4 * Manages VM statistics
5 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * Copyright (C) 2006 Silicon Graphics, Inc.,
9 * Christoph Lameter <christoph@lameter.com>
13 #include <linux/err.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/cpu.h>
17 #include <linux/vmstat.h>
18 #include <linux/sched.h>
19 #include <linux/math64.h>
21 #ifdef CONFIG_VM_EVENT_COUNTERS
22 DEFINE_PER_CPU(struct vm_event_state
, vm_event_states
) = {{0}};
23 EXPORT_PER_CPU_SYMBOL(vm_event_states
);
25 static void sum_vm_events(unsigned long *ret
, const struct cpumask
*cpumask
)
30 memset(ret
, 0, NR_VM_EVENT_ITEMS
* sizeof(unsigned long));
32 for_each_cpu(cpu
, cpumask
) {
33 struct vm_event_state
*this = &per_cpu(vm_event_states
, cpu
);
35 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++)
36 ret
[i
] += this->event
[i
];
41 * Accumulate the vm event counters across all CPUs.
42 * The result is unavoidably approximate - it can change
43 * during and after execution of this function.
45 void all_vm_events(unsigned long *ret
)
48 sum_vm_events(ret
, cpu_online_mask
);
51 EXPORT_SYMBOL_GPL(all_vm_events
);
55 * Fold the foreign cpu events into our own.
57 * This is adding to the events on one processor
58 * but keeps the global counts constant.
60 void vm_events_fold_cpu(int cpu
)
62 struct vm_event_state
*fold_state
= &per_cpu(vm_event_states
, cpu
);
65 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++) {
66 count_vm_events(i
, fold_state
->event
[i
]);
67 fold_state
->event
[i
] = 0;
70 #endif /* CONFIG_HOTPLUG */
72 #endif /* CONFIG_VM_EVENT_COUNTERS */
75 * Manage combined zone based / global counters
77 * vm_stat contains the global counters
79 atomic_long_t vm_stat
[NR_VM_ZONE_STAT_ITEMS
];
80 EXPORT_SYMBOL(vm_stat
);
84 static int calculate_pressure_threshold(struct zone
*zone
)
87 int watermark_distance
;
90 * As vmstats are not up to date, there is drift between the estimated
91 * and real values. For high thresholds and a high number of CPUs, it
92 * is possible for the min watermark to be breached while the estimated
93 * value looks fine. The pressure threshold is a reduced value such
94 * that even the maximum amount of drift will not accidentally breach
97 watermark_distance
= low_wmark_pages(zone
) - min_wmark_pages(zone
);
98 threshold
= max(1, (int)(watermark_distance
/ num_online_cpus()));
101 * Maximum threshold is 125
103 threshold
= min(125, threshold
);
108 static int calculate_threshold(struct zone
*zone
)
111 int mem
; /* memory in 128 MB units */
114 * The threshold scales with the number of processors and the amount
115 * of memory per zone. More memory means that we can defer updates for
116 * longer, more processors could lead to more contention.
117 * fls() is used to have a cheap way of logarithmic scaling.
119 * Some sample thresholds:
121 * Threshold Processors (fls) Zonesize fls(mem+1)
122 * ------------------------------------------------------------------
139 * 125 1024 10 8-16 GB 8
140 * 125 1024 10 16-32 GB 9
143 mem
= zone
->present_pages
>> (27 - PAGE_SHIFT
);
145 threshold
= 2 * fls(num_online_cpus()) * (1 + fls(mem
));
148 * Maximum threshold is 125
150 threshold
= min(125, threshold
);
156 * Refresh the thresholds for each zone.
158 static void refresh_zone_stat_thresholds(void)
164 for_each_populated_zone(zone
) {
165 unsigned long max_drift
, tolerate_drift
;
167 threshold
= calculate_threshold(zone
);
169 for_each_online_cpu(cpu
)
170 per_cpu_ptr(zone
->pageset
, cpu
)->stat_threshold
174 * Only set percpu_drift_mark if there is a danger that
175 * NR_FREE_PAGES reports the low watermark is ok when in fact
176 * the min watermark could be breached by an allocation
178 tolerate_drift
= low_wmark_pages(zone
) - min_wmark_pages(zone
);
179 max_drift
= num_online_cpus() * threshold
;
180 if (max_drift
> tolerate_drift
)
181 zone
->percpu_drift_mark
= high_wmark_pages(zone
) +
186 void reduce_pgdat_percpu_threshold(pg_data_t
*pgdat
)
194 for (i
= 0; i
< pgdat
->nr_zones
; i
++) {
195 zone
= &pgdat
->node_zones
[i
];
196 if (!zone
->percpu_drift_mark
)
199 threshold
= calculate_pressure_threshold(zone
);
200 for_each_online_cpu(cpu
)
201 per_cpu_ptr(zone
->pageset
, cpu
)->stat_threshold
207 void restore_pgdat_percpu_threshold(pg_data_t
*pgdat
)
215 for (i
= 0; i
< pgdat
->nr_zones
; i
++) {
216 zone
= &pgdat
->node_zones
[i
];
217 if (!zone
->percpu_drift_mark
)
220 threshold
= calculate_threshold(zone
);
221 for_each_online_cpu(cpu
)
222 per_cpu_ptr(zone
->pageset
, cpu
)->stat_threshold
229 * For use when we know that interrupts are disabled.
231 void __mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
234 struct per_cpu_pageset
*pcp
= this_cpu_ptr(zone
->pageset
);
236 s8
*p
= pcp
->vm_stat_diff
+ item
;
241 if (unlikely(x
> pcp
->stat_threshold
|| x
< -pcp
->stat_threshold
)) {
242 zone_page_state_add(x
, zone
, item
);
247 EXPORT_SYMBOL(__mod_zone_page_state
);
250 * For an unknown interrupt state
252 void mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
257 local_irq_save(flags
);
258 __mod_zone_page_state(zone
, item
, delta
);
259 local_irq_restore(flags
);
261 EXPORT_SYMBOL(mod_zone_page_state
);
264 * Optimized increment and decrement functions.
266 * These are only for a single page and therefore can take a struct page *
267 * argument instead of struct zone *. This allows the inclusion of the code
268 * generated for page_zone(page) into the optimized functions.
270 * No overflow check is necessary and therefore the differential can be
271 * incremented or decremented in place which may allow the compilers to
272 * generate better code.
273 * The increment or decrement is known and therefore one boundary check can
276 * NOTE: These functions are very performance sensitive. Change only
279 * Some processors have inc/dec instructions that are atomic vs an interrupt.
280 * However, the code must first determine the differential location in a zone
281 * based on the processor number and then inc/dec the counter. There is no
282 * guarantee without disabling preemption that the processor will not change
283 * in between and therefore the atomicity vs. interrupt cannot be exploited
284 * in a useful way here.
286 void __inc_zone_state(struct zone
*zone
, enum zone_stat_item item
)
288 struct per_cpu_pageset
*pcp
= this_cpu_ptr(zone
->pageset
);
289 s8
*p
= pcp
->vm_stat_diff
+ item
;
293 if (unlikely(*p
> pcp
->stat_threshold
)) {
294 int overstep
= pcp
->stat_threshold
/ 2;
296 zone_page_state_add(*p
+ overstep
, zone
, item
);
301 void __inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
303 __inc_zone_state(page_zone(page
), item
);
305 EXPORT_SYMBOL(__inc_zone_page_state
);
307 void __dec_zone_state(struct zone
*zone
, enum zone_stat_item item
)
309 struct per_cpu_pageset
*pcp
= this_cpu_ptr(zone
->pageset
);
310 s8
*p
= pcp
->vm_stat_diff
+ item
;
314 if (unlikely(*p
< - pcp
->stat_threshold
)) {
315 int overstep
= pcp
->stat_threshold
/ 2;
317 zone_page_state_add(*p
- overstep
, zone
, item
);
322 void __dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
324 __dec_zone_state(page_zone(page
), item
);
326 EXPORT_SYMBOL(__dec_zone_page_state
);
328 void inc_zone_state(struct zone
*zone
, enum zone_stat_item item
)
332 local_irq_save(flags
);
333 __inc_zone_state(zone
, item
);
334 local_irq_restore(flags
);
337 void inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
342 zone
= page_zone(page
);
343 local_irq_save(flags
);
344 __inc_zone_state(zone
, item
);
345 local_irq_restore(flags
);
347 EXPORT_SYMBOL(inc_zone_page_state
);
349 void dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
353 local_irq_save(flags
);
354 __dec_zone_page_state(page
, item
);
355 local_irq_restore(flags
);
357 EXPORT_SYMBOL(dec_zone_page_state
);
360 * Update the zone counters for one cpu.
362 * The cpu specified must be either the current cpu or a processor that
363 * is not online. If it is the current cpu then the execution thread must
364 * be pinned to the current cpu.
366 * Note that refresh_cpu_vm_stats strives to only access
367 * node local memory. The per cpu pagesets on remote zones are placed
368 * in the memory local to the processor using that pageset. So the
369 * loop over all zones will access a series of cachelines local to
372 * The call to zone_page_state_add updates the cachelines with the
373 * statistics in the remote zone struct as well as the global cachelines
374 * with the global counters. These could cause remote node cache line
375 * bouncing and will have to be only done when necessary.
377 void refresh_cpu_vm_stats(int cpu
)
381 int global_diff
[NR_VM_ZONE_STAT_ITEMS
] = { 0, };
383 for_each_populated_zone(zone
) {
384 struct per_cpu_pageset
*p
;
386 p
= per_cpu_ptr(zone
->pageset
, cpu
);
388 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
389 if (p
->vm_stat_diff
[i
]) {
393 local_irq_save(flags
);
394 v
= p
->vm_stat_diff
[i
];
395 p
->vm_stat_diff
[i
] = 0;
396 local_irq_restore(flags
);
397 atomic_long_add(v
, &zone
->vm_stat
[i
]);
400 /* 3 seconds idle till flush */
407 * Deal with draining the remote pageset of this
410 * Check if there are pages remaining in this pageset
411 * if not then there is nothing to expire.
413 if (!p
->expire
|| !p
->pcp
.count
)
417 * We never drain zones local to this processor.
419 if (zone_to_nid(zone
) == numa_node_id()) {
429 drain_zone_pages(zone
, &p
->pcp
);
433 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
435 atomic_long_add(global_diff
[i
], &vm_stat
[i
]);
442 * zonelist = the list of zones passed to the allocator
443 * z = the zone from which the allocation occurred.
445 * Must be called with interrupts disabled.
447 void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
449 if (z
->zone_pgdat
== preferred_zone
->zone_pgdat
) {
450 __inc_zone_state(z
, NUMA_HIT
);
452 __inc_zone_state(z
, NUMA_MISS
);
453 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
455 if (z
->node
== numa_node_id())
456 __inc_zone_state(z
, NUMA_LOCAL
);
458 __inc_zone_state(z
, NUMA_OTHER
);
462 #ifdef CONFIG_COMPACTION
463 struct contig_page_info
{
464 unsigned long free_pages
;
465 unsigned long free_blocks_total
;
466 unsigned long free_blocks_suitable
;
470 * Calculate the number of free pages in a zone, how many contiguous
471 * pages are free and how many are large enough to satisfy an allocation of
472 * the target size. Note that this function makes no attempt to estimate
473 * how many suitable free blocks there *might* be if MOVABLE pages were
474 * migrated. Calculating that is possible, but expensive and can be
475 * figured out from userspace
477 static void fill_contig_page_info(struct zone
*zone
,
478 unsigned int suitable_order
,
479 struct contig_page_info
*info
)
483 info
->free_pages
= 0;
484 info
->free_blocks_total
= 0;
485 info
->free_blocks_suitable
= 0;
487 for (order
= 0; order
< MAX_ORDER
; order
++) {
488 unsigned long blocks
;
490 /* Count number of free blocks */
491 blocks
= zone
->free_area
[order
].nr_free
;
492 info
->free_blocks_total
+= blocks
;
494 /* Count free base pages */
495 info
->free_pages
+= blocks
<< order
;
497 /* Count the suitable free blocks */
498 if (order
>= suitable_order
)
499 info
->free_blocks_suitable
+= blocks
<<
500 (order
- suitable_order
);
505 * A fragmentation index only makes sense if an allocation of a requested
506 * size would fail. If that is true, the fragmentation index indicates
507 * whether external fragmentation or a lack of memory was the problem.
508 * The value can be used to determine if page reclaim or compaction
511 static int __fragmentation_index(unsigned int order
, struct contig_page_info
*info
)
513 unsigned long requested
= 1UL << order
;
515 if (!info
->free_blocks_total
)
518 /* Fragmentation index only makes sense when a request would fail */
519 if (info
->free_blocks_suitable
)
523 * Index is between 0 and 1 so return within 3 decimal places
525 * 0 => allocation would fail due to lack of memory
526 * 1 => allocation would fail due to fragmentation
528 return 1000 - div_u64( (1000+(div_u64(info
->free_pages
* 1000ULL, requested
))), info
->free_blocks_total
);
531 /* Same as __fragmentation index but allocs contig_page_info on stack */
532 int fragmentation_index(struct zone
*zone
, unsigned int order
)
534 struct contig_page_info info
;
536 fill_contig_page_info(zone
, order
, &info
);
537 return __fragmentation_index(order
, &info
);
541 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
542 #include <linux/proc_fs.h>
543 #include <linux/seq_file.h>
545 static char * const migratetype_names
[MIGRATE_TYPES
] = {
553 static void *frag_start(struct seq_file
*m
, loff_t
*pos
)
557 for (pgdat
= first_online_pgdat();
559 pgdat
= next_online_pgdat(pgdat
))
565 static void *frag_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
567 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
570 return next_online_pgdat(pgdat
);
573 static void frag_stop(struct seq_file
*m
, void *arg
)
577 /* Walk all the zones in a node and print using a callback */
578 static void walk_zones_in_node(struct seq_file
*m
, pg_data_t
*pgdat
,
579 void (*print
)(struct seq_file
*m
, pg_data_t
*, struct zone
*))
582 struct zone
*node_zones
= pgdat
->node_zones
;
585 for (zone
= node_zones
; zone
- node_zones
< MAX_NR_ZONES
; ++zone
) {
586 if (!populated_zone(zone
))
589 spin_lock_irqsave(&zone
->lock
, flags
);
590 print(m
, pgdat
, zone
);
591 spin_unlock_irqrestore(&zone
->lock
, flags
);
596 #ifdef CONFIG_PROC_FS
597 static void frag_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
602 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
603 for (order
= 0; order
< MAX_ORDER
; ++order
)
604 seq_printf(m
, "%6lu ", zone
->free_area
[order
].nr_free
);
609 * This walks the free areas for each zone.
611 static int frag_show(struct seq_file
*m
, void *arg
)
613 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
614 walk_zones_in_node(m
, pgdat
, frag_show_print
);
618 static void pagetypeinfo_showfree_print(struct seq_file
*m
,
619 pg_data_t
*pgdat
, struct zone
*zone
)
623 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++) {
624 seq_printf(m
, "Node %4d, zone %8s, type %12s ",
627 migratetype_names
[mtype
]);
628 for (order
= 0; order
< MAX_ORDER
; ++order
) {
629 unsigned long freecount
= 0;
630 struct free_area
*area
;
631 struct list_head
*curr
;
633 area
= &(zone
->free_area
[order
]);
635 list_for_each(curr
, &area
->free_list
[mtype
])
637 seq_printf(m
, "%6lu ", freecount
);
643 /* Print out the free pages at each order for each migatetype */
644 static int pagetypeinfo_showfree(struct seq_file
*m
, void *arg
)
647 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
650 seq_printf(m
, "%-43s ", "Free pages count per migrate type at order");
651 for (order
= 0; order
< MAX_ORDER
; ++order
)
652 seq_printf(m
, "%6d ", order
);
655 walk_zones_in_node(m
, pgdat
, pagetypeinfo_showfree_print
);
660 static void pagetypeinfo_showblockcount_print(struct seq_file
*m
,
661 pg_data_t
*pgdat
, struct zone
*zone
)
665 unsigned long start_pfn
= zone
->zone_start_pfn
;
666 unsigned long end_pfn
= start_pfn
+ zone
->spanned_pages
;
667 unsigned long count
[MIGRATE_TYPES
] = { 0, };
669 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
675 page
= pfn_to_page(pfn
);
677 /* Watch for unexpected holes punched in the memmap */
678 if (!memmap_valid_within(pfn
, page
, zone
))
681 mtype
= get_pageblock_migratetype(page
);
683 if (mtype
< MIGRATE_TYPES
)
688 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
689 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
690 seq_printf(m
, "%12lu ", count
[mtype
]);
694 /* Print out the free pages at each order for each migratetype */
695 static int pagetypeinfo_showblockcount(struct seq_file
*m
, void *arg
)
698 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
700 seq_printf(m
, "\n%-23s", "Number of blocks type ");
701 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
702 seq_printf(m
, "%12s ", migratetype_names
[mtype
]);
704 walk_zones_in_node(m
, pgdat
, pagetypeinfo_showblockcount_print
);
710 * This prints out statistics in relation to grouping pages by mobility.
711 * It is expensive to collect so do not constantly read the file.
713 static int pagetypeinfo_show(struct seq_file
*m
, void *arg
)
715 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
717 /* check memoryless node */
718 if (!node_state(pgdat
->node_id
, N_HIGH_MEMORY
))
721 seq_printf(m
, "Page block order: %d\n", pageblock_order
);
722 seq_printf(m
, "Pages per block: %lu\n", pageblock_nr_pages
);
724 pagetypeinfo_showfree(m
, pgdat
);
725 pagetypeinfo_showblockcount(m
, pgdat
);
730 static const struct seq_operations fragmentation_op
= {
737 static int fragmentation_open(struct inode
*inode
, struct file
*file
)
739 return seq_open(file
, &fragmentation_op
);
742 static const struct file_operations fragmentation_file_operations
= {
743 .open
= fragmentation_open
,
746 .release
= seq_release
,
749 static const struct seq_operations pagetypeinfo_op
= {
753 .show
= pagetypeinfo_show
,
756 static int pagetypeinfo_open(struct inode
*inode
, struct file
*file
)
758 return seq_open(file
, &pagetypeinfo_op
);
761 static const struct file_operations pagetypeinfo_file_ops
= {
762 .open
= pagetypeinfo_open
,
765 .release
= seq_release
,
768 #ifdef CONFIG_ZONE_DMA
769 #define TEXT_FOR_DMA(xx) xx "_dma",
771 #define TEXT_FOR_DMA(xx)
774 #ifdef CONFIG_ZONE_DMA32
775 #define TEXT_FOR_DMA32(xx) xx "_dma32",
777 #define TEXT_FOR_DMA32(xx)
780 #ifdef CONFIG_HIGHMEM
781 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
783 #define TEXT_FOR_HIGHMEM(xx)
786 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
787 TEXT_FOR_HIGHMEM(xx) xx "_movable",
789 static const char * const vmstat_text
[] = {
790 /* Zoned VM counters */
803 "nr_slab_reclaimable",
804 "nr_slab_unreclaimable",
805 "nr_page_table_pages",
823 #ifdef CONFIG_VM_EVENT_COUNTERS
829 TEXTS_FOR_ZONES("pgalloc")
838 TEXTS_FOR_ZONES("pgrefill")
839 TEXTS_FOR_ZONES("pgsteal")
840 TEXTS_FOR_ZONES("pgscan_kswapd")
841 TEXTS_FOR_ZONES("pgscan_direct")
844 "zone_reclaim_failed",
850 "kswapd_low_wmark_hit_quickly",
851 "kswapd_high_wmark_hit_quickly",
852 "kswapd_skip_congestion_wait",
858 #ifdef CONFIG_COMPACTION
859 "compact_blocks_moved",
860 "compact_pages_moved",
861 "compact_pagemigrate_failed",
867 #ifdef CONFIG_HUGETLB_PAGE
868 "htlb_buddy_alloc_success",
869 "htlb_buddy_alloc_fail",
871 "unevictable_pgs_culled",
872 "unevictable_pgs_scanned",
873 "unevictable_pgs_rescued",
874 "unevictable_pgs_mlocked",
875 "unevictable_pgs_munlocked",
876 "unevictable_pgs_cleared",
877 "unevictable_pgs_stranded",
878 "unevictable_pgs_mlockfreed",
882 static void zoneinfo_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
886 seq_printf(m
, "Node %d, zone %8s", pgdat
->node_id
, zone
->name
);
895 zone_page_state(zone
, NR_FREE_PAGES
),
896 min_wmark_pages(zone
),
897 low_wmark_pages(zone
),
898 high_wmark_pages(zone
),
901 zone
->present_pages
);
903 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
904 seq_printf(m
, "\n %-12s %lu", vmstat_text
[i
],
905 zone_page_state(zone
, i
));
908 "\n protection: (%lu",
909 zone
->lowmem_reserve
[0]);
910 for (i
= 1; i
< ARRAY_SIZE(zone
->lowmem_reserve
); i
++)
911 seq_printf(m
, ", %lu", zone
->lowmem_reserve
[i
]);
915 for_each_online_cpu(i
) {
916 struct per_cpu_pageset
*pageset
;
918 pageset
= per_cpu_ptr(zone
->pageset
, i
);
929 seq_printf(m
, "\n vm stats threshold: %d",
930 pageset
->stat_threshold
);
934 "\n all_unreclaimable: %u"
935 "\n prev_priority: %i"
937 "\n inactive_ratio: %u",
938 zone
->all_unreclaimable
,
940 zone
->zone_start_pfn
,
941 zone
->inactive_ratio
);
946 * Output information about zones in @pgdat.
948 static int zoneinfo_show(struct seq_file
*m
, void *arg
)
950 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
951 walk_zones_in_node(m
, pgdat
, zoneinfo_show_print
);
955 static const struct seq_operations zoneinfo_op
= {
956 .start
= frag_start
, /* iterate over all zones. The same as in
960 .show
= zoneinfo_show
,
963 static int zoneinfo_open(struct inode
*inode
, struct file
*file
)
965 return seq_open(file
, &zoneinfo_op
);
968 static const struct file_operations proc_zoneinfo_file_operations
= {
969 .open
= zoneinfo_open
,
972 .release
= seq_release
,
975 static void *vmstat_start(struct seq_file
*m
, loff_t
*pos
)
978 #ifdef CONFIG_VM_EVENT_COUNTERS
983 if (*pos
>= ARRAY_SIZE(vmstat_text
))
986 #ifdef CONFIG_VM_EVENT_COUNTERS
987 v
= kmalloc(NR_VM_ZONE_STAT_ITEMS
* sizeof(unsigned long)
988 + sizeof(struct vm_event_state
), GFP_KERNEL
);
990 v
= kmalloc(NR_VM_ZONE_STAT_ITEMS
* sizeof(unsigned long),
995 return ERR_PTR(-ENOMEM
);
996 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
997 v
[i
] = global_page_state(i
);
998 #ifdef CONFIG_VM_EVENT_COUNTERS
999 e
= v
+ NR_VM_ZONE_STAT_ITEMS
;
1001 e
[PGPGIN
] /= 2; /* sectors -> kbytes */
1007 static void *vmstat_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
1010 if (*pos
>= ARRAY_SIZE(vmstat_text
))
1012 return (unsigned long *)m
->private + *pos
;
1015 static int vmstat_show(struct seq_file
*m
, void *arg
)
1017 unsigned long *l
= arg
;
1018 unsigned long off
= l
- (unsigned long *)m
->private;
1020 seq_printf(m
, "%s %lu\n", vmstat_text
[off
], *l
);
1024 static void vmstat_stop(struct seq_file
*m
, void *arg
)
1030 static const struct seq_operations vmstat_op
= {
1031 .start
= vmstat_start
,
1032 .next
= vmstat_next
,
1033 .stop
= vmstat_stop
,
1034 .show
= vmstat_show
,
1037 static int vmstat_open(struct inode
*inode
, struct file
*file
)
1039 return seq_open(file
, &vmstat_op
);
1042 static const struct file_operations proc_vmstat_file_operations
= {
1043 .open
= vmstat_open
,
1045 .llseek
= seq_lseek
,
1046 .release
= seq_release
,
1048 #endif /* CONFIG_PROC_FS */
1051 static DEFINE_PER_CPU(struct delayed_work
, vmstat_work
);
1052 int sysctl_stat_interval __read_mostly
= HZ
;
1054 static void vmstat_update(struct work_struct
*w
)
1056 refresh_cpu_vm_stats(smp_processor_id());
1057 schedule_delayed_work(&__get_cpu_var(vmstat_work
),
1058 round_jiffies_relative(sysctl_stat_interval
));
1061 static void __cpuinit
start_cpu_timer(int cpu
)
1063 struct delayed_work
*work
= &per_cpu(vmstat_work
, cpu
);
1065 INIT_DELAYED_WORK_DEFERRABLE(work
, vmstat_update
);
1066 schedule_delayed_work_on(cpu
, work
, __round_jiffies_relative(HZ
, cpu
));
1070 * Use the cpu notifier to insure that the thresholds are recalculated
1073 static int __cpuinit
vmstat_cpuup_callback(struct notifier_block
*nfb
,
1074 unsigned long action
,
1077 long cpu
= (long)hcpu
;
1081 case CPU_ONLINE_FROZEN
:
1082 start_cpu_timer(cpu
);
1083 node_set_state(cpu_to_node(cpu
), N_CPU
);
1085 case CPU_DOWN_PREPARE
:
1086 case CPU_DOWN_PREPARE_FROZEN
:
1087 cancel_rearming_delayed_work(&per_cpu(vmstat_work
, cpu
));
1088 per_cpu(vmstat_work
, cpu
).work
.func
= NULL
;
1090 case CPU_DOWN_FAILED
:
1091 case CPU_DOWN_FAILED_FROZEN
:
1092 start_cpu_timer(cpu
);
1095 case CPU_DEAD_FROZEN
:
1096 refresh_zone_stat_thresholds();
1104 static struct notifier_block __cpuinitdata vmstat_notifier
=
1105 { &vmstat_cpuup_callback
, NULL
, 0 };
1108 static int __init
setup_vmstat(void)
1113 refresh_zone_stat_thresholds();
1114 register_cpu_notifier(&vmstat_notifier
);
1116 for_each_online_cpu(cpu
)
1117 start_cpu_timer(cpu
);
1119 #ifdef CONFIG_PROC_FS
1120 proc_create("buddyinfo", S_IRUGO
, NULL
, &fragmentation_file_operations
);
1121 proc_create("pagetypeinfo", S_IRUGO
, NULL
, &pagetypeinfo_file_ops
);
1122 proc_create("vmstat", S_IRUGO
, NULL
, &proc_vmstat_file_operations
);
1123 proc_create("zoneinfo", S_IRUGO
, NULL
, &proc_zoneinfo_file_operations
);
1127 module_init(setup_vmstat
)
1129 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1130 #include <linux/debugfs.h>
1132 static struct dentry
*extfrag_debug_root
;
1135 * Return an index indicating how much of the available free memory is
1136 * unusable for an allocation of the requested size.
1138 static int unusable_free_index(unsigned int order
,
1139 struct contig_page_info
*info
)
1141 /* No free memory is interpreted as all free memory is unusable */
1142 if (info
->free_pages
== 0)
1146 * Index should be a value between 0 and 1. Return a value to 3
1149 * 0 => no fragmentation
1150 * 1 => high fragmentation
1152 return div_u64((info
->free_pages
- (info
->free_blocks_suitable
<< order
)) * 1000ULL, info
->free_pages
);
1156 static void unusable_show_print(struct seq_file
*m
,
1157 pg_data_t
*pgdat
, struct zone
*zone
)
1161 struct contig_page_info info
;
1163 seq_printf(m
, "Node %d, zone %8s ",
1166 for (order
= 0; order
< MAX_ORDER
; ++order
) {
1167 fill_contig_page_info(zone
, order
, &info
);
1168 index
= unusable_free_index(order
, &info
);
1169 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
1176 * Display unusable free space index
1178 * The unusable free space index measures how much of the available free
1179 * memory cannot be used to satisfy an allocation of a given size and is a
1180 * value between 0 and 1. The higher the value, the more of free memory is
1181 * unusable and by implication, the worse the external fragmentation is. This
1182 * can be expressed as a percentage by multiplying by 100.
1184 static int unusable_show(struct seq_file
*m
, void *arg
)
1186 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1188 /* check memoryless node */
1189 if (!node_state(pgdat
->node_id
, N_HIGH_MEMORY
))
1192 walk_zones_in_node(m
, pgdat
, unusable_show_print
);
1197 static const struct seq_operations unusable_op
= {
1198 .start
= frag_start
,
1201 .show
= unusable_show
,
1204 static int unusable_open(struct inode
*inode
, struct file
*file
)
1206 return seq_open(file
, &unusable_op
);
1209 static const struct file_operations unusable_file_ops
= {
1210 .open
= unusable_open
,
1212 .llseek
= seq_lseek
,
1213 .release
= seq_release
,
1216 static void extfrag_show_print(struct seq_file
*m
,
1217 pg_data_t
*pgdat
, struct zone
*zone
)
1222 /* Alloc on stack as interrupts are disabled for zone walk */
1223 struct contig_page_info info
;
1225 seq_printf(m
, "Node %d, zone %8s ",
1228 for (order
= 0; order
< MAX_ORDER
; ++order
) {
1229 fill_contig_page_info(zone
, order
, &info
);
1230 index
= __fragmentation_index(order
, &info
);
1231 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
1238 * Display fragmentation index for orders that allocations would fail for
1240 static int extfrag_show(struct seq_file
*m
, void *arg
)
1242 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1244 walk_zones_in_node(m
, pgdat
, extfrag_show_print
);
1249 static const struct seq_operations extfrag_op
= {
1250 .start
= frag_start
,
1253 .show
= extfrag_show
,
1256 static int extfrag_open(struct inode
*inode
, struct file
*file
)
1258 return seq_open(file
, &extfrag_op
);
1261 static const struct file_operations extfrag_file_ops
= {
1262 .open
= extfrag_open
,
1264 .llseek
= seq_lseek
,
1265 .release
= seq_release
,
1268 static int __init
extfrag_debug_init(void)
1270 extfrag_debug_root
= debugfs_create_dir("extfrag", NULL
);
1271 if (!extfrag_debug_root
)
1274 if (!debugfs_create_file("unusable_index", 0444,
1275 extfrag_debug_root
, NULL
, &unusable_file_ops
))
1278 if (!debugfs_create_file("extfrag_index", 0444,
1279 extfrag_debug_root
, NULL
, &extfrag_file_ops
))
1285 module_init(extfrag_debug_init
);