1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/mm/vmstat.c
4 *
5 * Manages VM statistics
6 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
7 *
8 * zoned VM statistics
9 * Copyright (C) 2006 Silicon Graphics, Inc.,
10 * Christoph Lameter <christoph@lameter.com>
11 * Copyright (C) 2008-2014 Christoph Lameter
12 */
13 #include <linux/fs.h>
14 #include <linux/mm.h>
15 #include <linux/err.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/cpu.h>
19 #include <linux/cpumask.h>
20 #include <linux/vmstat.h>
21 #include <linux/proc_fs.h>
22 #include <linux/seq_file.h>
23 #include <linux/debugfs.h>
24 #include <linux/sched.h>
25 #include <linux/math64.h>
26 #include <linux/writeback.h>
27 #include <linux/compaction.h>
28 #include <linux/mm_inline.h>
29 #include <linux/page_owner.h>
30 #include <linux/sched/isolation.h>
31
32 #include "internal.h"
33
34 #ifdef CONFIG_NUMA
35 int sysctl_vm_numa_stat = ENABLE_NUMA_STAT;
36
37 /* zero numa counters within a zone */
38 static void zero_zone_numa_counters(struct zone *zone)
39 {
40 int item, cpu;
41
42 for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++) {
43 atomic_long_set(&zone->vm_numa_event[item], 0);
44 for_each_online_cpu(cpu) {
45 per_cpu_ptr(zone->per_cpu_zonestats, cpu)->vm_numa_event[item]
46 = 0;
47 }
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_EVENT_ITEMS; item++)
66 atomic_long_set(&vm_numa_event[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(const struct ctl_table *table, int write,
78 void *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 cpus_read_lock();
133 sum_vm_events(ret);
134 cpus_read_unlock();
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_node_stat[NR_VM_NODE_STAT_ITEMS] __cacheline_aligned_in_smp;
164 atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS] __cacheline_aligned_in_smp;
165 EXPORT_SYMBOL(vm_zone_stat);
166 EXPORT_SYMBOL(vm_node_stat);
167
168 #ifdef CONFIG_NUMA
169 static void fold_vm_zone_numa_events(struct zone *zone)
170 {
171 unsigned long zone_numa_events[NR_VM_NUMA_EVENT_ITEMS] = { 0, };
172 int cpu;
173 enum numa_stat_item item;
174
175 for_each_online_cpu(cpu) {
176 struct per_cpu_zonestat *pzstats;
177
178 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
179 for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++)
180 zone_numa_events[item] += xchg(&pzstats->vm_numa_event[item], 0);
181 }
182
183 for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++)
184 zone_numa_event_add(zone_numa_events[item], zone, item);
185 }
186
187 void fold_vm_numa_events(void)
188 {
189 struct zone *zone;
190
191 for_each_populated_zone(zone)
192 fold_vm_zone_numa_events(zone);
193 }
194 #endif
195
196 #ifdef CONFIG_SMP
197
198 int calculate_pressure_threshold(struct zone *zone)
199 {
200 int threshold;
201 int watermark_distance;
202
203 /*
204 * As vmstats are not up to date, there is drift between the estimated
205 * and real values. For high thresholds and a high number of CPUs, it
206 * is possible for the min watermark to be breached while the estimated
207 * value looks fine. The pressure threshold is a reduced value such
208 * that even the maximum amount of drift will not accidentally breach
209 * the min watermark
210 */
211 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
212 threshold = max(1, (int)(watermark_distance / num_online_cpus()));
213
214 /*
215 * Maximum threshold is 125
216 */
217 threshold = min(125, threshold);
218
219 return threshold;
220 }
221
222 int calculate_normal_threshold(struct zone *zone)
223 {
224 int threshold;
225 int mem; /* memory in 128 MB units */
226
227 /*
228 * The threshold scales with the number of processors and the amount
229 * of memory per zone. More memory means that we can defer updates for
230 * longer, more processors could lead to more contention.
231 * fls() is used to have a cheap way of logarithmic scaling.
232 *
233 * Some sample thresholds:
234 *
235 * Threshold Processors (fls) Zonesize fls(mem)+1
236 * ------------------------------------------------------------------
237 * 8 1 1 0.9-1 GB 4
238 * 16 2 2 0.9-1 GB 4
239 * 20 2 2 1-2 GB 5
240 * 24 2 2 2-4 GB 6
241 * 28 2 2 4-8 GB 7
242 * 32 2 2 8-16 GB 8
243 * 4 2 2 <128M 1
244 * 30 4 3 2-4 GB 5
245 * 48 4 3 8-16 GB 8
246 * 32 8 4 1-2 GB 4
247 * 32 8 4 0.9-1GB 4
248 * 10 16 5 <128M 1
249 * 40 16 5 900M 4
250 * 70 64 7 2-4 GB 5
251 * 84 64 7 4-8 GB 6
252 * 108 512 9 4-8 GB 6
253 * 125 1024 10 8-16 GB 8
254 * 125 1024 10 16-32 GB 9
255 */
256
257 mem = zone_managed_pages(zone) >> (27 - PAGE_SHIFT);
258
259 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
260
261 /*
262 * Maximum threshold is 125
263 */
264 threshold = min(125, threshold);
265
266 return threshold;
267 }
268
269 /*
270 * Refresh the thresholds for each zone.
271 */
272 void refresh_zone_stat_thresholds(void)
273 {
274 struct pglist_data *pgdat;
275 struct zone *zone;
276 int cpu;
277 int threshold;
278
279 /* Zero current pgdat thresholds */
280 for_each_online_pgdat(pgdat) {
281 for_each_online_cpu(cpu) {
282 per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold = 0;
283 }
284 }
285
286 for_each_populated_zone(zone) {
287 struct pglist_data *pgdat = zone->zone_pgdat;
288 unsigned long max_drift, tolerate_drift;
289
290 threshold = calculate_normal_threshold(zone);
291
292 for_each_online_cpu(cpu) {
293 int pgdat_threshold;
294
295 per_cpu_ptr(zone->per_cpu_zonestats, cpu)->stat_threshold
296 = threshold;
297
298 /* Base nodestat threshold on the largest populated zone. */
299 pgdat_threshold = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold;
300 per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold
301 = max(threshold, pgdat_threshold);
302 }
303
304 /*
305 * Only set percpu_drift_mark if there is a danger that
306 * NR_FREE_PAGES reports the low watermark is ok when in fact
307 * the min watermark could be breached by an allocation
308 */
309 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
310 max_drift = num_online_cpus() * threshold;
311 if (max_drift > tolerate_drift)
312 zone->percpu_drift_mark = high_wmark_pages(zone) +
313 max_drift;
314 }
315 }
316
317 void set_pgdat_percpu_threshold(pg_data_t *pgdat,
318 int (*calculate_pressure)(struct zone *))
319 {
320 struct zone *zone;
321 int cpu;
322 int threshold;
323 int i;
324
325 for (i = 0; i < pgdat->nr_zones; i++) {
326 zone = &pgdat->node_zones[i];
327 if (!zone->percpu_drift_mark)
328 continue;
329
330 threshold = (*calculate_pressure)(zone);
331 for_each_online_cpu(cpu)
332 per_cpu_ptr(zone->per_cpu_zonestats, cpu)->stat_threshold
333 = threshold;
334 }
335 }
336
337 /*
338 * For use when we know that interrupts are disabled,
339 * or when we know that preemption is disabled and that
340 * particular counter cannot be updated from interrupt context.
341 */
342 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
343 long delta)
344 {
345 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
346 s8 __percpu *p = pcp->vm_stat_diff + item;
347 long x;
348 long t;
349
350 /*
351 * Accurate vmstat updates require a RMW. On !PREEMPT_RT kernels,
352 * atomicity is provided by IRQs being disabled -- either explicitly
353 * or via local_lock_irq. On PREEMPT_RT, local_lock_irq only disables
354 * CPU migrations and preemption potentially corrupts a counter so
355 * disable preemption.
356 */
357 preempt_disable_nested();
358
359 x = delta + __this_cpu_read(*p);
360
361 t = __this_cpu_read(pcp->stat_threshold);
362
363 if (unlikely(abs(x) > t)) {
364 zone_page_state_add(x, zone, item);
365 x = 0;
366 }
367 __this_cpu_write(*p, x);
368
369 preempt_enable_nested();
370 }
371 EXPORT_SYMBOL(__mod_zone_page_state);
372
373 void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
374 long delta)
375 {
376 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
377 s8 __percpu *p = pcp->vm_node_stat_diff + item;
378 long x;
379 long t;
380
381 if (vmstat_item_in_bytes(item)) {
382 /*
383 * Only cgroups use subpage accounting right now; at
384 * the global level, these items still change in
385 * multiples of whole pages. Store them as pages
386 * internally to keep the per-cpu counters compact.
387 */
388 VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1));
389 delta >>= PAGE_SHIFT;
390 }
391
392 /* See __mod_node_page_state */
393 preempt_disable_nested();
394
395 x = delta + __this_cpu_read(*p);
396
397 t = __this_cpu_read(pcp->stat_threshold);
398
399 if (unlikely(abs(x) > t)) {
400 node_page_state_add(x, pgdat, item);
401 x = 0;
402 }
403 __this_cpu_write(*p, x);
404
405 preempt_enable_nested();
406 }
407 EXPORT_SYMBOL(__mod_node_page_state);
408
409 /*
410 * Optimized increment and decrement functions.
411 *
412 * These are only for a single page and therefore can take a struct page *
413 * argument instead of struct zone *. This allows the inclusion of the code
414 * generated for page_zone(page) into the optimized functions.
415 *
416 * No overflow check is necessary and therefore the differential can be
417 * incremented or decremented in place which may allow the compilers to
418 * generate better code.
419 * The increment or decrement is known and therefore one boundary check can
420 * be omitted.
421 *
422 * NOTE: These functions are very performance sensitive. Change only
423 * with care.
424 *
425 * Some processors have inc/dec instructions that are atomic vs an interrupt.
426 * However, the code must first determine the differential location in a zone
427 * based on the processor number and then inc/dec the counter. There is no
428 * guarantee without disabling preemption that the processor will not change
429 * in between and therefore the atomicity vs. interrupt cannot be exploited
430 * in a useful way here.
431 */
432 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
433 {
434 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
435 s8 __percpu *p = pcp->vm_stat_diff + item;
436 s8 v, t;
437
438 /* See __mod_node_page_state */
439 preempt_disable_nested();
440
441 v = __this_cpu_inc_return(*p);
442 t = __this_cpu_read(pcp->stat_threshold);
443 if (unlikely(v > t)) {
444 s8 overstep = t >> 1;
445
446 zone_page_state_add(v + overstep, zone, item);
447 __this_cpu_write(*p, -overstep);
448 }
449
450 preempt_enable_nested();
451 }
452
453 void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
454 {
455 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
456 s8 __percpu *p = pcp->vm_node_stat_diff + item;
457 s8 v, t;
458
459 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
460
461 /* See __mod_node_page_state */
462 preempt_disable_nested();
463
464 v = __this_cpu_inc_return(*p);
465 t = __this_cpu_read(pcp->stat_threshold);
466 if (unlikely(v > t)) {
467 s8 overstep = t >> 1;
468
469 node_page_state_add(v + overstep, pgdat, item);
470 __this_cpu_write(*p, -overstep);
471 }
472
473 preempt_enable_nested();
474 }
475
476 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
477 {
478 __inc_zone_state(page_zone(page), item);
479 }
480 EXPORT_SYMBOL(__inc_zone_page_state);
481
482 void __inc_node_page_state(struct page *page, enum node_stat_item item)
483 {
484 __inc_node_state(page_pgdat(page), item);
485 }
486 EXPORT_SYMBOL(__inc_node_page_state);
487
488 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
489 {
490 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
491 s8 __percpu *p = pcp->vm_stat_diff + item;
492 s8 v, t;
493
494 /* See __mod_node_page_state */
495 preempt_disable_nested();
496
497 v = __this_cpu_dec_return(*p);
498 t = __this_cpu_read(pcp->stat_threshold);
499 if (unlikely(v < - t)) {
500 s8 overstep = t >> 1;
501
502 zone_page_state_add(v - overstep, zone, item);
503 __this_cpu_write(*p, overstep);
504 }
505
506 preempt_enable_nested();
507 }
508
509 void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
510 {
511 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
512 s8 __percpu *p = pcp->vm_node_stat_diff + item;
513 s8 v, t;
514
515 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
516
517 /* See __mod_node_page_state */
518 preempt_disable_nested();
519
520 v = __this_cpu_dec_return(*p);
521 t = __this_cpu_read(pcp->stat_threshold);
522 if (unlikely(v < - t)) {
523 s8 overstep = t >> 1;
524
525 node_page_state_add(v - overstep, pgdat, item);
526 __this_cpu_write(*p, overstep);
527 }
528
529 preempt_enable_nested();
530 }
531
532 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
533 {
534 __dec_zone_state(page_zone(page), item);
535 }
536 EXPORT_SYMBOL(__dec_zone_page_state);
537
538 void __dec_node_page_state(struct page *page, enum node_stat_item item)
539 {
540 __dec_node_state(page_pgdat(page), item);
541 }
542 EXPORT_SYMBOL(__dec_node_page_state);
543
544 #ifdef CONFIG_HAVE_CMPXCHG_LOCAL
545 /*
546 * If we have cmpxchg_local support then we do not need to incur the overhead
547 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
548 *
549 * mod_state() modifies the zone counter state through atomic per cpu
550 * operations.
551 *
552 * Overstep mode specifies how overstep should handled:
553 * 0 No overstepping
554 * 1 Overstepping half of threshold
555 * -1 Overstepping minus half of threshold
556 */
557 static inline void mod_zone_state(struct zone *zone,
558 enum zone_stat_item item, long delta, int overstep_mode)
559 {
560 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
561 s8 __percpu *p = pcp->vm_stat_diff + item;
562 long n, t, z;
563 s8 o;
564
565 o = this_cpu_read(*p);
566 do {
567 z = 0; /* overflow to zone counters */
568
569 /*
570 * The fetching of the stat_threshold is racy. We may apply
571 * a counter threshold to the wrong the cpu if we get
572 * rescheduled while executing here. However, the next
573 * counter update will apply the threshold again and
574 * therefore bring the counter under the threshold again.
575 *
576 * Most of the time the thresholds are the same anyways
577 * for all cpus in a zone.
578 */
579 t = this_cpu_read(pcp->stat_threshold);
580
581 n = delta + (long)o;
582
583 if (abs(n) > t) {
584 int os = overstep_mode * (t >> 1) ;
585
586 /* Overflow must be added to zone counters */
587 z = n + os;
588 n = -os;
589 }
590 } while (!this_cpu_try_cmpxchg(*p, &o, n));
591
592 if (z)
593 zone_page_state_add(z, zone, item);
594 }
595
596 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
597 long delta)
598 {
599 mod_zone_state(zone, item, delta, 0);
600 }
601 EXPORT_SYMBOL(mod_zone_page_state);
602
603 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
604 {
605 mod_zone_state(page_zone(page), item, 1, 1);
606 }
607 EXPORT_SYMBOL(inc_zone_page_state);
608
609 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
610 {
611 mod_zone_state(page_zone(page), item, -1, -1);
612 }
613 EXPORT_SYMBOL(dec_zone_page_state);
614
615 static inline void mod_node_state(struct pglist_data *pgdat,
616 enum node_stat_item item, int delta, int overstep_mode)
617 {
618 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
619 s8 __percpu *p = pcp->vm_node_stat_diff + item;
620 long n, t, z;
621 s8 o;
622
623 if (vmstat_item_in_bytes(item)) {
624 /*
625 * Only cgroups use subpage accounting right now; at
626 * the global level, these items still change in
627 * multiples of whole pages. Store them as pages
628 * internally to keep the per-cpu counters compact.
629 */
630 VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1));
631 delta >>= PAGE_SHIFT;
632 }
633
634 o = this_cpu_read(*p);
635 do {
636 z = 0; /* overflow to node counters */
637
638 /*
639 * The fetching of the stat_threshold is racy. We may apply
640 * a counter threshold to the wrong the cpu if we get
641 * rescheduled while executing here. However, the next
642 * counter update will apply the threshold again and
643 * therefore bring the counter under the threshold again.
644 *
645 * Most of the time the thresholds are the same anyways
646 * for all cpus in a node.
647 */
648 t = this_cpu_read(pcp->stat_threshold);
649
650 n = delta + (long)o;
651
652 if (abs(n) > t) {
653 int os = overstep_mode * (t >> 1) ;
654
655 /* Overflow must be added to node counters */
656 z = n + os;
657 n = -os;
658 }
659 } while (!this_cpu_try_cmpxchg(*p, &o, n));
660
661 if (z)
662 node_page_state_add(z, pgdat, item);
663 }
664
665 void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
666 long delta)
667 {
668 mod_node_state(pgdat, item, delta, 0);
669 }
670 EXPORT_SYMBOL(mod_node_page_state);
671
672 void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
673 {
674 mod_node_state(pgdat, item, 1, 1);
675 }
676
677 void inc_node_page_state(struct page *page, enum node_stat_item item)
678 {
679 mod_node_state(page_pgdat(page), item, 1, 1);
680 }
681 EXPORT_SYMBOL(inc_node_page_state);
682
683 void dec_node_page_state(struct page *page, enum node_stat_item item)
684 {
685 mod_node_state(page_pgdat(page), item, -1, -1);
686 }
687 EXPORT_SYMBOL(dec_node_page_state);
688 #else
689 /*
690 * Use interrupt disable to serialize counter updates
691 */
692 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
693 long delta)
694 {
695 unsigned long flags;
696
697 local_irq_save(flags);
698 __mod_zone_page_state(zone, item, delta);
699 local_irq_restore(flags);
700 }
701 EXPORT_SYMBOL(mod_zone_page_state);
702
703 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
704 {
705 unsigned long flags;
706 struct zone *zone;
707
708 zone = page_zone(page);
709 local_irq_save(flags);
710 __inc_zone_state(zone, item);
711 local_irq_restore(flags);
712 }
713 EXPORT_SYMBOL(inc_zone_page_state);
714
715 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
716 {
717 unsigned long flags;
718
719 local_irq_save(flags);
720 __dec_zone_page_state(page, item);
721 local_irq_restore(flags);
722 }
723 EXPORT_SYMBOL(dec_zone_page_state);
724
725 void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
726 {
727 unsigned long flags;
728
729 local_irq_save(flags);
730 __inc_node_state(pgdat, item);
731 local_irq_restore(flags);
732 }
733 EXPORT_SYMBOL(inc_node_state);
734
735 void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
736 long delta)
737 {
738 unsigned long flags;
739
740 local_irq_save(flags);
741 __mod_node_page_state(pgdat, item, delta);
742 local_irq_restore(flags);
743 }
744 EXPORT_SYMBOL(mod_node_page_state);
745
746 void inc_node_page_state(struct page *page, enum node_stat_item item)
747 {
748 unsigned long flags;
749 struct pglist_data *pgdat;
750
751 pgdat = page_pgdat(page);
752 local_irq_save(flags);
753 __inc_node_state(pgdat, item);
754 local_irq_restore(flags);
755 }
756 EXPORT_SYMBOL(inc_node_page_state);
757
758 void dec_node_page_state(struct page *page, enum node_stat_item item)
759 {
760 unsigned long flags;
761
762 local_irq_save(flags);
763 __dec_node_page_state(page, item);
764 local_irq_restore(flags);
765 }
766 EXPORT_SYMBOL(dec_node_page_state);
767 #endif
768
769 /*
770 * Fold a differential into the global counters.
771 * Returns the number of counters updated.
772 */
773 static int fold_diff(int *zone_diff, int *node_diff)
774 {
775 int i;
776 int changes = 0;
777
778 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
779 if (zone_diff[i]) {
780 atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
781 changes++;
782 }
783
784 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
785 if (node_diff[i]) {
786 atomic_long_add(node_diff[i], &vm_node_stat[i]);
787 changes++;
788 }
789 return changes;
790 }
791
792 /*
793 * Update the zone counters for the current cpu.
794 *
795 * Note that refresh_cpu_vm_stats strives to only access
796 * node local memory. The per cpu pagesets on remote zones are placed
797 * in the memory local to the processor using that pageset. So the
798 * loop over all zones will access a series of cachelines local to
799 * the processor.
800 *
801 * The call to zone_page_state_add updates the cachelines with the
802 * statistics in the remote zone struct as well as the global cachelines
803 * with the global counters. These could cause remote node cache line
804 * bouncing and will have to be only done when necessary.
805 *
806 * The function returns the number of global counters updated.
807 */
808 static int refresh_cpu_vm_stats(bool do_pagesets)
809 {
810 struct pglist_data *pgdat;
811 struct zone *zone;
812 int i;
813 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
814 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
815 int changes = 0;
816
817 for_each_populated_zone(zone) {
818 struct per_cpu_zonestat __percpu *pzstats = zone->per_cpu_zonestats;
819 struct per_cpu_pages __percpu *pcp = zone->per_cpu_pageset;
820
821 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
822 int v;
823
824 v = this_cpu_xchg(pzstats->vm_stat_diff[i], 0);
825 if (v) {
826
827 atomic_long_add(v, &zone->vm_stat[i]);
828 global_zone_diff[i] += v;
829 #ifdef CONFIG_NUMA
830 /* 3 seconds idle till flush */
831 __this_cpu_write(pcp->expire, 3);
832 #endif
833 }
834 }
835
836 if (do_pagesets) {
837 cond_resched();
838
839 changes += decay_pcp_high(zone, this_cpu_ptr(pcp));
840 #ifdef CONFIG_NUMA
841 /*
842 * Deal with draining the remote pageset of this
843 * processor
844 *
845 * Check if there are pages remaining in this pageset
846 * if not then there is nothing to expire.
847 */
848 if (!__this_cpu_read(pcp->expire) ||
849 !__this_cpu_read(pcp->count))
850 continue;
851
852 /*
853 * We never drain zones local to this processor.
854 */
855 if (zone_to_nid(zone) == numa_node_id()) {
856 __this_cpu_write(pcp->expire, 0);
857 continue;
858 }
859
860 if (__this_cpu_dec_return(pcp->expire)) {
861 changes++;
862 continue;
863 }
864
865 if (__this_cpu_read(pcp->count)) {
866 drain_zone_pages(zone, this_cpu_ptr(pcp));
867 changes++;
868 }
869 #endif
870 }
871 }
872
873 for_each_online_pgdat(pgdat) {
874 struct per_cpu_nodestat __percpu *p = pgdat->per_cpu_nodestats;
875
876 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
877 int v;
878
879 v = this_cpu_xchg(p->vm_node_stat_diff[i], 0);
880 if (v) {
881 atomic_long_add(v, &pgdat->vm_stat[i]);
882 global_node_diff[i] += v;
883 }
884 }
885 }
886
887 changes += fold_diff(global_zone_diff, global_node_diff);
888 return changes;
889 }
890
891 /*
892 * Fold the data for an offline cpu into the global array.
893 * There cannot be any access by the offline cpu and therefore
894 * synchronization is simplified.
895 */
896 void cpu_vm_stats_fold(int cpu)
897 {
898 struct pglist_data *pgdat;
899 struct zone *zone;
900 int i;
901 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
902 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
903
904 for_each_populated_zone(zone) {
905 struct per_cpu_zonestat *pzstats;
906
907 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
908
909 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
910 if (pzstats->vm_stat_diff[i]) {
911 int v;
912
913 v = pzstats->vm_stat_diff[i];
914 pzstats->vm_stat_diff[i] = 0;
915 atomic_long_add(v, &zone->vm_stat[i]);
916 global_zone_diff[i] += v;
917 }
918 }
919 #ifdef CONFIG_NUMA
920 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) {
921 if (pzstats->vm_numa_event[i]) {
922 unsigned long v;
923
924 v = pzstats->vm_numa_event[i];
925 pzstats->vm_numa_event[i] = 0;
926 zone_numa_event_add(v, zone, i);
927 }
928 }
929 #endif
930 }
931
932 for_each_online_pgdat(pgdat) {
933 struct per_cpu_nodestat *p;
934
935 p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu);
936
937 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
938 if (p->vm_node_stat_diff[i]) {
939 int v;
940
941 v = p->vm_node_stat_diff[i];
942 p->vm_node_stat_diff[i] = 0;
943 atomic_long_add(v, &pgdat->vm_stat[i]);
944 global_node_diff[i] += v;
945 }
946 }
947
948 fold_diff(global_zone_diff, global_node_diff);
949 }
950
951 /*
952 * this is only called if !populated_zone(zone), which implies no other users of
953 * pset->vm_stat_diff[] exist.
954 */
955 void drain_zonestat(struct zone *zone, struct per_cpu_zonestat *pzstats)
956 {
957 unsigned long v;
958 int i;
959
960 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
961 if (pzstats->vm_stat_diff[i]) {
962 v = pzstats->vm_stat_diff[i];
963 pzstats->vm_stat_diff[i] = 0;
964 zone_page_state_add(v, zone, i);
965 }
966 }
967
968 #ifdef CONFIG_NUMA
969 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) {
970 if (pzstats->vm_numa_event[i]) {
971 v = pzstats->vm_numa_event[i];
972 pzstats->vm_numa_event[i] = 0;
973 zone_numa_event_add(v, zone, i);
974 }
975 }
976 #endif
977 }
978 #endif
979
980 #ifdef CONFIG_NUMA
981 /*
982 * Determine the per node value of a stat item. This function
983 * is called frequently in a NUMA machine, so try to be as
984 * frugal as possible.
985 */
986 unsigned long sum_zone_node_page_state(int node,
987 enum zone_stat_item item)
988 {
989 struct zone *zones = NODE_DATA(node)->node_zones;
990 int i;
991 unsigned long count = 0;
992
993 for (i = 0; i < MAX_NR_ZONES; i++)
994 count += zone_page_state(zones + i, item);
995
996 return count;
997 }
998
999 /* Determine the per node value of a numa stat item. */
1000 unsigned long sum_zone_numa_event_state(int node,
1001 enum numa_stat_item item)
1002 {
1003 struct zone *zones = NODE_DATA(node)->node_zones;
1004 unsigned long count = 0;
1005 int i;
1006
1007 for (i = 0; i < MAX_NR_ZONES; i++)
1008 count += zone_numa_event_state(zones + i, item);
1009
1010 return count;
1011 }
1012
1013 /*
1014 * Determine the per node value of a stat item.
1015 */
1016 unsigned long node_page_state_pages(struct pglist_data *pgdat,
1017 enum node_stat_item item)
1018 {
1019 long x = atomic_long_read(&pgdat->vm_stat[item]);
1020 #ifdef CONFIG_SMP
1021 if (x < 0)
1022 x = 0;
1023 #endif
1024 return x;
1025 }
1026
1027 unsigned long node_page_state(struct pglist_data *pgdat,
1028 enum node_stat_item item)
1029 {
1030 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
1031
1032 return node_page_state_pages(pgdat, item);
1033 }
1034 #endif
1035
1036 /*
1037 * Count number of pages "struct page" and "struct page_ext" consume.
1038 * nr_memmap_boot_pages: # of pages allocated by boot allocator
1039 * nr_memmap_pages: # of pages that were allocated by buddy allocator
1040 */
1041 static atomic_long_t nr_memmap_boot_pages = ATOMIC_LONG_INIT(0);
1042 static atomic_long_t nr_memmap_pages = ATOMIC_LONG_INIT(0);
1043
1044 void memmap_boot_pages_add(long delta)
1045 {
1046 atomic_long_add(delta, &nr_memmap_boot_pages);
1047 }
1048
1049 void memmap_pages_add(long delta)
1050 {
1051 atomic_long_add(delta, &nr_memmap_pages);
1052 }
1053
1054 #ifdef CONFIG_COMPACTION
1055
1056 struct contig_page_info {
1057 unsigned long free_pages;
1058 unsigned long free_blocks_total;
1059 unsigned long free_blocks_suitable;
1060 };
1061
1062 /*
1063 * Calculate the number of free pages in a zone, how many contiguous
1064 * pages are free and how many are large enough to satisfy an allocation of
1065 * the target size. Note that this function makes no attempt to estimate
1066 * how many suitable free blocks there *might* be if MOVABLE pages were
1067 * migrated. Calculating that is possible, but expensive and can be
1068 * figured out from userspace
1069 */
1070 static void fill_contig_page_info(struct zone *zone,
1071 unsigned int suitable_order,
1072 struct contig_page_info *info)
1073 {
1074 unsigned int order;
1075
1076 info->free_pages = 0;
1077 info->free_blocks_total = 0;
1078 info->free_blocks_suitable = 0;
1079
1080 for (order = 0; order < NR_PAGE_ORDERS; order++) {
1081 unsigned long blocks;
1082
1083 /*
1084 * Count number of free blocks.
1085 *
1086 * Access to nr_free is lockless as nr_free is used only for
1087 * diagnostic purposes. Use data_race to avoid KCSAN warning.
1088 */
1089 blocks = data_race(zone->free_area[order].nr_free);
1090 info->free_blocks_total += blocks;
1091
1092 /* Count free base pages */
1093 info->free_pages += blocks << order;
1094
1095 /* Count the suitable free blocks */
1096 if (order >= suitable_order)
1097 info->free_blocks_suitable += blocks <<
1098 (order - suitable_order);
1099 }
1100 }
1101
1102 /*
1103 * A fragmentation index only makes sense if an allocation of a requested
1104 * size would fail. If that is true, the fragmentation index indicates
1105 * whether external fragmentation or a lack of memory was the problem.
1106 * The value can be used to determine if page reclaim or compaction
1107 * should be used
1108 */
1109 static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
1110 {
1111 unsigned long requested = 1UL << order;
1112
1113 if (WARN_ON_ONCE(order > MAX_PAGE_ORDER))
1114 return 0;
1115
1116 if (!info->free_blocks_total)
1117 return 0;
1118
1119 /* Fragmentation index only makes sense when a request would fail */
1120 if (info->free_blocks_suitable)
1121 return -1000;
1122
1123 /*
1124 * Index is between 0 and 1 so return within 3 decimal places
1125 *
1126 * 0 => allocation would fail due to lack of memory
1127 * 1 => allocation would fail due to fragmentation
1128 */
1129 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
1130 }
1131
1132 /*
1133 * Calculates external fragmentation within a zone wrt the given order.
1134 * It is defined as the percentage of pages found in blocks of size
1135 * less than 1 << order. It returns values in range [0, 100].
1136 */
1137 unsigned int extfrag_for_order(struct zone *zone, unsigned int order)
1138 {
1139 struct contig_page_info info;
1140
1141 fill_contig_page_info(zone, order, &info);
1142 if (info.free_pages == 0)
1143 return 0;
1144
1145 return div_u64((info.free_pages -
1146 (info.free_blocks_suitable << order)) * 100,
1147 info.free_pages);
1148 }
1149
1150 /* Same as __fragmentation index but allocs contig_page_info on stack */
1151 int fragmentation_index(struct zone *zone, unsigned int order)
1152 {
1153 struct contig_page_info info;
1154
1155 fill_contig_page_info(zone, order, &info);
1156 return __fragmentation_index(order, &info);
1157 }
1158 #endif
1159
1160 #if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || \
1161 defined(CONFIG_NUMA) || defined(CONFIG_MEMCG)
1162 #ifdef CONFIG_ZONE_DMA
1163 #define TEXT_FOR_DMA(xx) xx "_dma",
1164 #else
1165 #define TEXT_FOR_DMA(xx)
1166 #endif
1167
1168 #ifdef CONFIG_ZONE_DMA32
1169 #define TEXT_FOR_DMA32(xx) xx "_dma32",
1170 #else
1171 #define TEXT_FOR_DMA32(xx)
1172 #endif
1173
1174 #ifdef CONFIG_HIGHMEM
1175 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
1176 #else
1177 #define TEXT_FOR_HIGHMEM(xx)
1178 #endif
1179
1180 #ifdef CONFIG_ZONE_DEVICE
1181 #define TEXT_FOR_DEVICE(xx) xx "_device",
1182 #else
1183 #define TEXT_FOR_DEVICE(xx)
1184 #endif
1185
1186 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
1187 TEXT_FOR_HIGHMEM(xx) xx "_movable", \
1188 TEXT_FOR_DEVICE(xx)
1189
1190 const char * const vmstat_text[] = {
1191 /* enum zone_stat_item counters */
1192 "nr_free_pages",
1193 "nr_zone_inactive_anon",
1194 "nr_zone_active_anon",
1195 "nr_zone_inactive_file",
1196 "nr_zone_active_file",
1197 "nr_zone_unevictable",
1198 "nr_zone_write_pending",
1199 "nr_mlock",
1200 "nr_bounce",
1201 #if IS_ENABLED(CONFIG_ZSMALLOC)
1202 "nr_zspages",
1203 #endif
1204 "nr_free_cma",
1205 #ifdef CONFIG_UNACCEPTED_MEMORY
1206 "nr_unaccepted",
1207 #endif
1208
1209 /* enum numa_stat_item counters */
1210 #ifdef CONFIG_NUMA
1211 "numa_hit",
1212 "numa_miss",
1213 "numa_foreign",
1214 "numa_interleave",
1215 "numa_local",
1216 "numa_other",
1217 #endif
1218
1219 /* enum node_stat_item counters */
1220 "nr_inactive_anon",
1221 "nr_active_anon",
1222 "nr_inactive_file",
1223 "nr_active_file",
1224 "nr_unevictable",
1225 "nr_slab_reclaimable",
1226 "nr_slab_unreclaimable",
1227 "nr_isolated_anon",
1228 "nr_isolated_file",
1229 "workingset_nodes",
1230 "workingset_refault_anon",
1231 "workingset_refault_file",
1232 "workingset_activate_anon",
1233 "workingset_activate_file",
1234 "workingset_restore_anon",
1235 "workingset_restore_file",
1236 "workingset_nodereclaim",
1237 "nr_anon_pages",
1238 "nr_mapped",
1239 "nr_file_pages",
1240 "nr_dirty",
1241 "nr_writeback",
1242 "nr_writeback_temp",
1243 "nr_shmem",
1244 "nr_shmem_hugepages",
1245 "nr_shmem_pmdmapped",
1246 "nr_file_hugepages",
1247 "nr_file_pmdmapped",
1248 "nr_anon_transparent_hugepages",
1249 "nr_vmscan_write",
1250 "nr_vmscan_immediate_reclaim",
1251 "nr_dirtied",
1252 "nr_written",
1253 "nr_throttled_written",
1254 "nr_kernel_misc_reclaimable",
1255 "nr_foll_pin_acquired",
1256 "nr_foll_pin_released",
1257 "nr_kernel_stack",
1258 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
1259 "nr_shadow_call_stack",
1260 #endif
1261 "nr_page_table_pages",
1262 "nr_sec_page_table_pages",
1263 #ifdef CONFIG_IOMMU_SUPPORT
1264 "nr_iommu_pages",
1265 #endif
1266 #ifdef CONFIG_SWAP
1267 "nr_swapcached",
1268 #endif
1269 #ifdef CONFIG_NUMA_BALANCING
1270 "pgpromote_success",
1271 "pgpromote_candidate",
1272 #endif
1273 "pgdemote_kswapd",
1274 "pgdemote_direct",
1275 "pgdemote_khugepaged",
1276 /* system-wide enum vm_stat_item counters */
1277 "nr_dirty_threshold",
1278 "nr_dirty_background_threshold",
1279 "nr_memmap_pages",
1280 "nr_memmap_boot_pages",
1281
1282 #if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG)
1283 /* enum vm_event_item counters */
1284 "pgpgin",
1285 "pgpgout",
1286 "pswpin",
1287 "pswpout",
1288
1289 TEXTS_FOR_ZONES("pgalloc")
1290 TEXTS_FOR_ZONES("allocstall")
1291 TEXTS_FOR_ZONES("pgskip")
1292
1293 "pgfree",
1294 "pgactivate",
1295 "pgdeactivate",
1296 "pglazyfree",
1297
1298 "pgfault",
1299 "pgmajfault",
1300 "pglazyfreed",
1301
1302 "pgrefill",
1303 "pgreuse",
1304 "pgsteal_kswapd",
1305 "pgsteal_direct",
1306 "pgsteal_khugepaged",
1307 "pgscan_kswapd",
1308 "pgscan_direct",
1309 "pgscan_khugepaged",
1310 "pgscan_direct_throttle",
1311 "pgscan_anon",
1312 "pgscan_file",
1313 "pgsteal_anon",
1314 "pgsteal_file",
1315
1316 #ifdef CONFIG_NUMA
1317 "zone_reclaim_failed",
1318 #endif
1319 "pginodesteal",
1320 "slabs_scanned",
1321 "kswapd_inodesteal",
1322 "kswapd_low_wmark_hit_quickly",
1323 "kswapd_high_wmark_hit_quickly",
1324 "pageoutrun",
1325
1326 "pgrotated",
1327
1328 "drop_pagecache",
1329 "drop_slab",
1330 "oom_kill",
1331
1332 #ifdef CONFIG_NUMA_BALANCING
1333 "numa_pte_updates",
1334 "numa_huge_pte_updates",
1335 "numa_hint_faults",
1336 "numa_hint_faults_local",
1337 "numa_pages_migrated",
1338 #endif
1339 #ifdef CONFIG_MIGRATION
1340 "pgmigrate_success",
1341 "pgmigrate_fail",
1342 "thp_migration_success",
1343 "thp_migration_fail",
1344 "thp_migration_split",
1345 #endif
1346 #ifdef CONFIG_COMPACTION
1347 "compact_migrate_scanned",
1348 "compact_free_scanned",
1349 "compact_isolated",
1350 "compact_stall",
1351 "compact_fail",
1352 "compact_success",
1353 "compact_daemon_wake",
1354 "compact_daemon_migrate_scanned",
1355 "compact_daemon_free_scanned",
1356 #endif
1357
1358 #ifdef CONFIG_HUGETLB_PAGE
1359 "htlb_buddy_alloc_success",
1360 "htlb_buddy_alloc_fail",
1361 #endif
1362 #ifdef CONFIG_CMA
1363 "cma_alloc_success",
1364 "cma_alloc_fail",
1365 #endif
1366 "unevictable_pgs_culled",
1367 "unevictable_pgs_scanned",
1368 "unevictable_pgs_rescued",
1369 "unevictable_pgs_mlocked",
1370 "unevictable_pgs_munlocked",
1371 "unevictable_pgs_cleared",
1372 "unevictable_pgs_stranded",
1373
1374 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1375 "thp_fault_alloc",
1376 "thp_fault_fallback",
1377 "thp_fault_fallback_charge",
1378 "thp_collapse_alloc",
1379 "thp_collapse_alloc_failed",
1380 "thp_file_alloc",
1381 "thp_file_fallback",
1382 "thp_file_fallback_charge",
1383 "thp_file_mapped",
1384 "thp_split_page",
1385 "thp_split_page_failed",
1386 "thp_deferred_split_page",
1387 "thp_split_pmd",
1388 "thp_scan_exceed_none_pte",
1389 "thp_scan_exceed_swap_pte",
1390 "thp_scan_exceed_share_pte",
1391 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
1392 "thp_split_pud",
1393 #endif
1394 "thp_zero_page_alloc",
1395 "thp_zero_page_alloc_failed",
1396 "thp_swpout",
1397 "thp_swpout_fallback",
1398 #endif
1399 #ifdef CONFIG_MEMORY_BALLOON
1400 "balloon_inflate",
1401 "balloon_deflate",
1402 #ifdef CONFIG_BALLOON_COMPACTION
1403 "balloon_migrate",
1404 #endif
1405 #endif /* CONFIG_MEMORY_BALLOON */
1406 #ifdef CONFIG_DEBUG_TLBFLUSH
1407 "nr_tlb_remote_flush",
1408 "nr_tlb_remote_flush_received",
1409 "nr_tlb_local_flush_all",
1410 "nr_tlb_local_flush_one",
1411 #endif /* CONFIG_DEBUG_TLBFLUSH */
1412
1413 #ifdef CONFIG_SWAP
1414 "swap_ra",
1415 "swap_ra_hit",
1416 #ifdef CONFIG_KSM
1417 "ksm_swpin_copy",
1418 #endif
1419 #endif
1420 #ifdef CONFIG_KSM
1421 "cow_ksm",
1422 #endif
1423 #ifdef CONFIG_ZSWAP
1424 "zswpin",
1425 "zswpout",
1426 "zswpwb",
1427 #endif
1428 #ifdef CONFIG_X86
1429 "direct_map_level2_splits",
1430 "direct_map_level3_splits",
1431 #endif
1432 #ifdef CONFIG_PER_VMA_LOCK_STATS
1433 "vma_lock_success",
1434 "vma_lock_abort",
1435 "vma_lock_retry",
1436 "vma_lock_miss",
1437 #endif
1438 #endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */
1439 };
1440 #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */
1441
1442 #if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
1443 defined(CONFIG_PROC_FS)
1444 static void *frag_start(struct seq_file *m, loff_t *pos)
1445 {
1446 pg_data_t *pgdat;
1447 loff_t node = *pos;
1448
1449 for (pgdat = first_online_pgdat();
1450 pgdat && node;
1451 pgdat = next_online_pgdat(pgdat))
1452 --node;
1453
1454 return pgdat;
1455 }
1456
1457 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
1458 {
1459 pg_data_t *pgdat = (pg_data_t *)arg;
1460
1461 (*pos)++;
1462 return next_online_pgdat(pgdat);
1463 }
1464
1465 static void frag_stop(struct seq_file *m, void *arg)
1466 {
1467 }
1468
1469 /*
1470 * Walk zones in a node and print using a callback.
1471 * If @assert_populated is true, only use callback for zones that are populated.
1472 */
1473 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
1474 bool assert_populated, bool nolock,
1475 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
1476 {
1477 struct zone *zone;
1478 struct zone *node_zones = pgdat->node_zones;
1479 unsigned long flags;
1480
1481 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
1482 if (assert_populated && !populated_zone(zone))
1483 continue;
1484
1485 if (!nolock)
1486 spin_lock_irqsave(&zone->lock, flags);
1487 print(m, pgdat, zone);
1488 if (!nolock)
1489 spin_unlock_irqrestore(&zone->lock, flags);
1490 }
1491 }
1492 #endif
1493
1494 #ifdef CONFIG_PROC_FS
1495 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
1496 struct zone *zone)
1497 {
1498 int order;
1499
1500 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1501 for (order = 0; order < NR_PAGE_ORDERS; ++order)
1502 /*
1503 * Access to nr_free is lockless as nr_free is used only for
1504 * printing purposes. Use data_race to avoid KCSAN warning.
1505 */
1506 seq_printf(m, "%6lu ", data_race(zone->free_area[order].nr_free));
1507 seq_putc(m, '\n');
1508 }
1509
1510 /*
1511 * This walks the free areas for each zone.
1512 */
1513 static int frag_show(struct seq_file *m, void *arg)
1514 {
1515 pg_data_t *pgdat = (pg_data_t *)arg;
1516 walk_zones_in_node(m, pgdat, true, false, frag_show_print);
1517 return 0;
1518 }
1519
1520 static void pagetypeinfo_showfree_print(struct seq_file *m,
1521 pg_data_t *pgdat, struct zone *zone)
1522 {
1523 int order, mtype;
1524
1525 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
1526 seq_printf(m, "Node %4d, zone %8s, type %12s ",
1527 pgdat->node_id,
1528 zone->name,
1529 migratetype_names[mtype]);
1530 for (order = 0; order < NR_PAGE_ORDERS; ++order) {
1531 unsigned long freecount = 0;
1532 struct free_area *area;
1533 struct list_head *curr;
1534 bool overflow = false;
1535
1536 area = &(zone->free_area[order]);
1537
1538 list_for_each(curr, &area->free_list[mtype]) {
1539 /*
1540 * Cap the free_list iteration because it might
1541 * be really large and we are under a spinlock
1542 * so a long time spent here could trigger a
1543 * hard lockup detector. Anyway this is a
1544 * debugging tool so knowing there is a handful
1545 * of pages of this order should be more than
1546 * sufficient.
1547 */
1548 if (++freecount >= 100000) {
1549 overflow = true;
1550 break;
1551 }
1552 }
1553 seq_printf(m, "%s%6lu ", overflow ? ">" : "", freecount);
1554 spin_unlock_irq(&zone->lock);
1555 cond_resched();
1556 spin_lock_irq(&zone->lock);
1557 }
1558 seq_putc(m, '\n');
1559 }
1560 }
1561
1562 /* Print out the free pages at each order for each migatetype */
1563 static void pagetypeinfo_showfree(struct seq_file *m, void *arg)
1564 {
1565 int order;
1566 pg_data_t *pgdat = (pg_data_t *)arg;
1567
1568 /* Print header */
1569 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
1570 for (order = 0; order < NR_PAGE_ORDERS; ++order)
1571 seq_printf(m, "%6d ", order);
1572 seq_putc(m, '\n');
1573
1574 walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print);
1575 }
1576
1577 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
1578 pg_data_t *pgdat, struct zone *zone)
1579 {
1580 int mtype;
1581 unsigned long pfn;
1582 unsigned long start_pfn = zone->zone_start_pfn;
1583 unsigned long end_pfn = zone_end_pfn(zone);
1584 unsigned long count[MIGRATE_TYPES] = { 0, };
1585
1586 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
1587 struct page *page;
1588
1589 page = pfn_to_online_page(pfn);
1590 if (!page)
1591 continue;
1592
1593 if (page_zone(page) != zone)
1594 continue;
1595
1596 mtype = get_pageblock_migratetype(page);
1597
1598 if (mtype < MIGRATE_TYPES)
1599 count[mtype]++;
1600 }
1601
1602 /* Print counts */
1603 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1604 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1605 seq_printf(m, "%12lu ", count[mtype]);
1606 seq_putc(m, '\n');
1607 }
1608
1609 /* Print out the number of pageblocks for each migratetype */
1610 static void pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
1611 {
1612 int mtype;
1613 pg_data_t *pgdat = (pg_data_t *)arg;
1614
1615 seq_printf(m, "\n%-23s", "Number of blocks type ");
1616 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1617 seq_printf(m, "%12s ", migratetype_names[mtype]);
1618 seq_putc(m, '\n');
1619 walk_zones_in_node(m, pgdat, true, false,
1620 pagetypeinfo_showblockcount_print);
1621 }
1622
1623 /*
1624 * Print out the number of pageblocks for each migratetype that contain pages
1625 * of other types. This gives an indication of how well fallbacks are being
1626 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER
1627 * to determine what is going on
1628 */
1629 static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat)
1630 {
1631 #ifdef CONFIG_PAGE_OWNER
1632 int mtype;
1633
1634 if (!static_branch_unlikely(&page_owner_inited))
1635 return;
1636
1637 drain_all_pages(NULL);
1638
1639 seq_printf(m, "\n%-23s", "Number of mixed blocks ");
1640 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1641 seq_printf(m, "%12s ", migratetype_names[mtype]);
1642 seq_putc(m, '\n');
1643
1644 walk_zones_in_node(m, pgdat, true, true,
1645 pagetypeinfo_showmixedcount_print);
1646 #endif /* CONFIG_PAGE_OWNER */
1647 }
1648
1649 /*
1650 * This prints out statistics in relation to grouping pages by mobility.
1651 * It is expensive to collect so do not constantly read the file.
1652 */
1653 static int pagetypeinfo_show(struct seq_file *m, void *arg)
1654 {
1655 pg_data_t *pgdat = (pg_data_t *)arg;
1656
1657 /* check memoryless node */
1658 if (!node_state(pgdat->node_id, N_MEMORY))
1659 return 0;
1660
1661 seq_printf(m, "Page block order: %d\n", pageblock_order);
1662 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
1663 seq_putc(m, '\n');
1664 pagetypeinfo_showfree(m, pgdat);
1665 pagetypeinfo_showblockcount(m, pgdat);
1666 pagetypeinfo_showmixedcount(m, pgdat);
1667
1668 return 0;
1669 }
1670
1671 static const struct seq_operations fragmentation_op = {
1672 .start = frag_start,
1673 .next = frag_next,
1674 .stop = frag_stop,
1675 .show = frag_show,
1676 };
1677
1678 static const struct seq_operations pagetypeinfo_op = {
1679 .start = frag_start,
1680 .next = frag_next,
1681 .stop = frag_stop,
1682 .show = pagetypeinfo_show,
1683 };
1684
1685 static bool is_zone_first_populated(pg_data_t *pgdat, struct zone *zone)
1686 {
1687 int zid;
1688
1689 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1690 struct zone *compare = &pgdat->node_zones[zid];
1691
1692 if (populated_zone(compare))
1693 return zone == compare;
1694 }
1695
1696 return false;
1697 }
1698
1699 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
1700 struct zone *zone)
1701 {
1702 int i;
1703 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1704 if (is_zone_first_populated(pgdat, zone)) {
1705 seq_printf(m, "\n per-node stats");
1706 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1707 unsigned long pages = node_page_state_pages(pgdat, i);
1708
1709 if (vmstat_item_print_in_thp(i))
1710 pages /= HPAGE_PMD_NR;
1711 seq_printf(m, "\n %-12s %lu", node_stat_name(i),
1712 pages);
1713 }
1714 }
1715 seq_printf(m,
1716 "\n pages free %lu"
1717 "\n boost %lu"
1718 "\n min %lu"
1719 "\n low %lu"
1720 "\n high %lu"
1721 "\n spanned %lu"
1722 "\n present %lu"
1723 "\n managed %lu"
1724 "\n cma %lu",
1725 zone_page_state(zone, NR_FREE_PAGES),
1726 zone->watermark_boost,
1727 min_wmark_pages(zone),
1728 low_wmark_pages(zone),
1729 high_wmark_pages(zone),
1730 zone->spanned_pages,
1731 zone->present_pages,
1732 zone_managed_pages(zone),
1733 zone_cma_pages(zone));
1734
1735 seq_printf(m,
1736 "\n protection: (%ld",
1737 zone->lowmem_reserve[0]);
1738 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1739 seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
1740 seq_putc(m, ')');
1741
1742 /* If unpopulated, no other information is useful */
1743 if (!populated_zone(zone)) {
1744 seq_putc(m, '\n');
1745 return;
1746 }
1747
1748 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1749 seq_printf(m, "\n %-12s %lu", zone_stat_name(i),
1750 zone_page_state(zone, i));
1751
1752 #ifdef CONFIG_NUMA
1753 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
1754 seq_printf(m, "\n %-12s %lu", numa_stat_name(i),
1755 zone_numa_event_state(zone, i));
1756 #endif
1757
1758 seq_printf(m, "\n pagesets");
1759 for_each_online_cpu(i) {
1760 struct per_cpu_pages *pcp;
1761 struct per_cpu_zonestat __maybe_unused *pzstats;
1762
1763 pcp = per_cpu_ptr(zone->per_cpu_pageset, i);
1764 seq_printf(m,
1765 "\n cpu: %i"
1766 "\n count: %i"
1767 "\n high: %i"
1768 "\n batch: %i",
1769 i,
1770 pcp->count,
1771 pcp->high,
1772 pcp->batch);
1773 #ifdef CONFIG_SMP
1774 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, i);
1775 seq_printf(m, "\n vm stats threshold: %d",
1776 pzstats->stat_threshold);
1777 #endif
1778 }
1779 seq_printf(m,
1780 "\n node_unreclaimable: %u"
1781 "\n start_pfn: %lu",
1782 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES,
1783 zone->zone_start_pfn);
1784 seq_putc(m, '\n');
1785 }
1786
1787 /*
1788 * Output information about zones in @pgdat. All zones are printed regardless
1789 * of whether they are populated or not: lowmem_reserve_ratio operates on the
1790 * set of all zones and userspace would not be aware of such zones if they are
1791 * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio).
1792 */
1793 static int zoneinfo_show(struct seq_file *m, void *arg)
1794 {
1795 pg_data_t *pgdat = (pg_data_t *)arg;
1796 walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print);
1797 return 0;
1798 }
1799
1800 static const struct seq_operations zoneinfo_op = {
1801 .start = frag_start, /* iterate over all zones. The same as in
1802 * fragmentation. */
1803 .next = frag_next,
1804 .stop = frag_stop,
1805 .show = zoneinfo_show,
1806 };
1807
1808 #define NR_VMSTAT_ITEMS (NR_VM_ZONE_STAT_ITEMS + \
1809 NR_VM_NUMA_EVENT_ITEMS + \
1810 NR_VM_NODE_STAT_ITEMS + \
1811 NR_VM_STAT_ITEMS + \
1812 (IS_ENABLED(CONFIG_VM_EVENT_COUNTERS) ? \
1813 NR_VM_EVENT_ITEMS : 0))
1814
1815 static void *vmstat_start(struct seq_file *m, loff_t *pos)
1816 {
1817 unsigned long *v;
1818 int i;
1819
1820 if (*pos >= NR_VMSTAT_ITEMS)
1821 return NULL;
1822
1823 BUILD_BUG_ON(ARRAY_SIZE(vmstat_text) < NR_VMSTAT_ITEMS);
1824 fold_vm_numa_events();
1825 v = kmalloc_array(NR_VMSTAT_ITEMS, sizeof(unsigned long), GFP_KERNEL);
1826 m->private = v;
1827 if (!v)
1828 return ERR_PTR(-ENOMEM);
1829 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1830 v[i] = global_zone_page_state(i);
1831 v += NR_VM_ZONE_STAT_ITEMS;
1832
1833 #ifdef CONFIG_NUMA
1834 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
1835 v[i] = global_numa_event_state(i);
1836 v += NR_VM_NUMA_EVENT_ITEMS;
1837 #endif
1838
1839 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1840 v[i] = global_node_page_state_pages(i);
1841 if (vmstat_item_print_in_thp(i))
1842 v[i] /= HPAGE_PMD_NR;
1843 }
1844 v += NR_VM_NODE_STAT_ITEMS;
1845
1846 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1847 v + NR_DIRTY_THRESHOLD);
1848 v[NR_MEMMAP_PAGES] = atomic_long_read(&nr_memmap_pages);
1849 v[NR_MEMMAP_BOOT_PAGES] = atomic_long_read(&nr_memmap_boot_pages);
1850 v += NR_VM_STAT_ITEMS;
1851
1852 #ifdef CONFIG_VM_EVENT_COUNTERS
1853 all_vm_events(v);
1854 v[PGPGIN] /= 2; /* sectors -> kbytes */
1855 v[PGPGOUT] /= 2;
1856 #endif
1857 return (unsigned long *)m->private + *pos;
1858 }
1859
1860 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1861 {
1862 (*pos)++;
1863 if (*pos >= NR_VMSTAT_ITEMS)
1864 return NULL;
1865 return (unsigned long *)m->private + *pos;
1866 }
1867
1868 static int vmstat_show(struct seq_file *m, void *arg)
1869 {
1870 unsigned long *l = arg;
1871 unsigned long off = l - (unsigned long *)m->private;
1872
1873 seq_puts(m, vmstat_text[off]);
1874 seq_put_decimal_ull(m, " ", *l);
1875 seq_putc(m, '\n');
1876
1877 if (off == NR_VMSTAT_ITEMS - 1) {
1878 /*
1879 * We've come to the end - add any deprecated counters to avoid
1880 * breaking userspace which might depend on them being present.
1881 */
1882 seq_puts(m, "nr_unstable 0\n");
1883 }
1884 return 0;
1885 }
1886
1887 static void vmstat_stop(struct seq_file *m, void *arg)
1888 {
1889 kfree(m->private);
1890 m->private = NULL;
1891 }
1892
1893 static const struct seq_operations vmstat_op = {
1894 .start = vmstat_start,
1895 .next = vmstat_next,
1896 .stop = vmstat_stop,
1897 .show = vmstat_show,
1898 };
1899 #endif /* CONFIG_PROC_FS */
1900
1901 #ifdef CONFIG_SMP
1902 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1903 int sysctl_stat_interval __read_mostly = HZ;
1904
1905 #ifdef CONFIG_PROC_FS
1906 static void refresh_vm_stats(struct work_struct *work)
1907 {
1908 refresh_cpu_vm_stats(true);
1909 }
1910
1911 int vmstat_refresh(const struct ctl_table *table, int write,
1912 void *buffer, size_t *lenp, loff_t *ppos)
1913 {
1914 long val;
1915 int err;
1916 int i;
1917
1918 /*
1919 * The regular update, every sysctl_stat_interval, may come later
1920 * than expected: leaving a significant amount in per_cpu buckets.
1921 * This is particularly misleading when checking a quantity of HUGE
1922 * pages, immediately after running a test. /proc/sys/vm/stat_refresh,
1923 * which can equally be echo'ed to or cat'ted from (by root),
1924 * can be used to update the stats just before reading them.
1925 *
1926 * Oh, and since global_zone_page_state() etc. are so careful to hide
1927 * transiently negative values, report an error here if any of
1928 * the stats is negative, so we know to go looking for imbalance.
1929 */
1930 err = schedule_on_each_cpu(refresh_vm_stats);
1931 if (err)
1932 return err;
1933 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
1934 /*
1935 * Skip checking stats known to go negative occasionally.
1936 */
1937 switch (i) {
1938 case NR_ZONE_WRITE_PENDING:
1939 case NR_FREE_CMA_PAGES:
1940 continue;
1941 }
1942 val = atomic_long_read(&vm_zone_stat[i]);
1943 if (val < 0) {
1944 pr_warn("%s: %s %ld\n",
1945 __func__, zone_stat_name(i), val);
1946 }
1947 }
1948 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1949 /*
1950 * Skip checking stats known to go negative occasionally.
1951 */
1952 switch (i) {
1953 case NR_WRITEBACK:
1954 continue;
1955 }
1956 val = atomic_long_read(&vm_node_stat[i]);
1957 if (val < 0) {
1958 pr_warn("%s: %s %ld\n",
1959 __func__, node_stat_name(i), val);
1960 }
1961 }
1962 if (write)
1963 *ppos += *lenp;
1964 else
1965 *lenp = 0;
1966 return 0;
1967 }
1968 #endif /* CONFIG_PROC_FS */
1969
1970 static void vmstat_update(struct work_struct *w)
1971 {
1972 if (refresh_cpu_vm_stats(true)) {
1973 /*
1974 * Counters were updated so we expect more updates
1975 * to occur in the future. Keep on running the
1976 * update worker thread.
1977 */
1978 queue_delayed_work_on(smp_processor_id(), mm_percpu_wq,
1979 this_cpu_ptr(&vmstat_work),
1980 round_jiffies_relative(sysctl_stat_interval));
1981 }
1982 }
1983
1984 /*
1985 * Check if the diffs for a certain cpu indicate that
1986 * an update is needed.
1987 */
1988 static bool need_update(int cpu)
1989 {
1990 pg_data_t *last_pgdat = NULL;
1991 struct zone *zone;
1992
1993 for_each_populated_zone(zone) {
1994 struct per_cpu_zonestat *pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
1995 struct per_cpu_nodestat *n;
1996
1997 /*
1998 * The fast way of checking if there are any vmstat diffs.
1999 */
2000 if (memchr_inv(pzstats->vm_stat_diff, 0, sizeof(pzstats->vm_stat_diff)))
2001 return true;
2002
2003 if (last_pgdat == zone->zone_pgdat)
2004 continue;
2005 last_pgdat = zone->zone_pgdat;
2006 n = per_cpu_ptr(zone->zone_pgdat->per_cpu_nodestats, cpu);
2007 if (memchr_inv(n->vm_node_stat_diff, 0, sizeof(n->vm_node_stat_diff)))
2008 return true;
2009 }
2010 return false;
2011 }
2012
2013 /*
2014 * Switch off vmstat processing and then fold all the remaining differentials
2015 * until the diffs stay at zero. The function is used by NOHZ and can only be
2016 * invoked when tick processing is not active.
2017 */
2018 void quiet_vmstat(void)
2019 {
2020 if (system_state != SYSTEM_RUNNING)
2021 return;
2022
2023 if (!delayed_work_pending(this_cpu_ptr(&vmstat_work)))
2024 return;
2025
2026 if (!need_update(smp_processor_id()))
2027 return;
2028
2029 /*
2030 * Just refresh counters and do not care about the pending delayed
2031 * vmstat_update. It doesn't fire that often to matter and canceling
2032 * it would be too expensive from this path.
2033 * vmstat_shepherd will take care about that for us.
2034 */
2035 refresh_cpu_vm_stats(false);
2036 }
2037
2038 /*
2039 * Shepherd worker thread that checks the
2040 * differentials of processors that have their worker
2041 * threads for vm statistics updates disabled because of
2042 * inactivity.
2043 */
2044 static void vmstat_shepherd(struct work_struct *w);
2045
2046 static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd);
2047
2048 static void vmstat_shepherd(struct work_struct *w)
2049 {
2050 int cpu;
2051
2052 cpus_read_lock();
2053 /* Check processors whose vmstat worker threads have been disabled */
2054 for_each_online_cpu(cpu) {
2055 struct delayed_work *dw = &per_cpu(vmstat_work, cpu);
2056
2057 /*
2058 * In kernel users of vmstat counters either require the precise value and
2059 * they are using zone_page_state_snapshot interface or they can live with
2060 * an imprecision as the regular flushing can happen at arbitrary time and
2061 * cumulative error can grow (see calculate_normal_threshold).
2062 *
2063 * From that POV the regular flushing can be postponed for CPUs that have
2064 * been isolated from the kernel interference without critical
2065 * infrastructure ever noticing. Skip regular flushing from vmstat_shepherd
2066 * for all isolated CPUs to avoid interference with the isolated workload.
2067 */
2068 if (cpu_is_isolated(cpu))
2069 continue;
2070
2071 if (!delayed_work_pending(dw) && need_update(cpu))
2072 queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0);
2073
2074 cond_resched();
2075 }
2076 cpus_read_unlock();
2077
2078 schedule_delayed_work(&shepherd,
2079 round_jiffies_relative(sysctl_stat_interval));
2080 }
2081
2082 static void __init start_shepherd_timer(void)
2083 {
2084 int cpu;
2085
2086 for_each_possible_cpu(cpu)
2087 INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu),
2088 vmstat_update);
2089
2090 schedule_delayed_work(&shepherd,
2091 round_jiffies_relative(sysctl_stat_interval));
2092 }
2093
2094 static void __init init_cpu_node_state(void)
2095 {
2096 int node;
2097
2098 for_each_online_node(node) {
2099 if (!cpumask_empty(cpumask_of_node(node)))
2100 node_set_state(node, N_CPU);
2101 }
2102 }
2103
2104 static int vmstat_cpu_online(unsigned int cpu)
2105 {
2106 refresh_zone_stat_thresholds();
2107
2108 if (!node_state(cpu_to_node(cpu), N_CPU)) {
2109 node_set_state(cpu_to_node(cpu), N_CPU);
2110 }
2111
2112 return 0;
2113 }
2114
2115 static int vmstat_cpu_down_prep(unsigned int cpu)
2116 {
2117 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
2118 return 0;
2119 }
2120
2121 static int vmstat_cpu_dead(unsigned int cpu)
2122 {
2123 const struct cpumask *node_cpus;
2124 int node;
2125
2126 node = cpu_to_node(cpu);
2127
2128 refresh_zone_stat_thresholds();
2129 node_cpus = cpumask_of_node(node);
2130 if (!cpumask_empty(node_cpus))
2131 return 0;
2132
2133 node_clear_state(node, N_CPU);
2134
2135 return 0;
2136 }
2137
2138 #endif
2139
2140 struct workqueue_struct *mm_percpu_wq;
2141
2142 void __init init_mm_internals(void)
2143 {
2144 int ret __maybe_unused;
2145
2146 mm_percpu_wq = alloc_workqueue("mm_percpu_wq", WQ_MEM_RECLAIM, 0);
2147
2148 #ifdef CONFIG_SMP
2149 ret = cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD, "mm/vmstat:dead",
2150 NULL, vmstat_cpu_dead);
2151 if (ret < 0)
2152 pr_err("vmstat: failed to register 'dead' hotplug state\n");
2153
2154 ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "mm/vmstat:online",
2155 vmstat_cpu_online,
2156 vmstat_cpu_down_prep);
2157 if (ret < 0)
2158 pr_err("vmstat: failed to register 'online' hotplug state\n");
2159
2160 cpus_read_lock();
2161 init_cpu_node_state();
2162 cpus_read_unlock();
2163
2164 start_shepherd_timer();
2165 #endif
2166 #ifdef CONFIG_PROC_FS
2167 proc_create_seq("buddyinfo", 0444, NULL, &fragmentation_op);
2168 proc_create_seq("pagetypeinfo", 0400, NULL, &pagetypeinfo_op);
2169 proc_create_seq("vmstat", 0444, NULL, &vmstat_op);
2170 proc_create_seq("zoneinfo", 0444, NULL, &zoneinfo_op);
2171 #endif
2172 }
2173
2174 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
2175
2176 /*
2177 * Return an index indicating how much of the available free memory is
2178 * unusable for an allocation of the requested size.
2179 */
2180 static int unusable_free_index(unsigned int order,
2181 struct contig_page_info *info)
2182 {
2183 /* No free memory is interpreted as all free memory is unusable */
2184 if (info->free_pages == 0)
2185 return 1000;
2186
2187 /*
2188 * Index should be a value between 0 and 1. Return a value to 3
2189 * decimal places.
2190 *
2191 * 0 => no fragmentation
2192 * 1 => high fragmentation
2193 */
2194 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
2195
2196 }
2197
2198 static void unusable_show_print(struct seq_file *m,
2199 pg_data_t *pgdat, struct zone *zone)
2200 {
2201 unsigned int order;
2202 int index;
2203 struct contig_page_info info;
2204
2205 seq_printf(m, "Node %d, zone %8s ",
2206 pgdat->node_id,
2207 zone->name);
2208 for (order = 0; order < NR_PAGE_ORDERS; ++order) {
2209 fill_contig_page_info(zone, order, &info);
2210 index = unusable_free_index(order, &info);
2211 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
2212 }
2213
2214 seq_putc(m, '\n');
2215 }
2216
2217 /*
2218 * Display unusable free space index
2219 *
2220 * The unusable free space index measures how much of the available free
2221 * memory cannot be used to satisfy an allocation of a given size and is a
2222 * value between 0 and 1. The higher the value, the more of free memory is
2223 * unusable and by implication, the worse the external fragmentation is. This
2224 * can be expressed as a percentage by multiplying by 100.
2225 */
2226 static int unusable_show(struct seq_file *m, void *arg)
2227 {
2228 pg_data_t *pgdat = (pg_data_t *)arg;
2229
2230 /* check memoryless node */
2231 if (!node_state(pgdat->node_id, N_MEMORY))
2232 return 0;
2233
2234 walk_zones_in_node(m, pgdat, true, false, unusable_show_print);
2235
2236 return 0;
2237 }
2238
2239 static const struct seq_operations unusable_sops = {
2240 .start = frag_start,
2241 .next = frag_next,
2242 .stop = frag_stop,
2243 .show = unusable_show,
2244 };
2245
2246 DEFINE_SEQ_ATTRIBUTE(unusable);
2247
2248 static void extfrag_show_print(struct seq_file *m,
2249 pg_data_t *pgdat, struct zone *zone)
2250 {
2251 unsigned int order;
2252 int index;
2253
2254 /* Alloc on stack as interrupts are disabled for zone walk */
2255 struct contig_page_info info;
2256
2257 seq_printf(m, "Node %d, zone %8s ",
2258 pgdat->node_id,
2259 zone->name);
2260 for (order = 0; order < NR_PAGE_ORDERS; ++order) {
2261 fill_contig_page_info(zone, order, &info);
2262 index = __fragmentation_index(order, &info);
2263 seq_printf(m, "%2d.%03d ", index / 1000, index % 1000);
2264 }
2265
2266 seq_putc(m, '\n');
2267 }
2268
2269 /*
2270 * Display fragmentation index for orders that allocations would fail for
2271 */
2272 static int extfrag_show(struct seq_file *m, void *arg)
2273 {
2274 pg_data_t *pgdat = (pg_data_t *)arg;
2275
2276 walk_zones_in_node(m, pgdat, true, false, extfrag_show_print);
2277
2278 return 0;
2279 }
2280
2281 static const struct seq_operations extfrag_sops = {
2282 .start = frag_start,
2283 .next = frag_next,
2284 .stop = frag_stop,
2285 .show = extfrag_show,
2286 };
2287
2288 DEFINE_SEQ_ATTRIBUTE(extfrag);
2289
2290 static int __init extfrag_debug_init(void)
2291 {
2292 struct dentry *extfrag_debug_root;
2293
2294 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
2295
2296 debugfs_create_file("unusable_index", 0444, extfrag_debug_root, NULL,
2297 &unusable_fops);
2298
2299 debugfs_create_file("extfrag_index", 0444, extfrag_debug_root, NULL,
2300 &extfrag_fops);
2301
2302 return 0;
2303 }
2304
2305 module_init(extfrag_debug_init);
2306
2307 #endif
2308
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