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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 #ifdef CONFIG_VM_EVENT_COUNTERS
34 DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
35 EXPORT_PER_CPU_SYMBOL(vm_event_states);
36
37 static void sum_vm_events(unsigned long *ret)
38 {
39 int cpu;
40 int i;
41
42 memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
43
44 for_each_online_cpu(cpu) {
45 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
46
47 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
48 ret[i] += this->event[i];
49 }
50 }
51
52 /*
53 * Accumulate the vm event counters across all CPUs.
54 * The result is unavoidably approximate - it can change
55 * during and after execution of this function.
56 */
57 void all_vm_events(unsigned long *ret)
58 {
59 get_online_cpus();
60 sum_vm_events(ret);
61 put_online_cpus();
62 }
63 EXPORT_SYMBOL_GPL(all_vm_events);
64
65 /*
66 * Fold the foreign cpu events into our own.
67 *
68 * This is adding to the events on one processor
69 * but keeps the global counts constant.
70 */
71 void vm_events_fold_cpu(int cpu)
72 {
73 struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
74 int i;
75
76 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
77 count_vm_events(i, fold_state->event[i]);
78 fold_state->event[i] = 0;
79 }
80 }
81
82 #endif /* CONFIG_VM_EVENT_COUNTERS */
83
84 /*
85 * Manage combined zone based / global counters
86 *
87 * vm_stat contains the global counters
88 */
89 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
90 EXPORT_SYMBOL(vm_stat);
91
92 #ifdef CONFIG_SMP
93
94 int calculate_pressure_threshold(struct zone *zone)
95 {
96 int threshold;
97 int watermark_distance;
98
99 /*
100 * As vmstats are not up to date, there is drift between the estimated
101 * and real values. For high thresholds and a high number of CPUs, it
102 * is possible for the min watermark to be breached while the estimated
103 * value looks fine. The pressure threshold is a reduced value such
104 * that even the maximum amount of drift will not accidentally breach
105 * the min watermark
106 */
107 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
108 threshold = max(1, (int)(watermark_distance / num_online_cpus()));
109
110 /*
111 * Maximum threshold is 125
112 */
113 threshold = min(125, threshold);
114
115 return threshold;
116 }
117
118 int calculate_normal_threshold(struct zone *zone)
119 {
120 int threshold;
121 int mem; /* memory in 128 MB units */
122
123 /*
124 * The threshold scales with the number of processors and the amount
125 * of memory per zone. More memory means that we can defer updates for
126 * longer, more processors could lead to more contention.
127 * fls() is used to have a cheap way of logarithmic scaling.
128 *
129 * Some sample thresholds:
130 *
131 * Threshold Processors (fls) Zonesize fls(mem+1)
132 * ------------------------------------------------------------------
133 * 8 1 1 0.9-1 GB 4
134 * 16 2 2 0.9-1 GB 4
135 * 20 2 2 1-2 GB 5
136 * 24 2 2 2-4 GB 6
137 * 28 2 2 4-8 GB 7
138 * 32 2 2 8-16 GB 8
139 * 4 2 2 <128M 1
140 * 30 4 3 2-4 GB 5
141 * 48 4 3 8-16 GB 8
142 * 32 8 4 1-2 GB 4
143 * 32 8 4 0.9-1GB 4
144 * 10 16 5 <128M 1
145 * 40 16 5 900M 4
146 * 70 64 7 2-4 GB 5
147 * 84 64 7 4-8 GB 6
148 * 108 512 9 4-8 GB 6
149 * 125 1024 10 8-16 GB 8
150 * 125 1024 10 16-32 GB 9
151 */
152
153 mem = zone->managed_pages >> (27 - PAGE_SHIFT);
154
155 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
156
157 /*
158 * Maximum threshold is 125
159 */
160 threshold = min(125, threshold);
161
162 return threshold;
163 }
164
165 /*
166 * Refresh the thresholds for each zone.
167 */
168 void refresh_zone_stat_thresholds(void)
169 {
170 struct zone *zone;
171 int cpu;
172 int threshold;
173
174 for_each_populated_zone(zone) {
175 unsigned long max_drift, tolerate_drift;
176
177 threshold = calculate_normal_threshold(zone);
178
179 for_each_online_cpu(cpu)
180 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
181 = threshold;
182
183 /*
184 * Only set percpu_drift_mark if there is a danger that
185 * NR_FREE_PAGES reports the low watermark is ok when in fact
186 * the min watermark could be breached by an allocation
187 */
188 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
189 max_drift = num_online_cpus() * threshold;
190 if (max_drift > tolerate_drift)
191 zone->percpu_drift_mark = high_wmark_pages(zone) +
192 max_drift;
193 }
194 }
195
196 void set_pgdat_percpu_threshold(pg_data_t *pgdat,
197 int (*calculate_pressure)(struct zone *))
198 {
199 struct zone *zone;
200 int cpu;
201 int threshold;
202 int i;
203
204 for (i = 0; i < pgdat->nr_zones; i++) {
205 zone = &pgdat->node_zones[i];
206 if (!zone->percpu_drift_mark)
207 continue;
208
209 threshold = (*calculate_pressure)(zone);
210 for_each_online_cpu(cpu)
211 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
212 = threshold;
213 }
214 }
215
216 /*
217 * For use when we know that interrupts are disabled,
218 * or when we know that preemption is disabled and that
219 * particular counter cannot be updated from interrupt context.
220 */
221 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
222 int delta)
223 {
224 struct per_cpu_pageset __percpu *pcp = zone->pageset;
225 s8 __percpu *p = pcp->vm_stat_diff + item;
226 long x;
227 long t;
228
229 x = delta + __this_cpu_read(*p);
230
231 t = __this_cpu_read(pcp->stat_threshold);
232
233 if (unlikely(x > t || x < -t)) {
234 zone_page_state_add(x, zone, item);
235 x = 0;
236 }
237 __this_cpu_write(*p, x);
238 }
239 EXPORT_SYMBOL(__mod_zone_page_state);
240
241 /*
242 * Optimized increment and decrement functions.
243 *
244 * These are only for a single page and therefore can take a struct page *
245 * argument instead of struct zone *. This allows the inclusion of the code
246 * generated for page_zone(page) into the optimized functions.
247 *
248 * No overflow check is necessary and therefore the differential can be
249 * incremented or decremented in place which may allow the compilers to
250 * generate better code.
251 * The increment or decrement is known and therefore one boundary check can
252 * be omitted.
253 *
254 * NOTE: These functions are very performance sensitive. Change only
255 * with care.
256 *
257 * Some processors have inc/dec instructions that are atomic vs an interrupt.
258 * However, the code must first determine the differential location in a zone
259 * based on the processor number and then inc/dec the counter. There is no
260 * guarantee without disabling preemption that the processor will not change
261 * in between and therefore the atomicity vs. interrupt cannot be exploited
262 * in a useful way here.
263 */
264 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
265 {
266 struct per_cpu_pageset __percpu *pcp = zone->pageset;
267 s8 __percpu *p = pcp->vm_stat_diff + item;
268 s8 v, t;
269
270 v = __this_cpu_inc_return(*p);
271 t = __this_cpu_read(pcp->stat_threshold);
272 if (unlikely(v > t)) {
273 s8 overstep = t >> 1;
274
275 zone_page_state_add(v + overstep, zone, item);
276 __this_cpu_write(*p, -overstep);
277 }
278 }
279
280 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
281 {
282 __inc_zone_state(page_zone(page), item);
283 }
284 EXPORT_SYMBOL(__inc_zone_page_state);
285
286 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
287 {
288 struct per_cpu_pageset __percpu *pcp = zone->pageset;
289 s8 __percpu *p = pcp->vm_stat_diff + item;
290 s8 v, t;
291
292 v = __this_cpu_dec_return(*p);
293 t = __this_cpu_read(pcp->stat_threshold);
294 if (unlikely(v < - t)) {
295 s8 overstep = t >> 1;
296
297 zone_page_state_add(v - overstep, zone, item);
298 __this_cpu_write(*p, overstep);
299 }
300 }
301
302 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
303 {
304 __dec_zone_state(page_zone(page), item);
305 }
306 EXPORT_SYMBOL(__dec_zone_page_state);
307
308 #ifdef CONFIG_HAVE_CMPXCHG_LOCAL
309 /*
310 * If we have cmpxchg_local support then we do not need to incur the overhead
311 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
312 *
313 * mod_state() modifies the zone counter state through atomic per cpu
314 * operations.
315 *
316 * Overstep mode specifies how overstep should handled:
317 * 0 No overstepping
318 * 1 Overstepping half of threshold
319 * -1 Overstepping minus half of threshold
320 */
321 static inline void mod_state(struct zone *zone,
322 enum zone_stat_item item, int delta, int overstep_mode)
323 {
324 struct per_cpu_pageset __percpu *pcp = zone->pageset;
325 s8 __percpu *p = pcp->vm_stat_diff + item;
326 long o, n, t, z;
327
328 do {
329 z = 0; /* overflow to zone counters */
330
331 /*
332 * The fetching of the stat_threshold is racy. We may apply
333 * a counter threshold to the wrong the cpu if we get
334 * rescheduled while executing here. However, the next
335 * counter update will apply the threshold again and
336 * therefore bring the counter under the threshold again.
337 *
338 * Most of the time the thresholds are the same anyways
339 * for all cpus in a zone.
340 */
341 t = this_cpu_read(pcp->stat_threshold);
342
343 o = this_cpu_read(*p);
344 n = delta + o;
345
346 if (n > t || n < -t) {
347 int os = overstep_mode * (t >> 1) ;
348
349 /* Overflow must be added to zone counters */
350 z = n + os;
351 n = -os;
352 }
353 } while (this_cpu_cmpxchg(*p, o, n) != o);
354
355 if (z)
356 zone_page_state_add(z, zone, item);
357 }
358
359 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
360 int delta)
361 {
362 mod_state(zone, item, delta, 0);
363 }
364 EXPORT_SYMBOL(mod_zone_page_state);
365
366 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
367 {
368 mod_state(zone, item, 1, 1);
369 }
370
371 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
372 {
373 mod_state(page_zone(page), item, 1, 1);
374 }
375 EXPORT_SYMBOL(inc_zone_page_state);
376
377 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
378 {
379 mod_state(page_zone(page), item, -1, -1);
380 }
381 EXPORT_SYMBOL(dec_zone_page_state);
382 #else
383 /*
384 * Use interrupt disable to serialize counter updates
385 */
386 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
387 int delta)
388 {
389 unsigned long flags;
390
391 local_irq_save(flags);
392 __mod_zone_page_state(zone, item, delta);
393 local_irq_restore(flags);
394 }
395 EXPORT_SYMBOL(mod_zone_page_state);
396
397 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
398 {
399 unsigned long flags;
400
401 local_irq_save(flags);
402 __inc_zone_state(zone, item);
403 local_irq_restore(flags);
404 }
405
406 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
407 {
408 unsigned long flags;
409 struct zone *zone;
410
411 zone = page_zone(page);
412 local_irq_save(flags);
413 __inc_zone_state(zone, item);
414 local_irq_restore(flags);
415 }
416 EXPORT_SYMBOL(inc_zone_page_state);
417
418 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
419 {
420 unsigned long flags;
421
422 local_irq_save(flags);
423 __dec_zone_page_state(page, item);
424 local_irq_restore(flags);
425 }
426 EXPORT_SYMBOL(dec_zone_page_state);
427 #endif
428
429
430 /*
431 * Fold a differential into the global counters.
432 * Returns the number of counters updated.
433 */
434 static int fold_diff(int *diff)
435 {
436 int i;
437 int changes = 0;
438
439 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
440 if (diff[i]) {
441 atomic_long_add(diff[i], &vm_stat[i]);
442 changes++;
443 }
444 return changes;
445 }
446
447 /*
448 * Update the zone counters for the current cpu.
449 *
450 * Note that refresh_cpu_vm_stats strives to only access
451 * node local memory. The per cpu pagesets on remote zones are placed
452 * in the memory local to the processor using that pageset. So the
453 * loop over all zones will access a series of cachelines local to
454 * the processor.
455 *
456 * The call to zone_page_state_add updates the cachelines with the
457 * statistics in the remote zone struct as well as the global cachelines
458 * with the global counters. These could cause remote node cache line
459 * bouncing and will have to be only done when necessary.
460 *
461 * The function returns the number of global counters updated.
462 */
463 static int refresh_cpu_vm_stats(void)
464 {
465 struct zone *zone;
466 int i;
467 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
468 int changes = 0;
469
470 for_each_populated_zone(zone) {
471 struct per_cpu_pageset __percpu *p = zone->pageset;
472
473 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
474 int v;
475
476 v = this_cpu_xchg(p->vm_stat_diff[i], 0);
477 if (v) {
478
479 atomic_long_add(v, &zone->vm_stat[i]);
480 global_diff[i] += v;
481 #ifdef CONFIG_NUMA
482 /* 3 seconds idle till flush */
483 __this_cpu_write(p->expire, 3);
484 #endif
485 }
486 }
487 cond_resched();
488 #ifdef CONFIG_NUMA
489 /*
490 * Deal with draining the remote pageset of this
491 * processor
492 *
493 * Check if there are pages remaining in this pageset
494 * if not then there is nothing to expire.
495 */
496 if (!__this_cpu_read(p->expire) ||
497 !__this_cpu_read(p->pcp.count))
498 continue;
499
500 /*
501 * We never drain zones local to this processor.
502 */
503 if (zone_to_nid(zone) == numa_node_id()) {
504 __this_cpu_write(p->expire, 0);
505 continue;
506 }
507
508 if (__this_cpu_dec_return(p->expire))
509 continue;
510
511 if (__this_cpu_read(p->pcp.count)) {
512 drain_zone_pages(zone, this_cpu_ptr(&p->pcp));
513 changes++;
514 }
515 #endif
516 }
517 changes += fold_diff(global_diff);
518 return changes;
519 }
520
521 /*
522 * Fold the data for an offline cpu into the global array.
523 * There cannot be any access by the offline cpu and therefore
524 * synchronization is simplified.
525 */
526 void cpu_vm_stats_fold(int cpu)
527 {
528 struct zone *zone;
529 int i;
530 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
531
532 for_each_populated_zone(zone) {
533 struct per_cpu_pageset *p;
534
535 p = per_cpu_ptr(zone->pageset, cpu);
536
537 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
538 if (p->vm_stat_diff[i]) {
539 int v;
540
541 v = p->vm_stat_diff[i];
542 p->vm_stat_diff[i] = 0;
543 atomic_long_add(v, &zone->vm_stat[i]);
544 global_diff[i] += v;
545 }
546 }
547
548 fold_diff(global_diff);
549 }
550
551 /*
552 * this is only called if !populated_zone(zone), which implies no other users of
553 * pset->vm_stat_diff[] exsist.
554 */
555 void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
556 {
557 int i;
558
559 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
560 if (pset->vm_stat_diff[i]) {
561 int v = pset->vm_stat_diff[i];
562 pset->vm_stat_diff[i] = 0;
563 atomic_long_add(v, &zone->vm_stat[i]);
564 atomic_long_add(v, &vm_stat[i]);
565 }
566 }
567 #endif
568
569 #ifdef CONFIG_NUMA
570 /*
571 * zonelist = the list of zones passed to the allocator
572 * z = the zone from which the allocation occurred.
573 *
574 * Must be called with interrupts disabled.
575 *
576 * When __GFP_OTHER_NODE is set assume the node of the preferred
577 * zone is the local node. This is useful for daemons who allocate
578 * memory on behalf of other processes.
579 */
580 void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
581 {
582 if (z->zone_pgdat == preferred_zone->zone_pgdat) {
583 __inc_zone_state(z, NUMA_HIT);
584 } else {
585 __inc_zone_state(z, NUMA_MISS);
586 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
587 }
588 if (z->node == ((flags & __GFP_OTHER_NODE) ?
589 preferred_zone->node : numa_node_id()))
590 __inc_zone_state(z, NUMA_LOCAL);
591 else
592 __inc_zone_state(z, NUMA_OTHER);
593 }
594 #endif
595
596 #ifdef CONFIG_COMPACTION
597
598 struct contig_page_info {
599 unsigned long free_pages;
600 unsigned long free_blocks_total;
601 unsigned long free_blocks_suitable;
602 };
603
604 /*
605 * Calculate the number of free pages in a zone, how many contiguous
606 * pages are free and how many are large enough to satisfy an allocation of
607 * the target size. Note that this function makes no attempt to estimate
608 * how many suitable free blocks there *might* be if MOVABLE pages were
609 * migrated. Calculating that is possible, but expensive and can be
610 * figured out from userspace
611 */
612 static void fill_contig_page_info(struct zone *zone,
613 unsigned int suitable_order,
614 struct contig_page_info *info)
615 {
616 unsigned int order;
617
618 info->free_pages = 0;
619 info->free_blocks_total = 0;
620 info->free_blocks_suitable = 0;
621
622 for (order = 0; order < MAX_ORDER; order++) {
623 unsigned long blocks;
624
625 /* Count number of free blocks */
626 blocks = zone->free_area[order].nr_free;
627 info->free_blocks_total += blocks;
628
629 /* Count free base pages */
630 info->free_pages += blocks << order;
631
632 /* Count the suitable free blocks */
633 if (order >= suitable_order)
634 info->free_blocks_suitable += blocks <<
635 (order - suitable_order);
636 }
637 }
638
639 /*
640 * A fragmentation index only makes sense if an allocation of a requested
641 * size would fail. If that is true, the fragmentation index indicates
642 * whether external fragmentation or a lack of memory was the problem.
643 * The value can be used to determine if page reclaim or compaction
644 * should be used
645 */
646 static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
647 {
648 unsigned long requested = 1UL << order;
649
650 if (!info->free_blocks_total)
651 return 0;
652
653 /* Fragmentation index only makes sense when a request would fail */
654 if (info->free_blocks_suitable)
655 return -1000;
656
657 /*
658 * Index is between 0 and 1 so return within 3 decimal places
659 *
660 * 0 => allocation would fail due to lack of memory
661 * 1 => allocation would fail due to fragmentation
662 */
663 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
664 }
665
666 /* Same as __fragmentation index but allocs contig_page_info on stack */
667 int fragmentation_index(struct zone *zone, unsigned int order)
668 {
669 struct contig_page_info info;
670
671 fill_contig_page_info(zone, order, &info);
672 return __fragmentation_index(order, &info);
673 }
674 #endif
675
676 #if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
677 #ifdef CONFIG_ZONE_DMA
678 #define TEXT_FOR_DMA(xx) xx "_dma",
679 #else
680 #define TEXT_FOR_DMA(xx)
681 #endif
682
683 #ifdef CONFIG_ZONE_DMA32
684 #define TEXT_FOR_DMA32(xx) xx "_dma32",
685 #else
686 #define TEXT_FOR_DMA32(xx)
687 #endif
688
689 #ifdef CONFIG_HIGHMEM
690 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
691 #else
692 #define TEXT_FOR_HIGHMEM(xx)
693 #endif
694
695 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
696 TEXT_FOR_HIGHMEM(xx) xx "_movable",
697
698 const char * const vmstat_text[] = {
699 /* enum zone_stat_item countes */
700 "nr_free_pages",
701 "nr_alloc_batch",
702 "nr_inactive_anon",
703 "nr_active_anon",
704 "nr_inactive_file",
705 "nr_active_file",
706 "nr_unevictable",
707 "nr_mlock",
708 "nr_anon_pages",
709 "nr_mapped",
710 "nr_file_pages",
711 "nr_dirty",
712 "nr_writeback",
713 "nr_slab_reclaimable",
714 "nr_slab_unreclaimable",
715 "nr_page_table_pages",
716 "nr_kernel_stack",
717 "nr_unstable",
718 "nr_bounce",
719 "nr_vmscan_write",
720 "nr_vmscan_immediate_reclaim",
721 "nr_writeback_temp",
722 "nr_isolated_anon",
723 "nr_isolated_file",
724 "nr_shmem",
725 "nr_dirtied",
726 "nr_written",
727 "nr_pages_scanned",
728
729 #ifdef CONFIG_NUMA
730 "numa_hit",
731 "numa_miss",
732 "numa_foreign",
733 "numa_interleave",
734 "numa_local",
735 "numa_other",
736 #endif
737 "workingset_refault",
738 "workingset_activate",
739 "workingset_nodereclaim",
740 "nr_anon_transparent_hugepages",
741 "nr_free_cma",
742
743 /* enum writeback_stat_item counters */
744 "nr_dirty_threshold",
745 "nr_dirty_background_threshold",
746
747 #ifdef CONFIG_VM_EVENT_COUNTERS
748 /* enum vm_event_item counters */
749 "pgpgin",
750 "pgpgout",
751 "pswpin",
752 "pswpout",
753
754 TEXTS_FOR_ZONES("pgalloc")
755
756 "pgfree",
757 "pgactivate",
758 "pgdeactivate",
759
760 "pgfault",
761 "pgmajfault",
762
763 TEXTS_FOR_ZONES("pgrefill")
764 TEXTS_FOR_ZONES("pgsteal_kswapd")
765 TEXTS_FOR_ZONES("pgsteal_direct")
766 TEXTS_FOR_ZONES("pgscan_kswapd")
767 TEXTS_FOR_ZONES("pgscan_direct")
768 "pgscan_direct_throttle",
769
770 #ifdef CONFIG_NUMA
771 "zone_reclaim_failed",
772 #endif
773 "pginodesteal",
774 "slabs_scanned",
775 "kswapd_inodesteal",
776 "kswapd_low_wmark_hit_quickly",
777 "kswapd_high_wmark_hit_quickly",
778 "pageoutrun",
779 "allocstall",
780
781 "pgrotated",
782
783 "drop_pagecache",
784 "drop_slab",
785
786 #ifdef CONFIG_NUMA_BALANCING
787 "numa_pte_updates",
788 "numa_huge_pte_updates",
789 "numa_hint_faults",
790 "numa_hint_faults_local",
791 "numa_pages_migrated",
792 #endif
793 #ifdef CONFIG_MIGRATION
794 "pgmigrate_success",
795 "pgmigrate_fail",
796 #endif
797 #ifdef CONFIG_COMPACTION
798 "compact_migrate_scanned",
799 "compact_free_scanned",
800 "compact_isolated",
801 "compact_stall",
802 "compact_fail",
803 "compact_success",
804 #endif
805
806 #ifdef CONFIG_HUGETLB_PAGE
807 "htlb_buddy_alloc_success",
808 "htlb_buddy_alloc_fail",
809 #endif
810 "unevictable_pgs_culled",
811 "unevictable_pgs_scanned",
812 "unevictable_pgs_rescued",
813 "unevictable_pgs_mlocked",
814 "unevictable_pgs_munlocked",
815 "unevictable_pgs_cleared",
816 "unevictable_pgs_stranded",
817
818 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
819 "thp_fault_alloc",
820 "thp_fault_fallback",
821 "thp_collapse_alloc",
822 "thp_collapse_alloc_failed",
823 "thp_split",
824 "thp_zero_page_alloc",
825 "thp_zero_page_alloc_failed",
826 #endif
827 #ifdef CONFIG_MEMORY_BALLOON
828 "balloon_inflate",
829 "balloon_deflate",
830 #ifdef CONFIG_BALLOON_COMPACTION
831 "balloon_migrate",
832 #endif
833 #endif /* CONFIG_MEMORY_BALLOON */
834 #ifdef CONFIG_DEBUG_TLBFLUSH
835 #ifdef CONFIG_SMP
836 "nr_tlb_remote_flush",
837 "nr_tlb_remote_flush_received",
838 #endif /* CONFIG_SMP */
839 "nr_tlb_local_flush_all",
840 "nr_tlb_local_flush_one",
841 #endif /* CONFIG_DEBUG_TLBFLUSH */
842
843 #ifdef CONFIG_DEBUG_VM_VMACACHE
844 "vmacache_find_calls",
845 "vmacache_find_hits",
846 "vmacache_full_flushes",
847 #endif
848 #endif /* CONFIG_VM_EVENTS_COUNTERS */
849 };
850 #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
851
852
853 #if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
854 defined(CONFIG_PROC_FS)
855 static void *frag_start(struct seq_file *m, loff_t *pos)
856 {
857 pg_data_t *pgdat;
858 loff_t node = *pos;
859
860 for (pgdat = first_online_pgdat();
861 pgdat && node;
862 pgdat = next_online_pgdat(pgdat))
863 --node;
864
865 return pgdat;
866 }
867
868 static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
869 {
870 pg_data_t *pgdat = (pg_data_t *)arg;
871
872 (*pos)++;
873 return next_online_pgdat(pgdat);
874 }
875
876 static void frag_stop(struct seq_file *m, void *arg)
877 {
878 }
879
880 /* Walk all the zones in a node and print using a callback */
881 static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
882 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
883 {
884 struct zone *zone;
885 struct zone *node_zones = pgdat->node_zones;
886 unsigned long flags;
887
888 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
889 if (!populated_zone(zone))
890 continue;
891
892 spin_lock_irqsave(&zone->lock, flags);
893 print(m, pgdat, zone);
894 spin_unlock_irqrestore(&zone->lock, flags);
895 }
896 }
897 #endif
898
899 #ifdef CONFIG_PROC_FS
900 static char * const migratetype_names[MIGRATE_TYPES] = {
901 "Unmovable",
902 "Reclaimable",
903 "Movable",
904 "Reserve",
905 #ifdef CONFIG_CMA
906 "CMA",
907 #endif
908 #ifdef CONFIG_MEMORY_ISOLATION
909 "Isolate",
910 #endif
911 };
912
913 static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
914 struct zone *zone)
915 {
916 int order;
917
918 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
919 for (order = 0; order < MAX_ORDER; ++order)
920 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
921 seq_putc(m, '\n');
922 }
923
924 /*
925 * This walks the free areas for each zone.
926 */
927 static int frag_show(struct seq_file *m, void *arg)
928 {
929 pg_data_t *pgdat = (pg_data_t *)arg;
930 walk_zones_in_node(m, pgdat, frag_show_print);
931 return 0;
932 }
933
934 static void pagetypeinfo_showfree_print(struct seq_file *m,
935 pg_data_t *pgdat, struct zone *zone)
936 {
937 int order, mtype;
938
939 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
940 seq_printf(m, "Node %4d, zone %8s, type %12s ",
941 pgdat->node_id,
942 zone->name,
943 migratetype_names[mtype]);
944 for (order = 0; order < MAX_ORDER; ++order) {
945 unsigned long freecount = 0;
946 struct free_area *area;
947 struct list_head *curr;
948
949 area = &(zone->free_area[order]);
950
951 list_for_each(curr, &area->free_list[mtype])
952 freecount++;
953 seq_printf(m, "%6lu ", freecount);
954 }
955 seq_putc(m, '\n');
956 }
957 }
958
959 /* Print out the free pages at each order for each migatetype */
960 static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
961 {
962 int order;
963 pg_data_t *pgdat = (pg_data_t *)arg;
964
965 /* Print header */
966 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
967 for (order = 0; order < MAX_ORDER; ++order)
968 seq_printf(m, "%6d ", order);
969 seq_putc(m, '\n');
970
971 walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
972
973 return 0;
974 }
975
976 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
977 pg_data_t *pgdat, struct zone *zone)
978 {
979 int mtype;
980 unsigned long pfn;
981 unsigned long start_pfn = zone->zone_start_pfn;
982 unsigned long end_pfn = zone_end_pfn(zone);
983 unsigned long count[MIGRATE_TYPES] = { 0, };
984
985 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
986 struct page *page;
987
988 if (!pfn_valid(pfn))
989 continue;
990
991 page = pfn_to_page(pfn);
992
993 /* Watch for unexpected holes punched in the memmap */
994 if (!memmap_valid_within(pfn, page, zone))
995 continue;
996
997 mtype = get_pageblock_migratetype(page);
998
999 if (mtype < MIGRATE_TYPES)
1000 count[mtype]++;
1001 }
1002
1003 /* Print counts */
1004 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1005 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1006 seq_printf(m, "%12lu ", count[mtype]);
1007 seq_putc(m, '\n');
1008 }
1009
1010 /* Print out the free pages at each order for each migratetype */
1011 static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
1012 {
1013 int mtype;
1014 pg_data_t *pgdat = (pg_data_t *)arg;
1015
1016 seq_printf(m, "\n%-23s", "Number of blocks type ");
1017 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1018 seq_printf(m, "%12s ", migratetype_names[mtype]);
1019 seq_putc(m, '\n');
1020 walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
1021
1022 return 0;
1023 }
1024
1025 #ifdef CONFIG_PAGE_OWNER
1026 static void pagetypeinfo_showmixedcount_print(struct seq_file *m,
1027 pg_data_t *pgdat,
1028 struct zone *zone)
1029 {
1030 struct page *page;
1031 struct page_ext *page_ext;
1032 unsigned long pfn = zone->zone_start_pfn, block_end_pfn;
1033 unsigned long end_pfn = pfn + zone->spanned_pages;
1034 unsigned long count[MIGRATE_TYPES] = { 0, };
1035 int pageblock_mt, page_mt;
1036 int i;
1037
1038 /* Scan block by block. First and last block may be incomplete */
1039 pfn = zone->zone_start_pfn;
1040
1041 /*
1042 * Walk the zone in pageblock_nr_pages steps. If a page block spans
1043 * a zone boundary, it will be double counted between zones. This does
1044 * not matter as the mixed block count will still be correct
1045 */
1046 for (; pfn < end_pfn; ) {
1047 if (!pfn_valid(pfn)) {
1048 pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
1049 continue;
1050 }
1051
1052 block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages);
1053 block_end_pfn = min(block_end_pfn, end_pfn);
1054
1055 page = pfn_to_page(pfn);
1056 pageblock_mt = get_pfnblock_migratetype(page, pfn);
1057
1058 for (; pfn < block_end_pfn; pfn++) {
1059 if (!pfn_valid_within(pfn))
1060 continue;
1061
1062 page = pfn_to_page(pfn);
1063 if (PageBuddy(page)) {
1064 pfn += (1UL << page_order(page)) - 1;
1065 continue;
1066 }
1067
1068 if (PageReserved(page))
1069 continue;
1070
1071 page_ext = lookup_page_ext(page);
1072
1073 if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags))
1074 continue;
1075
1076 page_mt = gfpflags_to_migratetype(page_ext->gfp_mask);
1077 if (pageblock_mt != page_mt) {
1078 if (is_migrate_cma(pageblock_mt))
1079 count[MIGRATE_MOVABLE]++;
1080 else
1081 count[pageblock_mt]++;
1082
1083 pfn = block_end_pfn;
1084 break;
1085 }
1086 pfn += (1UL << page_ext->order) - 1;
1087 }
1088 }
1089
1090 /* Print counts */
1091 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
1092 for (i = 0; i < MIGRATE_TYPES; i++)
1093 seq_printf(m, "%12lu ", count[i]);
1094 seq_putc(m, '\n');
1095 }
1096 #endif /* CONFIG_PAGE_OWNER */
1097
1098 /*
1099 * Print out the number of pageblocks for each migratetype that contain pages
1100 * of other types. This gives an indication of how well fallbacks are being
1101 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER
1102 * to determine what is going on
1103 */
1104 static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat)
1105 {
1106 #ifdef CONFIG_PAGE_OWNER
1107 int mtype;
1108
1109 if (!page_owner_inited)
1110 return;
1111
1112 drain_all_pages(NULL);
1113
1114 seq_printf(m, "\n%-23s", "Number of mixed blocks ");
1115 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
1116 seq_printf(m, "%12s ", migratetype_names[mtype]);
1117 seq_putc(m, '\n');
1118
1119 walk_zones_in_node(m, pgdat, pagetypeinfo_showmixedcount_print);
1120 #endif /* CONFIG_PAGE_OWNER */
1121 }
1122
1123 /*
1124 * This prints out statistics in relation to grouping pages by mobility.
1125 * It is expensive to collect so do not constantly read the file.
1126 */
1127 static int pagetypeinfo_show(struct seq_file *m, void *arg)
1128 {
1129 pg_data_t *pgdat = (pg_data_t *)arg;
1130
1131 /* check memoryless node */
1132 if (!node_state(pgdat->node_id, N_MEMORY))
1133 return 0;
1134
1135 seq_printf(m, "Page block order: %d\n", pageblock_order);
1136 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
1137 seq_putc(m, '\n');
1138 pagetypeinfo_showfree(m, pgdat);
1139 pagetypeinfo_showblockcount(m, pgdat);
1140 pagetypeinfo_showmixedcount(m, pgdat);
1141
1142 return 0;
1143 }
1144
1145 static const struct seq_operations fragmentation_op = {
1146 .start = frag_start,
1147 .next = frag_next,
1148 .stop = frag_stop,
1149 .show = frag_show,
1150 };
1151
1152 static int fragmentation_open(struct inode *inode, struct file *file)
1153 {
1154 return seq_open(file, &fragmentation_op);
1155 }
1156
1157 static const struct file_operations fragmentation_file_operations = {
1158 .open = fragmentation_open,
1159 .read = seq_read,
1160 .llseek = seq_lseek,
1161 .release = seq_release,
1162 };
1163
1164 static const struct seq_operations pagetypeinfo_op = {
1165 .start = frag_start,
1166 .next = frag_next,
1167 .stop = frag_stop,
1168 .show = pagetypeinfo_show,
1169 };
1170
1171 static int pagetypeinfo_open(struct inode *inode, struct file *file)
1172 {
1173 return seq_open(file, &pagetypeinfo_op);
1174 }
1175
1176 static const struct file_operations pagetypeinfo_file_ops = {
1177 .open = pagetypeinfo_open,
1178 .read = seq_read,
1179 .llseek = seq_lseek,
1180 .release = seq_release,
1181 };
1182
1183 static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
1184 struct zone *zone)
1185 {
1186 int i;
1187 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
1188 seq_printf(m,
1189 "\n pages free %lu"
1190 "\n min %lu"
1191 "\n low %lu"
1192 "\n high %lu"
1193 "\n scanned %lu"
1194 "\n spanned %lu"
1195 "\n present %lu"
1196 "\n managed %lu",
1197 zone_page_state(zone, NR_FREE_PAGES),
1198 min_wmark_pages(zone),
1199 low_wmark_pages(zone),
1200 high_wmark_pages(zone),
1201 zone_page_state(zone, NR_PAGES_SCANNED),
1202 zone->spanned_pages,
1203 zone->present_pages,
1204 zone->managed_pages);
1205
1206 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1207 seq_printf(m, "\n %-12s %lu", vmstat_text[i],
1208 zone_page_state(zone, i));
1209
1210 seq_printf(m,
1211 "\n protection: (%ld",
1212 zone->lowmem_reserve[0]);
1213 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1214 seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
1215 seq_printf(m,
1216 ")"
1217 "\n pagesets");
1218 for_each_online_cpu(i) {
1219 struct per_cpu_pageset *pageset;
1220
1221 pageset = per_cpu_ptr(zone->pageset, i);
1222 seq_printf(m,
1223 "\n cpu: %i"
1224 "\n count: %i"
1225 "\n high: %i"
1226 "\n batch: %i",
1227 i,
1228 pageset->pcp.count,
1229 pageset->pcp.high,
1230 pageset->pcp.batch);
1231 #ifdef CONFIG_SMP
1232 seq_printf(m, "\n vm stats threshold: %d",
1233 pageset->stat_threshold);
1234 #endif
1235 }
1236 seq_printf(m,
1237 "\n all_unreclaimable: %u"
1238 "\n start_pfn: %lu"
1239 "\n inactive_ratio: %u",
1240 !zone_reclaimable(zone),
1241 zone->zone_start_pfn,
1242 zone->inactive_ratio);
1243 seq_putc(m, '\n');
1244 }
1245
1246 /*
1247 * Output information about zones in @pgdat.
1248 */
1249 static int zoneinfo_show(struct seq_file *m, void *arg)
1250 {
1251 pg_data_t *pgdat = (pg_data_t *)arg;
1252 walk_zones_in_node(m, pgdat, zoneinfo_show_print);
1253 return 0;
1254 }
1255
1256 static const struct seq_operations zoneinfo_op = {
1257 .start = frag_start, /* iterate over all zones. The same as in
1258 * fragmentation. */
1259 .next = frag_next,
1260 .stop = frag_stop,
1261 .show = zoneinfo_show,
1262 };
1263
1264 static int zoneinfo_open(struct inode *inode, struct file *file)
1265 {
1266 return seq_open(file, &zoneinfo_op);
1267 }
1268
1269 static const struct file_operations proc_zoneinfo_file_operations = {
1270 .open = zoneinfo_open,
1271 .read = seq_read,
1272 .llseek = seq_lseek,
1273 .release = seq_release,
1274 };
1275
1276 enum writeback_stat_item {
1277 NR_DIRTY_THRESHOLD,
1278 NR_DIRTY_BG_THRESHOLD,
1279 NR_VM_WRITEBACK_STAT_ITEMS,
1280 };
1281
1282 static void *vmstat_start(struct seq_file *m, loff_t *pos)
1283 {
1284 unsigned long *v;
1285 int i, stat_items_size;
1286
1287 if (*pos >= ARRAY_SIZE(vmstat_text))
1288 return NULL;
1289 stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1290 NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1291
1292 #ifdef CONFIG_VM_EVENT_COUNTERS
1293 stat_items_size += sizeof(struct vm_event_state);
1294 #endif
1295
1296 v = kmalloc(stat_items_size, GFP_KERNEL);
1297 m->private = v;
1298 if (!v)
1299 return ERR_PTR(-ENOMEM);
1300 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1301 v[i] = global_page_state(i);
1302 v += NR_VM_ZONE_STAT_ITEMS;
1303
1304 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1305 v + NR_DIRTY_THRESHOLD);
1306 v += NR_VM_WRITEBACK_STAT_ITEMS;
1307
1308 #ifdef CONFIG_VM_EVENT_COUNTERS
1309 all_vm_events(v);
1310 v[PGPGIN] /= 2; /* sectors -> kbytes */
1311 v[PGPGOUT] /= 2;
1312 #endif
1313 return (unsigned long *)m->private + *pos;
1314 }
1315
1316 static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1317 {
1318 (*pos)++;
1319 if (*pos >= ARRAY_SIZE(vmstat_text))
1320 return NULL;
1321 return (unsigned long *)m->private + *pos;
1322 }
1323
1324 static int vmstat_show(struct seq_file *m, void *arg)
1325 {
1326 unsigned long *l = arg;
1327 unsigned long off = l - (unsigned long *)m->private;
1328
1329 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1330 return 0;
1331 }
1332
1333 static void vmstat_stop(struct seq_file *m, void *arg)
1334 {
1335 kfree(m->private);
1336 m->private = NULL;
1337 }
1338
1339 static const struct seq_operations vmstat_op = {
1340 .start = vmstat_start,
1341 .next = vmstat_next,
1342 .stop = vmstat_stop,
1343 .show = vmstat_show,
1344 };
1345
1346 static int vmstat_open(struct inode *inode, struct file *file)
1347 {
1348 return seq_open(file, &vmstat_op);
1349 }
1350
1351 static const struct file_operations proc_vmstat_file_operations = {
1352 .open = vmstat_open,
1353 .read = seq_read,
1354 .llseek = seq_lseek,
1355 .release = seq_release,
1356 };
1357 #endif /* CONFIG_PROC_FS */
1358
1359 #ifdef CONFIG_SMP
1360 static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1361 int sysctl_stat_interval __read_mostly = HZ;
1362 static cpumask_var_t cpu_stat_off;
1363
1364 static void vmstat_update(struct work_struct *w)
1365 {
1366 if (refresh_cpu_vm_stats())
1367 /*
1368 * Counters were updated so we expect more updates
1369 * to occur in the future. Keep on running the
1370 * update worker thread.
1371 */
1372 schedule_delayed_work(this_cpu_ptr(&vmstat_work),
1373 round_jiffies_relative(sysctl_stat_interval));
1374 else {
1375 /*
1376 * We did not update any counters so the app may be in
1377 * a mode where it does not cause counter updates.
1378 * We may be uselessly running vmstat_update.
1379 * Defer the checking for differentials to the
1380 * shepherd thread on a different processor.
1381 */
1382 int r;
1383 /*
1384 * Shepherd work thread does not race since it never
1385 * changes the bit if its zero but the cpu
1386 * online / off line code may race if
1387 * worker threads are still allowed during
1388 * shutdown / startup.
1389 */
1390 r = cpumask_test_and_set_cpu(smp_processor_id(),
1391 cpu_stat_off);
1392 VM_BUG_ON(r);
1393 }
1394 }
1395
1396 /*
1397 * Check if the diffs for a certain cpu indicate that
1398 * an update is needed.
1399 */
1400 static bool need_update(int cpu)
1401 {
1402 struct zone *zone;
1403
1404 for_each_populated_zone(zone) {
1405 struct per_cpu_pageset *p = per_cpu_ptr(zone->pageset, cpu);
1406
1407 BUILD_BUG_ON(sizeof(p->vm_stat_diff[0]) != 1);
1408 /*
1409 * The fast way of checking if there are any vmstat diffs.
1410 * This works because the diffs are byte sized items.
1411 */
1412 if (memchr_inv(p->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS))
1413 return true;
1414
1415 }
1416 return false;
1417 }
1418
1419
1420 /*
1421 * Shepherd worker thread that checks the
1422 * differentials of processors that have their worker
1423 * threads for vm statistics updates disabled because of
1424 * inactivity.
1425 */
1426 static void vmstat_shepherd(struct work_struct *w);
1427
1428 static DECLARE_DELAYED_WORK(shepherd, vmstat_shepherd);
1429
1430 static void vmstat_shepherd(struct work_struct *w)
1431 {
1432 int cpu;
1433
1434 get_online_cpus();
1435 /* Check processors whose vmstat worker threads have been disabled */
1436 for_each_cpu(cpu, cpu_stat_off)
1437 if (need_update(cpu) &&
1438 cpumask_test_and_clear_cpu(cpu, cpu_stat_off))
1439
1440 schedule_delayed_work_on(cpu,
1441 &per_cpu(vmstat_work, cpu), 0);
1442
1443 put_online_cpus();
1444
1445 schedule_delayed_work(&shepherd,
1446 round_jiffies_relative(sysctl_stat_interval));
1447
1448 }
1449
1450 static void __init start_shepherd_timer(void)
1451 {
1452 int cpu;
1453
1454 for_each_possible_cpu(cpu)
1455 INIT_DELAYED_WORK(per_cpu_ptr(&vmstat_work, cpu),
1456 vmstat_update);
1457
1458 if (!alloc_cpumask_var(&cpu_stat_off, GFP_KERNEL))
1459 BUG();
1460 cpumask_copy(cpu_stat_off, cpu_online_mask);
1461
1462 schedule_delayed_work(&shepherd,
1463 round_jiffies_relative(sysctl_stat_interval));
1464 }
1465
1466 static void vmstat_cpu_dead(int node)
1467 {
1468 int cpu;
1469
1470 get_online_cpus();
1471 for_each_online_cpu(cpu)
1472 if (cpu_to_node(cpu) == node)
1473 goto end;
1474
1475 node_clear_state(node, N_CPU);
1476 end:
1477 put_online_cpus();
1478 }
1479
1480 /*
1481 * Use the cpu notifier to insure that the thresholds are recalculated
1482 * when necessary.
1483 */
1484 static int vmstat_cpuup_callback(struct notifier_block *nfb,
1485 unsigned long action,
1486 void *hcpu)
1487 {
1488 long cpu = (long)hcpu;
1489
1490 switch (action) {
1491 case CPU_ONLINE:
1492 case CPU_ONLINE_FROZEN:
1493 refresh_zone_stat_thresholds();
1494 node_set_state(cpu_to_node(cpu), N_CPU);
1495 cpumask_set_cpu(cpu, cpu_stat_off);
1496 break;
1497 case CPU_DOWN_PREPARE:
1498 case CPU_DOWN_PREPARE_FROZEN:
1499 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1500 cpumask_clear_cpu(cpu, cpu_stat_off);
1501 break;
1502 case CPU_DOWN_FAILED:
1503 case CPU_DOWN_FAILED_FROZEN:
1504 cpumask_set_cpu(cpu, cpu_stat_off);
1505 break;
1506 case CPU_DEAD:
1507 case CPU_DEAD_FROZEN:
1508 refresh_zone_stat_thresholds();
1509 vmstat_cpu_dead(cpu_to_node(cpu));
1510 break;
1511 default:
1512 break;
1513 }
1514 return NOTIFY_OK;
1515 }
1516
1517 static struct notifier_block vmstat_notifier =
1518 { &vmstat_cpuup_callback, NULL, 0 };
1519 #endif
1520
1521 static int __init setup_vmstat(void)
1522 {
1523 #ifdef CONFIG_SMP
1524 cpu_notifier_register_begin();
1525 __register_cpu_notifier(&vmstat_notifier);
1526
1527 start_shepherd_timer();
1528 cpu_notifier_register_done();
1529 #endif
1530 #ifdef CONFIG_PROC_FS
1531 proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1532 proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1533 proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1534 proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1535 #endif
1536 return 0;
1537 }
1538 module_init(setup_vmstat)
1539
1540 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1541
1542 /*
1543 * Return an index indicating how much of the available free memory is
1544 * unusable for an allocation of the requested size.
1545 */
1546 static int unusable_free_index(unsigned int order,
1547 struct contig_page_info *info)
1548 {
1549 /* No free memory is interpreted as all free memory is unusable */
1550 if (info->free_pages == 0)
1551 return 1000;
1552
1553 /*
1554 * Index should be a value between 0 and 1. Return a value to 3
1555 * decimal places.
1556 *
1557 * 0 => no fragmentation
1558 * 1 => high fragmentation
1559 */
1560 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1561
1562 }
1563
1564 static void unusable_show_print(struct seq_file *m,
1565 pg_data_t *pgdat, struct zone *zone)
1566 {
1567 unsigned int order;
1568 int index;
1569 struct contig_page_info info;
1570
1571 seq_printf(m, "Node %d, zone %8s ",
1572 pgdat->node_id,
1573 zone->name);
1574 for (order = 0; order < MAX_ORDER; ++order) {
1575 fill_contig_page_info(zone, order, &info);
1576 index = unusable_free_index(order, &info);
1577 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1578 }
1579
1580 seq_putc(m, '\n');
1581 }
1582
1583 /*
1584 * Display unusable free space index
1585 *
1586 * The unusable free space index measures how much of the available free
1587 * memory cannot be used to satisfy an allocation of a given size and is a
1588 * value between 0 and 1. The higher the value, the more of free memory is
1589 * unusable and by implication, the worse the external fragmentation is. This
1590 * can be expressed as a percentage by multiplying by 100.
1591 */
1592 static int unusable_show(struct seq_file *m, void *arg)
1593 {
1594 pg_data_t *pgdat = (pg_data_t *)arg;
1595
1596 /* check memoryless node */
1597 if (!node_state(pgdat->node_id, N_MEMORY))
1598 return 0;
1599
1600 walk_zones_in_node(m, pgdat, unusable_show_print);
1601
1602 return 0;
1603 }
1604
1605 static const struct seq_operations unusable_op = {
1606 .start = frag_start,
1607 .next = frag_next,
1608 .stop = frag_stop,
1609 .show = unusable_show,
1610 };
1611
1612 static int unusable_open(struct inode *inode, struct file *file)
1613 {
1614 return seq_open(file, &unusable_op);
1615 }
1616
1617 static const struct file_operations unusable_file_ops = {
1618 .open = unusable_open,
1619 .read = seq_read,
1620 .llseek = seq_lseek,
1621 .release = seq_release,
1622 };
1623
1624 static void extfrag_show_print(struct seq_file *m,
1625 pg_data_t *pgdat, struct zone *zone)
1626 {
1627 unsigned int order;
1628 int index;
1629
1630 /* Alloc on stack as interrupts are disabled for zone walk */
1631 struct contig_page_info info;
1632
1633 seq_printf(m, "Node %d, zone %8s ",
1634 pgdat->node_id,
1635 zone->name);
1636 for (order = 0; order < MAX_ORDER; ++order) {
1637 fill_contig_page_info(zone, order, &info);
1638 index = __fragmentation_index(order, &info);
1639 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1640 }
1641
1642 seq_putc(m, '\n');
1643 }
1644
1645 /*
1646 * Display fragmentation index for orders that allocations would fail for
1647 */
1648 static int extfrag_show(struct seq_file *m, void *arg)
1649 {
1650 pg_data_t *pgdat = (pg_data_t *)arg;
1651
1652 walk_zones_in_node(m, pgdat, extfrag_show_print);
1653
1654 return 0;
1655 }
1656
1657 static const struct seq_operations extfrag_op = {
1658 .start = frag_start,
1659 .next = frag_next,
1660 .stop = frag_stop,
1661 .show = extfrag_show,
1662 };
1663
1664 static int extfrag_open(struct inode *inode, struct file *file)
1665 {
1666 return seq_open(file, &extfrag_op);
1667 }
1668
1669 static const struct file_operations extfrag_file_ops = {
1670 .open = extfrag_open,
1671 .read = seq_read,
1672 .llseek = seq_lseek,
1673 .release = seq_release,
1674 };
1675
1676 static int __init extfrag_debug_init(void)
1677 {
1678 struct dentry *extfrag_debug_root;
1679
1680 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1681 if (!extfrag_debug_root)
1682 return -ENOMEM;
1683
1684 if (!debugfs_create_file("unusable_index", 0444,
1685 extfrag_debug_root, NULL, &unusable_file_ops))
1686 goto fail;
1687
1688 if (!debugfs_create_file("extfrag_index", 0444,
1689 extfrag_debug_root, NULL, &extfrag_file_ops))
1690 goto fail;
1691
1692 return 0;
1693 fail:
1694 debugfs_remove_recursive(extfrag_debug_root);
1695 return -ENOMEM;
1696 }
1697
1698 module_init(extfrag_debug_init);
1699 #endif