1 // SPDX-License-Identifier: GPL-2.0-only
5 * Manages VM statistics
6 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
9 * Copyright (C) 2006 Silicon Graphics, Inc.,
10 * Christoph Lameter <christoph@lameter.com>
11 * Copyright (C) 2008-2014 Christoph Lameter
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>
35 int sysctl_vm_numa_stat
= ENABLE_NUMA_STAT
;
37 /* zero numa counters within a zone */
38 static void zero_zone_numa_counters(struct zone
*zone
)
42 for (item
= 0; item
< NR_VM_NUMA_EVENT_ITEMS
; item
++) {
43 atomic_long_set(&zone
->vm_numa_event
[item
], 0);
44 for_each_online_cpu(cpu
) {
45 per_cpu_ptr(zone
->per_cpu_zonestats
, cpu
)->vm_numa_event
[item
]
51 /* zero numa counters of all the populated zones */
52 static void zero_zones_numa_counters(void)
56 for_each_populated_zone(zone
)
57 zero_zone_numa_counters(zone
);
60 /* zero global numa counters */
61 static void zero_global_numa_counters(void)
65 for (item
= 0; item
< NR_VM_NUMA_EVENT_ITEMS
; item
++)
66 atomic_long_set(&vm_numa_event
[item
], 0);
69 static void invalid_numa_statistics(void)
71 zero_zones_numa_counters();
72 zero_global_numa_counters();
75 static DEFINE_MUTEX(vm_numa_stat_lock
);
77 int sysctl_vm_numa_stat_handler(struct ctl_table
*table
, int write
,
78 void *buffer
, size_t *length
, loff_t
*ppos
)
82 mutex_lock(&vm_numa_stat_lock
);
84 oldval
= sysctl_vm_numa_stat
;
85 ret
= proc_dointvec_minmax(table
, write
, buffer
, length
, ppos
);
89 if (oldval
== sysctl_vm_numa_stat
)
91 else if (sysctl_vm_numa_stat
== ENABLE_NUMA_STAT
) {
92 static_branch_enable(&vm_numa_stat_key
);
93 pr_info("enable numa statistics\n");
95 static_branch_disable(&vm_numa_stat_key
);
96 invalid_numa_statistics();
97 pr_info("disable numa statistics, and clear numa counters\n");
101 mutex_unlock(&vm_numa_stat_lock
);
106 #ifdef CONFIG_VM_EVENT_COUNTERS
107 DEFINE_PER_CPU(struct vm_event_state
, vm_event_states
) = {{0}};
108 EXPORT_PER_CPU_SYMBOL(vm_event_states
);
110 static void sum_vm_events(unsigned long *ret
)
115 memset(ret
, 0, NR_VM_EVENT_ITEMS
* sizeof(unsigned long));
117 for_each_online_cpu(cpu
) {
118 struct vm_event_state
*this = &per_cpu(vm_event_states
, cpu
);
120 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++)
121 ret
[i
] += this->event
[i
];
126 * Accumulate the vm event counters across all CPUs.
127 * The result is unavoidably approximate - it can change
128 * during and after execution of this function.
130 void all_vm_events(unsigned long *ret
)
136 EXPORT_SYMBOL_GPL(all_vm_events
);
139 * Fold the foreign cpu events into our own.
141 * This is adding to the events on one processor
142 * but keeps the global counts constant.
144 void vm_events_fold_cpu(int cpu
)
146 struct vm_event_state
*fold_state
= &per_cpu(vm_event_states
, cpu
);
149 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++) {
150 count_vm_events(i
, fold_state
->event
[i
]);
151 fold_state
->event
[i
] = 0;
155 #endif /* CONFIG_VM_EVENT_COUNTERS */
158 * Manage combined zone based / global counters
160 * vm_stat contains the global counters
162 atomic_long_t vm_zone_stat
[NR_VM_ZONE_STAT_ITEMS
] __cacheline_aligned_in_smp
;
163 atomic_long_t vm_node_stat
[NR_VM_NODE_STAT_ITEMS
] __cacheline_aligned_in_smp
;
164 atomic_long_t vm_numa_event
[NR_VM_NUMA_EVENT_ITEMS
] __cacheline_aligned_in_smp
;
165 EXPORT_SYMBOL(vm_zone_stat
);
166 EXPORT_SYMBOL(vm_node_stat
);
170 int calculate_pressure_threshold(struct zone
*zone
)
173 int watermark_distance
;
176 * As vmstats are not up to date, there is drift between the estimated
177 * and real values. For high thresholds and a high number of CPUs, it
178 * is possible for the min watermark to be breached while the estimated
179 * value looks fine. The pressure threshold is a reduced value such
180 * that even the maximum amount of drift will not accidentally breach
183 watermark_distance
= low_wmark_pages(zone
) - min_wmark_pages(zone
);
184 threshold
= max(1, (int)(watermark_distance
/ num_online_cpus()));
187 * Maximum threshold is 125
189 threshold
= min(125, threshold
);
194 int calculate_normal_threshold(struct zone
*zone
)
197 int mem
; /* memory in 128 MB units */
200 * The threshold scales with the number of processors and the amount
201 * of memory per zone. More memory means that we can defer updates for
202 * longer, more processors could lead to more contention.
203 * fls() is used to have a cheap way of logarithmic scaling.
205 * Some sample thresholds:
207 * Threshold Processors (fls) Zonesize fls(mem)+1
208 * ------------------------------------------------------------------
225 * 125 1024 10 8-16 GB 8
226 * 125 1024 10 16-32 GB 9
229 mem
= zone_managed_pages(zone
) >> (27 - PAGE_SHIFT
);
231 threshold
= 2 * fls(num_online_cpus()) * (1 + fls(mem
));
234 * Maximum threshold is 125
236 threshold
= min(125, threshold
);
242 * Refresh the thresholds for each zone.
244 void refresh_zone_stat_thresholds(void)
246 struct pglist_data
*pgdat
;
251 /* Zero current pgdat thresholds */
252 for_each_online_pgdat(pgdat
) {
253 for_each_online_cpu(cpu
) {
254 per_cpu_ptr(pgdat
->per_cpu_nodestats
, cpu
)->stat_threshold
= 0;
258 for_each_populated_zone(zone
) {
259 struct pglist_data
*pgdat
= zone
->zone_pgdat
;
260 unsigned long max_drift
, tolerate_drift
;
262 threshold
= calculate_normal_threshold(zone
);
264 for_each_online_cpu(cpu
) {
267 per_cpu_ptr(zone
->per_cpu_zonestats
, cpu
)->stat_threshold
270 /* Base nodestat threshold on the largest populated zone. */
271 pgdat_threshold
= per_cpu_ptr(pgdat
->per_cpu_nodestats
, cpu
)->stat_threshold
;
272 per_cpu_ptr(pgdat
->per_cpu_nodestats
, cpu
)->stat_threshold
273 = max(threshold
, pgdat_threshold
);
277 * Only set percpu_drift_mark if there is a danger that
278 * NR_FREE_PAGES reports the low watermark is ok when in fact
279 * the min watermark could be breached by an allocation
281 tolerate_drift
= low_wmark_pages(zone
) - min_wmark_pages(zone
);
282 max_drift
= num_online_cpus() * threshold
;
283 if (max_drift
> tolerate_drift
)
284 zone
->percpu_drift_mark
= high_wmark_pages(zone
) +
289 void set_pgdat_percpu_threshold(pg_data_t
*pgdat
,
290 int (*calculate_pressure
)(struct zone
*))
297 for (i
= 0; i
< pgdat
->nr_zones
; i
++) {
298 zone
= &pgdat
->node_zones
[i
];
299 if (!zone
->percpu_drift_mark
)
302 threshold
= (*calculate_pressure
)(zone
);
303 for_each_online_cpu(cpu
)
304 per_cpu_ptr(zone
->per_cpu_zonestats
, cpu
)->stat_threshold
310 * For use when we know that interrupts are disabled,
311 * or when we know that preemption is disabled and that
312 * particular counter cannot be updated from interrupt context.
314 void __mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
317 struct per_cpu_zonestat __percpu
*pcp
= zone
->per_cpu_zonestats
;
318 s8 __percpu
*p
= pcp
->vm_stat_diff
+ item
;
322 x
= delta
+ __this_cpu_read(*p
);
324 t
= __this_cpu_read(pcp
->stat_threshold
);
326 if (unlikely(abs(x
) > t
)) {
327 zone_page_state_add(x
, zone
, item
);
330 __this_cpu_write(*p
, x
);
332 EXPORT_SYMBOL(__mod_zone_page_state
);
334 void __mod_node_page_state(struct pglist_data
*pgdat
, enum node_stat_item item
,
337 struct per_cpu_nodestat __percpu
*pcp
= pgdat
->per_cpu_nodestats
;
338 s8 __percpu
*p
= pcp
->vm_node_stat_diff
+ item
;
342 if (vmstat_item_in_bytes(item
)) {
344 * Only cgroups use subpage accounting right now; at
345 * the global level, these items still change in
346 * multiples of whole pages. Store them as pages
347 * internally to keep the per-cpu counters compact.
349 VM_WARN_ON_ONCE(delta
& (PAGE_SIZE
- 1));
350 delta
>>= PAGE_SHIFT
;
353 x
= delta
+ __this_cpu_read(*p
);
355 t
= __this_cpu_read(pcp
->stat_threshold
);
357 if (unlikely(abs(x
) > t
)) {
358 node_page_state_add(x
, pgdat
, item
);
361 __this_cpu_write(*p
, x
);
363 EXPORT_SYMBOL(__mod_node_page_state
);
366 * Optimized increment and decrement functions.
368 * These are only for a single page and therefore can take a struct page *
369 * argument instead of struct zone *. This allows the inclusion of the code
370 * generated for page_zone(page) into the optimized functions.
372 * No overflow check is necessary and therefore the differential can be
373 * incremented or decremented in place which may allow the compilers to
374 * generate better code.
375 * The increment or decrement is known and therefore one boundary check can
378 * NOTE: These functions are very performance sensitive. Change only
381 * Some processors have inc/dec instructions that are atomic vs an interrupt.
382 * However, the code must first determine the differential location in a zone
383 * based on the processor number and then inc/dec the counter. There is no
384 * guarantee without disabling preemption that the processor will not change
385 * in between and therefore the atomicity vs. interrupt cannot be exploited
386 * in a useful way here.
388 void __inc_zone_state(struct zone
*zone
, enum zone_stat_item item
)
390 struct per_cpu_zonestat __percpu
*pcp
= zone
->per_cpu_zonestats
;
391 s8 __percpu
*p
= pcp
->vm_stat_diff
+ item
;
394 v
= __this_cpu_inc_return(*p
);
395 t
= __this_cpu_read(pcp
->stat_threshold
);
396 if (unlikely(v
> t
)) {
397 s8 overstep
= t
>> 1;
399 zone_page_state_add(v
+ overstep
, zone
, item
);
400 __this_cpu_write(*p
, -overstep
);
404 void __inc_node_state(struct pglist_data
*pgdat
, enum node_stat_item item
)
406 struct per_cpu_nodestat __percpu
*pcp
= pgdat
->per_cpu_nodestats
;
407 s8 __percpu
*p
= pcp
->vm_node_stat_diff
+ item
;
410 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item
));
412 v
= __this_cpu_inc_return(*p
);
413 t
= __this_cpu_read(pcp
->stat_threshold
);
414 if (unlikely(v
> t
)) {
415 s8 overstep
= t
>> 1;
417 node_page_state_add(v
+ overstep
, pgdat
, item
);
418 __this_cpu_write(*p
, -overstep
);
422 void __inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
424 __inc_zone_state(page_zone(page
), item
);
426 EXPORT_SYMBOL(__inc_zone_page_state
);
428 void __inc_node_page_state(struct page
*page
, enum node_stat_item item
)
430 __inc_node_state(page_pgdat(page
), item
);
432 EXPORT_SYMBOL(__inc_node_page_state
);
434 void __dec_zone_state(struct zone
*zone
, enum zone_stat_item item
)
436 struct per_cpu_zonestat __percpu
*pcp
= zone
->per_cpu_zonestats
;
437 s8 __percpu
*p
= pcp
->vm_stat_diff
+ item
;
440 v
= __this_cpu_dec_return(*p
);
441 t
= __this_cpu_read(pcp
->stat_threshold
);
442 if (unlikely(v
< - t
)) {
443 s8 overstep
= t
>> 1;
445 zone_page_state_add(v
- overstep
, zone
, item
);
446 __this_cpu_write(*p
, overstep
);
450 void __dec_node_state(struct pglist_data
*pgdat
, enum node_stat_item item
)
452 struct per_cpu_nodestat __percpu
*pcp
= pgdat
->per_cpu_nodestats
;
453 s8 __percpu
*p
= pcp
->vm_node_stat_diff
+ item
;
456 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item
));
458 v
= __this_cpu_dec_return(*p
);
459 t
= __this_cpu_read(pcp
->stat_threshold
);
460 if (unlikely(v
< - t
)) {
461 s8 overstep
= t
>> 1;
463 node_page_state_add(v
- overstep
, pgdat
, item
);
464 __this_cpu_write(*p
, overstep
);
468 void __dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
470 __dec_zone_state(page_zone(page
), item
);
472 EXPORT_SYMBOL(__dec_zone_page_state
);
474 void __dec_node_page_state(struct page
*page
, enum node_stat_item item
)
476 __dec_node_state(page_pgdat(page
), item
);
478 EXPORT_SYMBOL(__dec_node_page_state
);
480 #ifdef CONFIG_HAVE_CMPXCHG_LOCAL
482 * If we have cmpxchg_local support then we do not need to incur the overhead
483 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
485 * mod_state() modifies the zone counter state through atomic per cpu
488 * Overstep mode specifies how overstep should handled:
490 * 1 Overstepping half of threshold
491 * -1 Overstepping minus half of threshold
493 static inline void mod_zone_state(struct zone
*zone
,
494 enum zone_stat_item item
, long delta
, int overstep_mode
)
496 struct per_cpu_zonestat __percpu
*pcp
= zone
->per_cpu_zonestats
;
497 s8 __percpu
*p
= pcp
->vm_stat_diff
+ item
;
501 z
= 0; /* overflow to zone counters */
504 * The fetching of the stat_threshold is racy. We may apply
505 * a counter threshold to the wrong the cpu if we get
506 * rescheduled while executing here. However, the next
507 * counter update will apply the threshold again and
508 * therefore bring the counter under the threshold again.
510 * Most of the time the thresholds are the same anyways
511 * for all cpus in a zone.
513 t
= this_cpu_read(pcp
->stat_threshold
);
515 o
= this_cpu_read(*p
);
519 int os
= overstep_mode
* (t
>> 1) ;
521 /* Overflow must be added to zone counters */
525 } while (this_cpu_cmpxchg(*p
, o
, n
) != o
);
528 zone_page_state_add(z
, zone
, item
);
531 void mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
534 mod_zone_state(zone
, item
, delta
, 0);
536 EXPORT_SYMBOL(mod_zone_page_state
);
538 void inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
540 mod_zone_state(page_zone(page
), item
, 1, 1);
542 EXPORT_SYMBOL(inc_zone_page_state
);
544 void dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
546 mod_zone_state(page_zone(page
), item
, -1, -1);
548 EXPORT_SYMBOL(dec_zone_page_state
);
550 static inline void mod_node_state(struct pglist_data
*pgdat
,
551 enum node_stat_item item
, int delta
, int overstep_mode
)
553 struct per_cpu_nodestat __percpu
*pcp
= pgdat
->per_cpu_nodestats
;
554 s8 __percpu
*p
= pcp
->vm_node_stat_diff
+ item
;
557 if (vmstat_item_in_bytes(item
)) {
559 * Only cgroups use subpage accounting right now; at
560 * the global level, these items still change in
561 * multiples of whole pages. Store them as pages
562 * internally to keep the per-cpu counters compact.
564 VM_WARN_ON_ONCE(delta
& (PAGE_SIZE
- 1));
565 delta
>>= PAGE_SHIFT
;
569 z
= 0; /* overflow to node counters */
572 * The fetching of the stat_threshold is racy. We may apply
573 * a counter threshold to the wrong the cpu if we get
574 * rescheduled while executing here. However, the next
575 * counter update will apply the threshold again and
576 * therefore bring the counter under the threshold again.
578 * Most of the time the thresholds are the same anyways
579 * for all cpus in a node.
581 t
= this_cpu_read(pcp
->stat_threshold
);
583 o
= this_cpu_read(*p
);
587 int os
= overstep_mode
* (t
>> 1) ;
589 /* Overflow must be added to node counters */
593 } while (this_cpu_cmpxchg(*p
, o
, n
) != o
);
596 node_page_state_add(z
, pgdat
, item
);
599 void mod_node_page_state(struct pglist_data
*pgdat
, enum node_stat_item item
,
602 mod_node_state(pgdat
, item
, delta
, 0);
604 EXPORT_SYMBOL(mod_node_page_state
);
606 void inc_node_state(struct pglist_data
*pgdat
, enum node_stat_item item
)
608 mod_node_state(pgdat
, item
, 1, 1);
611 void inc_node_page_state(struct page
*page
, enum node_stat_item item
)
613 mod_node_state(page_pgdat(page
), item
, 1, 1);
615 EXPORT_SYMBOL(inc_node_page_state
);
617 void dec_node_page_state(struct page
*page
, enum node_stat_item item
)
619 mod_node_state(page_pgdat(page
), item
, -1, -1);
621 EXPORT_SYMBOL(dec_node_page_state
);
624 * Use interrupt disable to serialize counter updates
626 void mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
631 local_irq_save(flags
);
632 __mod_zone_page_state(zone
, item
, delta
);
633 local_irq_restore(flags
);
635 EXPORT_SYMBOL(mod_zone_page_state
);
637 void inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
642 zone
= page_zone(page
);
643 local_irq_save(flags
);
644 __inc_zone_state(zone
, item
);
645 local_irq_restore(flags
);
647 EXPORT_SYMBOL(inc_zone_page_state
);
649 void dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
653 local_irq_save(flags
);
654 __dec_zone_page_state(page
, item
);
655 local_irq_restore(flags
);
657 EXPORT_SYMBOL(dec_zone_page_state
);
659 void inc_node_state(struct pglist_data
*pgdat
, enum node_stat_item item
)
663 local_irq_save(flags
);
664 __inc_node_state(pgdat
, item
);
665 local_irq_restore(flags
);
667 EXPORT_SYMBOL(inc_node_state
);
669 void mod_node_page_state(struct pglist_data
*pgdat
, enum node_stat_item item
,
674 local_irq_save(flags
);
675 __mod_node_page_state(pgdat
, item
, delta
);
676 local_irq_restore(flags
);
678 EXPORT_SYMBOL(mod_node_page_state
);
680 void inc_node_page_state(struct page
*page
, enum node_stat_item item
)
683 struct pglist_data
*pgdat
;
685 pgdat
= page_pgdat(page
);
686 local_irq_save(flags
);
687 __inc_node_state(pgdat
, item
);
688 local_irq_restore(flags
);
690 EXPORT_SYMBOL(inc_node_page_state
);
692 void dec_node_page_state(struct page
*page
, enum node_stat_item item
)
696 local_irq_save(flags
);
697 __dec_node_page_state(page
, item
);
698 local_irq_restore(flags
);
700 EXPORT_SYMBOL(dec_node_page_state
);
704 * Fold a differential into the global counters.
705 * Returns the number of counters updated.
707 static int fold_diff(int *zone_diff
, int *node_diff
)
712 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
714 atomic_long_add(zone_diff
[i
], &vm_zone_stat
[i
]);
718 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++)
720 atomic_long_add(node_diff
[i
], &vm_node_stat
[i
]);
727 static void fold_vm_zone_numa_events(struct zone
*zone
)
729 unsigned long zone_numa_events
[NR_VM_NUMA_EVENT_ITEMS
] = { 0, };
731 enum numa_stat_item item
;
733 for_each_online_cpu(cpu
) {
734 struct per_cpu_zonestat
*pzstats
;
736 pzstats
= per_cpu_ptr(zone
->per_cpu_zonestats
, cpu
);
737 for (item
= 0; item
< NR_VM_NUMA_EVENT_ITEMS
; item
++)
738 zone_numa_events
[item
] += xchg(&pzstats
->vm_numa_event
[item
], 0);
741 for (item
= 0; item
< NR_VM_NUMA_EVENT_ITEMS
; item
++)
742 zone_numa_event_add(zone_numa_events
[item
], zone
, item
);
745 void fold_vm_numa_events(void)
749 for_each_populated_zone(zone
)
750 fold_vm_zone_numa_events(zone
);
755 * Update the zone counters for the current cpu.
757 * Note that refresh_cpu_vm_stats strives to only access
758 * node local memory. The per cpu pagesets on remote zones are placed
759 * in the memory local to the processor using that pageset. So the
760 * loop over all zones will access a series of cachelines local to
763 * The call to zone_page_state_add updates the cachelines with the
764 * statistics in the remote zone struct as well as the global cachelines
765 * with the global counters. These could cause remote node cache line
766 * bouncing and will have to be only done when necessary.
768 * The function returns the number of global counters updated.
770 static int refresh_cpu_vm_stats(bool do_pagesets
)
772 struct pglist_data
*pgdat
;
775 int global_zone_diff
[NR_VM_ZONE_STAT_ITEMS
] = { 0, };
776 int global_node_diff
[NR_VM_NODE_STAT_ITEMS
] = { 0, };
779 for_each_populated_zone(zone
) {
780 struct per_cpu_zonestat __percpu
*pzstats
= zone
->per_cpu_zonestats
;
782 struct per_cpu_pages __percpu
*pcp
= zone
->per_cpu_pageset
;
785 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++) {
788 v
= this_cpu_xchg(pzstats
->vm_stat_diff
[i
], 0);
791 atomic_long_add(v
, &zone
->vm_stat
[i
]);
792 global_zone_diff
[i
] += v
;
794 /* 3 seconds idle till flush */
795 __this_cpu_write(pcp
->expire
, 3);
804 * Deal with draining the remote pageset of this
807 * Check if there are pages remaining in this pageset
808 * if not then there is nothing to expire.
810 if (!__this_cpu_read(pcp
->expire
) ||
811 !__this_cpu_read(pcp
->count
))
815 * We never drain zones local to this processor.
817 if (zone_to_nid(zone
) == numa_node_id()) {
818 __this_cpu_write(pcp
->expire
, 0);
822 if (__this_cpu_dec_return(pcp
->expire
))
825 if (__this_cpu_read(pcp
->count
)) {
826 drain_zone_pages(zone
, this_cpu_ptr(pcp
));
833 for_each_online_pgdat(pgdat
) {
834 struct per_cpu_nodestat __percpu
*p
= pgdat
->per_cpu_nodestats
;
836 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++) {
839 v
= this_cpu_xchg(p
->vm_node_stat_diff
[i
], 0);
841 atomic_long_add(v
, &pgdat
->vm_stat
[i
]);
842 global_node_diff
[i
] += v
;
847 changes
+= fold_diff(global_zone_diff
, global_node_diff
);
852 * Fold the data for an offline cpu into the global array.
853 * There cannot be any access by the offline cpu and therefore
854 * synchronization is simplified.
856 void cpu_vm_stats_fold(int cpu
)
858 struct pglist_data
*pgdat
;
861 int global_zone_diff
[NR_VM_ZONE_STAT_ITEMS
] = { 0, };
862 int global_node_diff
[NR_VM_NODE_STAT_ITEMS
] = { 0, };
864 for_each_populated_zone(zone
) {
865 struct per_cpu_zonestat
*pzstats
;
867 pzstats
= per_cpu_ptr(zone
->per_cpu_zonestats
, cpu
);
869 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++) {
870 if (pzstats
->vm_stat_diff
[i
]) {
873 v
= pzstats
->vm_stat_diff
[i
];
874 pzstats
->vm_stat_diff
[i
] = 0;
875 atomic_long_add(v
, &zone
->vm_stat
[i
]);
876 global_zone_diff
[i
] += v
;
880 for (i
= 0; i
< NR_VM_NUMA_EVENT_ITEMS
; i
++) {
881 if (pzstats
->vm_numa_event
[i
]) {
884 v
= pzstats
->vm_numa_event
[i
];
885 pzstats
->vm_numa_event
[i
] = 0;
886 zone_numa_event_add(v
, zone
, i
);
892 for_each_online_pgdat(pgdat
) {
893 struct per_cpu_nodestat
*p
;
895 p
= per_cpu_ptr(pgdat
->per_cpu_nodestats
, cpu
);
897 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++)
898 if (p
->vm_node_stat_diff
[i
]) {
901 v
= p
->vm_node_stat_diff
[i
];
902 p
->vm_node_stat_diff
[i
] = 0;
903 atomic_long_add(v
, &pgdat
->vm_stat
[i
]);
904 global_node_diff
[i
] += v
;
908 fold_diff(global_zone_diff
, global_node_diff
);
912 * this is only called if !populated_zone(zone), which implies no other users of
913 * pset->vm_stat_diff[] exist.
915 void drain_zonestat(struct zone
*zone
, struct per_cpu_zonestat
*pzstats
)
920 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++) {
921 if (pzstats
->vm_stat_diff
[i
]) {
922 v
= pzstats
->vm_stat_diff
[i
];
923 pzstats
->vm_stat_diff
[i
] = 0;
924 zone_page_state_add(v
, zone
, i
);
929 for (i
= 0; i
< NR_VM_NUMA_EVENT_ITEMS
; i
++) {
930 if (pzstats
->vm_numa_event
[i
]) {
931 v
= pzstats
->vm_numa_event
[i
];
932 pzstats
->vm_numa_event
[i
] = 0;
933 zone_numa_event_add(v
, zone
, i
);
942 * Determine the per node value of a stat item. This function
943 * is called frequently in a NUMA machine, so try to be as
944 * frugal as possible.
946 unsigned long sum_zone_node_page_state(int node
,
947 enum zone_stat_item item
)
949 struct zone
*zones
= NODE_DATA(node
)->node_zones
;
951 unsigned long count
= 0;
953 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
954 count
+= zone_page_state(zones
+ i
, item
);
959 /* Determine the per node value of a numa stat item. */
960 unsigned long sum_zone_numa_event_state(int node
,
961 enum numa_stat_item item
)
963 struct zone
*zones
= NODE_DATA(node
)->node_zones
;
964 unsigned long count
= 0;
967 for (i
= 0; i
< MAX_NR_ZONES
; i
++)
968 count
+= zone_numa_event_state(zones
+ i
, item
);
974 * Determine the per node value of a stat item.
976 unsigned long node_page_state_pages(struct pglist_data
*pgdat
,
977 enum node_stat_item item
)
979 long x
= atomic_long_read(&pgdat
->vm_stat
[item
]);
987 unsigned long node_page_state(struct pglist_data
*pgdat
,
988 enum node_stat_item item
)
990 VM_WARN_ON_ONCE(vmstat_item_in_bytes(item
));
992 return node_page_state_pages(pgdat
, item
);
996 #ifdef CONFIG_COMPACTION
998 struct contig_page_info
{
999 unsigned long free_pages
;
1000 unsigned long free_blocks_total
;
1001 unsigned long free_blocks_suitable
;
1005 * Calculate the number of free pages in a zone, how many contiguous
1006 * pages are free and how many are large enough to satisfy an allocation of
1007 * the target size. Note that this function makes no attempt to estimate
1008 * how many suitable free blocks there *might* be if MOVABLE pages were
1009 * migrated. Calculating that is possible, but expensive and can be
1010 * figured out from userspace
1012 static void fill_contig_page_info(struct zone
*zone
,
1013 unsigned int suitable_order
,
1014 struct contig_page_info
*info
)
1018 info
->free_pages
= 0;
1019 info
->free_blocks_total
= 0;
1020 info
->free_blocks_suitable
= 0;
1022 for (order
= 0; order
< MAX_ORDER
; order
++) {
1023 unsigned long blocks
;
1025 /* Count number of free blocks */
1026 blocks
= zone
->free_area
[order
].nr_free
;
1027 info
->free_blocks_total
+= blocks
;
1029 /* Count free base pages */
1030 info
->free_pages
+= blocks
<< order
;
1032 /* Count the suitable free blocks */
1033 if (order
>= suitable_order
)
1034 info
->free_blocks_suitable
+= blocks
<<
1035 (order
- suitable_order
);
1040 * A fragmentation index only makes sense if an allocation of a requested
1041 * size would fail. If that is true, the fragmentation index indicates
1042 * whether external fragmentation or a lack of memory was the problem.
1043 * The value can be used to determine if page reclaim or compaction
1046 static int __fragmentation_index(unsigned int order
, struct contig_page_info
*info
)
1048 unsigned long requested
= 1UL << order
;
1050 if (WARN_ON_ONCE(order
>= MAX_ORDER
))
1053 if (!info
->free_blocks_total
)
1056 /* Fragmentation index only makes sense when a request would fail */
1057 if (info
->free_blocks_suitable
)
1061 * Index is between 0 and 1 so return within 3 decimal places
1063 * 0 => allocation would fail due to lack of memory
1064 * 1 => allocation would fail due to fragmentation
1066 return 1000 - div_u64( (1000+(div_u64(info
->free_pages
* 1000ULL, requested
))), info
->free_blocks_total
);
1070 * Calculates external fragmentation within a zone wrt the given order.
1071 * It is defined as the percentage of pages found in blocks of size
1072 * less than 1 << order. It returns values in range [0, 100].
1074 unsigned int extfrag_for_order(struct zone
*zone
, unsigned int order
)
1076 struct contig_page_info info
;
1078 fill_contig_page_info(zone
, order
, &info
);
1079 if (info
.free_pages
== 0)
1082 return div_u64((info
.free_pages
-
1083 (info
.free_blocks_suitable
<< order
)) * 100,
1087 /* Same as __fragmentation index but allocs contig_page_info on stack */
1088 int fragmentation_index(struct zone
*zone
, unsigned int order
)
1090 struct contig_page_info info
;
1092 fill_contig_page_info(zone
, order
, &info
);
1093 return __fragmentation_index(order
, &info
);
1097 #if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || \
1098 defined(CONFIG_NUMA) || defined(CONFIG_MEMCG)
1099 #ifdef CONFIG_ZONE_DMA
1100 #define TEXT_FOR_DMA(xx) xx "_dma",
1102 #define TEXT_FOR_DMA(xx)
1105 #ifdef CONFIG_ZONE_DMA32
1106 #define TEXT_FOR_DMA32(xx) xx "_dma32",
1108 #define TEXT_FOR_DMA32(xx)
1111 #ifdef CONFIG_HIGHMEM
1112 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
1114 #define TEXT_FOR_HIGHMEM(xx)
1117 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
1118 TEXT_FOR_HIGHMEM(xx) xx "_movable",
1120 const char * const vmstat_text
[] = {
1121 /* enum zone_stat_item counters */
1123 "nr_zone_inactive_anon",
1124 "nr_zone_active_anon",
1125 "nr_zone_inactive_file",
1126 "nr_zone_active_file",
1127 "nr_zone_unevictable",
1128 "nr_zone_write_pending",
1131 #if IS_ENABLED(CONFIG_ZSMALLOC)
1136 /* enum numa_stat_item counters */
1146 /* enum node_stat_item counters */
1152 "nr_slab_reclaimable",
1153 "nr_slab_unreclaimable",
1157 "workingset_refault_anon",
1158 "workingset_refault_file",
1159 "workingset_activate_anon",
1160 "workingset_activate_file",
1161 "workingset_restore_anon",
1162 "workingset_restore_file",
1163 "workingset_nodereclaim",
1169 "nr_writeback_temp",
1171 "nr_shmem_hugepages",
1172 "nr_shmem_pmdmapped",
1173 "nr_file_hugepages",
1174 "nr_file_pmdmapped",
1175 "nr_anon_transparent_hugepages",
1177 "nr_vmscan_immediate_reclaim",
1180 "nr_kernel_misc_reclaimable",
1181 "nr_foll_pin_acquired",
1182 "nr_foll_pin_released",
1184 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
1185 "nr_shadow_call_stack",
1187 "nr_page_table_pages",
1192 /* enum writeback_stat_item counters */
1193 "nr_dirty_threshold",
1194 "nr_dirty_background_threshold",
1196 #if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG)
1197 /* enum vm_event_item counters */
1203 TEXTS_FOR_ZONES("pgalloc")
1204 TEXTS_FOR_ZONES("allocstall")
1205 TEXTS_FOR_ZONES("pgskip")
1224 "pgscan_direct_throttle",
1231 "zone_reclaim_failed",
1235 "kswapd_inodesteal",
1236 "kswapd_low_wmark_hit_quickly",
1237 "kswapd_high_wmark_hit_quickly",
1246 #ifdef CONFIG_NUMA_BALANCING
1248 "numa_huge_pte_updates",
1250 "numa_hint_faults_local",
1251 "numa_pages_migrated",
1253 #ifdef CONFIG_MIGRATION
1254 "pgmigrate_success",
1256 "thp_migration_success",
1257 "thp_migration_fail",
1258 "thp_migration_split",
1260 #ifdef CONFIG_COMPACTION
1261 "compact_migrate_scanned",
1262 "compact_free_scanned",
1267 "compact_daemon_wake",
1268 "compact_daemon_migrate_scanned",
1269 "compact_daemon_free_scanned",
1272 #ifdef CONFIG_HUGETLB_PAGE
1273 "htlb_buddy_alloc_success",
1274 "htlb_buddy_alloc_fail",
1277 "cma_alloc_success",
1280 "unevictable_pgs_culled",
1281 "unevictable_pgs_scanned",
1282 "unevictable_pgs_rescued",
1283 "unevictable_pgs_mlocked",
1284 "unevictable_pgs_munlocked",
1285 "unevictable_pgs_cleared",
1286 "unevictable_pgs_stranded",
1288 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1290 "thp_fault_fallback",
1291 "thp_fault_fallback_charge",
1292 "thp_collapse_alloc",
1293 "thp_collapse_alloc_failed",
1295 "thp_file_fallback",
1296 "thp_file_fallback_charge",
1299 "thp_split_page_failed",
1300 "thp_deferred_split_page",
1302 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
1305 "thp_zero_page_alloc",
1306 "thp_zero_page_alloc_failed",
1308 "thp_swpout_fallback",
1310 #ifdef CONFIG_MEMORY_BALLOON
1313 #ifdef CONFIG_BALLOON_COMPACTION
1316 #endif /* CONFIG_MEMORY_BALLOON */
1317 #ifdef CONFIG_DEBUG_TLBFLUSH
1318 "nr_tlb_remote_flush",
1319 "nr_tlb_remote_flush_received",
1320 "nr_tlb_local_flush_all",
1321 "nr_tlb_local_flush_one",
1322 #endif /* CONFIG_DEBUG_TLBFLUSH */
1324 #ifdef CONFIG_DEBUG_VM_VMACACHE
1325 "vmacache_find_calls",
1326 "vmacache_find_hits",
1333 "direct_map_level2_splits",
1334 "direct_map_level3_splits",
1336 #endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */
1338 #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */
1340 #if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
1341 defined(CONFIG_PROC_FS)
1342 static void *frag_start(struct seq_file
*m
, loff_t
*pos
)
1347 for (pgdat
= first_online_pgdat();
1349 pgdat
= next_online_pgdat(pgdat
))
1355 static void *frag_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
1357 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1360 return next_online_pgdat(pgdat
);
1363 static void frag_stop(struct seq_file
*m
, void *arg
)
1368 * Walk zones in a node and print using a callback.
1369 * If @assert_populated is true, only use callback for zones that are populated.
1371 static void walk_zones_in_node(struct seq_file
*m
, pg_data_t
*pgdat
,
1372 bool assert_populated
, bool nolock
,
1373 void (*print
)(struct seq_file
*m
, pg_data_t
*, struct zone
*))
1376 struct zone
*node_zones
= pgdat
->node_zones
;
1377 unsigned long flags
;
1379 for (zone
= node_zones
; zone
- node_zones
< MAX_NR_ZONES
; ++zone
) {
1380 if (assert_populated
&& !populated_zone(zone
))
1384 spin_lock_irqsave(&zone
->lock
, flags
);
1385 print(m
, pgdat
, zone
);
1387 spin_unlock_irqrestore(&zone
->lock
, flags
);
1392 #ifdef CONFIG_PROC_FS
1393 static void frag_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
1398 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
1399 for (order
= 0; order
< MAX_ORDER
; ++order
)
1400 seq_printf(m
, "%6lu ", zone
->free_area
[order
].nr_free
);
1405 * This walks the free areas for each zone.
1407 static int frag_show(struct seq_file
*m
, void *arg
)
1409 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1410 walk_zones_in_node(m
, pgdat
, true, false, frag_show_print
);
1414 static void pagetypeinfo_showfree_print(struct seq_file
*m
,
1415 pg_data_t
*pgdat
, struct zone
*zone
)
1419 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++) {
1420 seq_printf(m
, "Node %4d, zone %8s, type %12s ",
1423 migratetype_names
[mtype
]);
1424 for (order
= 0; order
< MAX_ORDER
; ++order
) {
1425 unsigned long freecount
= 0;
1426 struct free_area
*area
;
1427 struct list_head
*curr
;
1428 bool overflow
= false;
1430 area
= &(zone
->free_area
[order
]);
1432 list_for_each(curr
, &area
->free_list
[mtype
]) {
1434 * Cap the free_list iteration because it might
1435 * be really large and we are under a spinlock
1436 * so a long time spent here could trigger a
1437 * hard lockup detector. Anyway this is a
1438 * debugging tool so knowing there is a handful
1439 * of pages of this order should be more than
1442 if (++freecount
>= 100000) {
1447 seq_printf(m
, "%s%6lu ", overflow
? ">" : "", freecount
);
1448 spin_unlock_irq(&zone
->lock
);
1450 spin_lock_irq(&zone
->lock
);
1456 /* Print out the free pages at each order for each migatetype */
1457 static void pagetypeinfo_showfree(struct seq_file
*m
, void *arg
)
1460 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1463 seq_printf(m
, "%-43s ", "Free pages count per migrate type at order");
1464 for (order
= 0; order
< MAX_ORDER
; ++order
)
1465 seq_printf(m
, "%6d ", order
);
1468 walk_zones_in_node(m
, pgdat
, true, false, pagetypeinfo_showfree_print
);
1471 static void pagetypeinfo_showblockcount_print(struct seq_file
*m
,
1472 pg_data_t
*pgdat
, struct zone
*zone
)
1476 unsigned long start_pfn
= zone
->zone_start_pfn
;
1477 unsigned long end_pfn
= zone_end_pfn(zone
);
1478 unsigned long count
[MIGRATE_TYPES
] = { 0, };
1480 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
1483 page
= pfn_to_online_page(pfn
);
1487 if (page_zone(page
) != zone
)
1490 mtype
= get_pageblock_migratetype(page
);
1492 if (mtype
< MIGRATE_TYPES
)
1497 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
1498 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
1499 seq_printf(m
, "%12lu ", count
[mtype
]);
1503 /* Print out the number of pageblocks for each migratetype */
1504 static void pagetypeinfo_showblockcount(struct seq_file
*m
, void *arg
)
1507 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1509 seq_printf(m
, "\n%-23s", "Number of blocks type ");
1510 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
1511 seq_printf(m
, "%12s ", migratetype_names
[mtype
]);
1513 walk_zones_in_node(m
, pgdat
, true, false,
1514 pagetypeinfo_showblockcount_print
);
1518 * Print out the number of pageblocks for each migratetype that contain pages
1519 * of other types. This gives an indication of how well fallbacks are being
1520 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER
1521 * to determine what is going on
1523 static void pagetypeinfo_showmixedcount(struct seq_file
*m
, pg_data_t
*pgdat
)
1525 #ifdef CONFIG_PAGE_OWNER
1528 if (!static_branch_unlikely(&page_owner_inited
))
1531 drain_all_pages(NULL
);
1533 seq_printf(m
, "\n%-23s", "Number of mixed blocks ");
1534 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
1535 seq_printf(m
, "%12s ", migratetype_names
[mtype
]);
1538 walk_zones_in_node(m
, pgdat
, true, true,
1539 pagetypeinfo_showmixedcount_print
);
1540 #endif /* CONFIG_PAGE_OWNER */
1544 * This prints out statistics in relation to grouping pages by mobility.
1545 * It is expensive to collect so do not constantly read the file.
1547 static int pagetypeinfo_show(struct seq_file
*m
, void *arg
)
1549 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1551 /* check memoryless node */
1552 if (!node_state(pgdat
->node_id
, N_MEMORY
))
1555 seq_printf(m
, "Page block order: %d\n", pageblock_order
);
1556 seq_printf(m
, "Pages per block: %lu\n", pageblock_nr_pages
);
1558 pagetypeinfo_showfree(m
, pgdat
);
1559 pagetypeinfo_showblockcount(m
, pgdat
);
1560 pagetypeinfo_showmixedcount(m
, pgdat
);
1565 static const struct seq_operations fragmentation_op
= {
1566 .start
= frag_start
,
1572 static const struct seq_operations pagetypeinfo_op
= {
1573 .start
= frag_start
,
1576 .show
= pagetypeinfo_show
,
1579 static bool is_zone_first_populated(pg_data_t
*pgdat
, struct zone
*zone
)
1583 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1584 struct zone
*compare
= &pgdat
->node_zones
[zid
];
1586 if (populated_zone(compare
))
1587 return zone
== compare
;
1593 static void zoneinfo_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
1597 seq_printf(m
, "Node %d, zone %8s", pgdat
->node_id
, zone
->name
);
1598 if (is_zone_first_populated(pgdat
, zone
)) {
1599 seq_printf(m
, "\n per-node stats");
1600 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++) {
1601 unsigned long pages
= node_page_state_pages(pgdat
, i
);
1603 if (vmstat_item_print_in_thp(i
))
1604 pages
/= HPAGE_PMD_NR
;
1605 seq_printf(m
, "\n %-12s %lu", node_stat_name(i
),
1618 zone_page_state(zone
, NR_FREE_PAGES
),
1619 min_wmark_pages(zone
),
1620 low_wmark_pages(zone
),
1621 high_wmark_pages(zone
),
1622 zone
->spanned_pages
,
1623 zone
->present_pages
,
1624 zone_managed_pages(zone
),
1625 zone_cma_pages(zone
));
1628 "\n protection: (%ld",
1629 zone
->lowmem_reserve
[0]);
1630 for (i
= 1; i
< ARRAY_SIZE(zone
->lowmem_reserve
); i
++)
1631 seq_printf(m
, ", %ld", zone
->lowmem_reserve
[i
]);
1634 /* If unpopulated, no other information is useful */
1635 if (!populated_zone(zone
)) {
1640 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
1641 seq_printf(m
, "\n %-12s %lu", zone_stat_name(i
),
1642 zone_page_state(zone
, i
));
1645 for (i
= 0; i
< NR_VM_NUMA_EVENT_ITEMS
; i
++)
1646 seq_printf(m
, "\n %-12s %lu", numa_stat_name(i
),
1647 zone_numa_event_state(zone
, i
));
1650 seq_printf(m
, "\n pagesets");
1651 for_each_online_cpu(i
) {
1652 struct per_cpu_pages
*pcp
;
1653 struct per_cpu_zonestat __maybe_unused
*pzstats
;
1655 pcp
= per_cpu_ptr(zone
->per_cpu_pageset
, i
);
1666 pzstats
= per_cpu_ptr(zone
->per_cpu_zonestats
, i
);
1667 seq_printf(m
, "\n vm stats threshold: %d",
1668 pzstats
->stat_threshold
);
1672 "\n node_unreclaimable: %u"
1673 "\n start_pfn: %lu",
1674 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
,
1675 zone
->zone_start_pfn
);
1680 * Output information about zones in @pgdat. All zones are printed regardless
1681 * of whether they are populated or not: lowmem_reserve_ratio operates on the
1682 * set of all zones and userspace would not be aware of such zones if they are
1683 * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio).
1685 static int zoneinfo_show(struct seq_file
*m
, void *arg
)
1687 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1688 walk_zones_in_node(m
, pgdat
, false, false, zoneinfo_show_print
);
1692 static const struct seq_operations zoneinfo_op
= {
1693 .start
= frag_start
, /* iterate over all zones. The same as in
1697 .show
= zoneinfo_show
,
1700 #define NR_VMSTAT_ITEMS (NR_VM_ZONE_STAT_ITEMS + \
1701 NR_VM_NUMA_EVENT_ITEMS + \
1702 NR_VM_NODE_STAT_ITEMS + \
1703 NR_VM_WRITEBACK_STAT_ITEMS + \
1704 (IS_ENABLED(CONFIG_VM_EVENT_COUNTERS) ? \
1705 NR_VM_EVENT_ITEMS : 0))
1707 static void *vmstat_start(struct seq_file
*m
, loff_t
*pos
)
1712 if (*pos
>= NR_VMSTAT_ITEMS
)
1715 BUILD_BUG_ON(ARRAY_SIZE(vmstat_text
) < NR_VMSTAT_ITEMS
);
1716 fold_vm_numa_events();
1717 v
= kmalloc_array(NR_VMSTAT_ITEMS
, sizeof(unsigned long), GFP_KERNEL
);
1720 return ERR_PTR(-ENOMEM
);
1721 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
1722 v
[i
] = global_zone_page_state(i
);
1723 v
+= NR_VM_ZONE_STAT_ITEMS
;
1726 for (i
= 0; i
< NR_VM_NUMA_EVENT_ITEMS
; i
++)
1727 v
[i
] = global_numa_event_state(i
);
1728 v
+= NR_VM_NUMA_EVENT_ITEMS
;
1731 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++) {
1732 v
[i
] = global_node_page_state_pages(i
);
1733 if (vmstat_item_print_in_thp(i
))
1734 v
[i
] /= HPAGE_PMD_NR
;
1736 v
+= NR_VM_NODE_STAT_ITEMS
;
1738 global_dirty_limits(v
+ NR_DIRTY_BG_THRESHOLD
,
1739 v
+ NR_DIRTY_THRESHOLD
);
1740 v
+= NR_VM_WRITEBACK_STAT_ITEMS
;
1742 #ifdef CONFIG_VM_EVENT_COUNTERS
1744 v
[PGPGIN
] /= 2; /* sectors -> kbytes */
1747 return (unsigned long *)m
->private + *pos
;
1750 static void *vmstat_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
1753 if (*pos
>= NR_VMSTAT_ITEMS
)
1755 return (unsigned long *)m
->private + *pos
;
1758 static int vmstat_show(struct seq_file
*m
, void *arg
)
1760 unsigned long *l
= arg
;
1761 unsigned long off
= l
- (unsigned long *)m
->private;
1763 seq_puts(m
, vmstat_text
[off
]);
1764 seq_put_decimal_ull(m
, " ", *l
);
1767 if (off
== NR_VMSTAT_ITEMS
- 1) {
1769 * We've come to the end - add any deprecated counters to avoid
1770 * breaking userspace which might depend on them being present.
1772 seq_puts(m
, "nr_unstable 0\n");
1777 static void vmstat_stop(struct seq_file
*m
, void *arg
)
1783 static const struct seq_operations vmstat_op
= {
1784 .start
= vmstat_start
,
1785 .next
= vmstat_next
,
1786 .stop
= vmstat_stop
,
1787 .show
= vmstat_show
,
1789 #endif /* CONFIG_PROC_FS */
1792 static DEFINE_PER_CPU(struct delayed_work
, vmstat_work
);
1793 int sysctl_stat_interval __read_mostly
= HZ
;
1795 #ifdef CONFIG_PROC_FS
1796 static void refresh_vm_stats(struct work_struct
*work
)
1798 refresh_cpu_vm_stats(true);
1801 int vmstat_refresh(struct ctl_table
*table
, int write
,
1802 void *buffer
, size_t *lenp
, loff_t
*ppos
)
1809 * The regular update, every sysctl_stat_interval, may come later
1810 * than expected: leaving a significant amount in per_cpu buckets.
1811 * This is particularly misleading when checking a quantity of HUGE
1812 * pages, immediately after running a test. /proc/sys/vm/stat_refresh,
1813 * which can equally be echo'ed to or cat'ted from (by root),
1814 * can be used to update the stats just before reading them.
1816 * Oh, and since global_zone_page_state() etc. are so careful to hide
1817 * transiently negative values, report an error here if any of
1818 * the stats is negative, so we know to go looking for imbalance.
1820 err
= schedule_on_each_cpu(refresh_vm_stats
);
1823 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++) {
1825 * Skip checking stats known to go negative occasionally.
1828 case NR_ZONE_WRITE_PENDING
:
1829 case NR_FREE_CMA_PAGES
:
1832 val
= atomic_long_read(&vm_zone_stat
[i
]);
1834 pr_warn("%s: %s %ld\n",
1835 __func__
, zone_stat_name(i
), val
);
1838 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++) {
1840 * Skip checking stats known to go negative occasionally.
1846 val
= atomic_long_read(&vm_node_stat
[i
]);
1848 pr_warn("%s: %s %ld\n",
1849 __func__
, node_stat_name(i
), val
);
1858 #endif /* CONFIG_PROC_FS */
1860 static void vmstat_update(struct work_struct
*w
)
1862 if (refresh_cpu_vm_stats(true)) {
1864 * Counters were updated so we expect more updates
1865 * to occur in the future. Keep on running the
1866 * update worker thread.
1868 queue_delayed_work_on(smp_processor_id(), mm_percpu_wq
,
1869 this_cpu_ptr(&vmstat_work
),
1870 round_jiffies_relative(sysctl_stat_interval
));
1875 * Check if the diffs for a certain cpu indicate that
1876 * an update is needed.
1878 static bool need_update(int cpu
)
1880 pg_data_t
*last_pgdat
= NULL
;
1883 for_each_populated_zone(zone
) {
1884 struct per_cpu_zonestat
*pzstats
= per_cpu_ptr(zone
->per_cpu_zonestats
, cpu
);
1885 struct per_cpu_nodestat
*n
;
1888 * The fast way of checking if there are any vmstat diffs.
1890 if (memchr_inv(pzstats
->vm_stat_diff
, 0, sizeof(pzstats
->vm_stat_diff
)))
1893 if (last_pgdat
== zone
->zone_pgdat
)
1895 last_pgdat
= zone
->zone_pgdat
;
1896 n
= per_cpu_ptr(zone
->zone_pgdat
->per_cpu_nodestats
, cpu
);
1897 if (memchr_inv(n
->vm_node_stat_diff
, 0, sizeof(n
->vm_node_stat_diff
)))
1904 * Switch off vmstat processing and then fold all the remaining differentials
1905 * until the diffs stay at zero. The function is used by NOHZ and can only be
1906 * invoked when tick processing is not active.
1908 void quiet_vmstat(void)
1910 if (system_state
!= SYSTEM_RUNNING
)
1913 if (!delayed_work_pending(this_cpu_ptr(&vmstat_work
)))
1916 if (!need_update(smp_processor_id()))
1920 * Just refresh counters and do not care about the pending delayed
1921 * vmstat_update. It doesn't fire that often to matter and canceling
1922 * it would be too expensive from this path.
1923 * vmstat_shepherd will take care about that for us.
1925 refresh_cpu_vm_stats(false);
1929 * Shepherd worker thread that checks the
1930 * differentials of processors that have their worker
1931 * threads for vm statistics updates disabled because of
1934 static void vmstat_shepherd(struct work_struct
*w
);
1936 static DECLARE_DEFERRABLE_WORK(shepherd
, vmstat_shepherd
);
1938 static void vmstat_shepherd(struct work_struct
*w
)
1943 /* Check processors whose vmstat worker threads have been disabled */
1944 for_each_online_cpu(cpu
) {
1945 struct delayed_work
*dw
= &per_cpu(vmstat_work
, cpu
);
1947 if (!delayed_work_pending(dw
) && need_update(cpu
))
1948 queue_delayed_work_on(cpu
, mm_percpu_wq
, dw
, 0);
1954 schedule_delayed_work(&shepherd
,
1955 round_jiffies_relative(sysctl_stat_interval
));
1958 static void __init
start_shepherd_timer(void)
1962 for_each_possible_cpu(cpu
)
1963 INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work
, cpu
),
1966 schedule_delayed_work(&shepherd
,
1967 round_jiffies_relative(sysctl_stat_interval
));
1970 static void __init
init_cpu_node_state(void)
1974 for_each_online_node(node
) {
1975 if (cpumask_weight(cpumask_of_node(node
)) > 0)
1976 node_set_state(node
, N_CPU
);
1980 static int vmstat_cpu_online(unsigned int cpu
)
1982 refresh_zone_stat_thresholds();
1983 node_set_state(cpu_to_node(cpu
), N_CPU
);
1987 static int vmstat_cpu_down_prep(unsigned int cpu
)
1989 cancel_delayed_work_sync(&per_cpu(vmstat_work
, cpu
));
1993 static int vmstat_cpu_dead(unsigned int cpu
)
1995 const struct cpumask
*node_cpus
;
1998 node
= cpu_to_node(cpu
);
2000 refresh_zone_stat_thresholds();
2001 node_cpus
= cpumask_of_node(node
);
2002 if (cpumask_weight(node_cpus
) > 0)
2005 node_clear_state(node
, N_CPU
);
2011 struct workqueue_struct
*mm_percpu_wq
;
2013 void __init
init_mm_internals(void)
2015 int ret __maybe_unused
;
2017 mm_percpu_wq
= alloc_workqueue("mm_percpu_wq", WQ_MEM_RECLAIM
, 0);
2020 ret
= cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD
, "mm/vmstat:dead",
2021 NULL
, vmstat_cpu_dead
);
2023 pr_err("vmstat: failed to register 'dead' hotplug state\n");
2025 ret
= cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN
, "mm/vmstat:online",
2027 vmstat_cpu_down_prep
);
2029 pr_err("vmstat: failed to register 'online' hotplug state\n");
2032 init_cpu_node_state();
2035 start_shepherd_timer();
2037 #ifdef CONFIG_PROC_FS
2038 proc_create_seq("buddyinfo", 0444, NULL
, &fragmentation_op
);
2039 proc_create_seq("pagetypeinfo", 0400, NULL
, &pagetypeinfo_op
);
2040 proc_create_seq("vmstat", 0444, NULL
, &vmstat_op
);
2041 proc_create_seq("zoneinfo", 0444, NULL
, &zoneinfo_op
);
2045 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
2048 * Return an index indicating how much of the available free memory is
2049 * unusable for an allocation of the requested size.
2051 static int unusable_free_index(unsigned int order
,
2052 struct contig_page_info
*info
)
2054 /* No free memory is interpreted as all free memory is unusable */
2055 if (info
->free_pages
== 0)
2059 * Index should be a value between 0 and 1. Return a value to 3
2062 * 0 => no fragmentation
2063 * 1 => high fragmentation
2065 return div_u64((info
->free_pages
- (info
->free_blocks_suitable
<< order
)) * 1000ULL, info
->free_pages
);
2069 static void unusable_show_print(struct seq_file
*m
,
2070 pg_data_t
*pgdat
, struct zone
*zone
)
2074 struct contig_page_info info
;
2076 seq_printf(m
, "Node %d, zone %8s ",
2079 for (order
= 0; order
< MAX_ORDER
; ++order
) {
2080 fill_contig_page_info(zone
, order
, &info
);
2081 index
= unusable_free_index(order
, &info
);
2082 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
2089 * Display unusable free space index
2091 * The unusable free space index measures how much of the available free
2092 * memory cannot be used to satisfy an allocation of a given size and is a
2093 * value between 0 and 1. The higher the value, the more of free memory is
2094 * unusable and by implication, the worse the external fragmentation is. This
2095 * can be expressed as a percentage by multiplying by 100.
2097 static int unusable_show(struct seq_file
*m
, void *arg
)
2099 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
2101 /* check memoryless node */
2102 if (!node_state(pgdat
->node_id
, N_MEMORY
))
2105 walk_zones_in_node(m
, pgdat
, true, false, unusable_show_print
);
2110 static const struct seq_operations unusable_sops
= {
2111 .start
= frag_start
,
2114 .show
= unusable_show
,
2117 DEFINE_SEQ_ATTRIBUTE(unusable
);
2119 static void extfrag_show_print(struct seq_file
*m
,
2120 pg_data_t
*pgdat
, struct zone
*zone
)
2125 /* Alloc on stack as interrupts are disabled for zone walk */
2126 struct contig_page_info info
;
2128 seq_printf(m
, "Node %d, zone %8s ",
2131 for (order
= 0; order
< MAX_ORDER
; ++order
) {
2132 fill_contig_page_info(zone
, order
, &info
);
2133 index
= __fragmentation_index(order
, &info
);
2134 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
2141 * Display fragmentation index for orders that allocations would fail for
2143 static int extfrag_show(struct seq_file
*m
, void *arg
)
2145 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
2147 walk_zones_in_node(m
, pgdat
, true, false, extfrag_show_print
);
2152 static const struct seq_operations extfrag_sops
= {
2153 .start
= frag_start
,
2156 .show
= extfrag_show
,
2159 DEFINE_SEQ_ATTRIBUTE(extfrag
);
2161 static int __init
extfrag_debug_init(void)
2163 struct dentry
*extfrag_debug_root
;
2165 extfrag_debug_root
= debugfs_create_dir("extfrag", NULL
);
2167 debugfs_create_file("unusable_index", 0444, extfrag_debug_root
, NULL
,
2170 debugfs_create_file("extfrag_index", 0444, extfrag_debug_root
, NULL
,
2176 module_init(extfrag_debug_init
);