, |
1990 | struct contig_page_info *info) |
1991 | { |
1992 | /* No free memory is interpreted as all free memory is unusable */ |
1993 | if (info->free_pages == 0) |
1994 | return 1000; |
1995 | |
1996 | /* |
1997 | * Index should be a value between 0 and 1. Return a value to 3 |
1998 | * decimal places. |
1999 | * |
2000 | * 0 => no fragmentation |
2001 | * 1 => high fragmentation |
2002 | */ |
2003 | return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages); |
2004 | |
2005 | } |
2006 | |
2007 | static void unusable_show_print(struct seq_file *m, |
2008 | pg_data_t *pgdat, struct zone *zone) |
2009 | { |
2010 | unsigned int order; |
2011 | int index; |
2012 | struct contig_page_info info; |
2013 | |
2014 | seq_printf(m, "Node %d, zone %8s " , |
2015 | pgdat->node_id, |
2016 | zone->name); |
2017 | for (order = 0; order < MAX_ORDER; ++order) { |
2018 | fill_contig_page_info(zone, order, &info); |
2019 | index = unusable_free_index(order, &info); |
2020 | seq_printf(m, "%d.%03d " , index / 1000, index % 1000); |
2021 | } |
2022 | |
2023 | seq_putc(m, '\n'); |
2024 | } |
2025 | |
2026 | /* |
2027 | * Display unusable free space index |
2028 | * |
2029 | * The unusable free space index measures how much of the available free |
2030 | * memory cannot be used to satisfy an allocation of a given size and is a |
2031 | * value between 0 and 1. The higher the value, the more of free memory is |
2032 | * unusable and by implication, the worse the external fragmentation is. This |
2033 | * can be expressed as a percentage by multiplying by 100. |
2034 | */ |
2035 | static int unusable_show(struct seq_file *m, void *arg) |
2036 | { |
2037 | pg_data_t *pgdat = (pg_data_t *)arg; |
2038 | |
2039 | /* check memoryless node */ |
2040 | if (!node_state(pgdat->node_id, N_MEMORY)) |
2041 | return 0; |
2042 | |
2043 | walk_zones_in_node(m, pgdat, true, false, unusable_show_print); |
2044 | |
2045 | return 0; |
2046 | } |
2047 | |
2048 | static const struct seq_operations unusable_op = { |
2049 | .start = frag_start, |
2050 | .next = frag_next, |
2051 | .stop = frag_stop, |
2052 | .show = unusable_show, |
2053 | }; |
2054 | |
2055 | static int unusable_open(struct inode *inode, struct file *file) |
2056 | { |
2057 | return seq_open(file, &unusable_op); |
2058 | } |
2059 | |
2060 | static const struct file_operations unusable_file_ops = { |
2061 | .open = unusable_open, |
2062 | .read = seq_read, |
2063 | .llseek = seq_lseek, |
2064 | .release = seq_release, |
2065 | }; |
2066 | |
2067 | static void extfrag_show_print(struct seq_file *m, |
2068 | pg_data_t *pgdat, struct zone *zone) |
2069 | { |
2070 | unsigned int order; |
2071 | int index; |
2072 | |
2073 | /* Alloc on stack as interrupts are disabled for zone walk */ |
2074 | struct contig_page_info info; |
2075 | |
2076 | seq_printf(m, "Node %d, zone %8s " , |
2077 | pgdat->node_id, |
2078 | zone->name); |
2079 | for (order = 0; order < MAX_ORDER; ++order) { |
2080 | fill_contig_page_info(zone, order, &info); |
2081 | index = __fragmentation_index(order, &info); |
2082 | seq_printf(m, "%d.%03d " , index / 1000, index % 1000); |
2083 | } |
2084 | |
2085 | seq_putc(m, '\n'); |
2086 | } |
2087 | |
2088 | /* |
2089 | * Display fragmentation index for orders that allocations would fail for |
2090 | */ |
2091 | static int extfrag_show(struct seq_file *m, void *arg) |
2092 | { |
2093 | pg_data_t *pgdat = (pg_data_t *)arg; |
2094 | |
2095 | walk_zones_in_node(m, pgdat, true, false, extfrag_show_print); |
2096 | |
2097 | return 0; |
2098 | } |
2099 | |
2100 | static const struct seq_operations extfrag_op = { |
2101 | .start = frag_start, |
2102 | .next = frag_next, |
2103 | .stop = frag_stop, |
2104 | .show = extfrag_show, |
2105 | }; |
2106 | |
2107 | static int extfrag_open(struct inode *inode, struct file *file) |
2108 | { |
2109 | return seq_open(file, &extfrag_op); |
2110 | } |
2111 | |
2112 | static const struct file_operations extfrag_file_ops = { |
2113 | .open = extfrag_open, |
2114 | .read = seq_read, |
2115 | .llseek = seq_lseek, |
2116 | .release = seq_release, |
2117 | }; |
2118 | |
2119 | static int __init extfrag_debug_init(void) |
2120 | { |
2121 | struct dentry *extfrag_debug_root; |
2122 | |
2123 | extfrag_debug_root = debugfs_create_dir("extfrag" , NULL); |
2124 | |
2125 | debugfs_create_file("unusable_index" , 0444, extfrag_debug_root, NULL, |
2126 | &unusable_file_ops); |
2127 | |
2128 | debugfs_create_file("extfrag_index" , 0444, extfrag_debug_root, NULL, |
2129 | &extfrag_file_ops); |
2130 | |
2131 | return 0; |
2132 | } |
2133 | |
2134 | module_init(extfrag_debug_init); |
2135 | #endif |
2136 | |