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