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