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1/*
2 * linux/mm/vmstat.c
3 *
4 * Manages VM statistics
5 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
6 *
7 * zoned VM statistics
8 * Copyright (C) 2006 Silicon Graphics, Inc.,
9 * Christoph Lameter <christoph@lameter.com>
10 * Copyright (C) 2008-2014 Christoph Lameter
11 */
12#include <linux/fs.h>
13#include <linux/mm.h>
14#include <linux/err.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/cpu.h>
18#include <linux/cpumask.h>
19#include <linux/vmstat.h>
20#include <linux/proc_fs.h>
21#include <linux/seq_file.h>
22#include <linux/debugfs.h>
23#include <linux/sched.h>
24#include <linux/math64.h>
25#include <linux/writeback.h>
26#include <linux/compaction.h>
27#include <linux/mm_inline.h>
28#include <linux/page_ext.h>
29#include <linux/page_owner.h>
30
31#include "internal.h"
32
33#define NUMA_STATS_THRESHOLD (U16_MAX - 2)
34
35#ifdef CONFIG_NUMA
36int sysctl_vm_numa_stat = ENABLE_NUMA_STAT;
37
38/* zero numa counters within a zone */
39static void zero_zone_numa_counters(struct zone *zone)
40{
41 int item, cpu;
42
43 for (item = 0; item < NR_VM_NUMA_STAT_ITEMS; item++) {
44 atomic_long_set(&zone->vm_numa_stat[item], 0);
45 for_each_online_cpu(cpu)
46 per_cpu_ptr(zone->pageset, cpu)->vm_numa_stat_diff[item]
47 = 0;
48 }
49}
50
51/* zero numa counters of all the populated zones */
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_STAT_ITEMS; item++)
66 atomic_long_set(&vm_numa_stat[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 __user *buffer, size_t *length, loff_t *ppos)
79{
80 int ret, oldval;
81
82 mutex_lock(&vm_numa_stat_lock);
83 if (write)
84 oldval = sysctl_vm_numa_stat;
85 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
86 if (ret || !write)
87 goto out;
88
89 if (oldval == sysctl_vm_numa_stat)
90 goto out;
91 else if (sysctl_vm_numa_stat == ENABLE_NUMA_STAT) {
92 static_branch_enable(&vm_numa_stat_key);
93 pr_info("enable numa statistics\n");
94 } else {
95 static_branch_disable(&vm_numa_stat_key);
96 invalid_numa_statistics();
97 pr_info("disable numa statistics, and clear numa counters\n");
98 }
99
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 get_online_cpus();
133 sum_vm_events(ret);
134 put_online_cpus();
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_numa_stat[NR_VM_NUMA_STAT_ITEMS] __cacheline_aligned_in_smp;
164atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS] __cacheline_aligned_in_smp;
165EXPORT_SYMBOL(vm_zone_stat);
166EXPORT_SYMBOL(vm_numa_stat);
167EXPORT_SYMBOL(vm_node_stat);
168
169#ifdef CONFIG_SMP
170
171int calculate_pressure_threshold(struct zone *zone)
172{
173 int threshold;
174 int watermark_distance;
175
176 /*
177 * As vmstats are not up to date, there is drift between the estimated
178 * and real values. For high thresholds and a high number of CPUs, it
179 * is possible for the min watermark to be breached while the estimated
180 * value looks fine. The pressure threshold is a reduced value such
181 * that even the maximum amount of drift will not accidentally breach
182 * the min watermark
183 */
184 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
185 threshold = max(1, (int)(watermark_distance / num_online_cpus()));
186
187 /*
188 * Maximum threshold is 125
189 */
190 threshold = min(125, threshold);
191
192 return threshold;
193}
194
195int calculate_normal_threshold(struct zone *zone)
196{
197 int threshold;
198 int mem; /* memory in 128 MB units */
199
200 /*
201 * The threshold scales with the number of processors and the amount
202 * of memory per zone. More memory means that we can defer updates for
203 * longer, more processors could lead to more contention.
204 * fls() is used to have a cheap way of logarithmic scaling.
205 *
206 * Some sample thresholds:
207 *
208 * Threshold Processors (fls) Zonesize fls(mem+1)
209 * ------------------------------------------------------------------
210 * 8 1 1 0.9-1 GB 4
211 * 16 2 2 0.9-1 GB 4
212 * 20 2 2 1-2 GB 5
213 * 24 2 2 2-4 GB 6
214 * 28 2 2 4-8 GB 7
215 * 32 2 2 8-16 GB 8
216 * 4 2 2 <128M 1
217 * 30 4 3 2-4 GB 5
218 * 48 4 3 8-16 GB 8
219 * 32 8 4 1-2 GB 4
220 * 32 8 4 0.9-1GB 4
221 * 10 16 5 <128M 1
222 * 40 16 5 900M 4
223 * 70 64 7 2-4 GB 5
224 * 84 64 7 4-8 GB 6
225 * 108 512 9 4-8 GB 6
226 * 125 1024 10 8-16 GB 8
227 * 125 1024 10 16-32 GB 9
228 */
229
230 mem = zone->managed_pages >> (27 - PAGE_SHIFT);
231
232 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
233
234 /*
235 * Maximum threshold is 125
236 */
237 threshold = min(125, threshold);
238
239 return threshold;
240}
241
242/*
243 * Refresh the thresholds for each zone.
244 */
245void refresh_zone_stat_thresholds(void)
246{
247 struct pglist_data *pgdat;
248 struct zone *zone;
249 int cpu;
250 int threshold;
251
252 /* Zero current pgdat thresholds */
253 for_each_online_pgdat(pgdat) {
254 for_each_online_cpu(cpu) {
255 per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold = 0;
256 }
257 }
258
259 for_each_populated_zone(zone) {
260 struct pglist_data *pgdat = zone->zone_pgdat;
261 unsigned long max_drift, tolerate_drift;
262
263 threshold = calculate_normal_threshold(zone);
264
265 for_each_online_cpu(cpu) {
266 int pgdat_threshold;
267
268 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
269 = threshold;
270
271 /* Base nodestat threshold on the largest populated zone. */
272 pgdat_threshold = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold;
273 per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold
274 = max(threshold, pgdat_threshold);
275 }
276
277 /*
278 * Only set percpu_drift_mark if there is a danger that
279 * NR_FREE_PAGES reports the low watermark is ok when in fact
280 * the min watermark could be breached by an allocation
281 */
282 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
283 max_drift = num_online_cpus() * threshold;
284 if (max_drift > tolerate_drift)
285 zone->percpu_drift_mark = high_wmark_pages(zone) +
286 max_drift;
287 }
288}
289
290void set_pgdat_percpu_threshold(pg_data_t *pgdat,
291 int (*calculate_pressure)(struct zone *))
292{
293 struct zone *zone;
294 int cpu;
295 int threshold;
296 int i;
297
298 for (i = 0; i < pgdat->nr_zones; i++) {
299 zone = &pgdat->node_zones[i];
300 if (!zone->percpu_drift_mark)
301 continue;
302
303 threshold = (*calculate_pressure)(zone);
304 for_each_online_cpu(cpu)
305 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
306 = threshold;
307 }
308}
309
310/*
311 * For use when we know that interrupts are disabled,
312 * or when we know that preemption is disabled and that
313 * particular counter cannot be updated from interrupt context.
314 */
315void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
316 long delta)
317{
318 struct per_cpu_pageset __percpu *pcp = zone->pageset;
319 s8 __percpu *p = pcp->vm_stat_diff + item;
320 long x;
321 long t;
322
323 x = delta + __this_cpu_read(*p);
324
325 t = __this_cpu_read(pcp->stat_threshold);
326
327 if (unlikely(x > t || x < -t)) {
328 zone_page_state_add(x, zone, item);
329 x = 0;
330 }
331 __this_cpu_write(*p, x);
332}
333EXPORT_SYMBOL(__mod_zone_page_state);
334
335void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
336 long delta)
337{
338 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
339 s8 __percpu *p = pcp->vm_node_stat_diff + item;
340 long x;
341 long t;
342
343 x = delta + __this_cpu_read(*p);
344
345 t = __this_cpu_read(pcp->stat_threshold);
346
347 if (unlikely(x > t || x < -t)) {
348 node_page_state_add(x, pgdat, item);
349 x = 0;
350 }
351 __this_cpu_write(*p, x);
352}
353EXPORT_SYMBOL(__mod_node_page_state);
354
355/*
356 * Optimized increment and decrement functions.
357 *
358 * These are only for a single page and therefore can take a struct page *
359 * argument instead of struct zone *. This allows the inclusion of the code
360 * generated for page_zone(page) into the optimized functions.
361 *
362 * No overflow check is necessary and therefore the differential can be
363 * incremented or decremented in place which may allow the compilers to
364 * generate better code.
365 * The increment or decrement is known and therefore one boundary check can
366 * be omitted.
367 *
368 * NOTE: These functions are very performance sensitive. Change only
369 * with care.
370 *
371 * Some processors have inc/dec instructions that are atomic vs an interrupt.
372 * However, the code must first determine the differential location in a zone
373 * based on the processor number and then inc/dec the counter. There is no
374 * guarantee without disabling preemption that the processor will not change
375 * in between and therefore the atomicity vs. interrupt cannot be exploited
376 * in a useful way here.
377 */
378void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
379{
380 struct per_cpu_pageset __percpu *pcp = zone->pageset;
381 s8 __percpu *p = pcp->vm_stat_diff + item;
382 s8 v, t;
383
384 v = __this_cpu_inc_return(*p);
385 t = __this_cpu_read(pcp->stat_threshold);
386 if (unlikely(v > t)) {
387 s8 overstep = t >> 1;
388
389 zone_page_state_add(v + overstep, zone, item);
390 __this_cpu_write(*p, -overstep);
391 }
392}
393
394void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
395{
396 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
397 s8 __percpu *p = pcp->vm_node_stat_diff + item;
398 s8 v, t;
399
400 v = __this_cpu_inc_return(*p);
401 t = __this_cpu_read(pcp->stat_threshold);
402 if (unlikely(v > t)) {
403 s8 overstep = t >> 1;
404
405 node_page_state_add(v + overstep, pgdat, item);
406 __this_cpu_write(*p, -overstep);
407 }
408}
409
410void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
411{
412 __inc_zone_state(page_zone(page), item);
413}
414EXPORT_SYMBOL(__inc_zone_page_state);
415
416void __inc_node_page_state(struct page *page, enum node_stat_item item)
417{
418 __inc_node_state(page_pgdat(page), item);
419}
420EXPORT_SYMBOL(__inc_node_page_state);
421
422void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
423{
424 struct per_cpu_pageset __percpu *pcp = zone->pageset;
425 s8 __percpu *p = pcp->vm_stat_diff + item;
426 s8 v, t;
427
428 v = __this_cpu_dec_return(*p);
429 t = __this_cpu_read(pcp->stat_threshold);
430 if (unlikely(v < - t)) {
431 s8 overstep = t >> 1;
432
433 zone_page_state_add(v - overstep, zone, item);
434 __this_cpu_write(*p, overstep);
435 }
436}
437
438void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
439{
440 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
441 s8 __percpu *p = pcp->vm_node_stat_diff + item;
442 s8 v, t;
443
444 v = __this_cpu_dec_return(*p);
445 t = __this_cpu_read(pcp->stat_threshold);
446 if (unlikely(v < - t)) {
447 s8 overstep = t >> 1;
448
449 node_page_state_add(v - overstep, pgdat, item);
450 __this_cpu_write(*p, overstep);
451 }
452}
453
454void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
455{
456 __dec_zone_state(page_zone(page), item);
457}
458EXPORT_SYMBOL(__dec_zone_page_state);
459
460void __dec_node_page_state(struct page *page, enum node_stat_item item)
461{
462 __dec_node_state(page_pgdat(page), item);
463}
464EXPORT_SYMBOL(__dec_node_page_state);
465
466#ifdef CONFIG_HAVE_CMPXCHG_LOCAL
467/*
468 * If we have cmpxchg_local support then we do not need to incur the overhead
469 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
470 *
471 * mod_state() modifies the zone counter state through atomic per cpu
472 * operations.
473 *
474 * Overstep mode specifies how overstep should handled:
475 * 0 No overstepping
476 * 1 Overstepping half of threshold
477 * -1 Overstepping minus half of threshold
478*/
479static inline void mod_zone_state(struct zone *zone,
480 enum zone_stat_item item, long delta, int overstep_mode)
481{
482 struct per_cpu_pageset __percpu *pcp = zone->pageset;
483 s8 __percpu *p = pcp->vm_stat_diff + item;
484 long o, n, t, z;
485
486 do {
487 z = 0; /* overflow to zone counters */
488
489 /*
490 * The fetching of the stat_threshold is racy. We may apply
491 * a counter threshold to the wrong the cpu if we get
492 * rescheduled while executing here. However, the next
493 * counter update will apply the threshold again and
494 * therefore bring the counter under the threshold again.
495 *
496 * Most of the time the thresholds are the same anyways
497 * for all cpus in a zone.
498 */
499 t = this_cpu_read(pcp->stat_threshold);
500
501 o = this_cpu_read(*p);
502 n = delta + o;
503
504 if (n > t || n < -t) {
505 int os = overstep_mode * (t >> 1) ;
506
507 /* Overflow must be added to zone counters */
508 z = n + os;
509 n = -os;
510 }
511 } while (this_cpu_cmpxchg(*p, o, n) != o);
512
513 if (z)
514 zone_page_state_add(z, zone, item);
515}
516
517void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
518 long delta)
519{
520 mod_zone_state(zone, item, delta, 0);
521}
522EXPORT_SYMBOL(mod_zone_page_state);
523
524void inc_zone_page_state(struct page *page, enum zone_stat_item item)
525{
526 mod_zone_state(page_zone(page), item, 1, 1);
527}
528EXPORT_SYMBOL(inc_zone_page_state);
529
530void dec_zone_page_state(struct page *page, enum zone_stat_item item)
531{
532 mod_zone_state(page_zone(page), item, -1, -1);
533}
534EXPORT_SYMBOL(dec_zone_page_state);
535
536static inline void mod_node_state(struct pglist_data *pgdat,
537 enum node_stat_item item, int delta, int overstep_mode)
538{
539 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
540 s8 __percpu *p = pcp->vm_node_stat_diff + item;
541 long o, n, t, z;
542
543 do {
544 z = 0; /* overflow to node counters */
545
546 /*
547 * The fetching of the stat_threshold is racy. We may apply
548 * a counter threshold to the wrong the cpu if we get
549 * rescheduled while executing here. However, the next
550 * counter update will apply the threshold again and
551 * therefore bring the counter under the threshold again.
552 *
553 * Most of the time the thresholds are the same anyways
554 * for all cpus in a node.
555 */
556 t = this_cpu_read(pcp->stat_threshold);
557
558 o = this_cpu_read(*p);
559 n = delta + o;
560
561 if (n > t || n < -t) {
562 int os = overstep_mode * (t >> 1) ;
563
564 /* Overflow must be added to node counters */
565 z = n + os;
566 n = -os;
567 }
568 } while (this_cpu_cmpxchg(*p, o, n) != o);
569
570 if (z)
571 node_page_state_add(z, pgdat, item);
572}
573
574void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
575 long delta)
576{
577 mod_node_state(pgdat, item, delta, 0);
578}
579EXPORT_SYMBOL(mod_node_page_state);
580
581void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
582{
583 mod_node_state(pgdat, item, 1, 1);
584}
585
586void inc_node_page_state(struct page *page, enum node_stat_item item)
587{
588 mod_node_state(page_pgdat(page), item, 1, 1);
589}
590EXPORT_SYMBOL(inc_node_page_state);
591
592void dec_node_page_state(struct page *page, enum node_stat_item item)
593{
594 mod_node_state(page_pgdat(page), item, -1, -1);
595}
596EXPORT_SYMBOL(dec_node_page_state);
597#else
598/*
599 * Use interrupt disable to serialize counter updates
600 */
601void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
602 long delta)
603{
604 unsigned long flags;
605
606 local_irq_save(flags);
607 __mod_zone_page_state(zone, item, delta);
608 local_irq_restore(flags);
609}
610EXPORT_SYMBOL(mod_zone_page_state);
611
612void inc_zone_page_state(struct page *page, enum zone_stat_item item)
613{
614 unsigned long flags;
615 struct zone *zone;
616
617 zone = page_zone(page);
618 local_irq_save(flags);
619 __inc_zone_state(zone, item);
620 local_irq_restore(flags);
621}
622EXPORT_SYMBOL(inc_zone_page_state);
623
624void dec_zone_page_state(struct page *page, enum zone_stat_item item)
625{
626 unsigned long flags;
627
628 local_irq_save(flags);
629 __dec_zone_page_state(page, item);
630 local_irq_restore(flags);
631}
632EXPORT_SYMBOL(dec_zone_page_state);
633
634void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
635{
636 unsigned long flags;
637
638 local_irq_save(flags);
639 __inc_node_state(pgdat, item);
640 local_irq_restore(flags);
641}
642EXPORT_SYMBOL(inc_node_state);
643
644void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
645 long delta)
646{
647 unsigned long flags;
648
649 local_irq_save(flags);
650 __mod_node_page_state(pgdat, item, delta);
651 local_irq_restore(flags);
652}
653EXPORT_SYMBOL(mod_node_page_state);
654
655void inc_node_page_state(struct page *page, enum node_stat_item item)
656{
657 unsigned long flags;
658 struct pglist_data *pgdat;
659
660 pgdat = page_pgdat(page);
661 local_irq_save(flags);
662 __inc_node_state(pgdat, item);
663 local_irq_restore(flags);
664}
665EXPORT_SYMBOL(inc_node_page_state);
666
667void dec_node_page_state(struct page *page, enum node_stat_item item)
668{
669 unsigned long flags;
670
671 local_irq_save(flags);
672 __dec_node_page_state(page, item);
673 local_irq_restore(flags);
674}
675EXPORT_SYMBOL(dec_node_page_state);
676#endif
677
678/*
679 * Fold a differential into the global counters.
680 * Returns the number of counters updated.
681 */
682#ifdef CONFIG_NUMA
683static int fold_diff(int *zone_diff, int *numa_diff, int *node_diff)
684{
685 int i;
686 int changes = 0;
687
688 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
689 if (zone_diff[i]) {
690 atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
691 changes++;
692 }
693
694 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
695 if (numa_diff[i]) {
696 atomic_long_add(numa_diff[i], &vm_numa_stat[i]);
697 changes++;
698 }
699
700 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
701 if (node_diff[i]) {
702 atomic_long_add(node_diff[i], &vm_node_stat[i]);
703 changes++;
704 }
705 return changes;
706}
707#else
708static int fold_diff(int *zone_diff, int *node_diff)
709{
710 int i;
711 int changes = 0;
712
713 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
714 if (zone_diff[i]) {
715 atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
716 changes++;
717 }
718
719 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
720 if (node_diff[i]) {
721 atomic_long_add(node_diff[i], &vm_node_stat[i]);
722 changes++;
723 }
724 return changes;
725}
726#endif /* CONFIG_NUMA */
727
728/*
729 * Update the zone counters for the current cpu.
730 *
731 * Note that refresh_cpu_vm_stats strives to only access
732 * node local memory. The per cpu pagesets on remote zones are placed
733 * in the memory local to the processor using that pageset. So the
734 * loop over all zones will access a series of cachelines local to
735 * the processor.
736 *
737 * The call to zone_page_state_add updates the cachelines with the
738 * statistics in the remote zone struct as well as the global cachelines
739 * with the global counters. These could cause remote node cache line
740 * bouncing and will have to be only done when necessary.
741 *
742 * The function returns the number of global counters updated.
743 */
744static int refresh_cpu_vm_stats(bool do_pagesets)
745{
746 struct pglist_data *pgdat;
747 struct zone *zone;
748 int i;
749 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
750#ifdef CONFIG_NUMA
751 int global_numa_diff[NR_VM_NUMA_STAT_ITEMS] = { 0, };
752#endif
753 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
754 int changes = 0;
755
756 for_each_populated_zone(zone) {
757 struct per_cpu_pageset __percpu *p = zone->pageset;
758
759 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
760 int v;
761
762 v = this_cpu_xchg(p->vm_stat_diff[i], 0);
763 if (v) {
764
765 atomic_long_add(v, &zone->vm_stat[i]);
766 global_zone_diff[i] += v;
767#ifdef CONFIG_NUMA
768 /* 3 seconds idle till flush */
769 __this_cpu_write(p->expire, 3);
770#endif
771 }
772 }
773#ifdef CONFIG_NUMA
774 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) {
775 int v;
776
777 v = this_cpu_xchg(p->vm_numa_stat_diff[i], 0);
778 if (v) {
779
780 atomic_long_add(v, &zone->vm_numa_stat[i]);
781 global_numa_diff[i] += v;
782 __this_cpu_write(p->expire, 3);
783 }
784 }
785
786 if (do_pagesets) {
787 cond_resched();
788 /*
789 * Deal with draining the remote pageset of this
790 * processor
791 *
792 * Check if there are pages remaining in this pageset
793 * if not then there is nothing to expire.
794 */
795 if (!__this_cpu_read(p->expire) ||
796 !__this_cpu_read(p->pcp.count))
797 continue;
798
799 /*
800 * We never drain zones local to this processor.
801 */
802 if (zone_to_nid(zone) == numa_node_id()) {
803 __this_cpu_write(p->expire, 0);
804 continue;
805 }
806
807 if (__this_cpu_dec_return(p->expire))
808 continue;
809
810 if (__this_cpu_read(p->pcp.count)) {
811 drain_zone_pages(zone, this_cpu_ptr(&p->pcp));
812 changes++;
813 }
814 }
815#endif
816 }
817
818 for_each_online_pgdat(pgdat) {
819 struct per_cpu_nodestat __percpu *p = pgdat->per_cpu_nodestats;
820
821 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
822 int v;
823
824 v = this_cpu_xchg(p->vm_node_stat_diff[i], 0);
825 if (v) {
826 atomic_long_add(v, &pgdat->vm_stat[i]);
827 global_node_diff[i] += v;
828 }
829 }
830 }
831
832#ifdef CONFIG_NUMA
833 changes += fold_diff(global_zone_diff, global_numa_diff,
834 global_node_diff);
835#else
836 changes += fold_diff(global_zone_diff, global_node_diff);
837#endif
838 return changes;
839}
840
841/*
842 * Fold the data for an offline cpu into the global array.
843 * There cannot be any access by the offline cpu and therefore
844 * synchronization is simplified.
845 */
846void cpu_vm_stats_fold(int cpu)
847{
848 struct pglist_data *pgdat;
849 struct zone *zone;
850 int i;
851 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
852#ifdef CONFIG_NUMA
853 int global_numa_diff[NR_VM_NUMA_STAT_ITEMS] = { 0, };
854#endif
855 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
856
857 for_each_populated_zone(zone) {
858 struct per_cpu_pageset *p;
859
860 p = per_cpu_ptr(zone->pageset, cpu);
861
862 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
863 if (p->vm_stat_diff[i]) {
864 int v;
865
866 v = p->vm_stat_diff[i];
867 p->vm_stat_diff[i] = 0;
868 atomic_long_add(v, &zone->vm_stat[i]);
869 global_zone_diff[i] += v;
870 }
871
872#ifdef CONFIG_NUMA
873 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
874 if (p->vm_numa_stat_diff[i]) {
875 int v;
876
877 v = p->vm_numa_stat_diff[i];
878 p->vm_numa_stat_diff[i] = 0;
879 atomic_long_add(v, &zone->vm_numa_stat[i]);
880 global_numa_diff[i] += v;
881 }
882#endif
883 }
884
885 for_each_online_pgdat(pgdat) {
886 struct per_cpu_nodestat *p;
887
888 p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu);
889
890 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
891 if (p->vm_node_stat_diff[i]) {
892 int v;
893
894 v = p->vm_node_stat_diff[i];
895 p->vm_node_stat_diff[i] = 0;
896 atomic_long_add(v, &pgdat->vm_stat[i]);
897 global_node_diff[i] += v;
898 }
899 }
900
901#ifdef CONFIG_NUMA
902 fold_diff(global_zone_diff, global_numa_diff, global_node_diff);
903#else
904 fold_diff(global_zone_diff, global_node_diff);
905#endif
906}
907
908/*
909 * this is only called if !populated_zone(zone), which implies no other users of
910 * pset->vm_stat_diff[] exsist.
911 */
912void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
913{
914 int i;
915
916 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
917 if (pset->vm_stat_diff[i]) {
918 int v = pset->vm_stat_diff[i];
919 pset->vm_stat_diff[i] = 0;
920 atomic_long_add(v, &zone->vm_stat[i]);
921 atomic_long_add(v, &vm_zone_stat[i]);
922 }
923
924#ifdef CONFIG_NUMA
925 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
926 if (pset->vm_numa_stat_diff[i]) {
927 int v = pset->vm_numa_stat_diff[i];
928
929 pset->vm_numa_stat_diff[i] = 0;
930 atomic_long_add(v, &zone->vm_numa_stat[i]);
931 atomic_long_add(v, &vm_numa_stat[i]);
932 }
933#endif
934}
935#endif
936
937#ifdef CONFIG_NUMA
938void __inc_numa_state(struct zone *zone,
939 enum numa_stat_item item)
940{
941 struct per_cpu_pageset __percpu *pcp = zone->pageset;
942 u16 __percpu *p = pcp->vm_numa_stat_diff + item;
943 u16 v;
944
945 v = __this_cpu_inc_return(*p);
946
947 if (unlikely(v > NUMA_STATS_THRESHOLD)) {
948 zone_numa_state_add(v, zone, item);
949 __this_cpu_write(*p, 0);
950 }
951}
952
953/*
954 * Determine the per node value of a stat item. This function
955 * is called frequently in a NUMA machine, so try to be as
956 * frugal as possible.
957 */
958unsigned long sum_zone_node_page_state(int node,
959 enum zone_stat_item item)
960{
961 struct zone *zones = NODE_DATA(node)->node_zones;
962 int i;
963 unsigned long count = 0;
964
965 for (i = 0; i < MAX_NR_ZONES; i++)
966 count += zone_page_state(zones + i, item);
967
968 return count;
969}
970
971/*
972 * Determine the per node value of a numa stat item. To avoid deviation,
973 * the per cpu stat number in vm_numa_stat_diff[] is also included.
974 */
975unsigned long sum_zone_numa_state(int node,
976 enum numa_stat_item item)
977{
978 struct zone *zones = NODE_DATA(node)->node_zones;
979 int i;
980 unsigned long count = 0;
981
982 for (i = 0; i < MAX_NR_ZONES; i++)
983 count += zone_numa_state_snapshot(zones + i, item);
984
985 return count;
986}
987
988/*
989 * Determine the per node value of a stat item.
990 */
991unsigned long node_page_state(struct pglist_data *pgdat,
992 enum node_stat_item item)
993{
994 long x = atomic_long_read(&pgdat->vm_stat[item]);
995#ifdef CONFIG_SMP
996 if (x < 0)
997 x = 0;
998#endif
999 return x;
1000}
1001#endif
1002
1003#ifdef CONFIG_COMPACTION
1004
1005struct contig_page_info {
1006 unsigned long free_pages;
1007 unsigned long free_blocks_total;
1008 unsigned long free_blocks_suitable;
1009};
1010
1011/*
1012 * Calculate the number of free pages in a zone, how many contiguous
1013 * pages are free and how many are large enough to satisfy an allocation of
1014 * the target size. Note that this function makes no attempt to estimate
1015 * how many suitable free blocks there *might* be if MOVABLE pages were
1016 * migrated. Calculating that is possible, but expensive and can be
1017 * figured out from userspace
1018 */
1019static void fill_contig_page_info(struct zone *zone,
1020 unsigned int suitable_order,
1021 struct contig_page_info *info)
1022{
1023 unsigned int order;
1024
1025 info->free_pages = 0;
1026 info->free_blocks_total = 0;
1027 info->free_blocks_suitable = 0;
1028
1029 for (order = 0; order < MAX_ORDER; order++) {
1030 unsigned long blocks;
1031
1032 /* Count number of free blocks */
1033 blocks = zone->free_area[order].nr_free;
1034 info->free_blocks_total += blocks;
1035
1036 /* Count free base pages */
1037 info->free_pages += blocks << order;
1038
1039 /* Count the suitable free blocks */
1040 if (order >= suitable_order)
1041 info->free_blocks_suitable += blocks <<
1042 (order - suitable_order);
1043 }
1044}
1045
1046/*
1047 * A fragmentation index only makes sense if an allocation of a requested
1048 * size would fail. If that is true, the fragmentation index indicates
1049 * whether external fragmentation or a lack of memory was the problem.
1050 * The value can be used to determine if page reclaim or compaction
1051 * should be used
1052 */
1053static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
1054{
1055 unsigned long requested = 1UL << order;
1056
1057 if (WARN_ON_ONCE(order >= MAX_ORDER))
1058 return 0;
1059
1060 if (!info->free_blocks_total)
1061 return 0;
1062
1063 /* Fragmentation index only makes sense when a request would fail */
1064 if (info->free_blocks_suitable)
1065 return -1000;
1066
1067 /*
1068 * Index is between 0 and 1 so return within 3 decimal places
1069 *
1070 * 0 => allocation would fail due to lack of memory
1071 * 1 => allocation would fail due to fragmentation
1072 */
1073 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
1074}
1075
1076/* Same as __fragmentation index but allocs contig_page_info on stack */
1077int fragmentation_index(struct zone *zone, unsigned int order)
1078{
1079 struct contig_page_info info;
1080
1081 fill_contig_page_info(zone, order, &info);
1082 return __fragmentation_index(order, &info);
1083}
1084#endif
1085
1086#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
1087#ifdef CONFIG_ZONE_DMA
1088#define TEXT_FOR_DMA(xx) xx "_dma",
1089#else
1090#define TEXT_FOR_DMA(xx)
1091#endif
1092
1093#ifdef CONFIG_ZONE_DMA32
1094#define TEXT_FOR_DMA32(xx) xx "_dma32",
1095#else
1096#define TEXT_FOR_DMA32(xx)
1097#endif
1098
1099#ifdef CONFIG_HIGHMEM
1100#define TEXT_FOR_HIGHMEM(xx) xx "_high",
1101#else
1102#define TEXT_FOR_HIGHMEM(xx)
1103#endif
1104
1105#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
1106 TEXT_FOR_HIGHMEM(xx) xx "_movable",
1107
1108const char * const vmstat_text[] = {
1109 /* enum zone_stat_item countes */
1110 "nr_free_pages",
1111 "nr_zone_inactive_anon",
1112 "nr_zone_active_anon",
1113 "nr_zone_inactive_file",
1114 "nr_zone_active_file",
1115 "nr_zone_unevictable",
1116 "nr_zone_write_pending",
1117 "nr_mlock",
1118 "nr_page_table_pages",
1119 "nr_kernel_stack",
1120 "nr_bounce",
1121#if IS_ENABLED(CONFIG_ZSMALLOC)
1122 "nr_zspages",
1123#endif
1124 "nr_free_cma",
1125
1126 /* enum numa_stat_item counters */
1127#ifdef CONFIG_NUMA
1128 "numa_hit",
1129 "numa_miss",
1130 "numa_foreign",
1131 "numa_interleave",
1132 "numa_local",
1133 "numa_other",
1134#endif
1135
1136 /* Node-based counters */
1137 "nr_inactive_anon",
1138 "nr_active_anon",
1139 "nr_inactive_file",
1140 "nr_active_file",
1141 "nr_unevictable",
1142 "nr_slab_reclaimable",
1143 "nr_slab_unreclaimable",
1144 "nr_isolated_anon",
1145 "nr_isolated_file",
1146 "workingset_refault",
1147 "workingset_activate",
1148 "workingset_nodereclaim",
1149 "nr_anon_pages",
1150 "nr_mapped",
1151 "nr_file_pages",
1152 "nr_dirty",
1153 "nr_writeback",
1154 "nr_writeback_temp",
1155 "nr_shmem",
1156 "nr_shmem_hugepages",
1157 "nr_shmem_pmdmapped",
1158 "nr_anon_transparent_hugepages",
1159 "nr_unstable",
1160 "nr_vmscan_write",
1161 "nr_vmscan_immediate_reclaim",
1162 "nr_dirtied",
1163 "nr_written",
1164 "", /* nr_indirectly_reclaimable */
1165
1166 /* enum writeback_stat_item counters */
1167 "nr_dirty_threshold",
1168 "nr_dirty_background_threshold",
1169
1170#ifdef CONFIG_VM_EVENT_COUNTERS
1171 /* enum vm_event_item counters */
1172 "pgpgin",
1173 "pgpgout",
1174 "pswpin",
1175 "pswpout",
1176
1177 TEXTS_FOR_ZONES("pgalloc")
1178 TEXTS_FOR_ZONES("allocstall")
1179 TEXTS_FOR_ZONES("pgskip")
1180
1181 "pgfree",
1182 "pgactivate",
1183 "pgdeactivate",
1184 "pglazyfree",
1185
1186 "pgfault",
1187 "pgmajfault",
1188 "pglazyfreed",
1189
1190 "pgrefill",
1191 "pgsteal_kswapd",
1192 "pgsteal_direct",
1193 "pgscan_kswapd",
1194 "pgscan_direct",
1195 "pgscan_direct_throttle",
1196
1197#ifdef CONFIG_NUMA
1198 "zone_reclaim_failed",
1199#endif
1200 "pginodesteal",
1201 "slabs_scanned",
1202 "kswapd_inodesteal",
1203 "kswapd_low_wmark_hit_quickly",
1204 "kswapd_high_wmark_hit_quickly",
1205 "pageoutrun",
1206
1207 "pgrotated",
1208
1209 "drop_pagecache",
1210 "drop_slab",
1211 "oom_kill",
1212
1213#ifdef CONFIG_NUMA_BALANCING
1214 "numa_pte_updates",
1215 "numa_huge_pte_updates",
1216 "numa_hint_faults",
1217 "numa_hint_faults_local",
1218 "numa_pages_migrated",
1219#endif
1220#ifdef CONFIG_MIGRATION
1221 "pgmigrate_success",
1222 "pgmigrate_fail",
1223#endif
1224#ifdef CONFIG_COMPACTION
1225 "compact_migrate_scanned",
1226 "compact_free_scanned",
1227 "compact_isolated",
1228 "compact_stall",
1229 "compact_fail",
1230 "compact_success",
1231 "compact_daemon_wake",
1232 "compact_daemon_migrate_scanned",
1233 "compact_daemon_free_scanned",
1234#endif
1235
1236#ifdef CONFIG_HUGETLB_PAGE
1237 "htlb_buddy_alloc_success",
1238 "htlb_buddy_alloc_fail",
1239#endif
1240 "unevictable_pgs_culled",
1241 "unevictable_pgs_scanned",
1242 "unevictable_pgs_rescued",
1243 "unevictable_pgs_mlocked",
1244 "unevictable_pgs_munlocked",
1245 "unevictable_pgs_cleared",
1246 "unevictable_pgs_stranded",
1247
1248#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1249 "thp_fault_alloc",
1250 "thp_fault_fallback",
1251 "thp_collapse_alloc",
1252 "thp_collapse_alloc_failed",
1253 "thp_file_alloc",
1254 "thp_file_mapped",
1255 "thp_split_page",
1256 "thp_split_page_failed",
1257 "thp_deferred_split_page",
1258 "thp_split_pmd",
1259#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
1260 "thp_split_pud",
1261#endif
1262 "thp_zero_page_alloc",
1263 "thp_zero_page_alloc_failed",
1264 "thp_swpout",
1265 "thp_swpout_fallback",
1266#endif
1267#ifdef CONFIG_MEMORY_BALLOON
1268 "balloon_inflate",
1269 "balloon_deflate",
1270#ifdef CONFIG_BALLOON_COMPACTION
1271 "balloon_migrate",
1272#endif
1273#endif /* CONFIG_MEMORY_BALLOON */
1274#ifdef CONFIG_DEBUG_TLBFLUSH
1275#ifdef CONFIG_SMP
1276 "nr_tlb_remote_flush",
1277 "nr_tlb_remote_flush_received",
1278#endif /* CONFIG_SMP */
1279 "nr_tlb_local_flush_all",
1280 "nr_tlb_local_flush_one",
1281#endif /* CONFIG_DEBUG_TLBFLUSH */
1282
1283#ifdef CONFIG_DEBUG_VM_VMACACHE
1284 "vmacache_find_calls",
1285 "vmacache_find_hits",
1286 "vmacache_full_flushes",
1287#endif
1288#ifdef CONFIG_SWAP
1289 "swap_ra",
1290 "swap_ra_hit",
1291#endif
1292#endif /* CONFIG_VM_EVENTS_COUNTERS */
1293};
1294#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
1295
1296#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
1297 defined(CONFIG_PROC_FS)
1298static void *frag_start(struct seq_file *m, loff_t *pos)
1299{
1300 pg_data_t *pgdat;
1301 loff_t node = *pos;
1302
1303 for (pgdat = first_online_pgdat();
1304 pgdat && node;
1305 pgdat = next_online_pgdat(pgdat))
1306 --node;
1307
1308 return pgdat;
1309}
1310
1311static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
1312{
1313 pg_data_t *pgdat = (pg_data_t *)arg;
1314
1315 (*pos)++;
1316 return next_online_pgdat(pgdat);
1317}
1318
1319static void frag_stop(struct seq_file *m, void *arg)
1320{
1321}
1322
1323/*
1324 * Walk zones in a node and print using a callback.
1325 * If @assert_populated is true, only use callback for zones that are populated.
1326 */
1327static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
1328 bool assert_populated, bool nolock,
1329 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
1330{
1331 struct zone *zone;
1332 struct zone *node_zones = pgdat->node_zones;
1333 unsigned long flags;
1334
1335 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
1336 if (assert_populated && !populated_zone(zone))
1337 continue;
1338
1339 if (!nolock)
1340 spin_lock_irqsave(&zone->lock, flags);
1341 print(m, pgdat, zone);
1342 if (!nolock)
1343 spin_unlock_irqrestore(&zone->lock, flags);
1344 }
1345}
1346#endif
1347
1348#ifdef CONFIG_PROC_FS
1349static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
1350 struct zone *zone)
1351{
1352 int order;
1353
1354 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1355 for (order = 0; order < MAX_ORDER; ++order)
1356 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
1357 seq_putc(m, '\n');
1358}
1359
1360/*
1361 * This walks the free areas for each zone.
1362 */
1363static int frag_show(struct seq_file *m, void *arg)
1364{
1365 pg_data_t *pgdat = (pg_data_t *)arg;
1366 walk_zones_in_node(m, pgdat, true, false, frag_show_print);
1367 return 0;
1368}
1369
1370static void pagetypeinfo_showfree_print(struct seq_file *m,
1371 pg_data_t *pgdat, struct zone *zone)
1372{
1373 int order, mtype;
1374
1375 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
1376 seq_printf(m, "Node %4d, zone %8s, type %12s ",
1377 pgdat->node_id,
1378 zone->name,
1379 migratetype_names[mtype]);
1380 for (order = 0; order < MAX_ORDER; ++order) {
1381 unsigned long freecount = 0;
1382 struct free_area *area;
1383 struct list_head *curr;
1384
1385 area = &(zone->free_area[order]);
1386
1387 list_for_each(curr, &area->free_list[mtype])
1388 freecount++;
1389 seq_printf(m, "%6lu ", freecount);
1390 }
1391 seq_putc(m, '\n');
1392 }
1393}
1394
1395/* Print out the free pages at each order for each migatetype */
1396static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
1397{
1398 int order;
1399 pg_data_t *pgdat = (pg_data_t *)arg;
1400
1401 /* Print header */
1402 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
1403 for (order = 0; order < MAX_ORDER; ++order)
1404 seq_printf(m, "%6d ", order);
1405 seq_putc(m, '\n');
1406
1407 walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print);
1408
1409 return 0;
1410}
1411
1412static void pagetypeinfo_showblockcount_print(struct seq_file *m,
1413 pg_data_t *pgdat, struct zone *zone)
1414{
1415 int mtype;
1416 unsigned long pfn;
1417 unsigned long start_pfn = zone->zone_start_pfn;
1418 unsigned long end_pfn = zone_end_pfn(zone);
1419 unsigned long count[MIGRATE_TYPES] = { 0, };
1420
1421 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
1422 struct page *page;
1423
1424 page = pfn_to_online_page(pfn);
1425 if (!page)
1426 continue;
1427
1428 /* Watch for unexpected holes punched in the memmap */
1429 if (!memmap_valid_within(pfn, page, zone))
1430 continue;
1431
1432 if (page_zone(page) != zone)
1433 continue;
1434
1435 mtype = get_pageblock_migratetype(page);
1436
1437 if (mtype < MIGRATE_TYPES)
1438 count[mtype]++;
1439 }
1440
1441 /* Print counts */
1442 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1443 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1444 seq_printf(m, "%12lu ", count[mtype]);
1445 seq_putc(m, '\n');
1446}
1447
1448/* Print out the number of pageblocks for each migratetype */
1449static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
1450{
1451 int mtype;
1452 pg_data_t *pgdat = (pg_data_t *)arg;
1453
1454 seq_printf(m, "\n%-23s", "Number of blocks type ");
1455 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1456 seq_printf(m, "%12s ", migratetype_names[mtype]);
1457 seq_putc(m, '\n');
1458 walk_zones_in_node(m, pgdat, true, false,
1459 pagetypeinfo_showblockcount_print);
1460
1461 return 0;
1462}
1463
1464/*
1465 * Print out the number of pageblocks for each migratetype that contain pages
1466 * of other types. This gives an indication of how well fallbacks are being
1467 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER
1468 * to determine what is going on
1469 */
1470static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat)
1471{
1472#ifdef CONFIG_PAGE_OWNER
1473 int mtype;
1474
1475 if (!static_branch_unlikely(&page_owner_inited))
1476 return;
1477
1478 drain_all_pages(NULL);
1479
1480 seq_printf(m, "\n%-23s", "Number of mixed blocks ");
1481 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1482 seq_printf(m, "%12s ", migratetype_names[mtype]);
1483 seq_putc(m, '\n');
1484
1485 walk_zones_in_node(m, pgdat, true, true,
1486 pagetypeinfo_showmixedcount_print);
1487#endif /* CONFIG_PAGE_OWNER */
1488}
1489
1490/*
1491 * This prints out statistics in relation to grouping pages by mobility.
1492 * It is expensive to collect so do not constantly read the file.
1493 */
1494static int pagetypeinfo_show(struct seq_file *m, void *arg)
1495{
1496 pg_data_t *pgdat = (pg_data_t *)arg;
1497
1498 /* check memoryless node */
1499 if (!node_state(pgdat->node_id, N_MEMORY))
1500 return 0;
1501
1502 seq_printf(m, "Page block order: %d\n", pageblock_order);
1503 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
1504 seq_putc(m, '\n');
1505 pagetypeinfo_showfree(m, pgdat);
1506 pagetypeinfo_showblockcount(m, pgdat);
1507 pagetypeinfo_showmixedcount(m, pgdat);
1508
1509 return 0;
1510}
1511
1512static const struct seq_operations fragmentation_op = {
1513 .start = frag_start,
1514 .next = frag_next,
1515 .stop = frag_stop,
1516 .show = frag_show,
1517};
1518
1519static int fragmentation_open(struct inode *inode, struct file *file)
1520{
1521 return seq_open(file, &fragmentation_op);
1522}
1523
1524static const struct file_operations buddyinfo_file_operations = {
1525 .open = fragmentation_open,
1526 .read = seq_read,
1527 .llseek = seq_lseek,
1528 .release = seq_release,
1529};
1530
1531static const struct seq_operations pagetypeinfo_op = {
1532 .start = frag_start,
1533 .next = frag_next,
1534 .stop = frag_stop,
1535 .show = pagetypeinfo_show,
1536};
1537
1538static int pagetypeinfo_open(struct inode *inode, struct file *file)
1539{
1540 return seq_open(file, &pagetypeinfo_op);
1541}
1542
1543static const struct file_operations pagetypeinfo_file_operations = {
1544 .open = pagetypeinfo_open,
1545 .read = seq_read,
1546 .llseek = seq_lseek,
1547 .release = seq_release,
1548};
1549
1550static bool is_zone_first_populated(pg_data_t *pgdat, struct zone *zone)
1551{
1552 int zid;
1553
1554 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1555 struct zone *compare = &pgdat->node_zones[zid];
1556
1557 if (populated_zone(compare))
1558 return zone == compare;
1559 }
1560
1561 return false;
1562}
1563
1564static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
1565 struct zone *zone)
1566{
1567 int i;
1568 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1569 if (is_zone_first_populated(pgdat, zone)) {
1570 seq_printf(m, "\n per-node stats");
1571 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1572 seq_printf(m, "\n %-12s %lu",
1573 vmstat_text[i + NR_VM_ZONE_STAT_ITEMS +
1574 NR_VM_NUMA_STAT_ITEMS],
1575 node_page_state(pgdat, i));
1576 }
1577 }
1578 seq_printf(m,
1579 "\n pages free %lu"
1580 "\n min %lu"
1581 "\n low %lu"
1582 "\n high %lu"
1583 "\n spanned %lu"
1584 "\n present %lu"
1585 "\n managed %lu",
1586 zone_page_state(zone, NR_FREE_PAGES),
1587 min_wmark_pages(zone),
1588 low_wmark_pages(zone),
1589 high_wmark_pages(zone),
1590 zone->spanned_pages,
1591 zone->present_pages,
1592 zone->managed_pages);
1593
1594 seq_printf(m,
1595 "\n protection: (%ld",
1596 zone->lowmem_reserve[0]);
1597 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1598 seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
1599 seq_putc(m, ')');
1600
1601 /* If unpopulated, no other information is useful */
1602 if (!populated_zone(zone)) {
1603 seq_putc(m, '\n');
1604 return;
1605 }
1606
1607 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1608 seq_printf(m, "\n %-12s %lu", vmstat_text[i],
1609 zone_page_state(zone, i));
1610
1611#ifdef CONFIG_NUMA
1612 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
1613 seq_printf(m, "\n %-12s %lu",
1614 vmstat_text[i + NR_VM_ZONE_STAT_ITEMS],
1615 zone_numa_state_snapshot(zone, i));
1616#endif
1617
1618 seq_printf(m, "\n pagesets");
1619 for_each_online_cpu(i) {
1620 struct per_cpu_pageset *pageset;
1621
1622 pageset = per_cpu_ptr(zone->pageset, i);
1623 seq_printf(m,
1624 "\n cpu: %i"
1625 "\n count: %i"
1626 "\n high: %i"
1627 "\n batch: %i",
1628 i,
1629 pageset->pcp.count,
1630 pageset->pcp.high,
1631 pageset->pcp.batch);
1632#ifdef CONFIG_SMP
1633 seq_printf(m, "\n vm stats threshold: %d",
1634 pageset->stat_threshold);
1635#endif
1636 }
1637 seq_printf(m,
1638 "\n node_unreclaimable: %u"
1639 "\n start_pfn: %lu",
1640 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES,
1641 zone->zone_start_pfn);
1642 seq_putc(m, '\n');
1643}
1644
1645/*
1646 * Output information about zones in @pgdat. All zones are printed regardless
1647 * of whether they are populated or not: lowmem_reserve_ratio operates on the
1648 * set of all zones and userspace would not be aware of such zones if they are
1649 * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio).
1650 */
1651static int zoneinfo_show(struct seq_file *m, void *arg)
1652{
1653 pg_data_t *pgdat = (pg_data_t *)arg;
1654 walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print);
1655 return 0;
1656}
1657
1658static const struct seq_operations zoneinfo_op = {
1659 .start = frag_start, /* iterate over all zones. The same as in
1660 * fragmentation. */
1661 .next = frag_next,
1662 .stop = frag_stop,
1663 .show = zoneinfo_show,
1664};
1665
1666static int zoneinfo_open(struct inode *inode, struct file *file)
1667{
1668 return seq_open(file, &zoneinfo_op);
1669}
1670
1671static const struct file_operations zoneinfo_file_operations = {
1672 .open = zoneinfo_open,
1673 .read = seq_read,
1674 .llseek = seq_lseek,
1675 .release = seq_release,
1676};
1677
1678enum writeback_stat_item {
1679 NR_DIRTY_THRESHOLD,
1680 NR_DIRTY_BG_THRESHOLD,
1681 NR_VM_WRITEBACK_STAT_ITEMS,
1682};
1683
1684static void *vmstat_start(struct seq_file *m, loff_t *pos)
1685{
1686 unsigned long *v;
1687 int i, stat_items_size;
1688
1689 if (*pos >= ARRAY_SIZE(vmstat_text))
1690 return NULL;
1691 stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1692 NR_VM_NUMA_STAT_ITEMS * sizeof(unsigned long) +
1693 NR_VM_NODE_STAT_ITEMS * sizeof(unsigned long) +
1694 NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1695
1696#ifdef CONFIG_VM_EVENT_COUNTERS
1697 stat_items_size += sizeof(struct vm_event_state);
1698#endif
1699
1700 v = kmalloc(stat_items_size, GFP_KERNEL);
1701 m->private = v;
1702 if (!v)
1703 return ERR_PTR(-ENOMEM);
1704 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1705 v[i] = global_zone_page_state(i);
1706 v += NR_VM_ZONE_STAT_ITEMS;
1707
1708#ifdef CONFIG_NUMA
1709 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++)
1710 v[i] = global_numa_state(i);
1711 v += NR_VM_NUMA_STAT_ITEMS;
1712#endif
1713
1714 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
1715 v[i] = global_node_page_state(i);
1716 v += NR_VM_NODE_STAT_ITEMS;
1717
1718 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1719 v + NR_DIRTY_THRESHOLD);
1720 v += NR_VM_WRITEBACK_STAT_ITEMS;
1721
1722#ifdef CONFIG_VM_EVENT_COUNTERS
1723 all_vm_events(v);
1724 v[PGPGIN] /= 2; /* sectors -> kbytes */
1725 v[PGPGOUT] /= 2;
1726#endif
1727 return (unsigned long *)m->private + *pos;
1728}
1729
1730static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1731{
1732 (*pos)++;
1733 if (*pos >= ARRAY_SIZE(vmstat_text))
1734 return NULL;
1735 return (unsigned long *)m->private + *pos;
1736}
1737
1738static int vmstat_show(struct seq_file *m, void *arg)
1739{
1740 unsigned long *l = arg;
1741 unsigned long off = l - (unsigned long *)m->private;
1742
1743 /* Skip hidden vmstat items. */
1744 if (*vmstat_text[off] == '\0')
1745 return 0;
1746
1747 seq_puts(m, vmstat_text[off]);
1748 seq_put_decimal_ull(m, " ", *l);
1749 seq_putc(m, '\n');
1750 return 0;
1751}
1752
1753static void vmstat_stop(struct seq_file *m, void *arg)
1754{
1755 kfree(m->private);
1756 m->private = NULL;
1757}
1758
1759static const struct seq_operations vmstat_op = {
1760 .start = vmstat_start,
1761 .next = vmstat_next,
1762 .stop = vmstat_stop,
1763 .show = vmstat_show,
1764};
1765
1766static int vmstat_open(struct inode *inode, struct file *file)
1767{
1768 return seq_open(file, &vmstat_op);
1769}
1770
1771static const struct file_operations vmstat_file_operations = {
1772 .open = vmstat_open,
1773 .read = seq_read,
1774 .llseek = seq_lseek,
1775 .release = seq_release,
1776};
1777#endif /* CONFIG_PROC_FS */
1778
1779#ifdef CONFIG_SMP
1780static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1781int sysctl_stat_interval __read_mostly = HZ;
1782
1783#ifdef CONFIG_PROC_FS
1784static void refresh_vm_stats(struct work_struct *work)
1785{
1786 refresh_cpu_vm_stats(true);
1787}
1788
1789int vmstat_refresh(struct ctl_table *table, int write,
1790 void __user *buffer, size_t *lenp, loff_t *ppos)
1791{
1792 long val;
1793 int err;
1794 int i;
1795
1796 /*
1797 * The regular update, every sysctl_stat_interval, may come later
1798 * than expected: leaving a significant amount in per_cpu buckets.
1799 * This is particularly misleading when checking a quantity of HUGE
1800 * pages, immediately after running a test. /proc/sys/vm/stat_refresh,
1801 * which can equally be echo'ed to or cat'ted from (by root),
1802 * can be used to update the stats just before reading them.
1803 *
1804 * Oh, and since global_zone_page_state() etc. are so careful to hide
1805 * transiently negative values, report an error here if any of
1806 * the stats is negative, so we know to go looking for imbalance.
1807 */
1808 err = schedule_on_each_cpu(refresh_vm_stats);
1809 if (err)
1810 return err;
1811 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
1812 val = atomic_long_read(&vm_zone_stat[i]);
1813 if (val < 0) {
1814 pr_warn("%s: %s %ld\n",
1815 __func__, vmstat_text[i], val);
1816 err = -EINVAL;
1817 }
1818 }
1819#ifdef CONFIG_NUMA
1820 for (i = 0; i < NR_VM_NUMA_STAT_ITEMS; i++) {
1821 val = atomic_long_read(&vm_numa_stat[i]);
1822 if (val < 0) {
1823 pr_warn("%s: %s %ld\n",
1824 __func__, vmstat_text[i + NR_VM_ZONE_STAT_ITEMS], val);
1825 err = -EINVAL;
1826 }
1827 }
1828#endif
1829 if (err)
1830 return err;
1831 if (write)
1832 *ppos += *lenp;
1833 else
1834 *lenp = 0;
1835 return 0;
1836}
1837#endif /* CONFIG_PROC_FS */
1838
1839static void vmstat_update(struct work_struct *w)
1840{
1841 if (refresh_cpu_vm_stats(true)) {
1842 /*
1843 * Counters were updated so we expect more updates
1844 * to occur in the future. Keep on running the
1845 * update worker thread.
1846 */
1847 preempt_disable();
1848 queue_delayed_work_on(smp_processor_id(), mm_percpu_wq,
1849 this_cpu_ptr(&vmstat_work),
1850 round_jiffies_relative(sysctl_stat_interval));
1851 preempt_enable();
1852 }
1853}
1854
1855/*
1856 * Switch off vmstat processing and then fold all the remaining differentials
1857 * until the diffs stay at zero. The function is used by NOHZ and can only be
1858 * invoked when tick processing is not active.
1859 */
1860/*
1861 * Check if the diffs for a certain cpu indicate that
1862 * an update is needed.
1863 */
1864static bool need_update(int cpu)
1865{
1866 struct zone *zone;
1867
1868 for_each_populated_zone(zone) {
1869 struct per_cpu_pageset *p = per_cpu_ptr(zone->pageset, cpu);
1870
1871 BUILD_BUG_ON(sizeof(p->vm_stat_diff[0]) != 1);
1872#ifdef CONFIG_NUMA
1873 BUILD_BUG_ON(sizeof(p->vm_numa_stat_diff[0]) != 2);
1874#endif
1875
1876 /*
1877 * The fast way of checking if there are any vmstat diffs.
1878 * This works because the diffs are byte sized items.
1879 */
1880 if (memchr_inv(p->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS))
1881 return true;
1882#ifdef CONFIG_NUMA
1883 if (memchr_inv(p->vm_numa_stat_diff, 0, NR_VM_NUMA_STAT_ITEMS))
1884 return true;
1885#endif
1886 }
1887 return false;
1888}
1889
1890/*
1891 * Switch off vmstat processing and then fold all the remaining differentials
1892 * until the diffs stay at zero. The function is used by NOHZ and can only be
1893 * invoked when tick processing is not active.
1894 */
1895void quiet_vmstat(void)
1896{
1897 if (system_state != SYSTEM_RUNNING)
1898 return;
1899
1900 if (!delayed_work_pending(this_cpu_ptr(&vmstat_work)))
1901 return;
1902
1903 if (!need_update(smp_processor_id()))
1904 return;
1905
1906 /*
1907 * Just refresh counters and do not care about the pending delayed
1908 * vmstat_update. It doesn't fire that often to matter and canceling
1909 * it would be too expensive from this path.
1910 * vmstat_shepherd will take care about that for us.
1911 */
1912 refresh_cpu_vm_stats(false);
1913}
1914
1915/*
1916 * Shepherd worker thread that checks the
1917 * differentials of processors that have their worker
1918 * threads for vm statistics updates disabled because of
1919 * inactivity.
1920 */
1921static void vmstat_shepherd(struct work_struct *w);
1922
1923static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd);
1924
1925static void vmstat_shepherd(struct work_struct *w)
1926{
1927 int cpu;
1928
1929 get_online_cpus();
1930 /* Check processors whose vmstat worker threads have been disabled */
1931 for_each_online_cpu(cpu) {
1932 struct delayed_work *dw = &per_cpu(vmstat_work, cpu);
1933
1934 if (!delayed_work_pending(dw) && need_update(cpu))
1935 queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0);
1936 }
1937 put_online_cpus();
1938
1939 schedule_delayed_work(&shepherd,
1940 round_jiffies_relative(sysctl_stat_interval));
1941}
1942
1943static void __init start_shepherd_timer(void)
1944{
1945 int cpu;
1946
1947 for_each_possible_cpu(cpu)
1948 INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work, cpu),
1949 vmstat_update);
1950
1951 schedule_delayed_work(&shepherd,
1952 round_jiffies_relative(sysctl_stat_interval));
1953}
1954
1955static void __init init_cpu_node_state(void)
1956{
1957 int node;
1958
1959 for_each_online_node(node) {
1960 if (cpumask_weight(cpumask_of_node(node)) > 0)
1961 node_set_state(node, N_CPU);
1962 }
1963}
1964
1965static int vmstat_cpu_online(unsigned int cpu)
1966{
1967 refresh_zone_stat_thresholds();
1968 node_set_state(cpu_to_node(cpu), N_CPU);
1969 return 0;
1970}
1971
1972static int vmstat_cpu_down_prep(unsigned int cpu)
1973{
1974 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1975 return 0;
1976}
1977
1978static int vmstat_cpu_dead(unsigned int cpu)
1979{
1980 const struct cpumask *node_cpus;
1981 int node;
1982
1983 node = cpu_to_node(cpu);
1984
1985 refresh_zone_stat_thresholds();
1986 node_cpus = cpumask_of_node(node);
1987 if (cpumask_weight(node_cpus) > 0)
1988 return 0;
1989
1990 node_clear_state(node, N_CPU);
1991 return 0;
1992}
1993
1994#endif
1995
1996struct workqueue_struct *mm_percpu_wq;
1997
1998void __init init_mm_internals(void)
1999{
2000 int ret __maybe_unused;
2001
2002 mm_percpu_wq = alloc_workqueue("mm_percpu_wq", WQ_MEM_RECLAIM, 0);
2003
2004#ifdef CONFIG_SMP
2005 ret = cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD, "mm/vmstat:dead",
2006 NULL, vmstat_cpu_dead);
2007 if (ret < 0)
2008 pr_err("vmstat: failed to register 'dead' hotplug state\n");
2009
2010 ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "mm/vmstat:online",
2011 vmstat_cpu_online,
2012 vmstat_cpu_down_prep);
2013 if (ret < 0)
2014 pr_err("vmstat: failed to register 'online' hotplug state\n");
2015
2016 get_online_cpus();
2017 init_cpu_node_state();
2018 put_online_cpus();
2019
2020 start_shepherd_timer();
2021#endif
2022#ifdef CONFIG_PROC_FS
2023 proc_create("buddyinfo", 0444, NULL, &buddyinfo_file_operations);
2024 proc_create("pagetypeinfo", 0444, NULL, &pagetypeinfo_file_operations);
2025 proc_create("vmstat", 0444, NULL, &vmstat_file_operations);
2026 proc_create("zoneinfo", 0444, NULL, &zoneinfo_file_operations);
2027#endif
2028}
2029
2030#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
2031
2032/*
2033 * Return an index indicating how much of the available free memory is
2034 * unusable for an allocation of the requested size.
2035 */
2036static int unusable_free_index(unsigned int order,
2037 struct contig_page_info *info)
2038{
2039 /* No free memory is interpreted as all free memory is unusable */
2040 if (info->free_pages == 0)
2041 return 1000;
2042
2043 /*
2044 * Index should be a value between 0 and 1. Return a value to 3
2045 * decimal places.
2046 *
2047 * 0 => no fragmentation
2048 * 1 => high fragmentation
2049 */
2050 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
2051
2052}
2053
2054static void unusable_show_print(struct seq_file *m,
2055 pg_data_t *pgdat, struct zone *zone)
2056{
2057 unsigned int order;
2058 int index;
2059 struct contig_page_info info;
2060
2061 seq_printf(m, "Node %d, zone %8s ",
2062 pgdat->node_id,
2063 zone->name);
2064 for (order = 0; order < MAX_ORDER; ++order) {
2065 fill_contig_page_info(zone, order, &info);
2066 index = unusable_free_index(order, &info);
2067 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
2068 }
2069
2070 seq_putc(m, '\n');
2071}
2072
2073/*
2074 * Display unusable free space index
2075 *
2076 * The unusable free space index measures how much of the available free
2077 * memory cannot be used to satisfy an allocation of a given size and is a
2078 * value between 0 and 1. The higher the value, the more of free memory is
2079 * unusable and by implication, the worse the external fragmentation is. This
2080 * can be expressed as a percentage by multiplying by 100.
2081 */
2082static int unusable_show(struct seq_file *m, void *arg)
2083{
2084 pg_data_t *pgdat = (pg_data_t *)arg;
2085
2086 /* check memoryless node */
2087 if (!node_state(pgdat->node_id, N_MEMORY))
2088 return 0;
2089
2090 walk_zones_in_node(m, pgdat, true, false, unusable_show_print);
2091
2092 return 0;
2093}
2094
2095static const struct seq_operations unusable_op = {
2096 .start = frag_start,
2097 .next = frag_next,
2098 .stop = frag_stop,
2099 .show = unusable_show,
2100};
2101
2102static int unusable_open(struct inode *inode, struct file *file)
2103{
2104 return seq_open(file, &unusable_op);
2105}
2106
2107static const struct file_operations unusable_file_ops = {
2108 .open = unusable_open,
2109 .read = seq_read,
2110 .llseek = seq_lseek,
2111 .release = seq_release,
2112};
2113
2114static void extfrag_show_print(struct seq_file *m,
2115 pg_data_t *pgdat, struct zone *zone)
2116{
2117 unsigned int order;
2118 int index;
2119
2120 /* Alloc on stack as interrupts are disabled for zone walk */
2121 struct contig_page_info info;
2122
2123 seq_printf(m, "Node %d, zone %8s ",
2124 pgdat->node_id,
2125 zone->name);
2126 for (order = 0; order < MAX_ORDER; ++order) {
2127 fill_contig_page_info(zone, order, &info);
2128 index = __fragmentation_index(order, &info);
2129 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
2130 }
2131
2132 seq_putc(m, '\n');
2133}
2134
2135/*
2136 * Display fragmentation index for orders that allocations would fail for
2137 */
2138static int extfrag_show(struct seq_file *m, void *arg)
2139{
2140 pg_data_t *pgdat = (pg_data_t *)arg;
2141
2142 walk_zones_in_node(m, pgdat, true, false, extfrag_show_print);
2143
2144 return 0;
2145}
2146
2147static const struct seq_operations extfrag_op = {
2148 .start = frag_start,
2149 .next = frag_next,
2150 .stop = frag_stop,
2151 .show = extfrag_show,
2152};
2153
2154static int extfrag_open(struct inode *inode, struct file *file)
2155{
2156 return seq_open(file, &extfrag_op);
2157}
2158
2159static const struct file_operations extfrag_file_ops = {
2160 .open = extfrag_open,
2161 .read = seq_read,
2162 .llseek = seq_lseek,
2163 .release = seq_release,
2164};
2165
2166static int __init extfrag_debug_init(void)
2167{
2168 struct dentry *extfrag_debug_root;
2169
2170 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
2171 if (!extfrag_debug_root)
2172 return -ENOMEM;
2173
2174 if (!debugfs_create_file("unusable_index", 0444,
2175 extfrag_debug_root, NULL, &unusable_file_ops))
2176 goto fail;
2177
2178 if (!debugfs_create_file("extfrag_index", 0444,
2179 extfrag_debug_root, NULL, &extfrag_file_ops))
2180 goto fail;
2181
2182 return 0;
2183fail:
2184 debugfs_remove_recursive(extfrag_debug_root);
2185 return -ENOMEM;
2186}
2187
2188module_init(extfrag_debug_init);
2189#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 get_online_cpus();
133 sum_vm_events(ret);
134 put_online_cpus();
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_SMP
169
170int calculate_pressure_threshold(struct zone *zone)
171{
172 int threshold;
173 int watermark_distance;
174
175 /*
176 * As vmstats are not up to date, there is drift between the estimated
177 * and real values. For high thresholds and a high number of CPUs, it
178 * is possible for the min watermark to be breached while the estimated
179 * value looks fine. The pressure threshold is a reduced value such
180 * that even the maximum amount of drift will not accidentally breach
181 * the min watermark
182 */
183 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
184 threshold = max(1, (int)(watermark_distance / num_online_cpus()));
185
186 /*
187 * Maximum threshold is 125
188 */
189 threshold = min(125, threshold);
190
191 return threshold;
192}
193
194int calculate_normal_threshold(struct zone *zone)
195{
196 int threshold;
197 int mem; /* memory in 128 MB units */
198
199 /*
200 * The threshold scales with the number of processors and the amount
201 * of memory per zone. More memory means that we can defer updates for
202 * longer, more processors could lead to more contention.
203 * fls() is used to have a cheap way of logarithmic scaling.
204 *
205 * Some sample thresholds:
206 *
207 * Threshold Processors (fls) Zonesize fls(mem+1)
208 * ------------------------------------------------------------------
209 * 8 1 1 0.9-1 GB 4
210 * 16 2 2 0.9-1 GB 4
211 * 20 2 2 1-2 GB 5
212 * 24 2 2 2-4 GB 6
213 * 28 2 2 4-8 GB 7
214 * 32 2 2 8-16 GB 8
215 * 4 2 2 <128M 1
216 * 30 4 3 2-4 GB 5
217 * 48 4 3 8-16 GB 8
218 * 32 8 4 1-2 GB 4
219 * 32 8 4 0.9-1GB 4
220 * 10 16 5 <128M 1
221 * 40 16 5 900M 4
222 * 70 64 7 2-4 GB 5
223 * 84 64 7 4-8 GB 6
224 * 108 512 9 4-8 GB 6
225 * 125 1024 10 8-16 GB 8
226 * 125 1024 10 16-32 GB 9
227 */
228
229 mem = zone_managed_pages(zone) >> (27 - PAGE_SHIFT);
230
231 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
232
233 /*
234 * Maximum threshold is 125
235 */
236 threshold = min(125, threshold);
237
238 return threshold;
239}
240
241/*
242 * Refresh the thresholds for each zone.
243 */
244void refresh_zone_stat_thresholds(void)
245{
246 struct pglist_data *pgdat;
247 struct zone *zone;
248 int cpu;
249 int threshold;
250
251 /* Zero current pgdat thresholds */
252 for_each_online_pgdat(pgdat) {
253 for_each_online_cpu(cpu) {
254 per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold = 0;
255 }
256 }
257
258 for_each_populated_zone(zone) {
259 struct pglist_data *pgdat = zone->zone_pgdat;
260 unsigned long max_drift, tolerate_drift;
261
262 threshold = calculate_normal_threshold(zone);
263
264 for_each_online_cpu(cpu) {
265 int pgdat_threshold;
266
267 per_cpu_ptr(zone->per_cpu_zonestats, cpu)->stat_threshold
268 = threshold;
269
270 /* Base nodestat threshold on the largest populated zone. */
271 pgdat_threshold = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold;
272 per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold
273 = max(threshold, pgdat_threshold);
274 }
275
276 /*
277 * Only set percpu_drift_mark if there is a danger that
278 * NR_FREE_PAGES reports the low watermark is ok when in fact
279 * the min watermark could be breached by an allocation
280 */
281 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
282 max_drift = num_online_cpus() * threshold;
283 if (max_drift > tolerate_drift)
284 zone->percpu_drift_mark = high_wmark_pages(zone) +
285 max_drift;
286 }
287}
288
289void set_pgdat_percpu_threshold(pg_data_t *pgdat,
290 int (*calculate_pressure)(struct zone *))
291{
292 struct zone *zone;
293 int cpu;
294 int threshold;
295 int i;
296
297 for (i = 0; i < pgdat->nr_zones; i++) {
298 zone = &pgdat->node_zones[i];
299 if (!zone->percpu_drift_mark)
300 continue;
301
302 threshold = (*calculate_pressure)(zone);
303 for_each_online_cpu(cpu)
304 per_cpu_ptr(zone->per_cpu_zonestats, cpu)->stat_threshold
305 = threshold;
306 }
307}
308
309/*
310 * For use when we know that interrupts are disabled,
311 * or when we know that preemption is disabled and that
312 * particular counter cannot be updated from interrupt context.
313 */
314void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
315 long delta)
316{
317 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
318 s8 __percpu *p = pcp->vm_stat_diff + item;
319 long x;
320 long t;
321
322 x = delta + __this_cpu_read(*p);
323
324 t = __this_cpu_read(pcp->stat_threshold);
325
326 if (unlikely(abs(x) > t)) {
327 zone_page_state_add(x, zone, item);
328 x = 0;
329 }
330 __this_cpu_write(*p, x);
331}
332EXPORT_SYMBOL(__mod_zone_page_state);
333
334void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
335 long delta)
336{
337 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
338 s8 __percpu *p = pcp->vm_node_stat_diff + item;
339 long x;
340 long t;
341
342 if (vmstat_item_in_bytes(item)) {
343 /*
344 * Only cgroups use subpage accounting right now; at
345 * the global level, these items still change in
346 * multiples of whole pages. Store them as pages
347 * internally to keep the per-cpu counters compact.
348 */
349 VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1));
350 delta >>= PAGE_SHIFT;
351 }
352
353 x = delta + __this_cpu_read(*p);
354
355 t = __this_cpu_read(pcp->stat_threshold);
356
357 if (unlikely(abs(x) > t)) {
358 node_page_state_add(x, pgdat, item);
359 x = 0;
360 }
361 __this_cpu_write(*p, x);
362}
363EXPORT_SYMBOL(__mod_node_page_state);
364
365/*
366 * Optimized increment and decrement functions.
367 *
368 * These are only for a single page and therefore can take a struct page *
369 * argument instead of struct zone *. This allows the inclusion of the code
370 * generated for page_zone(page) into the optimized functions.
371 *
372 * No overflow check is necessary and therefore the differential can be
373 * incremented or decremented in place which may allow the compilers to
374 * generate better code.
375 * The increment or decrement is known and therefore one boundary check can
376 * be omitted.
377 *
378 * NOTE: These functions are very performance sensitive. Change only
379 * with care.
380 *
381 * Some processors have inc/dec instructions that are atomic vs an interrupt.
382 * However, the code must first determine the differential location in a zone
383 * based on the processor number and then inc/dec the counter. There is no
384 * guarantee without disabling preemption that the processor will not change
385 * in between and therefore the atomicity vs. interrupt cannot be exploited
386 * in a useful way here.
387 */
388void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
389{
390 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
391 s8 __percpu *p = pcp->vm_stat_diff + item;
392 s8 v, t;
393
394 v = __this_cpu_inc_return(*p);
395 t = __this_cpu_read(pcp->stat_threshold);
396 if (unlikely(v > t)) {
397 s8 overstep = t >> 1;
398
399 zone_page_state_add(v + overstep, zone, item);
400 __this_cpu_write(*p, -overstep);
401 }
402}
403
404void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
405{
406 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
407 s8 __percpu *p = pcp->vm_node_stat_diff + item;
408 s8 v, t;
409
410 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
411
412 v = __this_cpu_inc_return(*p);
413 t = __this_cpu_read(pcp->stat_threshold);
414 if (unlikely(v > t)) {
415 s8 overstep = t >> 1;
416
417 node_page_state_add(v + overstep, pgdat, item);
418 __this_cpu_write(*p, -overstep);
419 }
420}
421
422void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
423{
424 __inc_zone_state(page_zone(page), item);
425}
426EXPORT_SYMBOL(__inc_zone_page_state);
427
428void __inc_node_page_state(struct page *page, enum node_stat_item item)
429{
430 __inc_node_state(page_pgdat(page), item);
431}
432EXPORT_SYMBOL(__inc_node_page_state);
433
434void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
435{
436 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
437 s8 __percpu *p = pcp->vm_stat_diff + item;
438 s8 v, t;
439
440 v = __this_cpu_dec_return(*p);
441 t = __this_cpu_read(pcp->stat_threshold);
442 if (unlikely(v < - t)) {
443 s8 overstep = t >> 1;
444
445 zone_page_state_add(v - overstep, zone, item);
446 __this_cpu_write(*p, overstep);
447 }
448}
449
450void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
451{
452 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
453 s8 __percpu *p = pcp->vm_node_stat_diff + item;
454 s8 v, t;
455
456 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
457
458 v = __this_cpu_dec_return(*p);
459 t = __this_cpu_read(pcp->stat_threshold);
460 if (unlikely(v < - t)) {
461 s8 overstep = t >> 1;
462
463 node_page_state_add(v - overstep, pgdat, item);
464 __this_cpu_write(*p, overstep);
465 }
466}
467
468void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
469{
470 __dec_zone_state(page_zone(page), item);
471}
472EXPORT_SYMBOL(__dec_zone_page_state);
473
474void __dec_node_page_state(struct page *page, enum node_stat_item item)
475{
476 __dec_node_state(page_pgdat(page), item);
477}
478EXPORT_SYMBOL(__dec_node_page_state);
479
480#ifdef CONFIG_HAVE_CMPXCHG_LOCAL
481/*
482 * If we have cmpxchg_local support then we do not need to incur the overhead
483 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
484 *
485 * mod_state() modifies the zone counter state through atomic per cpu
486 * operations.
487 *
488 * Overstep mode specifies how overstep should handled:
489 * 0 No overstepping
490 * 1 Overstepping half of threshold
491 * -1 Overstepping minus half of threshold
492*/
493static inline void mod_zone_state(struct zone *zone,
494 enum zone_stat_item item, long delta, int overstep_mode)
495{
496 struct per_cpu_zonestat __percpu *pcp = zone->per_cpu_zonestats;
497 s8 __percpu *p = pcp->vm_stat_diff + item;
498 long o, n, t, z;
499
500 do {
501 z = 0; /* overflow to zone counters */
502
503 /*
504 * The fetching of the stat_threshold is racy. We may apply
505 * a counter threshold to the wrong the cpu if we get
506 * rescheduled while executing here. However, the next
507 * counter update will apply the threshold again and
508 * therefore bring the counter under the threshold again.
509 *
510 * Most of the time the thresholds are the same anyways
511 * for all cpus in a zone.
512 */
513 t = this_cpu_read(pcp->stat_threshold);
514
515 o = this_cpu_read(*p);
516 n = delta + o;
517
518 if (abs(n) > t) {
519 int os = overstep_mode * (t >> 1) ;
520
521 /* Overflow must be added to zone counters */
522 z = n + os;
523 n = -os;
524 }
525 } while (this_cpu_cmpxchg(*p, o, n) != o);
526
527 if (z)
528 zone_page_state_add(z, zone, item);
529}
530
531void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
532 long delta)
533{
534 mod_zone_state(zone, item, delta, 0);
535}
536EXPORT_SYMBOL(mod_zone_page_state);
537
538void inc_zone_page_state(struct page *page, enum zone_stat_item item)
539{
540 mod_zone_state(page_zone(page), item, 1, 1);
541}
542EXPORT_SYMBOL(inc_zone_page_state);
543
544void dec_zone_page_state(struct page *page, enum zone_stat_item item)
545{
546 mod_zone_state(page_zone(page), item, -1, -1);
547}
548EXPORT_SYMBOL(dec_zone_page_state);
549
550static inline void mod_node_state(struct pglist_data *pgdat,
551 enum node_stat_item item, int delta, int overstep_mode)
552{
553 struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
554 s8 __percpu *p = pcp->vm_node_stat_diff + item;
555 long o, n, t, z;
556
557 if (vmstat_item_in_bytes(item)) {
558 /*
559 * Only cgroups use subpage accounting right now; at
560 * the global level, these items still change in
561 * multiples of whole pages. Store them as pages
562 * internally to keep the per-cpu counters compact.
563 */
564 VM_WARN_ON_ONCE(delta & (PAGE_SIZE - 1));
565 delta >>= PAGE_SHIFT;
566 }
567
568 do {
569 z = 0; /* overflow to node counters */
570
571 /*
572 * The fetching of the stat_threshold is racy. We may apply
573 * a counter threshold to the wrong the cpu if we get
574 * rescheduled while executing here. However, the next
575 * counter update will apply the threshold again and
576 * therefore bring the counter under the threshold again.
577 *
578 * Most of the time the thresholds are the same anyways
579 * for all cpus in a node.
580 */
581 t = this_cpu_read(pcp->stat_threshold);
582
583 o = this_cpu_read(*p);
584 n = delta + o;
585
586 if (abs(n) > t) {
587 int os = overstep_mode * (t >> 1) ;
588
589 /* Overflow must be added to node counters */
590 z = n + os;
591 n = -os;
592 }
593 } while (this_cpu_cmpxchg(*p, o, n) != o);
594
595 if (z)
596 node_page_state_add(z, pgdat, item);
597}
598
599void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
600 long delta)
601{
602 mod_node_state(pgdat, item, delta, 0);
603}
604EXPORT_SYMBOL(mod_node_page_state);
605
606void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
607{
608 mod_node_state(pgdat, item, 1, 1);
609}
610
611void inc_node_page_state(struct page *page, enum node_stat_item item)
612{
613 mod_node_state(page_pgdat(page), item, 1, 1);
614}
615EXPORT_SYMBOL(inc_node_page_state);
616
617void dec_node_page_state(struct page *page, enum node_stat_item item)
618{
619 mod_node_state(page_pgdat(page), item, -1, -1);
620}
621EXPORT_SYMBOL(dec_node_page_state);
622#else
623/*
624 * Use interrupt disable to serialize counter updates
625 */
626void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
627 long delta)
628{
629 unsigned long flags;
630
631 local_irq_save(flags);
632 __mod_zone_page_state(zone, item, delta);
633 local_irq_restore(flags);
634}
635EXPORT_SYMBOL(mod_zone_page_state);
636
637void inc_zone_page_state(struct page *page, enum zone_stat_item item)
638{
639 unsigned long flags;
640 struct zone *zone;
641
642 zone = page_zone(page);
643 local_irq_save(flags);
644 __inc_zone_state(zone, item);
645 local_irq_restore(flags);
646}
647EXPORT_SYMBOL(inc_zone_page_state);
648
649void dec_zone_page_state(struct page *page, enum zone_stat_item item)
650{
651 unsigned long flags;
652
653 local_irq_save(flags);
654 __dec_zone_page_state(page, item);
655 local_irq_restore(flags);
656}
657EXPORT_SYMBOL(dec_zone_page_state);
658
659void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
660{
661 unsigned long flags;
662
663 local_irq_save(flags);
664 __inc_node_state(pgdat, item);
665 local_irq_restore(flags);
666}
667EXPORT_SYMBOL(inc_node_state);
668
669void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
670 long delta)
671{
672 unsigned long flags;
673
674 local_irq_save(flags);
675 __mod_node_page_state(pgdat, item, delta);
676 local_irq_restore(flags);
677}
678EXPORT_SYMBOL(mod_node_page_state);
679
680void inc_node_page_state(struct page *page, enum node_stat_item item)
681{
682 unsigned long flags;
683 struct pglist_data *pgdat;
684
685 pgdat = page_pgdat(page);
686 local_irq_save(flags);
687 __inc_node_state(pgdat, item);
688 local_irq_restore(flags);
689}
690EXPORT_SYMBOL(inc_node_page_state);
691
692void dec_node_page_state(struct page *page, enum node_stat_item item)
693{
694 unsigned long flags;
695
696 local_irq_save(flags);
697 __dec_node_page_state(page, item);
698 local_irq_restore(flags);
699}
700EXPORT_SYMBOL(dec_node_page_state);
701#endif
702
703/*
704 * Fold a differential into the global counters.
705 * Returns the number of counters updated.
706 */
707static int fold_diff(int *zone_diff, int *node_diff)
708{
709 int i;
710 int changes = 0;
711
712 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
713 if (zone_diff[i]) {
714 atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
715 changes++;
716 }
717
718 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
719 if (node_diff[i]) {
720 atomic_long_add(node_diff[i], &vm_node_stat[i]);
721 changes++;
722 }
723 return changes;
724}
725
726#ifdef CONFIG_NUMA
727static void fold_vm_zone_numa_events(struct zone *zone)
728{
729 unsigned long zone_numa_events[NR_VM_NUMA_EVENT_ITEMS] = { 0, };
730 int cpu;
731 enum numa_stat_item item;
732
733 for_each_online_cpu(cpu) {
734 struct per_cpu_zonestat *pzstats;
735
736 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
737 for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++)
738 zone_numa_events[item] += xchg(&pzstats->vm_numa_event[item], 0);
739 }
740
741 for (item = 0; item < NR_VM_NUMA_EVENT_ITEMS; item++)
742 zone_numa_event_add(zone_numa_events[item], zone, item);
743}
744
745void fold_vm_numa_events(void)
746{
747 struct zone *zone;
748
749 for_each_populated_zone(zone)
750 fold_vm_zone_numa_events(zone);
751}
752#endif
753
754/*
755 * Update the zone counters for the current cpu.
756 *
757 * Note that refresh_cpu_vm_stats strives to only access
758 * node local memory. The per cpu pagesets on remote zones are placed
759 * in the memory local to the processor using that pageset. So the
760 * loop over all zones will access a series of cachelines local to
761 * the processor.
762 *
763 * The call to zone_page_state_add updates the cachelines with the
764 * statistics in the remote zone struct as well as the global cachelines
765 * with the global counters. These could cause remote node cache line
766 * bouncing and will have to be only done when necessary.
767 *
768 * The function returns the number of global counters updated.
769 */
770static int refresh_cpu_vm_stats(bool do_pagesets)
771{
772 struct pglist_data *pgdat;
773 struct zone *zone;
774 int i;
775 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
776 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
777 int changes = 0;
778
779 for_each_populated_zone(zone) {
780 struct per_cpu_zonestat __percpu *pzstats = zone->per_cpu_zonestats;
781#ifdef CONFIG_NUMA
782 struct per_cpu_pages __percpu *pcp = zone->per_cpu_pageset;
783#endif
784
785 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
786 int v;
787
788 v = this_cpu_xchg(pzstats->vm_stat_diff[i], 0);
789 if (v) {
790
791 atomic_long_add(v, &zone->vm_stat[i]);
792 global_zone_diff[i] += v;
793#ifdef CONFIG_NUMA
794 /* 3 seconds idle till flush */
795 __this_cpu_write(pcp->expire, 3);
796#endif
797 }
798 }
799#ifdef CONFIG_NUMA
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(pcp->expire) ||
811 !__this_cpu_read(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(pcp->expire, 0);
819 continue;
820 }
821
822 if (__this_cpu_dec_return(pcp->expire))
823 continue;
824
825 if (__this_cpu_read(pcp->count)) {
826 drain_zone_pages(zone, this_cpu_ptr(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 changes += fold_diff(global_zone_diff, global_node_diff);
848 return changes;
849}
850
851/*
852 * Fold the data for an offline cpu into the global array.
853 * There cannot be any access by the offline cpu and therefore
854 * synchronization is simplified.
855 */
856void cpu_vm_stats_fold(int cpu)
857{
858 struct pglist_data *pgdat;
859 struct zone *zone;
860 int i;
861 int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
862 int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
863
864 for_each_populated_zone(zone) {
865 struct per_cpu_zonestat *pzstats;
866
867 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
868
869 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
870 if (pzstats->vm_stat_diff[i]) {
871 int v;
872
873 v = pzstats->vm_stat_diff[i];
874 pzstats->vm_stat_diff[i] = 0;
875 atomic_long_add(v, &zone->vm_stat[i]);
876 global_zone_diff[i] += v;
877 }
878 }
879#ifdef CONFIG_NUMA
880 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) {
881 if (pzstats->vm_numa_event[i]) {
882 unsigned long v;
883
884 v = pzstats->vm_numa_event[i];
885 pzstats->vm_numa_event[i] = 0;
886 zone_numa_event_add(v, zone, i);
887 }
888 }
889#endif
890 }
891
892 for_each_online_pgdat(pgdat) {
893 struct per_cpu_nodestat *p;
894
895 p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu);
896
897 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
898 if (p->vm_node_stat_diff[i]) {
899 int v;
900
901 v = p->vm_node_stat_diff[i];
902 p->vm_node_stat_diff[i] = 0;
903 atomic_long_add(v, &pgdat->vm_stat[i]);
904 global_node_diff[i] += v;
905 }
906 }
907
908 fold_diff(global_zone_diff, global_node_diff);
909}
910
911/*
912 * this is only called if !populated_zone(zone), which implies no other users of
913 * pset->vm_stat_diff[] exist.
914 */
915void drain_zonestat(struct zone *zone, struct per_cpu_zonestat *pzstats)
916{
917 unsigned long v;
918 int i;
919
920 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
921 if (pzstats->vm_stat_diff[i]) {
922 v = pzstats->vm_stat_diff[i];
923 pzstats->vm_stat_diff[i] = 0;
924 zone_page_state_add(v, zone, i);
925 }
926 }
927
928#ifdef CONFIG_NUMA
929 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++) {
930 if (pzstats->vm_numa_event[i]) {
931 v = pzstats->vm_numa_event[i];
932 pzstats->vm_numa_event[i] = 0;
933 zone_numa_event_add(v, zone, i);
934 }
935 }
936#endif
937}
938#endif
939
940#ifdef CONFIG_NUMA
941/*
942 * Determine the per node value of a stat item. This function
943 * is called frequently in a NUMA machine, so try to be as
944 * frugal as possible.
945 */
946unsigned long sum_zone_node_page_state(int node,
947 enum zone_stat_item item)
948{
949 struct zone *zones = NODE_DATA(node)->node_zones;
950 int i;
951 unsigned long count = 0;
952
953 for (i = 0; i < MAX_NR_ZONES; i++)
954 count += zone_page_state(zones + i, item);
955
956 return count;
957}
958
959/* Determine the per node value of a numa stat item. */
960unsigned long sum_zone_numa_event_state(int node,
961 enum numa_stat_item item)
962{
963 struct zone *zones = NODE_DATA(node)->node_zones;
964 unsigned long count = 0;
965 int i;
966
967 for (i = 0; i < MAX_NR_ZONES; i++)
968 count += zone_numa_event_state(zones + i, item);
969
970 return count;
971}
972
973/*
974 * Determine the per node value of a stat item.
975 */
976unsigned long node_page_state_pages(struct pglist_data *pgdat,
977 enum node_stat_item item)
978{
979 long x = atomic_long_read(&pgdat->vm_stat[item]);
980#ifdef CONFIG_SMP
981 if (x < 0)
982 x = 0;
983#endif
984 return x;
985}
986
987unsigned long node_page_state(struct pglist_data *pgdat,
988 enum node_stat_item item)
989{
990 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
991
992 return node_page_state_pages(pgdat, item);
993}
994#endif
995
996#ifdef CONFIG_COMPACTION
997
998struct contig_page_info {
999 unsigned long free_pages;
1000 unsigned long free_blocks_total;
1001 unsigned long free_blocks_suitable;
1002};
1003
1004/*
1005 * Calculate the number of free pages in a zone, how many contiguous
1006 * pages are free and how many are large enough to satisfy an allocation of
1007 * the target size. Note that this function makes no attempt to estimate
1008 * how many suitable free blocks there *might* be if MOVABLE pages were
1009 * migrated. Calculating that is possible, but expensive and can be
1010 * figured out from userspace
1011 */
1012static void fill_contig_page_info(struct zone *zone,
1013 unsigned int suitable_order,
1014 struct contig_page_info *info)
1015{
1016 unsigned int order;
1017
1018 info->free_pages = 0;
1019 info->free_blocks_total = 0;
1020 info->free_blocks_suitable = 0;
1021
1022 for (order = 0; order < MAX_ORDER; order++) {
1023 unsigned long blocks;
1024
1025 /* Count number of free blocks */
1026 blocks = zone->free_area[order].nr_free;
1027 info->free_blocks_total += blocks;
1028
1029 /* Count free base pages */
1030 info->free_pages += blocks << order;
1031
1032 /* Count the suitable free blocks */
1033 if (order >= suitable_order)
1034 info->free_blocks_suitable += blocks <<
1035 (order - suitable_order);
1036 }
1037}
1038
1039/*
1040 * A fragmentation index only makes sense if an allocation of a requested
1041 * size would fail. If that is true, the fragmentation index indicates
1042 * whether external fragmentation or a lack of memory was the problem.
1043 * The value can be used to determine if page reclaim or compaction
1044 * should be used
1045 */
1046static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
1047{
1048 unsigned long requested = 1UL << order;
1049
1050 if (WARN_ON_ONCE(order >= MAX_ORDER))
1051 return 0;
1052
1053 if (!info->free_blocks_total)
1054 return 0;
1055
1056 /* Fragmentation index only makes sense when a request would fail */
1057 if (info->free_blocks_suitable)
1058 return -1000;
1059
1060 /*
1061 * Index is between 0 and 1 so return within 3 decimal places
1062 *
1063 * 0 => allocation would fail due to lack of memory
1064 * 1 => allocation would fail due to fragmentation
1065 */
1066 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
1067}
1068
1069/*
1070 * Calculates external fragmentation within a zone wrt the given order.
1071 * It is defined as the percentage of pages found in blocks of size
1072 * less than 1 << order. It returns values in range [0, 100].
1073 */
1074unsigned int extfrag_for_order(struct zone *zone, unsigned int order)
1075{
1076 struct contig_page_info info;
1077
1078 fill_contig_page_info(zone, order, &info);
1079 if (info.free_pages == 0)
1080 return 0;
1081
1082 return div_u64((info.free_pages -
1083 (info.free_blocks_suitable << order)) * 100,
1084 info.free_pages);
1085}
1086
1087/* Same as __fragmentation index but allocs contig_page_info on stack */
1088int fragmentation_index(struct zone *zone, unsigned int order)
1089{
1090 struct contig_page_info info;
1091
1092 fill_contig_page_info(zone, order, &info);
1093 return __fragmentation_index(order, &info);
1094}
1095#endif
1096
1097#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || \
1098 defined(CONFIG_NUMA) || defined(CONFIG_MEMCG)
1099#ifdef CONFIG_ZONE_DMA
1100#define TEXT_FOR_DMA(xx) xx "_dma",
1101#else
1102#define TEXT_FOR_DMA(xx)
1103#endif
1104
1105#ifdef CONFIG_ZONE_DMA32
1106#define TEXT_FOR_DMA32(xx) xx "_dma32",
1107#else
1108#define TEXT_FOR_DMA32(xx)
1109#endif
1110
1111#ifdef CONFIG_HIGHMEM
1112#define TEXT_FOR_HIGHMEM(xx) xx "_high",
1113#else
1114#define TEXT_FOR_HIGHMEM(xx)
1115#endif
1116
1117#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
1118 TEXT_FOR_HIGHMEM(xx) xx "_movable",
1119
1120const char * const vmstat_text[] = {
1121 /* enum zone_stat_item counters */
1122 "nr_free_pages",
1123 "nr_zone_inactive_anon",
1124 "nr_zone_active_anon",
1125 "nr_zone_inactive_file",
1126 "nr_zone_active_file",
1127 "nr_zone_unevictable",
1128 "nr_zone_write_pending",
1129 "nr_mlock",
1130 "nr_bounce",
1131#if IS_ENABLED(CONFIG_ZSMALLOC)
1132 "nr_zspages",
1133#endif
1134 "nr_free_cma",
1135
1136 /* enum numa_stat_item counters */
1137#ifdef CONFIG_NUMA
1138 "numa_hit",
1139 "numa_miss",
1140 "numa_foreign",
1141 "numa_interleave",
1142 "numa_local",
1143 "numa_other",
1144#endif
1145
1146 /* enum node_stat_item counters */
1147 "nr_inactive_anon",
1148 "nr_active_anon",
1149 "nr_inactive_file",
1150 "nr_active_file",
1151 "nr_unevictable",
1152 "nr_slab_reclaimable",
1153 "nr_slab_unreclaimable",
1154 "nr_isolated_anon",
1155 "nr_isolated_file",
1156 "workingset_nodes",
1157 "workingset_refault_anon",
1158 "workingset_refault_file",
1159 "workingset_activate_anon",
1160 "workingset_activate_file",
1161 "workingset_restore_anon",
1162 "workingset_restore_file",
1163 "workingset_nodereclaim",
1164 "nr_anon_pages",
1165 "nr_mapped",
1166 "nr_file_pages",
1167 "nr_dirty",
1168 "nr_writeback",
1169 "nr_writeback_temp",
1170 "nr_shmem",
1171 "nr_shmem_hugepages",
1172 "nr_shmem_pmdmapped",
1173 "nr_file_hugepages",
1174 "nr_file_pmdmapped",
1175 "nr_anon_transparent_hugepages",
1176 "nr_vmscan_write",
1177 "nr_vmscan_immediate_reclaim",
1178 "nr_dirtied",
1179 "nr_written",
1180 "nr_kernel_misc_reclaimable",
1181 "nr_foll_pin_acquired",
1182 "nr_foll_pin_released",
1183 "nr_kernel_stack",
1184#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
1185 "nr_shadow_call_stack",
1186#endif
1187 "nr_page_table_pages",
1188#ifdef CONFIG_SWAP
1189 "nr_swapcached",
1190#endif
1191
1192 /* enum writeback_stat_item counters */
1193 "nr_dirty_threshold",
1194 "nr_dirty_background_threshold",
1195
1196#if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG)
1197 /* enum vm_event_item counters */
1198 "pgpgin",
1199 "pgpgout",
1200 "pswpin",
1201 "pswpout",
1202
1203 TEXTS_FOR_ZONES("pgalloc")
1204 TEXTS_FOR_ZONES("allocstall")
1205 TEXTS_FOR_ZONES("pgskip")
1206
1207 "pgfree",
1208 "pgactivate",
1209 "pgdeactivate",
1210 "pglazyfree",
1211
1212 "pgfault",
1213 "pgmajfault",
1214 "pglazyfreed",
1215
1216 "pgrefill",
1217 "pgreuse",
1218 "pgsteal_kswapd",
1219 "pgsteal_direct",
1220 "pgscan_kswapd",
1221 "pgscan_direct",
1222 "pgscan_direct_throttle",
1223 "pgscan_anon",
1224 "pgscan_file",
1225 "pgsteal_anon",
1226 "pgsteal_file",
1227
1228#ifdef CONFIG_NUMA
1229 "zone_reclaim_failed",
1230#endif
1231 "pginodesteal",
1232 "slabs_scanned",
1233 "kswapd_inodesteal",
1234 "kswapd_low_wmark_hit_quickly",
1235 "kswapd_high_wmark_hit_quickly",
1236 "pageoutrun",
1237
1238 "pgrotated",
1239
1240 "drop_pagecache",
1241 "drop_slab",
1242 "oom_kill",
1243
1244#ifdef CONFIG_NUMA_BALANCING
1245 "numa_pte_updates",
1246 "numa_huge_pte_updates",
1247 "numa_hint_faults",
1248 "numa_hint_faults_local",
1249 "numa_pages_migrated",
1250#endif
1251#ifdef CONFIG_MIGRATION
1252 "pgmigrate_success",
1253 "pgmigrate_fail",
1254 "thp_migration_success",
1255 "thp_migration_fail",
1256 "thp_migration_split",
1257#endif
1258#ifdef CONFIG_COMPACTION
1259 "compact_migrate_scanned",
1260 "compact_free_scanned",
1261 "compact_isolated",
1262 "compact_stall",
1263 "compact_fail",
1264 "compact_success",
1265 "compact_daemon_wake",
1266 "compact_daemon_migrate_scanned",
1267 "compact_daemon_free_scanned",
1268#endif
1269
1270#ifdef CONFIG_HUGETLB_PAGE
1271 "htlb_buddy_alloc_success",
1272 "htlb_buddy_alloc_fail",
1273#endif
1274#ifdef CONFIG_CMA
1275 "cma_alloc_success",
1276 "cma_alloc_fail",
1277#endif
1278 "unevictable_pgs_culled",
1279 "unevictable_pgs_scanned",
1280 "unevictable_pgs_rescued",
1281 "unevictable_pgs_mlocked",
1282 "unevictable_pgs_munlocked",
1283 "unevictable_pgs_cleared",
1284 "unevictable_pgs_stranded",
1285
1286#ifdef CONFIG_TRANSPARENT_HUGEPAGE
1287 "thp_fault_alloc",
1288 "thp_fault_fallback",
1289 "thp_fault_fallback_charge",
1290 "thp_collapse_alloc",
1291 "thp_collapse_alloc_failed",
1292 "thp_file_alloc",
1293 "thp_file_fallback",
1294 "thp_file_fallback_charge",
1295 "thp_file_mapped",
1296 "thp_split_page",
1297 "thp_split_page_failed",
1298 "thp_deferred_split_page",
1299 "thp_split_pmd",
1300#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
1301 "thp_split_pud",
1302#endif
1303 "thp_zero_page_alloc",
1304 "thp_zero_page_alloc_failed",
1305 "thp_swpout",
1306 "thp_swpout_fallback",
1307#endif
1308#ifdef CONFIG_MEMORY_BALLOON
1309 "balloon_inflate",
1310 "balloon_deflate",
1311#ifdef CONFIG_BALLOON_COMPACTION
1312 "balloon_migrate",
1313#endif
1314#endif /* CONFIG_MEMORY_BALLOON */
1315#ifdef CONFIG_DEBUG_TLBFLUSH
1316 "nr_tlb_remote_flush",
1317 "nr_tlb_remote_flush_received",
1318 "nr_tlb_local_flush_all",
1319 "nr_tlb_local_flush_one",
1320#endif /* CONFIG_DEBUG_TLBFLUSH */
1321
1322#ifdef CONFIG_DEBUG_VM_VMACACHE
1323 "vmacache_find_calls",
1324 "vmacache_find_hits",
1325#endif
1326#ifdef CONFIG_SWAP
1327 "swap_ra",
1328 "swap_ra_hit",
1329#endif
1330#ifdef CONFIG_X86
1331 "direct_map_level2_splits",
1332 "direct_map_level3_splits",
1333#endif
1334#endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */
1335};
1336#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */
1337
1338#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
1339 defined(CONFIG_PROC_FS)
1340static void *frag_start(struct seq_file *m, loff_t *pos)
1341{
1342 pg_data_t *pgdat;
1343 loff_t node = *pos;
1344
1345 for (pgdat = first_online_pgdat();
1346 pgdat && node;
1347 pgdat = next_online_pgdat(pgdat))
1348 --node;
1349
1350 return pgdat;
1351}
1352
1353static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
1354{
1355 pg_data_t *pgdat = (pg_data_t *)arg;
1356
1357 (*pos)++;
1358 return next_online_pgdat(pgdat);
1359}
1360
1361static void frag_stop(struct seq_file *m, void *arg)
1362{
1363}
1364
1365/*
1366 * Walk zones in a node and print using a callback.
1367 * If @assert_populated is true, only use callback for zones that are populated.
1368 */
1369static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
1370 bool assert_populated, bool nolock,
1371 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
1372{
1373 struct zone *zone;
1374 struct zone *node_zones = pgdat->node_zones;
1375 unsigned long flags;
1376
1377 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
1378 if (assert_populated && !populated_zone(zone))
1379 continue;
1380
1381 if (!nolock)
1382 spin_lock_irqsave(&zone->lock, flags);
1383 print(m, pgdat, zone);
1384 if (!nolock)
1385 spin_unlock_irqrestore(&zone->lock, flags);
1386 }
1387}
1388#endif
1389
1390#ifdef CONFIG_PROC_FS
1391static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
1392 struct zone *zone)
1393{
1394 int order;
1395
1396 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1397 for (order = 0; order < MAX_ORDER; ++order)
1398 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
1399 seq_putc(m, '\n');
1400}
1401
1402/*
1403 * This walks the free areas for each zone.
1404 */
1405static int frag_show(struct seq_file *m, void *arg)
1406{
1407 pg_data_t *pgdat = (pg_data_t *)arg;
1408 walk_zones_in_node(m, pgdat, true, false, frag_show_print);
1409 return 0;
1410}
1411
1412static void pagetypeinfo_showfree_print(struct seq_file *m,
1413 pg_data_t *pgdat, struct zone *zone)
1414{
1415 int order, mtype;
1416
1417 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
1418 seq_printf(m, "Node %4d, zone %8s, type %12s ",
1419 pgdat->node_id,
1420 zone->name,
1421 migratetype_names[mtype]);
1422 for (order = 0; order < MAX_ORDER; ++order) {
1423 unsigned long freecount = 0;
1424 struct free_area *area;
1425 struct list_head *curr;
1426 bool overflow = false;
1427
1428 area = &(zone->free_area[order]);
1429
1430 list_for_each(curr, &area->free_list[mtype]) {
1431 /*
1432 * Cap the free_list iteration because it might
1433 * be really large and we are under a spinlock
1434 * so a long time spent here could trigger a
1435 * hard lockup detector. Anyway this is a
1436 * debugging tool so knowing there is a handful
1437 * of pages of this order should be more than
1438 * sufficient.
1439 */
1440 if (++freecount >= 100000) {
1441 overflow = true;
1442 break;
1443 }
1444 }
1445 seq_printf(m, "%s%6lu ", overflow ? ">" : "", freecount);
1446 spin_unlock_irq(&zone->lock);
1447 cond_resched();
1448 spin_lock_irq(&zone->lock);
1449 }
1450 seq_putc(m, '\n');
1451 }
1452}
1453
1454/* Print out the free pages at each order for each migatetype */
1455static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
1456{
1457 int order;
1458 pg_data_t *pgdat = (pg_data_t *)arg;
1459
1460 /* Print header */
1461 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
1462 for (order = 0; order < MAX_ORDER; ++order)
1463 seq_printf(m, "%6d ", order);
1464 seq_putc(m, '\n');
1465
1466 walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print);
1467
1468 return 0;
1469}
1470
1471static void pagetypeinfo_showblockcount_print(struct seq_file *m,
1472 pg_data_t *pgdat, struct zone *zone)
1473{
1474 int mtype;
1475 unsigned long pfn;
1476 unsigned long start_pfn = zone->zone_start_pfn;
1477 unsigned long end_pfn = zone_end_pfn(zone);
1478 unsigned long count[MIGRATE_TYPES] = { 0, };
1479
1480 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
1481 struct page *page;
1482
1483 page = pfn_to_online_page(pfn);
1484 if (!page)
1485 continue;
1486
1487 if (page_zone(page) != zone)
1488 continue;
1489
1490 mtype = get_pageblock_migratetype(page);
1491
1492 if (mtype < MIGRATE_TYPES)
1493 count[mtype]++;
1494 }
1495
1496 /* Print counts */
1497 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1498 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1499 seq_printf(m, "%12lu ", count[mtype]);
1500 seq_putc(m, '\n');
1501}
1502
1503/* Print out the number of pageblocks for each migratetype */
1504static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
1505{
1506 int mtype;
1507 pg_data_t *pgdat = (pg_data_t *)arg;
1508
1509 seq_printf(m, "\n%-23s", "Number of blocks type ");
1510 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1511 seq_printf(m, "%12s ", migratetype_names[mtype]);
1512 seq_putc(m, '\n');
1513 walk_zones_in_node(m, pgdat, true, false,
1514 pagetypeinfo_showblockcount_print);
1515
1516 return 0;
1517}
1518
1519/*
1520 * Print out the number of pageblocks for each migratetype that contain pages
1521 * of other types. This gives an indication of how well fallbacks are being
1522 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER
1523 * to determine what is going on
1524 */
1525static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat)
1526{
1527#ifdef CONFIG_PAGE_OWNER
1528 int mtype;
1529
1530 if (!static_branch_unlikely(&page_owner_inited))
1531 return;
1532
1533 drain_all_pages(NULL);
1534
1535 seq_printf(m, "\n%-23s", "Number of mixed blocks ");
1536 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1537 seq_printf(m, "%12s ", migratetype_names[mtype]);
1538 seq_putc(m, '\n');
1539
1540 walk_zones_in_node(m, pgdat, true, true,
1541 pagetypeinfo_showmixedcount_print);
1542#endif /* CONFIG_PAGE_OWNER */
1543}
1544
1545/*
1546 * This prints out statistics in relation to grouping pages by mobility.
1547 * It is expensive to collect so do not constantly read the file.
1548 */
1549static int pagetypeinfo_show(struct seq_file *m, void *arg)
1550{
1551 pg_data_t *pgdat = (pg_data_t *)arg;
1552
1553 /* check memoryless node */
1554 if (!node_state(pgdat->node_id, N_MEMORY))
1555 return 0;
1556
1557 seq_printf(m, "Page block order: %d\n", pageblock_order);
1558 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
1559 seq_putc(m, '\n');
1560 pagetypeinfo_showfree(m, pgdat);
1561 pagetypeinfo_showblockcount(m, pgdat);
1562 pagetypeinfo_showmixedcount(m, pgdat);
1563
1564 return 0;
1565}
1566
1567static const struct seq_operations fragmentation_op = {
1568 .start = frag_start,
1569 .next = frag_next,
1570 .stop = frag_stop,
1571 .show = frag_show,
1572};
1573
1574static const struct seq_operations pagetypeinfo_op = {
1575 .start = frag_start,
1576 .next = frag_next,
1577 .stop = frag_stop,
1578 .show = pagetypeinfo_show,
1579};
1580
1581static bool is_zone_first_populated(pg_data_t *pgdat, struct zone *zone)
1582{
1583 int zid;
1584
1585 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
1586 struct zone *compare = &pgdat->node_zones[zid];
1587
1588 if (populated_zone(compare))
1589 return zone == compare;
1590 }
1591
1592 return false;
1593}
1594
1595static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
1596 struct zone *zone)
1597{
1598 int i;
1599 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1600 if (is_zone_first_populated(pgdat, zone)) {
1601 seq_printf(m, "\n per-node stats");
1602 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1603 unsigned long pages = node_page_state_pages(pgdat, i);
1604
1605 if (vmstat_item_print_in_thp(i))
1606 pages /= HPAGE_PMD_NR;
1607 seq_printf(m, "\n %-12s %lu", node_stat_name(i),
1608 pages);
1609 }
1610 }
1611 seq_printf(m,
1612 "\n pages free %lu"
1613 "\n min %lu"
1614 "\n low %lu"
1615 "\n high %lu"
1616 "\n spanned %lu"
1617 "\n present %lu"
1618 "\n managed %lu"
1619 "\n cma %lu",
1620 zone_page_state(zone, NR_FREE_PAGES),
1621 min_wmark_pages(zone),
1622 low_wmark_pages(zone),
1623 high_wmark_pages(zone),
1624 zone->spanned_pages,
1625 zone->present_pages,
1626 zone_managed_pages(zone),
1627 zone_cma_pages(zone));
1628
1629 seq_printf(m,
1630 "\n protection: (%ld",
1631 zone->lowmem_reserve[0]);
1632 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1633 seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
1634 seq_putc(m, ')');
1635
1636 /* If unpopulated, no other information is useful */
1637 if (!populated_zone(zone)) {
1638 seq_putc(m, '\n');
1639 return;
1640 }
1641
1642 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1643 seq_printf(m, "\n %-12s %lu", zone_stat_name(i),
1644 zone_page_state(zone, i));
1645
1646#ifdef CONFIG_NUMA
1647 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
1648 seq_printf(m, "\n %-12s %lu", numa_stat_name(i),
1649 zone_numa_event_state(zone, i));
1650#endif
1651
1652 seq_printf(m, "\n pagesets");
1653 for_each_online_cpu(i) {
1654 struct per_cpu_pages *pcp;
1655 struct per_cpu_zonestat __maybe_unused *pzstats;
1656
1657 pcp = per_cpu_ptr(zone->per_cpu_pageset, i);
1658 seq_printf(m,
1659 "\n cpu: %i"
1660 "\n count: %i"
1661 "\n high: %i"
1662 "\n batch: %i",
1663 i,
1664 pcp->count,
1665 pcp->high,
1666 pcp->batch);
1667#ifdef CONFIG_SMP
1668 pzstats = per_cpu_ptr(zone->per_cpu_zonestats, i);
1669 seq_printf(m, "\n vm stats threshold: %d",
1670 pzstats->stat_threshold);
1671#endif
1672 }
1673 seq_printf(m,
1674 "\n node_unreclaimable: %u"
1675 "\n start_pfn: %lu",
1676 pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES,
1677 zone->zone_start_pfn);
1678 seq_putc(m, '\n');
1679}
1680
1681/*
1682 * Output information about zones in @pgdat. All zones are printed regardless
1683 * of whether they are populated or not: lowmem_reserve_ratio operates on the
1684 * set of all zones and userspace would not be aware of such zones if they are
1685 * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio).
1686 */
1687static int zoneinfo_show(struct seq_file *m, void *arg)
1688{
1689 pg_data_t *pgdat = (pg_data_t *)arg;
1690 walk_zones_in_node(m, pgdat, false, false, zoneinfo_show_print);
1691 return 0;
1692}
1693
1694static const struct seq_operations zoneinfo_op = {
1695 .start = frag_start, /* iterate over all zones. The same as in
1696 * fragmentation. */
1697 .next = frag_next,
1698 .stop = frag_stop,
1699 .show = zoneinfo_show,
1700};
1701
1702#define NR_VMSTAT_ITEMS (NR_VM_ZONE_STAT_ITEMS + \
1703 NR_VM_NUMA_EVENT_ITEMS + \
1704 NR_VM_NODE_STAT_ITEMS + \
1705 NR_VM_WRITEBACK_STAT_ITEMS + \
1706 (IS_ENABLED(CONFIG_VM_EVENT_COUNTERS) ? \
1707 NR_VM_EVENT_ITEMS : 0))
1708
1709static void *vmstat_start(struct seq_file *m, loff_t *pos)
1710{
1711 unsigned long *v;
1712 int i;
1713
1714 if (*pos >= NR_VMSTAT_ITEMS)
1715 return NULL;
1716
1717 BUILD_BUG_ON(ARRAY_SIZE(vmstat_text) < NR_VMSTAT_ITEMS);
1718 fold_vm_numa_events();
1719 v = kmalloc_array(NR_VMSTAT_ITEMS, sizeof(unsigned long), GFP_KERNEL);
1720 m->private = v;
1721 if (!v)
1722 return ERR_PTR(-ENOMEM);
1723 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1724 v[i] = global_zone_page_state(i);
1725 v += NR_VM_ZONE_STAT_ITEMS;
1726
1727#ifdef CONFIG_NUMA
1728 for (i = 0; i < NR_VM_NUMA_EVENT_ITEMS; i++)
1729 v[i] = global_numa_event_state(i);
1730 v += NR_VM_NUMA_EVENT_ITEMS;
1731#endif
1732
1733 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1734 v[i] = global_node_page_state_pages(i);
1735 if (vmstat_item_print_in_thp(i))
1736 v[i] /= HPAGE_PMD_NR;
1737 }
1738 v += NR_VM_NODE_STAT_ITEMS;
1739
1740 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1741 v + NR_DIRTY_THRESHOLD);
1742 v += NR_VM_WRITEBACK_STAT_ITEMS;
1743
1744#ifdef CONFIG_VM_EVENT_COUNTERS
1745 all_vm_events(v);
1746 v[PGPGIN] /= 2; /* sectors -> kbytes */
1747 v[PGPGOUT] /= 2;
1748#endif
1749 return (unsigned long *)m->private + *pos;
1750}
1751
1752static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1753{
1754 (*pos)++;
1755 if (*pos >= NR_VMSTAT_ITEMS)
1756 return NULL;
1757 return (unsigned long *)m->private + *pos;
1758}
1759
1760static int vmstat_show(struct seq_file *m, void *arg)
1761{
1762 unsigned long *l = arg;
1763 unsigned long off = l - (unsigned long *)m->private;
1764
1765 seq_puts(m, vmstat_text[off]);
1766 seq_put_decimal_ull(m, " ", *l);
1767 seq_putc(m, '\n');
1768
1769 if (off == NR_VMSTAT_ITEMS - 1) {
1770 /*
1771 * We've come to the end - add any deprecated counters to avoid
1772 * breaking userspace which might depend on them being present.
1773 */
1774 seq_puts(m, "nr_unstable 0\n");
1775 }
1776 return 0;
1777}
1778
1779static void vmstat_stop(struct seq_file *m, void *arg)
1780{
1781 kfree(m->private);
1782 m->private = NULL;
1783}
1784
1785static const struct seq_operations vmstat_op = {
1786 .start = vmstat_start,
1787 .next = vmstat_next,
1788 .stop = vmstat_stop,
1789 .show = vmstat_show,
1790};
1791#endif /* CONFIG_PROC_FS */
1792
1793#ifdef CONFIG_SMP
1794static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1795int sysctl_stat_interval __read_mostly = HZ;
1796
1797#ifdef CONFIG_PROC_FS
1798static void refresh_vm_stats(struct work_struct *work)
1799{
1800 refresh_cpu_vm_stats(true);
1801}
1802
1803int vmstat_refresh(struct ctl_table *table, int write,
1804 void *buffer, size_t *lenp, loff_t *ppos)
1805{
1806 long val;
1807 int err;
1808 int i;
1809
1810 /*
1811 * The regular update, every sysctl_stat_interval, may come later
1812 * than expected: leaving a significant amount in per_cpu buckets.
1813 * This is particularly misleading when checking a quantity of HUGE
1814 * pages, immediately after running a test. /proc/sys/vm/stat_refresh,
1815 * which can equally be echo'ed to or cat'ted from (by root),
1816 * can be used to update the stats just before reading them.
1817 *
1818 * Oh, and since global_zone_page_state() etc. are so careful to hide
1819 * transiently negative values, report an error here if any of
1820 * the stats is negative, so we know to go looking for imbalance.
1821 */
1822 err = schedule_on_each_cpu(refresh_vm_stats);
1823 if (err)
1824 return err;
1825 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
1826 /*
1827 * Skip checking stats known to go negative occasionally.
1828 */
1829 switch (i) {
1830 case NR_ZONE_WRITE_PENDING:
1831 case NR_FREE_CMA_PAGES:
1832 continue;
1833 }
1834 val = atomic_long_read(&vm_zone_stat[i]);
1835 if (val < 0) {
1836 pr_warn("%s: %s %ld\n",
1837 __func__, zone_stat_name(i), val);
1838 }
1839 }
1840 for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
1841 /*
1842 * Skip checking stats known to go negative occasionally.
1843 */
1844 switch (i) {
1845 case NR_WRITEBACK:
1846 continue;
1847 }
1848 val = atomic_long_read(&vm_node_stat[i]);
1849 if (val < 0) {
1850 pr_warn("%s: %s %ld\n",
1851 __func__, node_stat_name(i), val);
1852 }
1853 }
1854 if (write)
1855 *ppos += *lenp;
1856 else
1857 *lenp = 0;
1858 return 0;
1859}
1860#endif /* CONFIG_PROC_FS */
1861
1862static void vmstat_update(struct work_struct *w)
1863{
1864 if (refresh_cpu_vm_stats(true)) {
1865 /*
1866 * Counters were updated so we expect more updates
1867 * to occur in the future. Keep on running the
1868 * update worker thread.
1869 */
1870 queue_delayed_work_on(smp_processor_id(), mm_percpu_wq,
1871 this_cpu_ptr(&vmstat_work),
1872 round_jiffies_relative(sysctl_stat_interval));
1873 }
1874}
1875
1876/*
1877 * Switch off vmstat processing and then fold all the remaining differentials
1878 * until the diffs stay at zero. The function is used by NOHZ and can only be
1879 * invoked when tick processing is not active.
1880 */
1881/*
1882 * Check if the diffs for a certain cpu indicate that
1883 * an update is needed.
1884 */
1885static bool need_update(int cpu)
1886{
1887 pg_data_t *last_pgdat = NULL;
1888 struct zone *zone;
1889
1890 for_each_populated_zone(zone) {
1891 struct per_cpu_zonestat *pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu);
1892 struct per_cpu_nodestat *n;
1893
1894 /*
1895 * The fast way of checking if there are any vmstat diffs.
1896 */
1897 if (memchr_inv(pzstats->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS *
1898 sizeof(pzstats->vm_stat_diff[0])))
1899 return true;
1900
1901 if (last_pgdat == zone->zone_pgdat)
1902 continue;
1903 last_pgdat = zone->zone_pgdat;
1904 n = per_cpu_ptr(zone->zone_pgdat->per_cpu_nodestats, cpu);
1905 if (memchr_inv(n->vm_node_stat_diff, 0, NR_VM_NODE_STAT_ITEMS *
1906 sizeof(n->vm_node_stat_diff[0])))
1907 return true;
1908 }
1909 return false;
1910}
1911
1912/*
1913 * Switch off vmstat processing and then fold all the remaining differentials
1914 * until the diffs stay at zero. The function is used by NOHZ and can only be
1915 * invoked when tick processing is not active.
1916 */
1917void quiet_vmstat(void)
1918{
1919 if (system_state != SYSTEM_RUNNING)
1920 return;
1921
1922 if (!delayed_work_pending(this_cpu_ptr(&vmstat_work)))
1923 return;
1924
1925 if (!need_update(smp_processor_id()))
1926 return;
1927
1928 /*
1929 * Just refresh counters and do not care about the pending delayed
1930 * vmstat_update. It doesn't fire that often to matter and canceling
1931 * it would be too expensive from this path.
1932 * vmstat_shepherd will take care about that for us.
1933 */
1934 refresh_cpu_vm_stats(false);
1935}
1936
1937/*
1938 * Shepherd worker thread that checks the
1939 * differentials of processors that have their worker
1940 * threads for vm statistics updates disabled because of
1941 * inactivity.
1942 */
1943static void vmstat_shepherd(struct work_struct *w);
1944
1945static DECLARE_DEFERRABLE_WORK(shepherd, vmstat_shepherd);
1946
1947static void vmstat_shepherd(struct work_struct *w)
1948{
1949 int cpu;
1950
1951 get_online_cpus();
1952 /* Check processors whose vmstat worker threads have been disabled */
1953 for_each_online_cpu(cpu) {
1954 struct delayed_work *dw = &per_cpu(vmstat_work, cpu);
1955
1956 if (!delayed_work_pending(dw) && need_update(cpu))
1957 queue_delayed_work_on(cpu, mm_percpu_wq, dw, 0);
1958
1959 cond_resched();
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