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")
1222 "pgscan_direct_throttle",
1229 "zone_reclaim_failed",
1233 "kswapd_inodesteal",
1234 "kswapd_low_wmark_hit_quickly",
1235 "kswapd_high_wmark_hit_quickly",
1244 #ifdef CONFIG_NUMA_BALANCING
1246 "numa_huge_pte_updates",
1248 "numa_hint_faults_local",
1249 "numa_pages_migrated",
1251 #ifdef CONFIG_MIGRATION
1252 "pgmigrate_success",
1254 "thp_migration_success",
1255 "thp_migration_fail",
1256 "thp_migration_split",
1258 #ifdef CONFIG_COMPACTION
1259 "compact_migrate_scanned",
1260 "compact_free_scanned",
1265 "compact_daemon_wake",
1266 "compact_daemon_migrate_scanned",
1267 "compact_daemon_free_scanned",
1270 #ifdef CONFIG_HUGETLB_PAGE
1271 "htlb_buddy_alloc_success",
1272 "htlb_buddy_alloc_fail",
1275 "cma_alloc_success",
1278 "unevictable_pgs_culled",
1279 "unevictable_pgs_scanned",
1280 "unevictable_pgs_rescued",
1281 "unevictable_pgs_mlocked",
1282 "unevictable_pgs_munlocked",
1283 "unevictable_pgs_cleared",
1284 "unevictable_pgs_stranded",
1286 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
1288 "thp_fault_fallback",
1289 "thp_fault_fallback_charge",
1290 "thp_collapse_alloc",
1291 "thp_collapse_alloc_failed",
1293 "thp_file_fallback",
1294 "thp_file_fallback_charge",
1297 "thp_split_page_failed",
1298 "thp_deferred_split_page",
1300 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
1303 "thp_zero_page_alloc",
1304 "thp_zero_page_alloc_failed",
1306 "thp_swpout_fallback",
1308 #ifdef CONFIG_MEMORY_BALLOON
1311 #ifdef CONFIG_BALLOON_COMPACTION
1314 #endif /* CONFIG_MEMORY_BALLOON */
1315 #ifdef CONFIG_DEBUG_TLBFLUSH
1316 "nr_tlb_remote_flush",
1317 "nr_tlb_remote_flush_received",
1318 "nr_tlb_local_flush_all",
1319 "nr_tlb_local_flush_one",
1320 #endif /* CONFIG_DEBUG_TLBFLUSH */
1322 #ifdef CONFIG_DEBUG_VM_VMACACHE
1323 "vmacache_find_calls",
1324 "vmacache_find_hits",
1331 "direct_map_level2_splits",
1332 "direct_map_level3_splits",
1334 #endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */
1336 #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */
1338 #if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
1339 defined(CONFIG_PROC_FS)
1340 static void *frag_start(struct seq_file
*m
, loff_t
*pos
)
1345 for (pgdat
= first_online_pgdat();
1347 pgdat
= next_online_pgdat(pgdat
))
1353 static void *frag_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
1355 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1358 return next_online_pgdat(pgdat
);
1361 static void frag_stop(struct seq_file
*m
, void *arg
)
1366 * Walk zones in a node and print using a callback.
1367 * If @assert_populated is true, only use callback for zones that are populated.
1369 static void walk_zones_in_node(struct seq_file
*m
, pg_data_t
*pgdat
,
1370 bool assert_populated
, bool nolock
,
1371 void (*print
)(struct seq_file
*m
, pg_data_t
*, struct zone
*))
1374 struct zone
*node_zones
= pgdat
->node_zones
;
1375 unsigned long flags
;
1377 for (zone
= node_zones
; zone
- node_zones
< MAX_NR_ZONES
; ++zone
) {
1378 if (assert_populated
&& !populated_zone(zone
))
1382 spin_lock_irqsave(&zone
->lock
, flags
);
1383 print(m
, pgdat
, zone
);
1385 spin_unlock_irqrestore(&zone
->lock
, flags
);
1390 #ifdef CONFIG_PROC_FS
1391 static void frag_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
1396 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
1397 for (order
= 0; order
< MAX_ORDER
; ++order
)
1398 seq_printf(m
, "%6lu ", zone
->free_area
[order
].nr_free
);
1403 * This walks the free areas for each zone.
1405 static int frag_show(struct seq_file
*m
, void *arg
)
1407 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1408 walk_zones_in_node(m
, pgdat
, true, false, frag_show_print
);
1412 static void pagetypeinfo_showfree_print(struct seq_file
*m
,
1413 pg_data_t
*pgdat
, struct zone
*zone
)
1417 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++) {
1418 seq_printf(m
, "Node %4d, zone %8s, type %12s ",
1421 migratetype_names
[mtype
]);
1422 for (order
= 0; order
< MAX_ORDER
; ++order
) {
1423 unsigned long freecount
= 0;
1424 struct free_area
*area
;
1425 struct list_head
*curr
;
1426 bool overflow
= false;
1428 area
= &(zone
->free_area
[order
]);
1430 list_for_each(curr
, &area
->free_list
[mtype
]) {
1432 * Cap the free_list iteration because it might
1433 * be really large and we are under a spinlock
1434 * so a long time spent here could trigger a
1435 * hard lockup detector. Anyway this is a
1436 * debugging tool so knowing there is a handful
1437 * of pages of this order should be more than
1440 if (++freecount
>= 100000) {
1445 seq_printf(m
, "%s%6lu ", overflow
? ">" : "", freecount
);
1446 spin_unlock_irq(&zone
->lock
);
1448 spin_lock_irq(&zone
->lock
);
1454 /* Print out the free pages at each order for each migatetype */
1455 static int pagetypeinfo_showfree(struct seq_file
*m
, void *arg
)
1458 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1461 seq_printf(m
, "%-43s ", "Free pages count per migrate type at order");
1462 for (order
= 0; order
< MAX_ORDER
; ++order
)
1463 seq_printf(m
, "%6d ", order
);
1466 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 int 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
);
1520 * Print out the number of pageblocks for each migratetype that contain pages
1521 * of other types. This gives an indication of how well fallbacks are being
1522 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER
1523 * to determine what is going on
1525 static void pagetypeinfo_showmixedcount(struct seq_file
*m
, pg_data_t
*pgdat
)
1527 #ifdef CONFIG_PAGE_OWNER
1530 if (!static_branch_unlikely(&page_owner_inited
))
1533 drain_all_pages(NULL
);
1535 seq_printf(m
, "\n%-23s", "Number of mixed blocks ");
1536 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
1537 seq_printf(m
, "%12s ", migratetype_names
[mtype
]);
1540 walk_zones_in_node(m
, pgdat
, true, true,
1541 pagetypeinfo_showmixedcount_print
);
1542 #endif /* CONFIG_PAGE_OWNER */
1546 * This prints out statistics in relation to grouping pages by mobility.
1547 * It is expensive to collect so do not constantly read the file.
1549 static int pagetypeinfo_show(struct seq_file
*m
, void *arg
)
1551 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1553 /* check memoryless node */
1554 if (!node_state(pgdat
->node_id
, N_MEMORY
))
1557 seq_printf(m
, "Page block order: %d\n", pageblock_order
);
1558 seq_printf(m
, "Pages per block: %lu\n", pageblock_nr_pages
);
1560 pagetypeinfo_showfree(m
, pgdat
);
1561 pagetypeinfo_showblockcount(m
, pgdat
);
1562 pagetypeinfo_showmixedcount(m
, pgdat
);
1567 static const struct seq_operations fragmentation_op
= {
1568 .start
= frag_start
,
1574 static const struct seq_operations pagetypeinfo_op
= {
1575 .start
= frag_start
,
1578 .show
= pagetypeinfo_show
,
1581 static bool is_zone_first_populated(pg_data_t
*pgdat
, struct zone
*zone
)
1585 for (zid
= 0; zid
< MAX_NR_ZONES
; zid
++) {
1586 struct zone
*compare
= &pgdat
->node_zones
[zid
];
1588 if (populated_zone(compare
))
1589 return zone
== compare
;
1595 static void zoneinfo_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
1599 seq_printf(m
, "Node %d, zone %8s", pgdat
->node_id
, zone
->name
);
1600 if (is_zone_first_populated(pgdat
, zone
)) {
1601 seq_printf(m
, "\n per-node stats");
1602 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++) {
1603 unsigned long pages
= node_page_state_pages(pgdat
, i
);
1605 if (vmstat_item_print_in_thp(i
))
1606 pages
/= HPAGE_PMD_NR
;
1607 seq_printf(m
, "\n %-12s %lu", node_stat_name(i
),
1620 zone_page_state(zone
, NR_FREE_PAGES
),
1621 min_wmark_pages(zone
),
1622 low_wmark_pages(zone
),
1623 high_wmark_pages(zone
),
1624 zone
->spanned_pages
,
1625 zone
->present_pages
,
1626 zone_managed_pages(zone
),
1627 zone_cma_pages(zone
));
1630 "\n protection: (%ld",
1631 zone
->lowmem_reserve
[0]);
1632 for (i
= 1; i
< ARRAY_SIZE(zone
->lowmem_reserve
); i
++)
1633 seq_printf(m
, ", %ld", zone
->lowmem_reserve
[i
]);
1636 /* If unpopulated, no other information is useful */
1637 if (!populated_zone(zone
)) {
1642 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
1643 seq_printf(m
, "\n %-12s %lu", zone_stat_name(i
),
1644 zone_page_state(zone
, i
));
1647 for (i
= 0; i
< NR_VM_NUMA_EVENT_ITEMS
; i
++)
1648 seq_printf(m
, "\n %-12s %lu", numa_stat_name(i
),
1649 zone_numa_event_state(zone
, i
));
1652 seq_printf(m
, "\n pagesets");
1653 for_each_online_cpu(i
) {
1654 struct per_cpu_pages
*pcp
;
1655 struct per_cpu_zonestat __maybe_unused
*pzstats
;
1657 pcp
= per_cpu_ptr(zone
->per_cpu_pageset
, i
);
1668 pzstats
= per_cpu_ptr(zone
->per_cpu_zonestats
, i
);
1669 seq_printf(m
, "\n vm stats threshold: %d",
1670 pzstats
->stat_threshold
);
1674 "\n node_unreclaimable: %u"
1675 "\n start_pfn: %lu",
1676 pgdat
->kswapd_failures
>= MAX_RECLAIM_RETRIES
,
1677 zone
->zone_start_pfn
);
1682 * Output information about zones in @pgdat. All zones are printed regardless
1683 * of whether they are populated or not: lowmem_reserve_ratio operates on the
1684 * set of all zones and userspace would not be aware of such zones if they are
1685 * suppressed here (zoneinfo displays the effect of lowmem_reserve_ratio).
1687 static int zoneinfo_show(struct seq_file
*m
, void *arg
)
1689 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1690 walk_zones_in_node(m
, pgdat
, false, false, zoneinfo_show_print
);
1694 static const struct seq_operations zoneinfo_op
= {
1695 .start
= frag_start
, /* iterate over all zones. The same as in
1699 .show
= zoneinfo_show
,
1702 #define NR_VMSTAT_ITEMS (NR_VM_ZONE_STAT_ITEMS + \
1703 NR_VM_NUMA_EVENT_ITEMS + \
1704 NR_VM_NODE_STAT_ITEMS + \
1705 NR_VM_WRITEBACK_STAT_ITEMS + \
1706 (IS_ENABLED(CONFIG_VM_EVENT_COUNTERS) ? \
1707 NR_VM_EVENT_ITEMS : 0))
1709 static void *vmstat_start(struct seq_file
*m
, loff_t
*pos
)
1714 if (*pos
>= NR_VMSTAT_ITEMS
)
1717 BUILD_BUG_ON(ARRAY_SIZE(vmstat_text
) < NR_VMSTAT_ITEMS
);
1718 fold_vm_numa_events();
1719 v
= kmalloc_array(NR_VMSTAT_ITEMS
, sizeof(unsigned long), GFP_KERNEL
);
1722 return ERR_PTR(-ENOMEM
);
1723 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
1724 v
[i
] = global_zone_page_state(i
);
1725 v
+= NR_VM_ZONE_STAT_ITEMS
;
1728 for (i
= 0; i
< NR_VM_NUMA_EVENT_ITEMS
; i
++)
1729 v
[i
] = global_numa_event_state(i
);
1730 v
+= NR_VM_NUMA_EVENT_ITEMS
;
1733 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++) {
1734 v
[i
] = global_node_page_state_pages(i
);
1735 if (vmstat_item_print_in_thp(i
))
1736 v
[i
] /= HPAGE_PMD_NR
;
1738 v
+= NR_VM_NODE_STAT_ITEMS
;
1740 global_dirty_limits(v
+ NR_DIRTY_BG_THRESHOLD
,
1741 v
+ NR_DIRTY_THRESHOLD
);
1742 v
+= NR_VM_WRITEBACK_STAT_ITEMS
;
1744 #ifdef CONFIG_VM_EVENT_COUNTERS
1746 v
[PGPGIN
] /= 2; /* sectors -> kbytes */
1749 return (unsigned long *)m
->private + *pos
;
1752 static void *vmstat_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
1755 if (*pos
>= NR_VMSTAT_ITEMS
)
1757 return (unsigned long *)m
->private + *pos
;
1760 static int vmstat_show(struct seq_file
*m
, void *arg
)
1762 unsigned long *l
= arg
;
1763 unsigned long off
= l
- (unsigned long *)m
->private;
1765 seq_puts(m
, vmstat_text
[off
]);
1766 seq_put_decimal_ull(m
, " ", *l
);
1769 if (off
== NR_VMSTAT_ITEMS
- 1) {
1771 * We've come to the end - add any deprecated counters to avoid
1772 * breaking userspace which might depend on them being present.
1774 seq_puts(m
, "nr_unstable 0\n");
1779 static void vmstat_stop(struct seq_file
*m
, void *arg
)
1785 static const struct seq_operations vmstat_op
= {
1786 .start
= vmstat_start
,
1787 .next
= vmstat_next
,
1788 .stop
= vmstat_stop
,
1789 .show
= vmstat_show
,
1791 #endif /* CONFIG_PROC_FS */
1794 static DEFINE_PER_CPU(struct delayed_work
, vmstat_work
);
1795 int sysctl_stat_interval __read_mostly
= HZ
;
1797 #ifdef CONFIG_PROC_FS
1798 static void refresh_vm_stats(struct work_struct
*work
)
1800 refresh_cpu_vm_stats(true);
1803 int vmstat_refresh(struct ctl_table
*table
, int write
,
1804 void *buffer
, size_t *lenp
, loff_t
*ppos
)
1811 * The regular update, every sysctl_stat_interval, may come later
1812 * than expected: leaving a significant amount in per_cpu buckets.
1813 * This is particularly misleading when checking a quantity of HUGE
1814 * pages, immediately after running a test. /proc/sys/vm/stat_refresh,
1815 * which can equally be echo'ed to or cat'ted from (by root),
1816 * can be used to update the stats just before reading them.
1818 * Oh, and since global_zone_page_state() etc. are so careful to hide
1819 * transiently negative values, report an error here if any of
1820 * the stats is negative, so we know to go looking for imbalance.
1822 err
= schedule_on_each_cpu(refresh_vm_stats
);
1825 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++) {
1827 * Skip checking stats known to go negative occasionally.
1830 case NR_ZONE_WRITE_PENDING
:
1831 case NR_FREE_CMA_PAGES
:
1834 val
= atomic_long_read(&vm_zone_stat
[i
]);
1836 pr_warn("%s: %s %ld\n",
1837 __func__
, zone_stat_name(i
), val
);
1840 for (i
= 0; i
< NR_VM_NODE_STAT_ITEMS
; i
++) {
1842 * Skip checking stats known to go negative occasionally.
1848 val
= atomic_long_read(&vm_node_stat
[i
]);
1850 pr_warn("%s: %s %ld\n",
1851 __func__
, node_stat_name(i
), val
);
1860 #endif /* CONFIG_PROC_FS */
1862 static void vmstat_update(struct work_struct
*w
)
1864 if (refresh_cpu_vm_stats(true)) {
1866 * Counters were updated so we expect more updates
1867 * to occur in the future. Keep on running the
1868 * update worker thread.
1870 queue_delayed_work_on(smp_processor_id(), mm_percpu_wq
,
1871 this_cpu_ptr(&vmstat_work
),
1872 round_jiffies_relative(sysctl_stat_interval
));
1877 * Switch off vmstat processing and then fold all the remaining differentials
1878 * until the diffs stay at zero. The function is used by NOHZ and can only be
1879 * invoked when tick processing is not active.
1882 * Check if the diffs for a certain cpu indicate that
1883 * an update is needed.
1885 static bool need_update(int cpu
)
1887 pg_data_t
*last_pgdat
= NULL
;
1890 for_each_populated_zone(zone
) {
1891 struct per_cpu_zonestat
*pzstats
= per_cpu_ptr(zone
->per_cpu_zonestats
, cpu
);
1892 struct per_cpu_nodestat
*n
;
1895 * The fast way of checking if there are any vmstat diffs.
1897 if (memchr_inv(pzstats
->vm_stat_diff
, 0, NR_VM_ZONE_STAT_ITEMS
*
1898 sizeof(pzstats
->vm_stat_diff
[0])))
1901 if (last_pgdat
== zone
->zone_pgdat
)
1903 last_pgdat
= zone
->zone_pgdat
;
1904 n
= per_cpu_ptr(zone
->zone_pgdat
->per_cpu_nodestats
, cpu
);
1905 if (memchr_inv(n
->vm_node_stat_diff
, 0, NR_VM_NODE_STAT_ITEMS
*
1906 sizeof(n
->vm_node_stat_diff
[0])))
1913 * Switch off vmstat processing and then fold all the remaining differentials
1914 * until the diffs stay at zero. The function is used by NOHZ and can only be
1915 * invoked when tick processing is not active.
1917 void quiet_vmstat(void)
1919 if (system_state
!= SYSTEM_RUNNING
)
1922 if (!delayed_work_pending(this_cpu_ptr(&vmstat_work
)))
1925 if (!need_update(smp_processor_id()))
1929 * Just refresh counters and do not care about the pending delayed
1930 * vmstat_update. It doesn't fire that often to matter and canceling
1931 * it would be too expensive from this path.
1932 * vmstat_shepherd will take care about that for us.
1934 refresh_cpu_vm_stats(false);
1938 * Shepherd worker thread that checks the
1939 * differentials of processors that have their worker
1940 * threads for vm statistics updates disabled because of
1943 static void vmstat_shepherd(struct work_struct
*w
);
1945 static DECLARE_DEFERRABLE_WORK(shepherd
, vmstat_shepherd
);
1947 static void vmstat_shepherd(struct work_struct
*w
)
1952 /* Check processors whose vmstat worker threads have been disabled */
1953 for_each_online_cpu(cpu
) {
1954 struct delayed_work
*dw
= &per_cpu(vmstat_work
, cpu
);
1956 if (!delayed_work_pending(dw
) && need_update(cpu
))
1957 queue_delayed_work_on(cpu
, mm_percpu_wq
, dw
, 0);
1963 schedule_delayed_work(&shepherd
,
1964 round_jiffies_relative(sysctl_stat_interval
));
1967 static void __init
start_shepherd_timer(void)
1971 for_each_possible_cpu(cpu
)
1972 INIT_DEFERRABLE_WORK(per_cpu_ptr(&vmstat_work
, cpu
),
1975 schedule_delayed_work(&shepherd
,
1976 round_jiffies_relative(sysctl_stat_interval
));
1979 static void __init
init_cpu_node_state(void)
1983 for_each_online_node(node
) {
1984 if (cpumask_weight(cpumask_of_node(node
)) > 0)
1985 node_set_state(node
, N_CPU
);
1989 static int vmstat_cpu_online(unsigned int cpu
)
1991 refresh_zone_stat_thresholds();
1992 node_set_state(cpu_to_node(cpu
), N_CPU
);
1996 static int vmstat_cpu_down_prep(unsigned int cpu
)
1998 cancel_delayed_work_sync(&per_cpu(vmstat_work
, cpu
));
2002 static int vmstat_cpu_dead(unsigned int cpu
)
2004 const struct cpumask
*node_cpus
;
2007 node
= cpu_to_node(cpu
);
2009 refresh_zone_stat_thresholds();
2010 node_cpus
= cpumask_of_node(node
);
2011 if (cpumask_weight(node_cpus
) > 0)
2014 node_clear_state(node
, N_CPU
);
2020 struct workqueue_struct
*mm_percpu_wq
;
2022 void __init
init_mm_internals(void)
2024 int ret __maybe_unused
;
2026 mm_percpu_wq
= alloc_workqueue("mm_percpu_wq", WQ_MEM_RECLAIM
, 0);
2029 ret
= cpuhp_setup_state_nocalls(CPUHP_MM_VMSTAT_DEAD
, "mm/vmstat:dead",
2030 NULL
, vmstat_cpu_dead
);
2032 pr_err("vmstat: failed to register 'dead' hotplug state\n");
2034 ret
= cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN
, "mm/vmstat:online",
2036 vmstat_cpu_down_prep
);
2038 pr_err("vmstat: failed to register 'online' hotplug state\n");
2041 init_cpu_node_state();
2044 start_shepherd_timer();
2046 #ifdef CONFIG_PROC_FS
2047 proc_create_seq("buddyinfo", 0444, NULL
, &fragmentation_op
);
2048 proc_create_seq("pagetypeinfo", 0400, NULL
, &pagetypeinfo_op
);
2049 proc_create_seq("vmstat", 0444, NULL
, &vmstat_op
);
2050 proc_create_seq("zoneinfo", 0444, NULL
, &zoneinfo_op
);
2054 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
2057 * Return an index indicating how much of the available free memory is
2058 * unusable for an allocation of the requested size.
2060 static int unusable_free_index(unsigned int order
,
2061 struct contig_page_info
*info
)
2063 /* No free memory is interpreted as all free memory is unusable */
2064 if (info
->free_pages
== 0)
2068 * Index should be a value between 0 and 1. Return a value to 3
2071 * 0 => no fragmentation
2072 * 1 => high fragmentation
2074 return div_u64((info
->free_pages
- (info
->free_blocks_suitable
<< order
)) * 1000ULL, info
->free_pages
);
2078 static void unusable_show_print(struct seq_file
*m
,
2079 pg_data_t
*pgdat
, struct zone
*zone
)
2083 struct contig_page_info info
;
2085 seq_printf(m
, "Node %d, zone %8s ",
2088 for (order
= 0; order
< MAX_ORDER
; ++order
) {
2089 fill_contig_page_info(zone
, order
, &info
);
2090 index
= unusable_free_index(order
, &info
);
2091 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
2098 * Display unusable free space index
2100 * The unusable free space index measures how much of the available free
2101 * memory cannot be used to satisfy an allocation of a given size and is a
2102 * value between 0 and 1. The higher the value, the more of free memory is
2103 * unusable and by implication, the worse the external fragmentation is. This
2104 * can be expressed as a percentage by multiplying by 100.
2106 static int unusable_show(struct seq_file
*m
, void *arg
)
2108 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
2110 /* check memoryless node */
2111 if (!node_state(pgdat
->node_id
, N_MEMORY
))
2114 walk_zones_in_node(m
, pgdat
, true, false, unusable_show_print
);
2119 static const struct seq_operations unusable_sops
= {
2120 .start
= frag_start
,
2123 .show
= unusable_show
,
2126 DEFINE_SEQ_ATTRIBUTE(unusable
);
2128 static void extfrag_show_print(struct seq_file
*m
,
2129 pg_data_t
*pgdat
, struct zone
*zone
)
2134 /* Alloc on stack as interrupts are disabled for zone walk */
2135 struct contig_page_info info
;
2137 seq_printf(m
, "Node %d, zone %8s ",
2140 for (order
= 0; order
< MAX_ORDER
; ++order
) {
2141 fill_contig_page_info(zone
, order
, &info
);
2142 index
= __fragmentation_index(order
, &info
);
2143 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
2150 * Display fragmentation index for orders that allocations would fail for
2152 static int extfrag_show(struct seq_file
*m
, void *arg
)
2154 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
2156 walk_zones_in_node(m
, pgdat
, true, false, extfrag_show_print
);
2161 static const struct seq_operations extfrag_sops
= {
2162 .start
= frag_start
,
2165 .show
= extfrag_show
,
2168 DEFINE_SEQ_ATTRIBUTE(extfrag
);
2170 static int __init
extfrag_debug_init(void)
2172 struct dentry
*extfrag_debug_root
;
2174 extfrag_debug_root
= debugfs_create_dir("extfrag", NULL
);
2176 debugfs_create_file("unusable_index", 0444, extfrag_debug_root
, NULL
,
2179 debugfs_create_file("extfrag_index", 0444, extfrag_debug_root
, NULL
,
2185 module_init(extfrag_debug_init
);