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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_ext.h>
30#include <linux/page_owner.h>
31
32#include "internal.h"
33
34#define NUMA_STATS_THRESHOLD (U16_MAX - 2)
35
36#ifdef CONFIG_NUMA
37int sysctl_vm_numa_stat = ENABLE_NUMA_STAT;
38
39/* zero numa counters within a zone */
40static void zero_zone_numa_counters(struct zone *zone)
41{
42 int item, cpu;
43
44 for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++) {
45 atomic_long_set(&zone->vm_numa_stat[item], 0);
46 for_each_online_cpu(cpu)
47 per_cpu_ptr(zone->pageset, cpu)->vm_numa_stat_diff[item]
48 = 0;
49 }
50}
51
52/* zero numa counters of all the populated zones */
53static void zero_zones_numa_counters(void)
54{
55 struct zone *zone;
56
57 for_each_populated_zone(zone)
58 zero_zone_numa_counters(zone);
59}
60
61/* zero global numa counters */
62static void zero_global_numa_counters(void)
63{
64 int item;
65
66 for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++)
67 atomic_long_set(&vm_numa_stat[item], 0);
68}
69
70static void invalid_numa_statistics(void)
71{
72 zero_zones_numa_counters();
73 zero_global_numa_counters();
74}
75
76static DEFINE_MUTEX(vm_numa_stat_lock);
77
78int sysctl_vm_numa_stat_handler(struct ctl_table *table, int write,
79 void *buffer, size_t *length, loff_t *ppos)
80{
81 int ret, oldval;
82
83 mutex_lock(&vm_numa_stat_lock);
84 if (write)
85 oldval = sysctl_vm_numa_stat;
86 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
87 if (ret || !write)
88 goto out;
89
90 if (oldval == sysctl_vm_numa_stat)
91 goto out;
92 else if (sysctl_vm_numa_stat == ENABLE_NUMA_STAT) {
93 static_branch_enable(&vm_numa_stat_key);
94 pr_info("enable numa statistics\n");
95 } else {
96 static_branch_disable(&vm_numa_stat_key);
97 invalid_numa_statistics();
98 pr_info("disable numa statistics, and clear numa counters\n");
99 }
100
101out:
102 mutex_unlock(&vm_numa_stat_lock);
103 return ret;
104}
105#endif
106
107#ifdef CONFIG_VM_EVENT_COUNTERS
108DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
109EXPORT_PER_CPU_SYMBOL(vm_event_states);
110
111static void sum_vm_events(unsigned long *ret)
112{
113 int cpu;
114 int i;
115
116 memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
117
118 for_each_online_cpu(cpu) {
119 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
120
121 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
122 ret[i] += this->event[i];
123 }
124}
125
126/*
127 * Accumulate the vm event counters across all CPUs.
128 * The result is unavoidably approximate - it can change
129 * during and after execution of this function.
130*/
131void all_vm_events(unsigned long *ret)
132{
133 get_online_cpus();
134 sum_vm_events(ret);
135 put_online_cpus();
136}
137EXPORT_SYMBOL_GPL(all_vm_events);
138
139/*
140 * Fold the foreign cpu events into our own.
141 *
142 * This is adding to the events on one processor
143 * but keeps the global counts constant.
144 */
145void vm_events_fold_cpu(int cpu)
146{
147 struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
148 int i;
149
150 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
151 count_vm_events(i, fold_state->event[i]);
152 fold_state->event[i] = 0;
153 }
154}
155
156#endif /* CONFIG_VM_EVENT_COUNTERS */
157
158/*
159 * Manage combined zone based / global counters
160 *
161 * vm_stat contains the global counters
162 */
163atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
164atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS] __cacheline_aligned_in_smp;
165atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS] __cacheline_aligned_in_smp;
166EXPORT_SYMBOL(vm_zone_stat);
167EXPORT_SYMBOL(vm_numa_stat);
168EXPORT_SYMBOL(vm_node_stat);
169
170#ifdef CONFIG_SMP
171
172int calculate_pressure_threshold(struct zone *zone)
173{
174 int threshold;
175 int watermark_distance;
176
177 /*
178 * As vmstats are not up to date, there is drift between the estimated
179 * and real values. For high thresholds and a high number of CPUs, it
180 * is possible for the min watermark to be breached while the estimated
181 * value looks fine. The pressure threshold is a reduced value such
182 * that even the maximum amount of drift will not accidentally breach
183 * the min watermark
184 */
185 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
186 threshold = max(1, (int)(watermark_distance / num_online_cpus()));
187
188 /*
189 * Maximum threshold is 125
190 */
191 threshold = min(125, threshold);
192
193 return threshold;
194}
195
196int calculate_normal_threshold(struct zone *zone)
197{
198 int threshold;
199 int mem; /* memory in 128 MB units */
200
201 /*
202 * The threshold scales with the number of processors and the amount
203 * of memory per zone. More memory means that we can defer updates for
204 * longer, more processors could lead to more contention.
205 * fls() is used to have a cheap way of logarithmic scaling.
206 *
207 * Some sample thresholds:
208 *
209 * Threshold Processors (fls) Zonesize fls(mem+1)
210 * ------------------------------------------------------------------
211 * 8 1 1 0.9-1 GB 4
212 * 16 2 2 0.9-1 GB 4
213 * 20 2 2 1-2 GB 5
214 * 24 2 2 2-4 GB 6
215 * 28 2 2 4-8 GB 7
216 * 32 2 2 8-16 GB 8
217 * 4 2 2 <128M 1
218 * 30 4 3 2-4 GB 5
219 * 48 4 3 8-16 GB 8
220 * 32 8 4 1-2 GB 4
221 * 32 8 4 0.9-1GB 4
222 * 10 16 5 <128M 1
223 * 40 16 5 900M 4
224 * 70 64 7 2-4 GB 5
225 * 84 64 7 4-8 GB 6
226 * 108 512 9 4-8 GB 6
227 * 125 1024 10 8-16 GB 8
228 * 125 1024 10 16-32 GB 9
229 */
230
231 mem = zone_managed_pages(zone) >> (27 - PAGE_SHIFT);
232
233 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
234
235 /*
236 * Maximum threshold is 125
237 */
238 threshold = min(125, threshold);
239
240 return threshold;
241}
242
243/*
244 * Refresh the thresholds for each zone.
245 */
246void refresh_zone_stat_thresholds(void)
247{
248 struct pglist_data *pgdat;
249 struct zone *zone;
250 int cpu;
251 int threshold;
252
253 /* Zero current pgdat thresholds */
254 for_each_online_pgdat(pgdat) {
255 for_each_online_cpu(cpu) {
256 per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold = 0;
257 }
258 }
259
260 for_each_populated_zone(zone) {
261 struct pglist_data *pgdat = zone->zone_pgdat;
262 unsigned long max_drift, tolerate_drift;
263
264 threshold = calculate_normal_threshold(zone);
265
266 for_each_online_cpu(cpu) {
267 int pgdat_threshold;
268
269 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
270 = threshold;
271
272 /* Base nodestat threshold on the largest populated zone. */
273 pgdat_threshold = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold;
274 per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold
275 = max(threshold, pgdat_threshold);
276 }
277
278 /*
279 * Only set percpu_drift_mark if there is a danger that
280 * NR_FREE_PAGES reports the low watermark is ok when in fact
281 * the min watermark could be breached by an allocation
282 */
283 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
284 max_drift = num_online_cpus() * threshold;
285 if (max_drift > tolerate_drift)
286 zone->percpu_drift_mark = high_wmark_pages(zone) +
287 max_drift;
288 }
289}
290
291void set_pgdat_percpu_threshold(pg_data_t *pgdat,
292 int (*calculate_pressure)(struct zone *))
293{
294 struct zone *zone;
295 int cpu;
296 int threshold;
297 int i;
298
299 for (i = 0; i < pgdat->nr_zones; i++) {
300 zone = &pgdat->node_zones[i];
301 if (!zone->percpu_drift_mark)
302 continue;
303
304 threshold = (*calculate_pressure)(zone);
305 for_each_online_cpu(cpu)
306 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
307 = threshold;
308 }
309}
310
311/*
312 * For use when we know that interrupts are disabled,
313 * or when we know that preemption is disabled and that
314 * particular counter cannot be updated from interrupt context.
315 */
316void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
317 long delta)
318{
319 struct per_cpu_pageset __percpu *pcp = zone->pageset;
320 s8 __percpu *p = pcp->vm_stat_diff + item;
321 long x;
322 long t;
323
324 x = delta + __this_cpu_read(*p);
325
326 t = __this_cpu_read(pcp->stat_threshold);
327
328 if (unlikely(x > t || x < -t)) {
329 zone_page_state_add(x, zone, item);
330 x = 0;
331 }
332 __this_cpu_write(*p, x);
333}
334EXPORT_SYMBOL(__mod_zone_page_state);
335
336void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
337 long delta)
338{
339 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
340 s8 __percpu *p = pcp->vm_node_stat_diff + item;
341 long x;
342 long t;
343
344 if (vmstat_item_in_bytes(item)) {
345 VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1));
346 delta >>= PAGE_SHIFT;
347 }
348
349 x = delta + __this_cpu_read(*p);
350
351 t = __this_cpu_read(pcp->stat_threshold);
352
353 if (unlikely(x > t || x < -t)) {
354 node_page_state_add(x, pgdat, item);
355 x = 0;
356 }
357 __this_cpu_write(*p, x);
358}
359EXPORT_SYMBOL(__mod_node_page_state);
360
361/*
362 * Optimized increment and decrement functions.
363 *
364 * These are only for a single page and therefore can take a struct page *
365 * argument instead of struct zone *. This allows the inclusion of the code
366 * generated for page_zone(page) into the optimized functions.
367 *
368 * No overflow check is necessary and therefore the differential can be
369 * incremented or decremented in place which may allow the compilers to
370 * generate better code.
371 * The increment or decrement is known and therefore one boundary check can
372 * be omitted.
373 *
374 * NOTE: These functions are very performance sensitive. Change only
375 * with care.
376 *
377 * Some processors have inc/dec instructions that are atomic vs an interrupt.
378 * However, the code must first determine the differential location in a zone
379 * based on the processor number and then inc/dec the counter. There is no
380 * guarantee without disabling preemption that the processor will not change
381 * in between and therefore the atomicity vs. interrupt cannot be exploited
382 * in a useful way here.
383 */
384void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
385{
386 struct per_cpu_pageset __percpu *pcp = zone->pageset;
387 s8 __percpu *p = pcp->vm_stat_diff + item;
388 s8 v, t;
389
390 v = __this_cpu_inc_return(*p);
391 t = __this_cpu_read(pcp->stat_threshold);
392 if (unlikely(v > t)) {
393 s8 overstep = t >> 1;
394
395 zone_page_state_add(v + overstep, zone, item);
396 __this_cpu_write(*p, -overstep);
397 }
398}
399
400void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
401{
402 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
403 s8 __percpu *p = pcp->vm_node_stat_diff + item;
404 s8 v, t;
405
406 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
407
408 v = __this_cpu_inc_return(*p);
409 t = __this_cpu_read(pcp->stat_threshold);
410 if (unlikely(v > t)) {
411 s8 overstep = t >> 1;
412
413 node_page_state_add(v + overstep, pgdat, item);
414 __this_cpu_write(*p, -overstep);
415 }
416}
417
418void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
419{
420 __inc_zone_state(page_zone(page), item);
421}
422EXPORT_SYMBOL(__inc_zone_page_state);
423
424void __inc_node_page_state(struct page *page, enum node_stat_item item)
425{
426 __inc_node_state(page_pgdat(page), item);
427}
428EXPORT_SYMBOL(__inc_node_page_state);
429
430void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
431{
432 struct per_cpu_pageset __percpu *pcp = zone->pageset;
433 s8 __percpu *p = pcp->vm_stat_diff + item;
434 s8 v, t;
435
436 v = __this_cpu_dec_return(*p);
437 t = __this_cpu_read(pcp->stat_threshold);
438 if (unlikely(v < - t)) {
439 s8 overstep = t >> 1;
440
441 zone_page_state_add(v - overstep, zone, item);
442 __this_cpu_write(*p, overstep);
443 }
444}
445
446void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
447{
448 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
449 s8 __percpu *p = pcp->vm_node_stat_diff + item;
450 s8 v, t;
451
452 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
453
454 v = __this_cpu_dec_return(*p);
455 t = __this_cpu_read(pcp->stat_threshold);
456 if (unlikely(v < - t)) {
457 s8 overstep = t >> 1;
458
459 node_page_state_add(v - overstep, pgdat, item);
460 __this_cpu_write(*p, overstep);
461 }
462}
463
464void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
465{
466 __dec_zone_state(page_zone(page), item);
467}
468EXPORT_SYMBOL(__dec_zone_page_state);
469
470void __dec_node_page_state(struct page *page, enum node_stat_item item)
471{
472 __dec_node_state(page_pgdat(page), item);
473}
474EXPORT_SYMBOL(__dec_node_page_state);
475
476#ifdef CONFIG_HAVE_CMPXCHG_LOCAL
477/*
478 * If we have cmpxchg_local support then we do not need to incur the overhead
479 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
480 *
481 * mod_state() modifies the zone counter state through atomic per cpu
482 * operations.
483 *
484 * Overstep mode specifies how overstep should handled:
485 * 0 No overstepping
486 * 1 Overstepping half of threshold
487 * -1 Overstepping minus half of threshold
488*/
489static inline void mod_zone_state(struct zone *zone,
490 enum zone_stat_item item, long delta, int overstep_mode)
491{
492 struct per_cpu_pageset __percpu *pcp = zone->pageset;
493 s8 __percpu *p = pcp->vm_stat_diff + item;
494 long o, n, t, z;
495
496 do {
497 z = 0; /* overflow to zone counters */
498
499 /*
500 * The fetching of the stat_threshold is racy. We may apply
501 * a counter threshold to the wrong the cpu if we get
502 * rescheduled while executing here. However, the next
503 * counter update will apply the threshold again and
504 * therefore bring the counter under the threshold again.
505 *
506 * Most of the time the thresholds are the same anyways
507 * for all cpus in a zone.
508 */
509 t = this_cpu_read(pcp->stat_threshold);
510
511 o = this_cpu_read(*p);
512 n = delta + o;
513
514 if (n > t || n < -t) {
515 int os = overstep_mode * (t >> 1) ;
516
517 /* Overflow must be added to zone counters */
518 z = n + os;
519 n = -os;
520 }
521 } while (this_cpu_cmpxchg(*p, o, n) != o);
522
523 if (z)
524 zone_page_state_add(z, zone, item);
525}
526
527void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
528 long delta)
529{
530 mod_zone_state(zone, item, delta, 0);
531}
532EXPORT_SYMBOL(mod_zone_page_state);
533
534void inc_zone_page_state(struct page *page, enum zone_stat_item item)
535{
536 mod_zone_state(page_zone(page), item, 1, 1);
537}
538EXPORT_SYMBOL(inc_zone_page_state);
539
540void dec_zone_page_state(struct page *page, enum zone_stat_item item)
541{
542 mod_zone_state(page_zone(page), item, -1, -1);
543}
544EXPORT_SYMBOL(dec_zone_page_state);
545
546static inline void mod_node_state(struct pglist_data *pgdat,
547 enum node_stat_item item, int delta, int overstep_mode)
548{
549 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
550 s8 __percpu *p = pcp->vm_node_stat_diff + item;
551 long o, n, t, z;
552
553 if (vmstat_item_in_bytes(item)) {
554 VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1));
555 delta >>= PAGE_SHIFT;
556 }
557
558 do {
559 z = 0; /* overflow to node counters */
560
561 /*
562 * The fetching of the stat_threshold is racy. We may apply
563 * a counter threshold to the wrong the cpu if we get
564 * rescheduled while executing here. However, the next
565 * counter update will apply the threshold again and
566 * therefore bring the counter under the threshold again.
567 *
568 * Most of the time the thresholds are the same anyways
569 * for all cpus in a node.
570 */
571 t = this_cpu_read(pcp->stat_threshold);
572
573 o = this_cpu_read(*p);
574 n = delta + o;
575
576 if (n > t || n < -t) {
577 int os = overstep_mode * (t >> 1) ;
578
579 /* Overflow must be added to node counters */
580 z = n + os;
581 n = -os;
582 }
583 } while (this_cpu_cmpxchg(*p, o, n) != o);
584
585 if (z)
586 node_page_state_add(z, pgdat, item);
587}
588
589void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
590 long delta)
591{
592 mod_node_state(pgdat, item, delta, 0);
593}
594EXPORT_SYMBOL(mod_node_page_state);
595
596void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
597{
598 mod_node_state(pgdat, item, 1, 1);
599}
600
601void inc_node_page_state(struct page *page, enum node_stat_item item)
602{
603 mod_node_state(page_pgdat(page), item, 1, 1);
604}
605EXPORT_SYMBOL(inc_node_page_state);
606
607void dec_node_page_state(struct page *page, enum node_stat_item item)
608{
609 mod_node_state(page_pgdat(page), item, -1, -1);
610}
611EXPORT_SYMBOL(dec_node_page_state);
612#else
613/*
614 * Use interrupt disable to serialize counter updates
615 */
616void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
617 long delta)
618{
619 unsigned long flags;
620
621 local_irq_save(flags);
622 __mod_zone_page_state(zone, item, delta);
623 local_irq_restore(flags);
624}
625EXPORT_SYMBOL(mod_zone_page_state);
626
627void inc_zone_page_state(struct page *page, enum zone_stat_item item)
628{
629 unsigned long flags;
630 struct zone *zone;
631
632 zone = page_zone(page);
633 local_irq_save(flags);
634 __inc_zone_state(zone, item);
635 local_irq_restore(flags);
636}
637EXPORT_SYMBOL(inc_zone_page_state);
638
639void dec_zone_page_state(struct page *page, enum zone_stat_item item)
640{
641 unsigned long flags;
642
643 local_irq_save(flags);
644 __dec_zone_page_state(page, item);
645 local_irq_restore(flags);
646}
647EXPORT_SYMBOL(dec_zone_page_state);
648
649void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
650{
651 unsigned long flags;
652
653 local_irq_save(flags);
654 __inc_node_state(pgdat, item);
655 local_irq_restore(flags);
656}
657EXPORT_SYMBOL(inc_node_state);
658
659void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
660 long delta)
661{
662 unsigned long flags;
663
664 local_irq_save(flags);
665 __mod_node_page_state(pgdat, item, delta);
666 local_irq_restore(flags);
667}
668EXPORT_SYMBOL(mod_node_page_state);
669
670void inc_node_page_state(struct page *page, enum node_stat_item item)
671{
672 unsigned long flags;
673 struct pglist_data *pgdat;
674
675 pgdat = page_pgdat(page);
676 local_irq_save(flags);
677 __inc_node_state(pgdat, item);
678 local_irq_restore(flags);
679}
680EXPORT_SYMBOL(inc_node_page_state);
681
682void dec_node_page_state(struct page *page, enum node_stat_item item)
683{
684 unsigned long flags;
685
686 local_irq_save(flags);
687 __dec_node_page_state(page, item);
688 local_irq_restore(flags);
689}
690EXPORT_SYMBOL(dec_node_page_state);
691#endif
692
693/*
694 * Fold a differential into the global counters.
695 * Returns the number of counters updated.
696 */
697#ifdef CONFIG_NUMA
698static int fold_diff(int *zone_diff, int *numa_diff, int *node_diff)
699{
700 int i;
701 int changes = 0;
702
703 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
704 if (zone_diff[i]) {
705 atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
706 changes++;
707 }
708
709 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
710 if (numa_diff[i]) {
711 atomic_long_add(numa_diff[i], &vm_numa_stat[i]);
712 changes++;
713 }
714
715 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
716 if (node_diff[i]) {
717 atomic_long_add(node_diff[i], &vm_node_stat[i]);
718 changes++;
719 }
720 return changes;
721}
722#else
723static int fold_diff(int *zone_diff, int *node_diff)
724{
725 int i;
726 int changes = 0;
727
728 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
729 if (zone_diff[i]) {
730 atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
731 changes++;
732 }
733
734 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
735 if (node_diff[i]) {
736 atomic_long_add(node_diff[i], &vm_node_stat[i]);
737 changes++;
738 }
739 return changes;
740}
741#endif /* CONFIG_NUMA */
742
743/*
744 * Update the zone counters for the current cpu.
745 *
746 * Note that refresh_cpu_vm_stats strives to only access
747 * node local memory. The per cpu pagesets on remote zones are placed
748 * in the memory local to the processor using that pageset. So the
749 * loop over all zones will access a series of cachelines local to
750 * the processor.
751 *
752 * The call to zone_page_state_add updates the cachelines with the
753 * statistics in the remote zone struct as well as the global cachelines
754 * with the global counters. These could cause remote node cache line
755 * bouncing and will have to be only done when necessary.
756 *
757 * The function returns the number of global counters updated.
758 */
759static int refresh_cpu_vm_stats(bool do_pagesets)
760{
761 struct pglist_data *pgdat;
762 struct zone *zone;
763 int i;
764 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
765#ifdef CONFIG_NUMA
766 int global_numa_diff[NR_VM_NUMA_STAT_ITEMS] = { 0, };
767#endif
768 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
769 int changes = 0;
770
771 for_each_populated_zone(zone) {
772 struct per_cpu_pageset __percpu *p = zone->pageset;
773
774 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
775 int v;
776
777 v = this_cpu_xchg(p->vm_stat_diff[i], 0);
778 if (v) {
779
780 atomic_long_add(v, &zone->vm_stat[i]);
781 global_zone_diff[i] += v;
782#ifdef CONFIG_NUMA
783 /* 3 seconds idle till flush */
784 __this_cpu_write(p->expire, 3);
785#endif
786 }
787 }
788#ifdef CONFIG_NUMA
789 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) {
790 int v;
791
792 v = this_cpu_xchg(p->vm_numa_stat_diff[i], 0);
793 if (v) {
794
795 atomic_long_add(v, &zone->vm_numa_stat[i]);
796 global_numa_diff[i] += v;
797 __this_cpu_write(p->expire, 3);
798 }
799 }
800
801 if (do_pagesets) {
802 cond_resched();
803 /*
804 * Deal with draining the remote pageset of this
805 * processor
806 *
807 * Check if there are pages remaining in this pageset
808 * if not then there is nothing to expire.
809 */
810 if (!__this_cpu_read(p->expire) ||
811 !__this_cpu_read(p->pcp.count))
812 continue;
813
814 /*
815 * We never drain zones local to this processor.
816 */
817 if (zone_to_nid(zone) == numa_node_id()) {
818 __this_cpu_write(p->expire, 0);
819 continue;
820 }
821
822 if (__this_cpu_dec_return(p->expire))
823 continue;
824
825 if (__this_cpu_read(p->pcp.count)) {
826 drain_zone_pages(zone, this_cpu_ptr(&p->pcp));
827 changes++;
828 }
829 }
830#endif
831 }
832
833 for_each_online_pgdat(pgdat) {
834 struct per_cpu_nodestat __percpu *p = pgdat->per_cpu_nodestats;
835
836 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
837 int v;
838
839 v = this_cpu_xchg(p->vm_node_stat_diff[i], 0);
840 if (v) {
841 atomic_long_add(v, &pgdat->vm_stat[i]);
842 global_node_diff[i] += v;
843 }
844 }
845 }
846
847#ifdef CONFIG_NUMA
848 changes += fold_diff(global_zone_diff, global_numa_diff,
849 global_node_diff);
850#else
851 changes += fold_diff(global_zone_diff, global_node_diff);
852#endif
853 return changes;
854}
855
856/*
857 * Fold the data for an offline cpu into the global array.
858 * There cannot be any access by the offline cpu and therefore
859 * synchronization is simplified.
860 */
861void cpu_vm_stats_fold(int cpu)
862{
863 struct pglist_data *pgdat;
864 struct zone *zone;
865 int i;
866 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
867#ifdef CONFIG_NUMA
868 int global_numa_diff[NR_VM_NUMA_STAT_ITEMS] = { 0, };
869#endif
870 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
871
872 for_each_populated_zone(zone) {
873 struct per_cpu_pageset *p;
874
875 p = per_cpu_ptr(zone->pageset, cpu);
876
877 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
878 if (p->vm_stat_diff[i]) {
879 int v;
880
881 v = p->vm_stat_diff[i];
882 p->vm_stat_diff[i] = 0;
883 atomic_long_add(v, &zone->vm_stat[i]);
884 global_zone_diff[i] += v;
885 }
886
887#ifdef CONFIG_NUMA
888 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
889 if (p->vm_numa_stat_diff[i]) {
890 int v;
891
892 v = p->vm_numa_stat_diff[i];
893 p->vm_numa_stat_diff[i] = 0;
894 atomic_long_add(v, &zone->vm_numa_stat[i]);
895 global_numa_diff[i] += v;
896 }
897#endif
898 }
899
900 for_each_online_pgdat(pgdat) {
901 struct per_cpu_nodestat *p;
902
903 p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu);
904
905 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
906 if (p->vm_node_stat_diff[i]) {
907 int v;
908
909 v = p->vm_node_stat_diff[i];
910 p->vm_node_stat_diff[i] = 0;
911 atomic_long_add(v, &pgdat->vm_stat[i]);
912 global_node_diff[i] += v;
913 }
914 }
915
916#ifdef CONFIG_NUMA
917 fold_diff(global_zone_diff, global_numa_diff, global_node_diff);
918#else
919 fold_diff(global_zone_diff, global_node_diff);
920#endif
921}
922
923/*
924 * this is only called if !populated_zone(zone), which implies no other users of
925 * pset->vm_stat_diff[] exsist.
926 */
927void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
928{
929 int i;
930
931 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
932 if (pset->vm_stat_diff[i]) {
933 int v = pset->vm_stat_diff[i];
934 pset->vm_stat_diff[i] = 0;
935 atomic_long_add(v, &zone->vm_stat[i]);
936 atomic_long_add(v, &vm_zone_stat[i]);
937 }
938
939#ifdef CONFIG_NUMA
940 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
941 if (pset->vm_numa_stat_diff[i]) {
942 int v = pset->vm_numa_stat_diff[i];
943
944 pset->vm_numa_stat_diff[i] = 0;
945 atomic_long_add(v, &zone->vm_numa_stat[i]);
946 atomic_long_add(v, &vm_numa_stat[i]);
947 }
948#endif
949}
950#endif
951
952#ifdef CONFIG_NUMA
953void __inc_numa_state(struct zone *zone,
954 enum numa_stat_item item)
955{
956 struct per_cpu_pageset __percpu *pcp = zone->pageset;
957 u16 __percpu *p = pcp->vm_numa_stat_diff + item;
958 u16 v;
959
960 v = __this_cpu_inc_return(*p);
961
962 if (unlikely(v > NUMA_STATS_THRESHOLD)) {
963 zone_numa_state_add(v, zone, item);
964 __this_cpu_write(*p, 0);
965 }
966}
967
968/*
969 * Determine the per node value of a stat item. This function
970 * is called frequently in a NUMA machine, so try to be as
971 * frugal as possible.
972 */
973unsigned long sum_zone_node_page_state(int node,
974 enum zone_stat_item item)
975{
976 struct zone *zones = NODE_DATA(node)->node_zones;
977 int i;
978 unsigned long count = 0;
979
980 for (i = 0; i < MAX_NR_ZONES; i++)
981 count += zone_page_state(zones + i, item);
982
983 return count;
984}
985
986/*
987 * Determine the per node value of a numa stat item. To avoid deviation,
988 * the per cpu stat number in vm_numa_stat_diff[] is also included.
989 */
990unsigned long sum_zone_numa_state(int node,
991 enum numa_stat_item item)
992{
993 struct zone *zones = NODE_DATA(node)->node_zones;
994 int i;
995 unsigned long count = 0;
996
997 for (i = 0; i < MAX_NR_ZONES; i++)
998 count += zone_numa_state_snapshot(zones + i, item);
999
1000 return count;
1001}
1002
1003/*
1004 * Determine the per node value of a stat item.
1005 */
1006unsigned long node_page_state_pages(struct pglist_data *pgdat,
1007 enum node_stat_item item)
1008{
1009 long x = atomic_long_read(&pgdat->vm_stat[item]);
1010#ifdef CONFIG_SMP
1011 if (x < 0)
1012 x = 0;
1013#endif
1014 return x;
1015}
1016
1017unsigned long node_page_state(struct pglist_data *pgdat,
1018 enum node_stat_item item)
1019{
1020 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
1021
1022 return node_page_state_pages(pgdat, item);
1023}
1024#endif
1025
1026#ifdef CONFIG_COMPACTION
1027
1028struct contig_page_info {
1029 unsigned long free_pages;
1030 unsigned long free_blocks_total;
1031 unsigned long free_blocks_suitable;
1032};
1033
1034/*
1035 * Calculate the number of free pages in a zone, how many contiguous
1036 * pages are free and how many are large enough to satisfy an allocation of
1037 * the target size. Note that this function makes no attempt to estimate
1038 * how many suitable free blocks there *might* be if MOVABLE pages were
1039 * migrated. Calculating that is possible, but expensive and can be
1040 * figured out from userspace
1041 */
1042static void fill_contig_page_info(struct zone *zone,
1043 unsigned int suitable_order,
1044 struct contig_page_info *info)
1045{
1046 unsigned int order;
1047
1048 info->free_pages = 0;
1049 info->free_blocks_total = 0;
1050 info->free_blocks_suitable = 0;
1051
1052 for (order = 0; order < MAX_ORDER; order++) {
1053 unsigned long blocks;
1054
1055 /* Count number of free blocks */
1056 blocks = zone->free_area[order].nr_free;
1057 info->free_blocks_total += blocks;
1058
1059 /* Count free base pages */
1060 info->free_pages += blocks << order;
1061
1062 /* Count the suitable free blocks */
1063 if (order >= suitable_order)
1064 info->free_blocks_suitable += blocks <<
1065 (order - suitable_order);
1066 }
1067}
1068
1069/*
1070 * A fragmentation index only makes sense if an allocation of a requested
1071 * size would fail. If that is true, the fragmentation index indicates
1072 * whether external fragmentation or a lack of memory was the problem.
1073 * The value can be used to determine if page reclaim or compaction
1074 * should be used
1075 */
1076static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
1077{
1078 unsigned long requested = 1UL << order;
1079
1080 if (WARN_ON_ONCE(order >= MAX_ORDER))
1081 return 0;
1082
1083 if (!info->free_blocks_total)
1084 return 0;
1085
1086 /* Fragmentation index only makes sense when a request would fail */
1087 if (info->free_blocks_suitable)
1088 return -1000;
1089
1090 /*
1091 * Index is between 0 and 1 so return within 3 decimal places
1092 *
1093 * 0 => allocation would fail due to lack of memory
1094 * 1 => allocation would fail due to fragmentation
1095 */
1096 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
1097}
1098
1099/*
1100 * Calculates external fragmentation within a zone wrt the given order.
1101 * It is defined as the percentage of pages found in blocks of size
1102 * less than 1 << order. It returns values in range [0, 100].
1103 */
1104unsigned int extfrag_for_order(struct zone *zone, unsigned int order)
1105{
1106 struct contig_page_info info;
1107
1108 fill_contig_page_info(zone, order, &info);
1109 if (info.free_pages == 0)
1110 return 0;
1111
1112 return div_u64((info.free_pages -
1113 (info.free_blocks_suitable << order)) * 100,
1114 info.free_pages);
1115}
1116
1117/* Same as __fragmentation index but allocs contig_page_info on stack */
1118int fragmentation_index(struct zone *zone, unsigned int order)
1119{
1120 struct contig_page_info info;
1121
1122 fill_contig_page_info(zone, order, &info);
1123 return __fragmentation_index(order, &info);
1124}
1125#endif
1126
1127#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || \
1128 defined(CONFIG_NUMA) || defined(CONFIG_MEMCG)
1129#ifdef CONFIG_ZONE_DMA
1130#define TEXT_FOR_DMA(xx) xx "_dma",
1131#else
1132#define TEXT_FOR_DMA(xx)
1133#endif
1134
1135#ifdef CONFIG_ZONE_DMA32
1136#define TEXT_FOR_DMA32(xx) xx "_dma32",
1137#else
1138#define TEXT_FOR_DMA32(xx)
1139#endif
1140
1141#ifdef CONFIG_HIGHMEM
1142#define TEXT_FOR_HIGHMEM(xx) xx "_high",
1143#else
1144#define TEXT_FOR_HIGHMEM(xx)
1145#endif
1146
1147#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
1148 TEXT_FOR_HIGHMEM(xx) xx "_movable",
1149
1150const char * const vmstat_text[] = {
1151 /* enum zone_stat_item counters */
1152 "nr_free_pages",
1153 "nr_zone_inactive_anon",
1154 "nr_zone_active_anon",
1155 "nr_zone_inactive_file",
1156 "nr_zone_active_file",
1157 "nr_zone_unevictable",
1158 "nr_zone_write_pending",
1159 "nr_mlock",
1160 "nr_page_table_pages",
1161 "nr_bounce",
1162#if IS_ENABLED(CONFIG_ZSMALLOC)
1163 "nr_zspages",
1164#endif
1165 "nr_free_cma",
1166
1167 /* enum numa_stat_item counters */
1168#ifdef CONFIG_NUMA
1169 "numa_hit",
1170 "numa_miss",
1171 "numa_foreign",
1172 "numa_interleave",
1173 "numa_local",
1174 "numa_other",
1175#endif
1176
1177 /* enum node_stat_item counters */
1178 "nr_inactive_anon",
1179 "nr_active_anon",
1180 "nr_inactive_file",
1181 "nr_active_file",
1182 "nr_unevictable",
1183 "nr_slab_reclaimable",
1184 "nr_slab_unreclaimable",
1185 "nr_isolated_anon",
1186 "nr_isolated_file",
1187 "workingset_nodes",
1188 "workingset_refault_anon",
1189 "workingset_refault_file",
1190 "workingset_activate_anon",
1191 "workingset_activate_file",
1192 "workingset_restore_anon",
1193 "workingset_restore_file",
1194 "workingset_nodereclaim",
1195 "nr_anon_pages",
1196 "nr_mapped",
1197 "nr_file_pages",
1198 "nr_dirty",
1199 "nr_writeback",
1200 "nr_writeback_temp",
1201 "nr_shmem",
1202 "nr_shmem_hugepages",
1203 "nr_shmem_pmdmapped",
1204 "nr_file_hugepages",
1205 "nr_file_pmdmapped",
1206 "nr_anon_transparent_hugepages",
1207 "nr_vmscan_write",
1208 "nr_vmscan_immediate_reclaim",
1209 "nr_dirtied",
1210 "nr_written",
1211 "nr_kernel_misc_reclaimable",
1212 "nr_foll_pin_acquired",
1213 "nr_foll_pin_released",
1214 "nr_kernel_stack",
1215#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
1216 "nr_shadow_call_stack",
1217#endif
1218
1219 /* enum writeback_stat_item counters */
1220 "nr_dirty_threshold",
1221 "nr_dirty_background_threshold",
1222
1223#if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG)
1224 /* enum vm_event_item counters */
1225 "pgpgin",
1226 "pgpgout",
1227 "pswpin",
1228 "pswpout",
1229
1230 TEXTS_FOR_ZONES("pgalloc")
1231 TEXTS_FOR_ZONES("allocstall")
1232 TEXTS_FOR_ZONES("pgskip")
1233
1234 "pgfree",
1235 "pgactivate",
1236 "pgdeactivate",
1237 "pglazyfree",
1238
1239 "pgfault",
1240 "pgmajfault",
1241 "pglazyfreed",
1242
1243 "pgrefill",
1244 "pgreuse",
1245 "pgsteal_kswapd",
1246 "pgsteal_direct",
1247 "pgscan_kswapd",
1248 "pgscan_direct",
1249 "pgscan_direct_throttle",
1250 "pgscan_anon",
1251 "pgscan_file",
1252 "pgsteal_anon",
1253 "pgsteal_file",
1254
1255#ifdef CONFIG_NUMA
1256 "zone_reclaim_failed",
1257#endif
1258 "pginodesteal",
1259 "slabs_scanned",
1260 "kswapd_inodesteal",
1261 "kswapd_low_wmark_hit_quickly",
1262 "kswapd_high_wmark_hit_quickly",
1263 "pageoutrun",
1264
1265 "pgrotated",
1266
1267 "drop_pagecache",
1268 "drop_slab",
1269 "oom_kill",
1270
1271#ifdef CONFIG_NUMA_BALANCING
1272 "numa_pte_updates",
1273 "numa_huge_pte_updates",
1274 "numa_hint_faults",
1275 "numa_hint_faults_local",
1276 "numa_pages_migrated",
1277#endif
1278#ifdef CONFIG_MIGRATION
1279 "pgmigrate_success",
1280 "pgmigrate_fail",
1281 "thp_migration_success",
1282 "thp_migration_fail",
1283 "thp_migration_split",
1284#endif
1285#ifdef CONFIG_COMPACTION
1286 "compact_migrate_scanned",
1287 "compact_free_scanned",
1288 "compact_isolated",
1289 "compact_stall",
1290 "compact_fail",
1291 "compact_success",
1292 "compact_daemon_wake",
1293 "compact_daemon_migrate_scanned",
1294 "compact_daemon_free_scanned",
1295#endif
1296
1297#ifdef CONFIG_HUGETLB_PAGE
1298 "htlb_buddy_alloc_success",
1299 "htlb_buddy_alloc_fail",
1300#endif
1301 "unevictable_pgs_culled",
1302 "unevictable_pgs_scanned",
1303 "unevictable_pgs_rescued",
1304 "unevictable_pgs_mlocked",
1305 "unevictable_pgs_munlocked",
1306 "unevictable_pgs_cleared",
1307 "unevictable_pgs_stranded",
1308
1309#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1310 "thp_fault_alloc",
1311 "thp_fault_fallback",
1312 "thp_fault_fallback_charge",
1313 "thp_collapse_alloc",
1314 "thp_collapse_alloc_failed",
1315 "thp_file_alloc",
1316 "thp_file_fallback",
1317 "thp_file_fallback_charge",
1318 "thp_file_mapped",
1319 "thp_split_page",
1320 "thp_split_page_failed",
1321 "thp_deferred_split_page",
1322 "thp_split_pmd",
1323#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
1324 "thp_split_pud",
1325#endif
1326 "thp_zero_page_alloc",
1327 "thp_zero_page_alloc_failed",
1328 "thp_swpout",
1329 "thp_swpout_fallback",
1330#endif
1331#ifdef CONFIG_MEMORY_BALLOON
1332 "balloon_inflate",
1333 "balloon_deflate",
1334#ifdef CONFIG_BALLOON_COMPACTION
1335 "balloon_migrate",
1336#endif
1337#endif /* CONFIG_MEMORY_BALLOON */
1338#ifdef CONFIG_DEBUG_TLBFLUSH
1339 "nr_tlb_remote_flush",
1340 "nr_tlb_remote_flush_received",
1341 "nr_tlb_local_flush_all",
1342 "nr_tlb_local_flush_one",
1343#endif /* CONFIG_DEBUG_TLBFLUSH */
1344
1345#ifdef CONFIG_DEBUG_VM_VMACACHE
1346 "vmacache_find_calls",
1347 "vmacache_find_hits",
1348#endif
1349#ifdef CONFIG_SWAP
1350 "swap_ra",
1351 "swap_ra_hit",
1352#endif
1353#endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */
1354};
1355#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */
1356
1357#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
1358 defined(CONFIG_PROC_FS)
1359static void *frag_start(struct seq_file *m, loff_t *pos)
1360{
1361 pg_data_t *pgdat;
1362 loff_t node = *pos;
1363
1364 for (pgdat = first_online_pgdat();
1365 pgdat && node;
1366 pgdat = next_online_pgdat(pgdat))
1367 --node;
1368
1369 return pgdat;
1370}
1371
1372static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
1373{
1374 pg_data_t *pgdat = (pg_data_t *)arg;
1375
1376 (*pos)++;
1377 return next_online_pgdat(pgdat);
1378}
1379
1380static void frag_stop(struct seq_file *m, void *arg)
1381{
1382}
1383
1384/*
1385 * Walk zones in a node and print using a callback.
1386 * If @assert_populated is true, only use callback for zones that are populated.
1387 */
1388static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
1389 bool assert_populated, bool nolock,
1390 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
1391{
1392 struct zone *zone;
1393 struct zone *node_zones = pgdat->node_zones;
1394 unsigned long flags;
1395
1396 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
1397 if (assert_populated && !populated_zone(zone))
1398 continue;
1399
1400 if (!nolock)
1401 spin_lock_irqsave(&zone->lock, flags);
1402 print(m, pgdat, zone);
1403 if (!nolock)
1404 spin_unlock_irqrestore(&zone->lock, flags);
1405 }
1406}
1407#endif
1408
1409#ifdef CONFIG_PROC_FS
1410static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
1411 struct zone *zone)
1412{
1413 int order;
1414
1415 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1416 for (order = 0; order < MAX_ORDER; ++order)
1417 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
1418 seq_putc(m, '\n');
1419}
1420
1421/*
1422 * This walks the free areas for each zone.
1423 */
1424static int frag_show(struct seq_file *m, void *arg)
1425{
1426 pg_data_t *pgdat = (pg_data_t *)arg;
1427 walk_zones_in_node(m, pgdat, true, false, frag_show_print);
1428 return 0;
1429}
1430
1431static void pagetypeinfo_showfree_print(struct seq_file *m,
1432 pg_data_t *pgdat, struct zone *zone)
1433{
1434 int order, mtype;
1435
1436 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
1437 seq_printf(m, "Node %4d, zone %8s, type %12s ",
1438 pgdat->node_id,
1439 zone->name,
1440 migratetype_names[mtype]);
1441 for (order = 0; order < MAX_ORDER; ++order) {
1442 unsigned long freecount = 0;
1443 struct free_area *area;
1444 struct list_head *curr;
1445 bool overflow = false;
1446
1447 area = &(zone->free_area[order]);
1448
1449 list_for_each(curr, &area->free_list[mtype]) {
1450 /*
1451 * Cap the free_list iteration because it might
1452 * be really large and we are under a spinlock
1453 * so a long time spent here could trigger a
1454 * hard lockup detector. Anyway this is a
1455 * debugging tool so knowing there is a handful
1456 * of pages of this order should be more than
1457 * sufficient.
1458 */
1459 if (++freecount >= 100000) {
1460 overflow = true;
1461 break;
1462 }
1463 }
1464 seq_printf(m, "%s%6lu ", overflow ? ">" : "", freecount);
1465 spin_unlock_irq(&zone->lock);
1466 cond_resched();
1467 spin_lock_irq(&zone->lock);
1468 }
1469 seq_putc(m, '\n');
1470 }
1471}
1472
1473/* Print out the free pages at each order for each migatetype */
1474static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
1475{
1476 int order;
1477 pg_data_t *pgdat = (pg_data_t *)arg;
1478
1479 /* Print header */
1480 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
1481 for (order = 0; order < MAX_ORDER; ++order)
1482 seq_printf(m, "%6d ", order);
1483 seq_putc(m, '\n');
1484
1485 walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print);
1486
1487 return 0;
1488}
1489
1490static void pagetypeinfo_showblockcount_print(struct seq_file *m,
1491 pg_data_t *pgdat, struct zone *zone)
1492{
1493 int mtype;
1494 unsigned long pfn;
1495 unsigned long start_pfn = zone->zone_start_pfn;
1496 unsigned long end_pfn = zone_end_pfn(zone);
1497 unsigned long count[MIGRATE_TYPES] = { 0, };
1498
1499 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
1500 struct page *page;
1501
1502 page = pfn_to_online_page(pfn);
1503 if (!page)
1504 continue;
1505
1506 /* Watch for unexpected holes punched in the memmap */
1507 if (!memmap_valid_within(pfn, page, zone))
1508 continue;
1509
1510 if (page_zone(page) != zone)
1511 continue;
1512
1513 mtype = get_pageblock_migratetype(page);
1514
1515 if (mtype < MIGRATE_TYPES)
1516 count[mtype]++;
1517 }
1518
1519 /* Print counts */
1520 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1521 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1522 seq_printf(m, "%12lu ", count[mtype]);
1523 seq_putc(m, '\n');
1524}
1525
1526/* Print out the number of pageblocks for each migratetype */
1527static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
1528{
1529 int mtype;
1530 pg_data_t *pgdat = (pg_data_t *)arg;
1531
1532 seq_printf(m, "\n%-23s", "Number of blocks type ");
1533 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1534 seq_printf(m, "%12s ", migratetype_names[mtype]);
1535 seq_putc(m, '\n');
1536 walk_zones_in_node(m, pgdat, true, false,
1537 pagetypeinfo_showblockcount_print);
1538
1539 return 0;
1540}
1541
1542/*
1543 * Print out the number of pageblocks for each migratetype that contain pages
1544 * of other types. This gives an indication of how well fallbacks are being
1545 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER
1546 * to determine what is going on
1547 */
1548static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat)
1549{
1550#ifdef CONFIG_PAGE_OWNER
1551 int mtype;
1552
1553 if (!static_branch_unlikely(&page_owner_inited))
1554 return;
1555
1556 drain_all_pages(NULL);
1557
1558 seq_printf(m, "\n%-23s", "Number of mixed blocks ");
1559 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1560 seq_printf(m, "%12s ", migratetype_names[mtype]);
1561 seq_putc(m, '\n');
1562
1563 walk_zones_in_node(m, pgdat, true, true,
1564 pagetypeinfo_showmixedcount_print);
1565#endif /* CONFIG_PAGE_OWNER */
1566}
1567
1568/*
1569 * This prints out statistics in relation to grouping pages by mobility.
1570 * It is expensive to collect so do not constantly read the file.
1571 */
1572static int pagetypeinfo_show(struct seq_file *m, void *arg)
1573{
1574 pg_data_t *pgdat = (pg_data_t *)arg;
1575
1576 /* check memoryless node */
1577 if (!node_state(pgdat->node_id, N_MEMORY))
1578 return 0;
1579
1580 seq_printf(m, "Page block order: %d\n", pageblock_order);
1581 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
1582 seq_putc(m, '\n');
1583 pagetypeinfo_showfree(m, pgdat);
1584 pagetypeinfo_showblockcount(m, pgdat);
1585 pagetypeinfo_showmixedcount(m, pgdat);
1586
1587 return 0;
1588}
1589
1590static const struct seq_operations fragmentation_op = {
1591 .start = frag_start,
1592 .next = frag_next,
1593 .stop = frag_stop,
1594 .show = frag_show,
1595};
1596
1597static const struct seq_operations pagetypeinfo_op = {
1598 .start = frag_start,
1599 .next = frag_next,
1600 .stop = frag_stop,
1601 .show = pagetypeinfo_show,
1602};
1603
1604static bool is_zone_first_populated(pg_data_t *pgdat, struct zone *zone)
1605{
1606 int zid;
1607
1608 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1609 struct zone *compare = &pgdat->node_zones[zid];
1610
1611 if (populated_zone(compare))
1612 return zone == compare;
1613 }
1614
1615 return false;
1616}
1617
1618static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
1619 struct zone *zone)
1620{
1621 int i;
1622 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1623 if (is_zone_first_populated(pgdat, zone)) {
1624 seq_printf(m, "\n per-node stats");
1625 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1626 seq_printf(m, "\n %-12s %lu", node_stat_name(i),
1627 node_page_state_pages(pgdat, i));
1628 }
1629 }
1630 seq_printf(m,
1631 "\n pages free %lu"
1632 "\n min %lu"
1633 "\n low %lu"
1634 "\n high %lu"
1635 "\n spanned %lu"
1636 "\n present %lu"
1637 "\n managed %lu",
1638 zone_page_state(zone, NR_FREE_PAGES),
1639 min_wmark_pages(zone),
1640 low_wmark_pages(zone),
1641 high_wmark_pages(zone),
1642 zone->spanned_pages,
1643 zone->present_pages,
1644 zone_managed_pages(zone));
1645
1646 seq_printf(m,
1647 "\n protection: (%ld",
1648 zone->lowmem_reserve[0]);
1649 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1650 seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
1651 seq_putc(m, ')');
1652
1653 /* If unpopulated, no other information is useful */
1654 if (!populated_zone(zone)) {
1655 seq_putc(m, '\n');
1656 return;
1657 }
1658
1659 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1660 seq_printf(m, "\n %-12s %lu", zone_stat_name(i),
1661 zone_page_state(zone, i));
1662
1663#ifdef CONFIG_NUMA
1664 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
1665 seq_printf(m, "\n %-12s %lu", numa_stat_name(i),
1666 zone_numa_state_snapshot(zone, i));
1667#endif
1668
1669 seq_printf(m, "\n pagesets");
1670 for_each_online_cpu(i) {
1671 struct per_cpu_pageset *pageset;
1672
1673 pageset = per_cpu_ptr(zone->pageset, i);
1674 seq_printf(m,
1675 "\n cpu: %i"
1676 "\n count: %i"
1677 "\n high: %i"
1678 "\n batch: %i",
1679 i,
1680 pageset->pcp.count,
1681 pageset->pcp.high,
1682 pageset->pcp.batch);
1683#ifdef CONFIG_SMP
1684 seq_printf(m, "\n vm stats threshold: %d",
1685 pageset->stat_threshold);
1686#endif
1687 }
1688 seq_printf(m,
1689 "\n node_unreclaimable: %u"
1690 "\n start_pfn: %lu",
1691 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES,
1692 zone->zone_start_pfn);
1693 seq_putc(m, '\n');
1694}
1695
1696/*
1697 * Output information about zones in @pgdat. All zones are printed regardless
1698 * of whether they are populated or not: lowmem_reserve_ratio operates on the
1699 * set of all zones and userspace would not be aware of such zones if they are
1700 * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio).
1701 */
1702static int zoneinfo_show(struct seq_file *m, void *arg)
1703{
1704 pg_data_t *pgdat = (pg_data_t *)arg;
1705 walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print);
1706 return 0;
1707}
1708
1709static const struct seq_operations zoneinfo_op = {
1710 .start = frag_start, /* iterate over all zones. The same as in
1711 * fragmentation. */
1712 .next = frag_next,
1713 .stop = frag_stop,
1714 .show = zoneinfo_show,
1715};
1716
1717#define NR_VMSTAT_ITEMS (NR_VM_ZONE_STAT_ITEMS + \
1718 NR_VM_NUMA_STAT_ITEMS + \
1719 NR_VM_NODE_STAT_ITEMS + \
1720 NR_VM_WRITEBACK_STAT_ITEMS + \
1721 (IS_ENABLED(CONFIG_VM_EVENT_COUNTERS) ? \
1722 NR_VM_EVENT_ITEMS : 0))
1723
1724static void *vmstat_start(struct seq_file *m, loff_t *pos)
1725{
1726 unsigned long *v;
1727 int i;
1728
1729 if (*pos >= NR_VMSTAT_ITEMS)
1730 return NULL;
1731
1732 BUILD_BUG_ON(ARRAY_SIZE(vmstat_text) < NR_VMSTAT_ITEMS);
1733 v = kmalloc_array(NR_VMSTAT_ITEMS, sizeof(unsigned long), GFP_KERNEL);
1734 m->private = v;
1735 if (!v)
1736 return ERR_PTR(-ENOMEM);
1737 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1738 v[i] = global_zone_page_state(i);
1739 v += NR_VM_ZONE_STAT_ITEMS;
1740
1741#ifdef CONFIG_NUMA
1742 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
1743 v[i] = global_numa_state(i);
1744 v += NR_VM_NUMA_STAT_ITEMS;
1745#endif
1746
1747 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
1748 v[i] = global_node_page_state_pages(i);
1749 v += NR_VM_NODE_STAT_ITEMS;
1750
1751 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1752 v + NR_DIRTY_THRESHOLD);
1753 v += NR_VM_WRITEBACK_STAT_ITEMS;
1754
1755#ifdef CONFIG_VM_EVENT_COUNTERS
1756 all_vm_events(v);
1757 v[PGPGIN] /= 2; /* sectors -> kbytes */
1758 v[PGPGOUT] /= 2;
1759#endif
1760 return (unsigned long *)m->private + *pos;
1761}
1762
1763static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1764{
1765 (*pos)++;
1766 if (*pos >= NR_VMSTAT_ITEMS)
1767 return NULL;
1768 return (unsigned long *)m->private + *pos;
1769}
1770
1771static int vmstat_show(struct seq_file *m, void *arg)
1772{
1773 unsigned long *l = arg;
1774 unsigned long off = l - (unsigned long *)m->private;
1775
1776 seq_puts(m, vmstat_text[off]);
1777 seq_put_decimal_ull(m, " ", *l);
1778 seq_putc(m, '\n');
1779
1780 if (off == NR_VMSTAT_ITEMS - 1) {
1781 /*
1782 * We've come to the end - add any deprecated counters to avoid
1783 * breaking userspace which might depend on them being present.
1784 */
1785 seq_puts(m, "nr_unstable 0\n");
1786 }
1787 return 0;
1788}
1789
1790static void vmstat_stop(struct seq_file *m, void *arg)
1791{
1792 kfree(m->private);
1793 m->private = NULL;
1794}
1795
1796static const struct seq_operations vmstat_op = {
1797 .start = vmstat_start,
1798 .next = vmstat_next,
1799 .stop = vmstat_stop,
1800 .show = vmstat_show,
1801};
1802#endif /* CONFIG_PROC_FS */
1803
1804#ifdef CONFIG_SMP
1805static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1806int sysctl_stat_interval __read_mostly = HZ;
1807
1808#ifdef CONFIG_PROC_FS
1809static void refresh_vm_stats(struct work_struct *work)
1810{
1811 refresh_cpu_vm_stats(true);
1812}
1813
1814int vmstat_refresh(struct ctl_table *table, int write,
1815 void *buffer, size_t *lenp, loff_t *ppos)
1816{
1817 long val;
1818 int err;
1819 int i;
1820
1821 /*
1822 * The regular update, every sysctl_stat_interval, may come later
1823 * than expected: leaving a significant amount in per_cpu buckets.
1824 * This is particularly misleading when checking a quantity of HUGE
1825 * pages, immediately after running a test. /proc/sys/vm/stat_refresh,
1826 * which can equally be echo'ed to or cat'ted from (by root),
1827 * can be used to update the stats just before reading them.
1828 *
1829 * Oh, and since global_zone_page_state() etc. are so careful to hide
1830 * transiently negative values, report an error here if any of
1831 * the stats is negative, so we know to go looking for imbalance.
1832 */
1833 err = schedule_on_each_cpu(refresh_vm_stats);
1834 if (err)
1835 return err;
1836 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
1837 val = atomic_long_read(&vm_zone_stat[i]);
1838 if (val < 0) {
1839 pr_warn("%s: %s %ld\n",
1840 __func__, zone_stat_name(i), val);
1841 err = -EINVAL;
1842 }
1843 }
1844#ifdef CONFIG_NUMA
1845 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) {
1846 val = atomic_long_read(&vm_numa_stat[i]);
1847 if (val < 0) {
1848 pr_warn("%s: %s %ld\n",
1849 __func__, numa_stat_name(i), val);
1850 err = -EINVAL;
1851 }
1852 }
1853#endif
1854 if (err)
1855 return err;
1856 if (write)
1857 *ppos += *lenp;
1858 else
1859 *lenp = 0;
1860 return 0;
1861}
1862#endif /* CONFIG_PROC_FS */
1863
1864static void vmstat_update(struct work_struct *w)
1865{
1866 if (refresh_cpu_vm_stats(true)) {
1867 /*
1868 * Counters were updated so we expect more updates
1869 * to occur in the future. Keep on running the
1870 * update worker thread.
1871 */
1872 queue_delayed_work_on(smp_processor_id(), mm_percpu_wq,
1873 this_cpu_ptr(&vmstat_work),
1874 round_jiffies_relative(sysctl_stat_interval));
1875 }
1876}
1877
1878/*
1879 * Switch off vmstat processing and then fold all the remaining differentials
1880 * until the diffs stay at zero. The function is used by NOHZ and can only be
1881 * invoked when tick processing is not active.
1882 */
1883/*
1884 * Check if the diffs for a certain cpu indicate that
1885 * an update is needed.
1886 */
1887static bool need_update(int cpu)
1888{
1889 struct zone *zone;
1890
1891 for_each_populated_zone(zone) {
1892 struct per_cpu_pageset *p = per_cpu_ptr(zone->pageset, cpu);
1893
1894 BUILD_BUG_ON(sizeof(p->vm_stat_diff[0]) != 1);
1895#ifdef CONFIG_NUMA
1896 BUILD_BUG_ON(sizeof(p->vm_numa_stat_diff[0]) != 2);
1897#endif
1898
1899 /*
1900 * The fast way of checking if there are any vmstat diffs.
1901 */
1902 if (memchr_inv(p->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS *
1903 sizeof(p->vm_stat_diff[0])))
1904 return true;
1905#ifdef CONFIG_NUMA
1906 if (memchr_inv(p->vm_numa_stat_diff, 0, NR_VM_NUMA_STAT_ITEMS *
1907 sizeof(p->vm_numa_stat_diff[0])))
1908 return true;
1909#endif
1910 }
1911 return false;
1912}
1913
1914/*
1915 * Switch off vmstat processing and then fold all the remaining differentials
1916 * until the diffs stay at zero. The function is used by NOHZ and can only be
1917 * invoked when tick processing is not active.
1918 */
1919void quiet_vmstat(void)
1920{
1921 if (system_state != SYSTEM_RUNNING)
1922 return;
1923
1924 if (!delayed_work_pending(this_cpu_ptr(&vmstat_work)))
1925 return;
1926
1927 if (!need_update(smp_processor_id()))
1928 return;
1929
1930 /*
1931 * Just refresh counters and do not care about the pending delayed
1932 * vmstat_update. It doesn't fire that often to matter and canceling
1933 * it would be too expensive from this path.
1934 * vmstat_shepherd will take care about that for us.
1935 */
1936 refresh_cpu_vm_stats(false);
1937}
1938
1939/*
1940 * Shepherd worker thread that checks the
1941 * differentials of processors that have their worker
1942 * threads for vm statistics updates disabled because of
1943 * inactivity.
1944 */
1945static void vmstat_shepherd(struct work_struct *w);
1946
1947static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd);
1948
1949static void vmstat_shepherd(struct work_struct *w)
1950{
1951 int cpu;
1952
1953 get_online_cpus();
1954 /* Check processors whose vmstat worker threads have been disabled */
1955 for_each_online_cpu(cpu) {
1956 struct delayed_work *dw = &per_cpu(vmstat_work, cpu);
1957
1958 if (!delayed_work_pending(dw) && need_update(cpu))
1959 queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0);
1960 }
1961 put_online_cpus();
1962
1963 schedule_delayed_work(&shepherd,
1964 round_jiffies_relative(sysctl_stat_interval));
1965}
1966
1967static void __init start_shepherd_timer(void)
1968{
1969 int cpu;
1970
1971 for_each_possible_cpu(cpu)
1972 INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu),
1973 vmstat_update);
1974
1975 schedule_delayed_work(&shepherd,
1976 round_jiffies_relative(sysctl_stat_interval));
1977}
1978
1979static void __init init_cpu_node_state(void)
1980{
1981 int node;
1982
1983 for_each_online_node(node) {
1984 if (cpumask_weight(cpumask_of_node(node)) > 0)
1985 node_set_state(node, N_CPU);
1986 }
1987}
1988
1989static int vmstat_cpu_online(unsigned int cpu)
1990{
1991 refresh_zone_stat_thresholds();
1992 node_set_state(cpu_to_node(cpu), N_CPU);
1993 return 0;
1994}
1995
1996static int vmstat_cpu_down_prep(unsigned int cpu)
1997{
1998 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1999 return 0;
2000}
2001
2002static int vmstat_cpu_dead(unsigned int cpu)
2003{
2004 const struct cpumask *node_cpus;
2005 int node;
2006
2007 node = cpu_to_node(cpu);
2008
2009 refresh_zone_stat_thresholds();
2010 node_cpus = cpumask_of_node(node);
2011 if (cpumask_weight(node_cpus) > 0)
2012 return 0;
2013
2014 node_clear_state(node, N_CPU);
2015 return 0;
2016}
2017
2018#endif
2019
2020struct workqueue_struct *mm_percpu_wq;
2021
2022void __init init_mm_internals(void)
2023{
2024 int ret __maybe_unused;
2025
2026 mm_percpu_wq = alloc_workqueue("mm_percpu_wq", WQ_MEM_RECLAIM, 0);
2027
2028#ifdef CONFIG_SMP
2029 ret = cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD, "mm/vmstat:dead",
2030 NULL, vmstat_cpu_dead);
2031 if (ret < 0)
2032 pr_err("vmstat: failed to register 'dead' hotplug state\n");
2033
2034 ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "mm/vmstat:online",
2035 vmstat_cpu_online,
2036 vmstat_cpu_down_prep);
2037 if (ret < 0)
2038 pr_err("vmstat: failed to register 'online' hotplug state\n");
2039
2040 get_online_cpus();
2041 init_cpu_node_state();
2042 put_online_cpus();
2043
2044 start_shepherd_timer();
2045#endif
2046#ifdef CONFIG_PROC_FS
2047 proc_create_seq("buddyinfo", 0444, NULL, &fragmentation_op);
2048 proc_create_seq("pagetypeinfo", 0400, NULL, &pagetypeinfo_op);
2049 proc_create_seq("vmstat", 0444, NULL, &vmstat_op);
2050 proc_create_seq("zoneinfo", 0444, NULL, &zoneinfo_op);
2051#endif
2052}
2053
2054#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
2055
2056/*
2057 * Return an index indicating how much of the available free memory is
2058 * unusable for an allocation of the requested size.
2059 */
2060static int unusable_free_index(unsigned int order,
2061 struct contig_page_info *info)
2062{
2063 /* No free memory is interpreted as all free memory is unusable */
2064 if (info->free_pages == 0)
2065 return 1000;
2066
2067 /*
2068 * Index should be a value between 0 and 1. Return a value to 3
2069 * decimal places.
2070 *
2071 * 0 => no fragmentation
2072 * 1 => high fragmentation
2073 */
2074 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
2075
2076}
2077
2078static void unusable_show_print(struct seq_file *m,
2079 pg_data_t *pgdat, struct zone *zone)
2080{
2081 unsigned int order;
2082 int index;
2083 struct contig_page_info info;
2084
2085 seq_printf(m, "Node %d, zone %8s ",
2086 pgdat->node_id,
2087 zone->name);
2088 for (order = 0; order < MAX_ORDER; ++order) {
2089 fill_contig_page_info(zone, order, &info);
2090 index = unusable_free_index(order, &info);
2091 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
2092 }
2093
2094 seq_putc(m, '\n');
2095}
2096
2097/*
2098 * Display unusable free space index
2099 *
2100 * The unusable free space index measures how much of the available free
2101 * memory cannot be used to satisfy an allocation of a given size and is a
2102 * value between 0 and 1. The higher the value, the more of free memory is
2103 * unusable and by implication, the worse the external fragmentation is. This
2104 * can be expressed as a percentage by multiplying by 100.
2105 */
2106static int unusable_show(struct seq_file *m, void *arg)
2107{
2108 pg_data_t *pgdat = (pg_data_t *)arg;
2109
2110 /* check memoryless node */
2111 if (!node_state(pgdat->node_id, N_MEMORY))
2112 return 0;
2113
2114 walk_zones_in_node(m, pgdat, true, false, unusable_show_print);
2115
2116 return 0;
2117}
2118
2119static const struct seq_operations unusable_sops = {
2120 .start = frag_start,
2121 .next = frag_next,
2122 .stop = frag_stop,
2123 .show = unusable_show,
2124};
2125
2126DEFINE_SEQ_ATTRIBUTE(unusable);
2127
2128static void extfrag_show_print(struct seq_file *m,
2129 pg_data_t *pgdat, struct zone *zone)
2130{
2131 unsigned int order;
2132 int index;
2133
2134 /* Alloc on stack as interrupts are disabled for zone walk */
2135 struct contig_page_info info;
2136
2137 seq_printf(m, "Node %d, zone %8s ",
2138 pgdat->node_id,
2139 zone->name);
2140 for (order = 0; order < MAX_ORDER; ++order) {
2141 fill_contig_page_info(zone, order, &info);
2142 index = __fragmentation_index(order, &info);
2143 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
2144 }
2145
2146 seq_putc(m, '\n');
2147}
2148
2149/*
2150 * Display fragmentation index for orders that allocations would fail for
2151 */
2152static int extfrag_show(struct seq_file *m, void *arg)
2153{
2154 pg_data_t *pgdat = (pg_data_t *)arg;
2155
2156 walk_zones_in_node(m, pgdat, true, false, extfrag_show_print);
2157
2158 return 0;
2159}
2160
2161static const struct seq_operations extfrag_sops = {
2162 .start = frag_start,
2163 .next = frag_next,
2164 .stop = frag_stop,
2165 .show = extfrag_show,
2166};
2167
2168DEFINE_SEQ_ATTRIBUTE(extfrag);
2169
2170static int __init extfrag_debug_init(void)
2171{
2172 struct dentry *extfrag_debug_root;
2173
2174 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
2175
2176 debugfs_create_file("unusable_index", 0444, extfrag_debug_root, NULL,
2177 &unusable_fops);
2178
2179 debugfs_create_file("extfrag_index", 0444, extfrag_debug_root, NULL,
2180 &extfrag_fops);
2181
2182 return 0;
2183}
2184
2185module_init(extfrag_debug_init);
2186#endif
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_ext.h>
30#include <linux/page_owner.h>
31
32#include "internal.h"
33
34#ifdef CONFIG_NUMA
35int sysctl_vm_numa_stat = ENABLE_NUMA_STAT;
36
37/* zero numa counters within a zone */
38static 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 */
52static 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 */
61static 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
69static void invalid_numa_statistics(void)
70{
71 zero_zones_numa_counters();
72 zero_global_numa_counters();
73}
74
75static DEFINE_MUTEX(vm_numa_stat_lock);
76
77int sysctl_vm_numa_stat_handler(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
100out:
101 mutex_unlock(&vm_numa_stat_lock);
102 return ret;
103}
104#endif
105
106#ifdef CONFIG_VM_EVENT_COUNTERS
107DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
108EXPORT_PER_CPU_SYMBOL(vm_event_states);
109
110static 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*/
130void all_vm_events(unsigned long *ret)
131{
132 cpus_read_lock();
133 sum_vm_events(ret);
134 cpus_read_unlock();
135}
136EXPORT_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 */
144void 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 */
162atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
163atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS] __cacheline_aligned_in_smp;
164atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS] __cacheline_aligned_in_smp;
165EXPORT_SYMBOL(vm_zone_stat);
166EXPORT_SYMBOL(vm_node_stat);
167
168#ifdef CONFIG_NUMA
169static 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
187void 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
198int 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
222int 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 */
272void 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
317void 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 */
342void __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}
371EXPORT_SYMBOL(__mod_zone_page_state);
372
373void __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}
407EXPORT_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 */
432void __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
453void __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
476void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
477{
478 __inc_zone_state(page_zone(page), item);
479}
480EXPORT_SYMBOL(__inc_zone_page_state);
481
482void __inc_node_page_state(struct page *page, enum node_stat_item item)
483{
484 __inc_node_state(page_pgdat(page), item);
485}
486EXPORT_SYMBOL(__inc_node_page_state);
487
488void __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
509void __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
532void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
533{
534 __dec_zone_state(page_zone(page), item);
535}
536EXPORT_SYMBOL(__dec_zone_page_state);
537
538void __dec_node_page_state(struct page *page, enum node_stat_item item)
539{
540 __dec_node_state(page_pgdat(page), item);
541}
542EXPORT_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*/
557static 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 o, n, t, z;
563
564 do {
565 z = 0; /* overflow to zone counters */
566
567 /*
568 * The fetching of the stat_threshold is racy. We may apply
569 * a counter threshold to the wrong the cpu if we get
570 * rescheduled while executing here. However, the next
571 * counter update will apply the threshold again and
572 * therefore bring the counter under the threshold again.
573 *
574 * Most of the time the thresholds are the same anyways
575 * for all cpus in a zone.
576 */
577 t = this_cpu_read(pcp->stat_threshold);
578
579 o = this_cpu_read(*p);
580 n = delta + o;
581
582 if (abs(n) > t) {
583 int os = overstep_mode * (t >> 1) ;
584
585 /* Overflow must be added to zone counters */
586 z = n + os;
587 n = -os;
588 }
589 } while (this_cpu_cmpxchg(*p, o, n) != o);
590
591 if (z)
592 zone_page_state_add(z, zone, item);
593}
594
595void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
596 long delta)
597{
598 mod_zone_state(zone, item, delta, 0);
599}
600EXPORT_SYMBOL(mod_zone_page_state);
601
602void inc_zone_page_state(struct page *page, enum zone_stat_item item)
603{
604 mod_zone_state(page_zone(page), item, 1, 1);
605}
606EXPORT_SYMBOL(inc_zone_page_state);
607
608void dec_zone_page_state(struct page *page, enum zone_stat_item item)
609{
610 mod_zone_state(page_zone(page), item, -1, -1);
611}
612EXPORT_SYMBOL(dec_zone_page_state);
613
614static inline void mod_node_state(struct pglist_data *pgdat,
615 enum node_stat_item item, int delta, int overstep_mode)
616{
617 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
618 s8 __percpu *p = pcp->vm_node_stat_diff + item;
619 long o, n, t, z;
620
621 if (vmstat_item_in_bytes(item)) {
622 /*
623 * Only cgroups use subpage accounting right now; at
624 * the global level, these items still change in
625 * multiples of whole pages. Store them as pages
626 * internally to keep the per-cpu counters compact.
627 */
628 VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1));
629 delta >>= PAGE_SHIFT;
630 }
631
632 do {
633 z = 0; /* overflow to node counters */
634
635 /*
636 * The fetching of the stat_threshold is racy. We may apply
637 * a counter threshold to the wrong the cpu if we get
638 * rescheduled while executing here. However, the next
639 * counter update will apply the threshold again and
640 * therefore bring the counter under the threshold again.
641 *
642 * Most of the time the thresholds are the same anyways
643 * for all cpus in a node.
644 */
645 t = this_cpu_read(pcp->stat_threshold);
646
647 o = this_cpu_read(*p);
648 n = delta + o;
649
650 if (abs(n) > t) {
651 int os = overstep_mode * (t >> 1) ;
652
653 /* Overflow must be added to node counters */
654 z = n + os;
655 n = -os;
656 }
657 } while (this_cpu_cmpxchg(*p, o, n) != o);
658
659 if (z)
660 node_page_state_add(z, pgdat, item);
661}
662
663void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
664 long delta)
665{
666 mod_node_state(pgdat, item, delta, 0);
667}
668EXPORT_SYMBOL(mod_node_page_state);
669
670void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
671{
672 mod_node_state(pgdat, item, 1, 1);
673}
674
675void inc_node_page_state(struct page *page, enum node_stat_item item)
676{
677 mod_node_state(page_pgdat(page), item, 1, 1);
678}
679EXPORT_SYMBOL(inc_node_page_state);
680
681void dec_node_page_state(struct page *page, enum node_stat_item item)
682{
683 mod_node_state(page_pgdat(page), item, -1, -1);
684}
685EXPORT_SYMBOL(dec_node_page_state);
686#else
687/*
688 * Use interrupt disable to serialize counter updates
689 */
690void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
691 long delta)
692{
693 unsigned long flags;
694
695 local_irq_save(flags);
696 __mod_zone_page_state(zone, item, delta);
697 local_irq_restore(flags);
698}
699EXPORT_SYMBOL(mod_zone_page_state);
700
701void inc_zone_page_state(struct page *page, enum zone_stat_item item)
702{
703 unsigned long flags;
704 struct zone *zone;
705
706 zone = page_zone(page);
707 local_irq_save(flags);
708 __inc_zone_state(zone, item);
709 local_irq_restore(flags);
710}
711EXPORT_SYMBOL(inc_zone_page_state);
712
713void dec_zone_page_state(struct page *page, enum zone_stat_item item)
714{
715 unsigned long flags;
716
717 local_irq_save(flags);
718 __dec_zone_page_state(page, item);
719 local_irq_restore(flags);
720}
721EXPORT_SYMBOL(dec_zone_page_state);
722
723void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
724{
725 unsigned long flags;
726
727 local_irq_save(flags);
728 __inc_node_state(pgdat, item);
729 local_irq_restore(flags);
730}
731EXPORT_SYMBOL(inc_node_state);
732
733void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
734 long delta)
735{
736 unsigned long flags;
737
738 local_irq_save(flags);
739 __mod_node_page_state(pgdat, item, delta);
740 local_irq_restore(flags);
741}
742EXPORT_SYMBOL(mod_node_page_state);
743
744void inc_node_page_state(struct page *page, enum node_stat_item item)
745{
746 unsigned long flags;
747 struct pglist_data *pgdat;
748
749 pgdat = page_pgdat(page);
750 local_irq_save(flags);
751 __inc_node_state(pgdat, item);
752 local_irq_restore(flags);
753}
754EXPORT_SYMBOL(inc_node_page_state);
755
756void dec_node_page_state(struct page *page, enum node_stat_item item)
757{
758 unsigned long flags;
759
760 local_irq_save(flags);
761 __dec_node_page_state(page, item);
762 local_irq_restore(flags);
763}
764EXPORT_SYMBOL(dec_node_page_state);
765#endif
766
767/*
768 * Fold a differential into the global counters.
769 * Returns the number of counters updated.
770 */
771static int fold_diff(int *zone_diff, int *node_diff)
772{
773 int i;
774 int changes = 0;
775
776 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
777 if (zone_diff[i]) {
778 atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
779 changes++;
780 }
781
782 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
783 if (node_diff[i]) {
784 atomic_long_add(node_diff[i], &vm_node_stat[i]);
785 changes++;
786 }
787 return changes;
788}
789
790/*
791 * Update the zone counters for the current cpu.
792 *
793 * Note that refresh_cpu_vm_stats strives to only access
794 * node local memory. The per cpu pagesets on remote zones are placed
795 * in the memory local to the processor using that pageset. So the
796 * loop over all zones will access a series of cachelines local to
797 * the processor.
798 *
799 * The call to zone_page_state_add updates the cachelines with the
800 * statistics in the remote zone struct as well as the global cachelines
801 * with the global counters. These could cause remote node cache line
802 * bouncing and will have to be only done when necessary.
803 *
804 * The function returns the number of global counters updated.
805 */
806static int refresh_cpu_vm_stats(bool do_pagesets)
807{
808 struct pglist_data *pgdat;
809 struct zone *zone;
810 int i;
811 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
812 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
813 int changes = 0;
814
815 for_each_populated_zone(zone) {
816 struct per_cpu_zonestat __percpu *pzstats = zone->per_cpu_zonestats;
817#ifdef CONFIG_NUMA
818 struct per_cpu_pages __percpu *pcp = zone->per_cpu_pageset;
819#endif
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#ifdef CONFIG_NUMA
836
837 if (do_pagesets) {
838 cond_resched();
839 /*
840 * Deal with draining the remote pageset of this
841 * processor
842 *
843 * Check if there are pages remaining in this pageset
844 * if not then there is nothing to expire.
845 */
846 if (!__this_cpu_read(pcp->expire) ||
847 !__this_cpu_read(pcp->count))
848 continue;
849
850 /*
851 * We never drain zones local to this processor.
852 */
853 if (zone_to_nid(zone) == numa_node_id()) {
854 __this_cpu_write(pcp->expire, 0);
855 continue;
856 }
857
858 if (__this_cpu_dec_return(pcp->expire))
859 continue;
860
861 if (__this_cpu_read(pcp->count)) {
862 drain_zone_pages(zone, this_cpu_ptr(pcp));
863 changes++;
864 }
865 }
866#endif
867 }
868
869 for_each_online_pgdat(pgdat) {
870 struct per_cpu_nodestat __percpu *p = pgdat->per_cpu_nodestats;
871
872 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
873 int v;
874
875 v = this_cpu_xchg(p->vm_node_stat_diff[i], 0);
876 if (v) {
877 atomic_long_add(v, &pgdat->vm_stat[i]);
878 global_node_diff[i] += v;
879 }
880 }
881 }
882
883 changes += fold_diff(global_zone_diff, global_node_diff);
884 return changes;
885}
886
887/*
888 * Fold the data for an offline cpu into the global array.
889 * There cannot be any access by the offline cpu and therefore
890 * synchronization is simplified.
891 */
892void cpu_vm_stats_fold(int cpu)
893{
894 struct pglist_data *pgdat;
895 struct zone *zone;
896 int i;
897 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
898 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
899
900 for_each_populated_zone(zone) {
901 struct per_cpu_zonestat *pzstats;
902
903 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
904
905 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
906 if (pzstats->vm_stat_diff[i]) {
907 int v;
908
909 v = pzstats->vm_stat_diff[i];
910 pzstats->vm_stat_diff[i] = 0;
911 atomic_long_add(v, &zone->vm_stat[i]);
912 global_zone_diff[i] += v;
913 }
914 }
915#ifdef CONFIG_NUMA
916 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) {
917 if (pzstats->vm_numa_event[i]) {
918 unsigned long v;
919
920 v = pzstats->vm_numa_event[i];
921 pzstats->vm_numa_event[i] = 0;
922 zone_numa_event_add(v, zone, i);
923 }
924 }
925#endif
926 }
927
928 for_each_online_pgdat(pgdat) {
929 struct per_cpu_nodestat *p;
930
931 p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu);
932
933 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
934 if (p->vm_node_stat_diff[i]) {
935 int v;
936
937 v = p->vm_node_stat_diff[i];
938 p->vm_node_stat_diff[i] = 0;
939 atomic_long_add(v, &pgdat->vm_stat[i]);
940 global_node_diff[i] += v;
941 }
942 }
943
944 fold_diff(global_zone_diff, global_node_diff);
945}
946
947/*
948 * this is only called if !populated_zone(zone), which implies no other users of
949 * pset->vm_stat_diff[] exist.
950 */
951void drain_zonestat(struct zone *zone, struct per_cpu_zonestat *pzstats)
952{
953 unsigned long v;
954 int i;
955
956 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
957 if (pzstats->vm_stat_diff[i]) {
958 v = pzstats->vm_stat_diff[i];
959 pzstats->vm_stat_diff[i] = 0;
960 zone_page_state_add(v, zone, i);
961 }
962 }
963
964#ifdef CONFIG_NUMA
965 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) {
966 if (pzstats->vm_numa_event[i]) {
967 v = pzstats->vm_numa_event[i];
968 pzstats->vm_numa_event[i] = 0;
969 zone_numa_event_add(v, zone, i);
970 }
971 }
972#endif
973}
974#endif
975
976#ifdef CONFIG_NUMA
977/*
978 * Determine the per node value of a stat item. This function
979 * is called frequently in a NUMA machine, so try to be as
980 * frugal as possible.
981 */
982unsigned long sum_zone_node_page_state(int node,
983 enum zone_stat_item item)
984{
985 struct zone *zones = NODE_DATA(node)->node_zones;
986 int i;
987 unsigned long count = 0;
988
989 for (i = 0; i < MAX_NR_ZONES; i++)
990 count += zone_page_state(zones + i, item);
991
992 return count;
993}
994
995/* Determine the per node value of a numa stat item. */
996unsigned long sum_zone_numa_event_state(int node,
997 enum numa_stat_item item)
998{
999 struct zone *zones = NODE_DATA(node)->node_zones;
1000 unsigned long count = 0;
1001 int i;
1002
1003 for (i = 0; i < MAX_NR_ZONES; i++)
1004 count += zone_numa_event_state(zones + i, item);
1005
1006 return count;
1007}
1008
1009/*
1010 * Determine the per node value of a stat item.
1011 */
1012unsigned long node_page_state_pages(struct pglist_data *pgdat,
1013 enum node_stat_item item)
1014{
1015 long x = atomic_long_read(&pgdat->vm_stat[item]);
1016#ifdef CONFIG_SMP
1017 if (x < 0)
1018 x = 0;
1019#endif
1020 return x;
1021}
1022
1023unsigned long node_page_state(struct pglist_data *pgdat,
1024 enum node_stat_item item)
1025{
1026 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
1027
1028 return node_page_state_pages(pgdat, item);
1029}
1030#endif
1031
1032#ifdef CONFIG_COMPACTION
1033
1034struct contig_page_info {
1035 unsigned long free_pages;
1036 unsigned long free_blocks_total;
1037 unsigned long free_blocks_suitable;
1038};
1039
1040/*
1041 * Calculate the number of free pages in a zone, how many contiguous
1042 * pages are free and how many are large enough to satisfy an allocation of
1043 * the target size. Note that this function makes no attempt to estimate
1044 * how many suitable free blocks there *might* be if MOVABLE pages were
1045 * migrated. Calculating that is possible, but expensive and can be
1046 * figured out from userspace
1047 */
1048static void fill_contig_page_info(struct zone *zone,
1049 unsigned int suitable_order,
1050 struct contig_page_info *info)
1051{
1052 unsigned int order;
1053
1054 info->free_pages = 0;
1055 info->free_blocks_total = 0;
1056 info->free_blocks_suitable = 0;
1057
1058 for (order = 0; order < MAX_ORDER; order++) {
1059 unsigned long blocks;
1060
1061 /*
1062 * Count number of free blocks.
1063 *
1064 * Access to nr_free is lockless as nr_free is used only for
1065 * diagnostic purposes. Use data_race to avoid KCSAN warning.
1066 */
1067 blocks = data_race(zone->free_area[order].nr_free);
1068 info->free_blocks_total += blocks;
1069
1070 /* Count free base pages */
1071 info->free_pages += blocks << order;
1072
1073 /* Count the suitable free blocks */
1074 if (order >= suitable_order)
1075 info->free_blocks_suitable += blocks <<
1076 (order - suitable_order);
1077 }
1078}
1079
1080/*
1081 * A fragmentation index only makes sense if an allocation of a requested
1082 * size would fail. If that is true, the fragmentation index indicates
1083 * whether external fragmentation or a lack of memory was the problem.
1084 * The value can be used to determine if page reclaim or compaction
1085 * should be used
1086 */
1087static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
1088{
1089 unsigned long requested = 1UL << order;
1090
1091 if (WARN_ON_ONCE(order >= MAX_ORDER))
1092 return 0;
1093
1094 if (!info->free_blocks_total)
1095 return 0;
1096
1097 /* Fragmentation index only makes sense when a request would fail */
1098 if (info->free_blocks_suitable)
1099 return -1000;
1100
1101 /*
1102 * Index is between 0 and 1 so return within 3 decimal places
1103 *
1104 * 0 => allocation would fail due to lack of memory
1105 * 1 => allocation would fail due to fragmentation
1106 */
1107 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
1108}
1109
1110/*
1111 * Calculates external fragmentation within a zone wrt the given order.
1112 * It is defined as the percentage of pages found in blocks of size
1113 * less than 1 << order. It returns values in range [0, 100].
1114 */
1115unsigned int extfrag_for_order(struct zone *zone, unsigned int order)
1116{
1117 struct contig_page_info info;
1118
1119 fill_contig_page_info(zone, order, &info);
1120 if (info.free_pages == 0)
1121 return 0;
1122
1123 return div_u64((info.free_pages -
1124 (info.free_blocks_suitable << order)) * 100,
1125 info.free_pages);
1126}
1127
1128/* Same as __fragmentation index but allocs contig_page_info on stack */
1129int fragmentation_index(struct zone *zone, unsigned int order)
1130{
1131 struct contig_page_info info;
1132
1133 fill_contig_page_info(zone, order, &info);
1134 return __fragmentation_index(order, &info);
1135}
1136#endif
1137
1138#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || \
1139 defined(CONFIG_NUMA) || defined(CONFIG_MEMCG)
1140#ifdef CONFIG_ZONE_DMA
1141#define TEXT_FOR_DMA(xx) xx "_dma",
1142#else
1143#define TEXT_FOR_DMA(xx)
1144#endif
1145
1146#ifdef CONFIG_ZONE_DMA32
1147#define TEXT_FOR_DMA32(xx) xx "_dma32",
1148#else
1149#define TEXT_FOR_DMA32(xx)
1150#endif
1151
1152#ifdef CONFIG_HIGHMEM
1153#define TEXT_FOR_HIGHMEM(xx) xx "_high",
1154#else
1155#define TEXT_FOR_HIGHMEM(xx)
1156#endif
1157
1158#ifdef CONFIG_ZONE_DEVICE
1159#define TEXT_FOR_DEVICE(xx) xx "_device",
1160#else
1161#define TEXT_FOR_DEVICE(xx)
1162#endif
1163
1164#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
1165 TEXT_FOR_HIGHMEM(xx) xx "_movable", \
1166 TEXT_FOR_DEVICE(xx)
1167
1168const char * const vmstat_text[] = {
1169 /* enum zone_stat_item counters */
1170 "nr_free_pages",
1171 "nr_zone_inactive_anon",
1172 "nr_zone_active_anon",
1173 "nr_zone_inactive_file",
1174 "nr_zone_active_file",
1175 "nr_zone_unevictable",
1176 "nr_zone_write_pending",
1177 "nr_mlock",
1178 "nr_bounce",
1179#if IS_ENABLED(CONFIG_ZSMALLOC)
1180 "nr_zspages",
1181#endif
1182 "nr_free_cma",
1183
1184 /* enum numa_stat_item counters */
1185#ifdef CONFIG_NUMA
1186 "numa_hit",
1187 "numa_miss",
1188 "numa_foreign",
1189 "numa_interleave",
1190 "numa_local",
1191 "numa_other",
1192#endif
1193
1194 /* enum node_stat_item counters */
1195 "nr_inactive_anon",
1196 "nr_active_anon",
1197 "nr_inactive_file",
1198 "nr_active_file",
1199 "nr_unevictable",
1200 "nr_slab_reclaimable",
1201 "nr_slab_unreclaimable",
1202 "nr_isolated_anon",
1203 "nr_isolated_file",
1204 "workingset_nodes",
1205 "workingset_refault_anon",
1206 "workingset_refault_file",
1207 "workingset_activate_anon",
1208 "workingset_activate_file",
1209 "workingset_restore_anon",
1210 "workingset_restore_file",
1211 "workingset_nodereclaim",
1212 "nr_anon_pages",
1213 "nr_mapped",
1214 "nr_file_pages",
1215 "nr_dirty",
1216 "nr_writeback",
1217 "nr_writeback_temp",
1218 "nr_shmem",
1219 "nr_shmem_hugepages",
1220 "nr_shmem_pmdmapped",
1221 "nr_file_hugepages",
1222 "nr_file_pmdmapped",
1223 "nr_anon_transparent_hugepages",
1224 "nr_vmscan_write",
1225 "nr_vmscan_immediate_reclaim",
1226 "nr_dirtied",
1227 "nr_written",
1228 "nr_throttled_written",
1229 "nr_kernel_misc_reclaimable",
1230 "nr_foll_pin_acquired",
1231 "nr_foll_pin_released",
1232 "nr_kernel_stack",
1233#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
1234 "nr_shadow_call_stack",
1235#endif
1236 "nr_page_table_pages",
1237 "nr_sec_page_table_pages",
1238#ifdef CONFIG_SWAP
1239 "nr_swapcached",
1240#endif
1241#ifdef CONFIG_NUMA_BALANCING
1242 "pgpromote_success",
1243 "pgpromote_candidate",
1244#endif
1245
1246 /* enum writeback_stat_item counters */
1247 "nr_dirty_threshold",
1248 "nr_dirty_background_threshold",
1249
1250#if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG)
1251 /* enum vm_event_item counters */
1252 "pgpgin",
1253 "pgpgout",
1254 "pswpin",
1255 "pswpout",
1256
1257 TEXTS_FOR_ZONES("pgalloc")
1258 TEXTS_FOR_ZONES("allocstall")
1259 TEXTS_FOR_ZONES("pgskip")
1260
1261 "pgfree",
1262 "pgactivate",
1263 "pgdeactivate",
1264 "pglazyfree",
1265
1266 "pgfault",
1267 "pgmajfault",
1268 "pglazyfreed",
1269
1270 "pgrefill",
1271 "pgreuse",
1272 "pgsteal_kswapd",
1273 "pgsteal_direct",
1274 "pgsteal_khugepaged",
1275 "pgdemote_kswapd",
1276 "pgdemote_direct",
1277 "pgdemote_khugepaged",
1278 "pgscan_kswapd",
1279 "pgscan_direct",
1280 "pgscan_khugepaged",
1281 "pgscan_direct_throttle",
1282 "pgscan_anon",
1283 "pgscan_file",
1284 "pgsteal_anon",
1285 "pgsteal_file",
1286
1287#ifdef CONFIG_NUMA
1288 "zone_reclaim_failed",
1289#endif
1290 "pginodesteal",
1291 "slabs_scanned",
1292 "kswapd_inodesteal",
1293 "kswapd_low_wmark_hit_quickly",
1294 "kswapd_high_wmark_hit_quickly",
1295 "pageoutrun",
1296
1297 "pgrotated",
1298
1299 "drop_pagecache",
1300 "drop_slab",
1301 "oom_kill",
1302
1303#ifdef CONFIG_NUMA_BALANCING
1304 "numa_pte_updates",
1305 "numa_huge_pte_updates",
1306 "numa_hint_faults",
1307 "numa_hint_faults_local",
1308 "numa_pages_migrated",
1309#endif
1310#ifdef CONFIG_MIGRATION
1311 "pgmigrate_success",
1312 "pgmigrate_fail",
1313 "thp_migration_success",
1314 "thp_migration_fail",
1315 "thp_migration_split",
1316#endif
1317#ifdef CONFIG_COMPACTION
1318 "compact_migrate_scanned",
1319 "compact_free_scanned",
1320 "compact_isolated",
1321 "compact_stall",
1322 "compact_fail",
1323 "compact_success",
1324 "compact_daemon_wake",
1325 "compact_daemon_migrate_scanned",
1326 "compact_daemon_free_scanned",
1327#endif
1328
1329#ifdef CONFIG_HUGETLB_PAGE
1330 "htlb_buddy_alloc_success",
1331 "htlb_buddy_alloc_fail",
1332#endif
1333#ifdef CONFIG_CMA
1334 "cma_alloc_success",
1335 "cma_alloc_fail",
1336#endif
1337 "unevictable_pgs_culled",
1338 "unevictable_pgs_scanned",
1339 "unevictable_pgs_rescued",
1340 "unevictable_pgs_mlocked",
1341 "unevictable_pgs_munlocked",
1342 "unevictable_pgs_cleared",
1343 "unevictable_pgs_stranded",
1344
1345#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1346 "thp_fault_alloc",
1347 "thp_fault_fallback",
1348 "thp_fault_fallback_charge",
1349 "thp_collapse_alloc",
1350 "thp_collapse_alloc_failed",
1351 "thp_file_alloc",
1352 "thp_file_fallback",
1353 "thp_file_fallback_charge",
1354 "thp_file_mapped",
1355 "thp_split_page",
1356 "thp_split_page_failed",
1357 "thp_deferred_split_page",
1358 "thp_split_pmd",
1359 "thp_scan_exceed_none_pte",
1360 "thp_scan_exceed_swap_pte",
1361 "thp_scan_exceed_share_pte",
1362#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
1363 "thp_split_pud",
1364#endif
1365 "thp_zero_page_alloc",
1366 "thp_zero_page_alloc_failed",
1367 "thp_swpout",
1368 "thp_swpout_fallback",
1369#endif
1370#ifdef CONFIG_MEMORY_BALLOON
1371 "balloon_inflate",
1372 "balloon_deflate",
1373#ifdef CONFIG_BALLOON_COMPACTION
1374 "balloon_migrate",
1375#endif
1376#endif /* CONFIG_MEMORY_BALLOON */
1377#ifdef CONFIG_DEBUG_TLBFLUSH
1378 "nr_tlb_remote_flush",
1379 "nr_tlb_remote_flush_received",
1380 "nr_tlb_local_flush_all",
1381 "nr_tlb_local_flush_one",
1382#endif /* CONFIG_DEBUG_TLBFLUSH */
1383
1384#ifdef CONFIG_SWAP
1385 "swap_ra",
1386 "swap_ra_hit",
1387#ifdef CONFIG_KSM
1388 "ksm_swpin_copy",
1389#endif
1390#endif
1391#ifdef CONFIG_KSM
1392 "cow_ksm",
1393#endif
1394#ifdef CONFIG_ZSWAP
1395 "zswpin",
1396 "zswpout",
1397#endif
1398#ifdef CONFIG_X86
1399 "direct_map_level2_splits",
1400 "direct_map_level3_splits",
1401#endif
1402#endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */
1403};
1404#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */
1405
1406#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
1407 defined(CONFIG_PROC_FS)
1408static void *frag_start(struct seq_file *m, loff_t *pos)
1409{
1410 pg_data_t *pgdat;
1411 loff_t node = *pos;
1412
1413 for (pgdat = first_online_pgdat();
1414 pgdat && node;
1415 pgdat = next_online_pgdat(pgdat))
1416 --node;
1417
1418 return pgdat;
1419}
1420
1421static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
1422{
1423 pg_data_t *pgdat = (pg_data_t *)arg;
1424
1425 (*pos)++;
1426 return next_online_pgdat(pgdat);
1427}
1428
1429static void frag_stop(struct seq_file *m, void *arg)
1430{
1431}
1432
1433/*
1434 * Walk zones in a node and print using a callback.
1435 * If @assert_populated is true, only use callback for zones that are populated.
1436 */
1437static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
1438 bool assert_populated, bool nolock,
1439 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
1440{
1441 struct zone *zone;
1442 struct zone *node_zones = pgdat->node_zones;
1443 unsigned long flags;
1444
1445 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
1446 if (assert_populated && !populated_zone(zone))
1447 continue;
1448
1449 if (!nolock)
1450 spin_lock_irqsave(&zone->lock, flags);
1451 print(m, pgdat, zone);
1452 if (!nolock)
1453 spin_unlock_irqrestore(&zone->lock, flags);
1454 }
1455}
1456#endif
1457
1458#ifdef CONFIG_PROC_FS
1459static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
1460 struct zone *zone)
1461{
1462 int order;
1463
1464 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1465 for (order = 0; order < MAX_ORDER; ++order)
1466 /*
1467 * Access to nr_free is lockless as nr_free is used only for
1468 * printing purposes. Use data_race to avoid KCSAN warning.
1469 */
1470 seq_printf(m, "%6lu ", data_race(zone->free_area[order].nr_free));
1471 seq_putc(m, '\n');
1472}
1473
1474/*
1475 * This walks the free areas for each zone.
1476 */
1477static int frag_show(struct seq_file *m, void *arg)
1478{
1479 pg_data_t *pgdat = (pg_data_t *)arg;
1480 walk_zones_in_node(m, pgdat, true, false, frag_show_print);
1481 return 0;
1482}
1483
1484static void pagetypeinfo_showfree_print(struct seq_file *m,
1485 pg_data_t *pgdat, struct zone *zone)
1486{
1487 int order, mtype;
1488
1489 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
1490 seq_printf(m, "Node %4d, zone %8s, type %12s ",
1491 pgdat->node_id,
1492 zone->name,
1493 migratetype_names[mtype]);
1494 for (order = 0; order < MAX_ORDER; ++order) {
1495 unsigned long freecount = 0;
1496 struct free_area *area;
1497 struct list_head *curr;
1498 bool overflow = false;
1499
1500 area = &(zone->free_area[order]);
1501
1502 list_for_each(curr, &area->free_list[mtype]) {
1503 /*
1504 * Cap the free_list iteration because it might
1505 * be really large and we are under a spinlock
1506 * so a long time spent here could trigger a
1507 * hard lockup detector. Anyway this is a
1508 * debugging tool so knowing there is a handful
1509 * of pages of this order should be more than
1510 * sufficient.
1511 */
1512 if (++freecount >= 100000) {
1513 overflow = true;
1514 break;
1515 }
1516 }
1517 seq_printf(m, "%s%6lu ", overflow ? ">" : "", freecount);
1518 spin_unlock_irq(&zone->lock);
1519 cond_resched();
1520 spin_lock_irq(&zone->lock);
1521 }
1522 seq_putc(m, '\n');
1523 }
1524}
1525
1526/* Print out the free pages at each order for each migatetype */
1527static void pagetypeinfo_showfree(struct seq_file *m, void *arg)
1528{
1529 int order;
1530 pg_data_t *pgdat = (pg_data_t *)arg;
1531
1532 /* Print header */
1533 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
1534 for (order = 0; order < MAX_ORDER; ++order)
1535 seq_printf(m, "%6d ", order);
1536 seq_putc(m, '\n');
1537
1538 walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print);
1539}
1540
1541static void pagetypeinfo_showblockcount_print(struct seq_file *m,
1542 pg_data_t *pgdat, struct zone *zone)
1543{
1544 int mtype;
1545 unsigned long pfn;
1546 unsigned long start_pfn = zone->zone_start_pfn;
1547 unsigned long end_pfn = zone_end_pfn(zone);
1548 unsigned long count[MIGRATE_TYPES] = { 0, };
1549
1550 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
1551 struct page *page;
1552
1553 page = pfn_to_online_page(pfn);
1554 if (!page)
1555 continue;
1556
1557 if (page_zone(page) != zone)
1558 continue;
1559
1560 mtype = get_pageblock_migratetype(page);
1561
1562 if (mtype < MIGRATE_TYPES)
1563 count[mtype]++;
1564 }
1565
1566 /* Print counts */
1567 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1568 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1569 seq_printf(m, "%12lu ", count[mtype]);
1570 seq_putc(m, '\n');
1571}
1572
1573/* Print out the number of pageblocks for each migratetype */
1574static void pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
1575{
1576 int mtype;
1577 pg_data_t *pgdat = (pg_data_t *)arg;
1578
1579 seq_printf(m, "\n%-23s", "Number of blocks type ");
1580 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1581 seq_printf(m, "%12s ", migratetype_names[mtype]);
1582 seq_putc(m, '\n');
1583 walk_zones_in_node(m, pgdat, true, false,
1584 pagetypeinfo_showblockcount_print);
1585}
1586
1587/*
1588 * Print out the number of pageblocks for each migratetype that contain pages
1589 * of other types. This gives an indication of how well fallbacks are being
1590 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER
1591 * to determine what is going on
1592 */
1593static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat)
1594{
1595#ifdef CONFIG_PAGE_OWNER
1596 int mtype;
1597
1598 if (!static_branch_unlikely(&page_owner_inited))
1599 return;
1600
1601 drain_all_pages(NULL);
1602
1603 seq_printf(m, "\n%-23s", "Number of mixed blocks ");
1604 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1605 seq_printf(m, "%12s ", migratetype_names[mtype]);
1606 seq_putc(m, '\n');
1607
1608 walk_zones_in_node(m, pgdat, true, true,
1609 pagetypeinfo_showmixedcount_print);
1610#endif /* CONFIG_PAGE_OWNER */
1611}
1612
1613/*
1614 * This prints out statistics in relation to grouping pages by mobility.
1615 * It is expensive to collect so do not constantly read the file.
1616 */
1617static int pagetypeinfo_show(struct seq_file *m, void *arg)
1618{
1619 pg_data_t *pgdat = (pg_data_t *)arg;
1620
1621 /* check memoryless node */
1622 if (!node_state(pgdat->node_id, N_MEMORY))
1623 return 0;
1624
1625 seq_printf(m, "Page block order: %d\n", pageblock_order);
1626 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
1627 seq_putc(m, '\n');
1628 pagetypeinfo_showfree(m, pgdat);
1629 pagetypeinfo_showblockcount(m, pgdat);
1630 pagetypeinfo_showmixedcount(m, pgdat);
1631
1632 return 0;
1633}
1634
1635static const struct seq_operations fragmentation_op = {
1636 .start = frag_start,
1637 .next = frag_next,
1638 .stop = frag_stop,
1639 .show = frag_show,
1640};
1641
1642static const struct seq_operations pagetypeinfo_op = {
1643 .start = frag_start,
1644 .next = frag_next,
1645 .stop = frag_stop,
1646 .show = pagetypeinfo_show,
1647};
1648
1649static bool is_zone_first_populated(pg_data_t *pgdat, struct zone *zone)
1650{
1651 int zid;
1652
1653 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1654 struct zone *compare = &pgdat->node_zones[zid];
1655
1656 if (populated_zone(compare))
1657 return zone == compare;
1658 }
1659
1660 return false;
1661}
1662
1663static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
1664 struct zone *zone)
1665{
1666 int i;
1667 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1668 if (is_zone_first_populated(pgdat, zone)) {
1669 seq_printf(m, "\n per-node stats");
1670 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1671 unsigned long pages = node_page_state_pages(pgdat, i);
1672
1673 if (vmstat_item_print_in_thp(i))
1674 pages /= HPAGE_PMD_NR;
1675 seq_printf(m, "\n %-12s %lu", node_stat_name(i),
1676 pages);
1677 }
1678 }
1679 seq_printf(m,
1680 "\n pages free %lu"
1681 "\n boost %lu"
1682 "\n min %lu"
1683 "\n low %lu"
1684 "\n high %lu"
1685 "\n spanned %lu"
1686 "\n present %lu"
1687 "\n managed %lu"
1688 "\n cma %lu",
1689 zone_page_state(zone, NR_FREE_PAGES),
1690 zone->watermark_boost,
1691 min_wmark_pages(zone),
1692 low_wmark_pages(zone),
1693 high_wmark_pages(zone),
1694 zone->spanned_pages,
1695 zone->present_pages,
1696 zone_managed_pages(zone),
1697 zone_cma_pages(zone));
1698
1699 seq_printf(m,
1700 "\n protection: (%ld",
1701 zone->lowmem_reserve[0]);
1702 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1703 seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
1704 seq_putc(m, ')');
1705
1706 /* If unpopulated, no other information is useful */
1707 if (!populated_zone(zone)) {
1708 seq_putc(m, '\n');
1709 return;
1710 }
1711
1712 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1713 seq_printf(m, "\n %-12s %lu", zone_stat_name(i),
1714 zone_page_state(zone, i));
1715
1716#ifdef CONFIG_NUMA
1717 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
1718 seq_printf(m, "\n %-12s %lu", numa_stat_name(i),
1719 zone_numa_event_state(zone, i));
1720#endif
1721
1722 seq_printf(m, "\n pagesets");
1723 for_each_online_cpu(i) {
1724 struct per_cpu_pages *pcp;
1725 struct per_cpu_zonestat __maybe_unused *pzstats;
1726
1727 pcp = per_cpu_ptr(zone->per_cpu_pageset, i);
1728 seq_printf(m,
1729 "\n cpu: %i"
1730 "\n count: %i"
1731 "\n high: %i"
1732 "\n batch: %i",
1733 i,
1734 pcp->count,
1735 pcp->high,
1736 pcp->batch);
1737#ifdef CONFIG_SMP
1738 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, i);
1739 seq_printf(m, "\n vm stats threshold: %d",
1740 pzstats->stat_threshold);
1741#endif
1742 }
1743 seq_printf(m,
1744 "\n node_unreclaimable: %u"
1745 "\n start_pfn: %lu",
1746 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES,
1747 zone->zone_start_pfn);
1748 seq_putc(m, '\n');
1749}
1750
1751/*
1752 * Output information about zones in @pgdat. All zones are printed regardless
1753 * of whether they are populated or not: lowmem_reserve_ratio operates on the
1754 * set of all zones and userspace would not be aware of such zones if they are
1755 * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio).
1756 */
1757static int zoneinfo_show(struct seq_file *m, void *arg)
1758{
1759 pg_data_t *pgdat = (pg_data_t *)arg;
1760 walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print);
1761 return 0;
1762}
1763
1764static const struct seq_operations zoneinfo_op = {
1765 .start = frag_start, /* iterate over all zones. The same as in
1766 * fragmentation. */
1767 .next = frag_next,
1768 .stop = frag_stop,
1769 .show = zoneinfo_show,
1770};
1771
1772#define NR_VMSTAT_ITEMS (NR_VM_ZONE_STAT_ITEMS + \
1773 NR_VM_NUMA_EVENT_ITEMS + \
1774 NR_VM_NODE_STAT_ITEMS + \
1775 NR_VM_WRITEBACK_STAT_ITEMS + \
1776 (IS_ENABLED(CONFIG_VM_EVENT_COUNTERS) ? \
1777 NR_VM_EVENT_ITEMS : 0))
1778
1779static void *vmstat_start(struct seq_file *m, loff_t *pos)
1780{
1781 unsigned long *v;
1782 int i;
1783
1784 if (*pos >= NR_VMSTAT_ITEMS)
1785 return NULL;
1786
1787 BUILD_BUG_ON(ARRAY_SIZE(vmstat_text) < NR_VMSTAT_ITEMS);
1788 fold_vm_numa_events();
1789 v = kmalloc_array(NR_VMSTAT_ITEMS, sizeof(unsigned long), GFP_KERNEL);
1790 m->private = v;
1791 if (!v)
1792 return ERR_PTR(-ENOMEM);
1793 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1794 v[i] = global_zone_page_state(i);
1795 v += NR_VM_ZONE_STAT_ITEMS;
1796
1797#ifdef CONFIG_NUMA
1798 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
1799 v[i] = global_numa_event_state(i);
1800 v += NR_VM_NUMA_EVENT_ITEMS;
1801#endif
1802
1803 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1804 v[i] = global_node_page_state_pages(i);
1805 if (vmstat_item_print_in_thp(i))
1806 v[i] /= HPAGE_PMD_NR;
1807 }
1808 v += NR_VM_NODE_STAT_ITEMS;
1809
1810 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1811 v + NR_DIRTY_THRESHOLD);
1812 v += NR_VM_WRITEBACK_STAT_ITEMS;
1813
1814#ifdef CONFIG_VM_EVENT_COUNTERS
1815 all_vm_events(v);
1816 v[PGPGIN] /= 2; /* sectors -> kbytes */
1817 v[PGPGOUT] /= 2;
1818#endif
1819 return (unsigned long *)m->private + *pos;
1820}
1821
1822static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1823{
1824 (*pos)++;
1825 if (*pos >= NR_VMSTAT_ITEMS)
1826 return NULL;
1827 return (unsigned long *)m->private + *pos;
1828}
1829
1830static int vmstat_show(struct seq_file *m, void *arg)
1831{
1832 unsigned long *l = arg;
1833 unsigned long off = l - (unsigned long *)m->private;
1834
1835 seq_puts(m, vmstat_text[off]);
1836 seq_put_decimal_ull(m, " ", *l);
1837 seq_putc(m, '\n');
1838
1839 if (off == NR_VMSTAT_ITEMS - 1) {
1840 /*
1841 * We've come to the end - add any deprecated counters to avoid
1842 * breaking userspace which might depend on them being present.
1843 */
1844 seq_puts(m, "nr_unstable 0\n");
1845 }
1846 return 0;
1847}
1848
1849static void vmstat_stop(struct seq_file *m, void *arg)
1850{
1851 kfree(m->private);
1852 m->private = NULL;
1853}
1854
1855static const struct seq_operations vmstat_op = {
1856 .start = vmstat_start,
1857 .next = vmstat_next,
1858 .stop = vmstat_stop,
1859 .show = vmstat_show,
1860};
1861#endif /* CONFIG_PROC_FS */
1862
1863#ifdef CONFIG_SMP
1864static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1865int sysctl_stat_interval __read_mostly = HZ;
1866
1867#ifdef CONFIG_PROC_FS
1868static void refresh_vm_stats(struct work_struct *work)
1869{
1870 refresh_cpu_vm_stats(true);
1871}
1872
1873int vmstat_refresh(struct ctl_table *table, int write,
1874 void *buffer, size_t *lenp, loff_t *ppos)
1875{
1876 long val;
1877 int err;
1878 int i;
1879
1880 /*
1881 * The regular update, every sysctl_stat_interval, may come later
1882 * than expected: leaving a significant amount in per_cpu buckets.
1883 * This is particularly misleading when checking a quantity of HUGE
1884 * pages, immediately after running a test. /proc/sys/vm/stat_refresh,
1885 * which can equally be echo'ed to or cat'ted from (by root),
1886 * can be used to update the stats just before reading them.
1887 *
1888 * Oh, and since global_zone_page_state() etc. are so careful to hide
1889 * transiently negative values, report an error here if any of
1890 * the stats is negative, so we know to go looking for imbalance.
1891 */
1892 err = schedule_on_each_cpu(refresh_vm_stats);
1893 if (err)
1894 return err;
1895 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
1896 /*
1897 * Skip checking stats known to go negative occasionally.
1898 */
1899 switch (i) {
1900 case NR_ZONE_WRITE_PENDING:
1901 case NR_FREE_CMA_PAGES:
1902 continue;
1903 }
1904 val = atomic_long_read(&vm_zone_stat[i]);
1905 if (val < 0) {
1906 pr_warn("%s: %s %ld\n",
1907 __func__, zone_stat_name(i), val);
1908 }
1909 }
1910 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1911 /*
1912 * Skip checking stats known to go negative occasionally.
1913 */
1914 switch (i) {
1915 case NR_WRITEBACK:
1916 continue;
1917 }
1918 val = atomic_long_read(&vm_node_stat[i]);
1919 if (val < 0) {
1920 pr_warn("%s: %s %ld\n",
1921 __func__, node_stat_name(i), val);
1922 }
1923 }
1924 if (write)
1925 *ppos += *lenp;
1926 else
1927 *lenp = 0;
1928 return 0;
1929}
1930#endif /* CONFIG_PROC_FS */
1931
1932static void vmstat_update(struct work_struct *w)
1933{
1934 if (refresh_cpu_vm_stats(true)) {
1935 /*
1936 * Counters were updated so we expect more updates
1937 * to occur in the future. Keep on running the
1938 * update worker thread.
1939 */
1940 queue_delayed_work_on(smp_processor_id(), mm_percpu_wq,
1941 this_cpu_ptr(&vmstat_work),
1942 round_jiffies_relative(sysctl_stat_interval));
1943 }
1944}
1945
1946/*
1947 * Check if the diffs for a certain cpu indicate that
1948 * an update is needed.
1949 */
1950static bool need_update(int cpu)
1951{
1952 pg_data_t *last_pgdat = NULL;
1953 struct zone *zone;
1954
1955 for_each_populated_zone(zone) {
1956 struct per_cpu_zonestat *pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
1957 struct per_cpu_nodestat *n;
1958
1959 /*
1960 * The fast way of checking if there are any vmstat diffs.
1961 */
1962 if (memchr_inv(pzstats->vm_stat_diff, 0, sizeof(pzstats->vm_stat_diff)))
1963 return true;
1964
1965 if (last_pgdat == zone->zone_pgdat)
1966 continue;
1967 last_pgdat = zone->zone_pgdat;
1968 n = per_cpu_ptr(zone->zone_pgdat->per_cpu_nodestats, cpu);
1969 if (memchr_inv(n->vm_node_stat_diff, 0, sizeof(n->vm_node_stat_diff)))
1970 return true;
1971 }
1972 return false;
1973}
1974
1975/*
1976 * Switch off vmstat processing and then fold all the remaining differentials
1977 * until the diffs stay at zero. The function is used by NOHZ and can only be
1978 * invoked when tick processing is not active.
1979 */
1980void quiet_vmstat(void)
1981{
1982 if (system_state != SYSTEM_RUNNING)
1983 return;
1984
1985 if (!delayed_work_pending(this_cpu_ptr(&vmstat_work)))
1986 return;
1987
1988 if (!need_update(smp_processor_id()))
1989 return;
1990
1991 /*
1992 * Just refresh counters and do not care about the pending delayed
1993 * vmstat_update. It doesn't fire that often to matter and canceling
1994 * it would be too expensive from this path.
1995 * vmstat_shepherd will take care about that for us.
1996 */
1997 refresh_cpu_vm_stats(false);
1998}
1999
2000/*
2001 * Shepherd worker thread that checks the
2002 * differentials of processors that have their worker
2003 * threads for vm statistics updates disabled because of
2004 * inactivity.
2005 */
2006static void vmstat_shepherd(struct work_struct *w);
2007
2008static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd);
2009
2010static void vmstat_shepherd(struct work_struct *w)
2011{
2012 int cpu;
2013
2014 cpus_read_lock();
2015 /* Check processors whose vmstat worker threads have been disabled */
2016 for_each_online_cpu(cpu) {
2017 struct delayed_work *dw = &per_cpu(vmstat_work, cpu);
2018
2019 if (!delayed_work_pending(dw) && need_update(cpu))
2020 queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0);
2021
2022 cond_resched();
2023 }
2024 cpus_read_unlock();
2025
2026 schedule_delayed_work(&shepherd,
2027 round_jiffies_relative(sysctl_stat_interval));
2028}
2029
2030static void __init start_shepherd_timer(void)
2031{
2032 int cpu;
2033
2034 for_each_possible_cpu(cpu)
2035 INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu),
2036 vmstat_update);
2037
2038 schedule_delayed_work(&shepherd,
2039 round_jiffies_relative(sysctl_stat_interval));
2040}
2041
2042static void __init init_cpu_node_state(void)
2043{
2044 int node;
2045
2046 for_each_online_node(node) {
2047 if (!cpumask_empty(cpumask_of_node(node)))
2048 node_set_state(node, N_CPU);
2049 }
2050}
2051
2052static int vmstat_cpu_online(unsigned int cpu)
2053{
2054 refresh_zone_stat_thresholds();
2055
2056 if (!node_state(cpu_to_node(cpu), N_CPU)) {
2057 node_set_state(cpu_to_node(cpu), N_CPU);
2058 }
2059
2060 return 0;
2061}
2062
2063static int vmstat_cpu_down_prep(unsigned int cpu)
2064{
2065 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
2066 return 0;
2067}
2068
2069static int vmstat_cpu_dead(unsigned int cpu)
2070{
2071 const struct cpumask *node_cpus;
2072 int node;
2073
2074 node = cpu_to_node(cpu);
2075
2076 refresh_zone_stat_thresholds();
2077 node_cpus = cpumask_of_node(node);
2078 if (!cpumask_empty(node_cpus))
2079 return 0;
2080
2081 node_clear_state(node, N_CPU);
2082
2083 return 0;
2084}
2085
2086#endif
2087
2088struct workqueue_struct *mm_percpu_wq;
2089
2090void __init init_mm_internals(void)
2091{
2092 int ret __maybe_unused;
2093
2094 mm_percpu_wq = alloc_workqueue("mm_percpu_wq", WQ_MEM_RECLAIM, 0);
2095
2096#ifdef CONFIG_SMP
2097 ret = cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD, "mm/vmstat:dead",
2098 NULL, vmstat_cpu_dead);
2099 if (ret < 0)
2100 pr_err("vmstat: failed to register 'dead' hotplug state\n");
2101
2102 ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "mm/vmstat:online",
2103 vmstat_cpu_online,
2104 vmstat_cpu_down_prep);
2105 if (ret < 0)
2106 pr_err("vmstat: failed to register 'online' hotplug state\n");
2107
2108 cpus_read_lock();
2109 init_cpu_node_state();
2110 cpus_read_unlock();
2111
2112 start_shepherd_timer();
2113#endif
2114#ifdef CONFIG_PROC_FS
2115 proc_create_seq("buddyinfo", 0444, NULL, &fragmentation_op);
2116 proc_create_seq("pagetypeinfo", 0400, NULL, &pagetypeinfo_op);
2117 proc_create_seq("vmstat", 0444, NULL, &vmstat_op);
2118 proc_create_seq("zoneinfo", 0444, NULL, &zoneinfo_op);
2119#endif
2120}
2121
2122#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
2123
2124/*
2125 * Return an index indicating how much of the available free memory is
2126 * unusable for an allocation of the requested size.
2127 */
2128static int unusable_free_index(unsigned int order,
2129 struct contig_page_info *info)
2130{
2131 /* No free memory is interpreted as all free memory is unusable */
2132 if (info->free_pages == 0)
2133 return 1000;
2134
2135 /*
2136 * Index should be a value between 0 and 1. Return a value to 3
2137 * decimal places.
2138 *
2139 * 0 => no fragmentation
2140 * 1 => high fragmentation
2141 */
2142 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
2143
2144}
2145
2146static void unusable_show_print(struct seq_file *m,
2147 pg_data_t *pgdat, struct zone *zone)
2148{
2149 unsigned int order;
2150 int index;
2151 struct contig_page_info info;
2152
2153 seq_printf(m, "Node %d, zone %8s ",
2154 pgdat->node_id,
2155 zone->name);
2156 for (order = 0; order < MAX_ORDER; ++order) {
2157 fill_contig_page_info(zone, order, &info);
2158 index = unusable_free_index(order, &info);
2159 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
2160 }
2161
2162 seq_putc(m, '\n');
2163}
2164
2165/*
2166 * Display unusable free space index
2167 *
2168 * The unusable free space index measures how much of the available free
2169 * memory cannot be used to satisfy an allocation of a given size and is a
2170 * value between 0 and 1. The higher the value, the more of free memory is
2171 * unusable and by implication, the worse the external fragmentation is. This
2172 * can be expressed as a percentage by multiplying by 100.
2173 */
2174static int unusable_show(struct seq_file *m, void *arg)
2175{
2176 pg_data_t *pgdat = (pg_data_t *)arg;
2177
2178 /* check memoryless node */
2179 if (!node_state(pgdat->node_id, N_MEMORY))
2180 return 0;
2181
2182 walk_zones_in_node(m, pgdat, true, false, unusable_show_print);
2183
2184 return 0;
2185}
2186
2187static const struct seq_operations unusable_sops = {
2188 .start = frag_start,
2189 .next = frag_next,
2190 .stop = frag_stop,
2191 .show = unusable_show,
2192};
2193
2194DEFINE_SEQ_ATTRIBUTE(unusable);
2195
2196static void extfrag_show_print(struct seq_file *m,
2197 pg_data_t *pgdat, struct zone *zone)
2198{
2199 unsigned int order;
2200 int index;
2201
2202 /* Alloc on stack as interrupts are disabled for zone walk */
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 < MAX_ORDER; ++order) {
2209 fill_contig_page_info(zone, order, &info);
2210 index = __fragmentation_index(order, &info);
2211 seq_printf(m, "%2d.%03d ", index / 1000, index % 1000);
2212 }
2213
2214 seq_putc(m, '\n');
2215}
2216
2217/*
2218 * Display fragmentation index for orders that allocations would fail for
2219 */
2220static int extfrag_show(struct seq_file *m, void *arg)
2221{
2222 pg_data_t *pgdat = (pg_data_t *)arg;
2223
2224 walk_zones_in_node(m, pgdat, true, false, extfrag_show_print);
2225
2226 return 0;
2227}
2228
2229static const struct seq_operations extfrag_sops = {
2230 .start = frag_start,
2231 .next = frag_next,
2232 .stop = frag_stop,
2233 .show = extfrag_show,
2234};
2235
2236DEFINE_SEQ_ATTRIBUTE(extfrag);
2237
2238static int __init extfrag_debug_init(void)
2239{
2240 struct dentry *extfrag_debug_root;
2241
2242 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
2243
2244 debugfs_create_file("unusable_index", 0444, extfrag_debug_root, NULL,
2245 &unusable_fops);
2246
2247 debugfs_create_file("extfrag_index", 0444, extfrag_debug_root, NULL,
2248 &extfrag_fops);
2249
2250 return 0;
2251}
2252
2253module_init(extfrag_debug_init);
2254#endif