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>
20 #include <linux/writeback.h>
22 #ifdef CONFIG_VM_EVENT_COUNTERS
23 DEFINE_PER_CPU(struct vm_event_state
, vm_event_states
) = {{0}};
24 EXPORT_PER_CPU_SYMBOL(vm_event_states
);
26 static void sum_vm_events(unsigned long *ret
)
31 memset(ret
, 0, NR_VM_EVENT_ITEMS
* sizeof(unsigned long));
33 for_each_online_cpu(cpu
) {
34 struct vm_event_state
*this = &per_cpu(vm_event_states
, cpu
);
36 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++)
37 ret
[i
] += this->event
[i
];
42 * Accumulate the vm event counters across all CPUs.
43 * The result is unavoidably approximate - it can change
44 * during and after execution of this function.
46 void all_vm_events(unsigned long *ret
)
52 EXPORT_SYMBOL_GPL(all_vm_events
);
56 * Fold the foreign cpu events into our own.
58 * This is adding to the events on one processor
59 * but keeps the global counts constant.
61 void vm_events_fold_cpu(int cpu
)
63 struct vm_event_state
*fold_state
= &per_cpu(vm_event_states
, cpu
);
66 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++) {
67 count_vm_events(i
, fold_state
->event
[i
]);
68 fold_state
->event
[i
] = 0;
71 #endif /* CONFIG_HOTPLUG */
73 #endif /* CONFIG_VM_EVENT_COUNTERS */
76 * Manage combined zone based / global counters
78 * vm_stat contains the global counters
80 atomic_long_t vm_stat
[NR_VM_ZONE_STAT_ITEMS
];
81 EXPORT_SYMBOL(vm_stat
);
85 static int calculate_threshold(struct zone
*zone
)
88 int mem
; /* memory in 128 MB units */
91 * The threshold scales with the number of processors and the amount
92 * of memory per zone. More memory means that we can defer updates for
93 * longer, more processors could lead to more contention.
94 * fls() is used to have a cheap way of logarithmic scaling.
96 * Some sample thresholds:
98 * Threshold Processors (fls) Zonesize fls(mem+1)
99 * ------------------------------------------------------------------
116 * 125 1024 10 8-16 GB 8
117 * 125 1024 10 16-32 GB 9
120 mem
= zone
->present_pages
>> (27 - PAGE_SHIFT
);
122 threshold
= 2 * fls(num_online_cpus()) * (1 + fls(mem
));
125 * Maximum threshold is 125
127 threshold
= min(125, threshold
);
133 * Refresh the thresholds for each zone.
135 static void refresh_zone_stat_thresholds(void)
141 for_each_populated_zone(zone
) {
142 unsigned long max_drift
, tolerate_drift
;
144 threshold
= calculate_threshold(zone
);
146 for_each_online_cpu(cpu
)
147 per_cpu_ptr(zone
->pageset
, cpu
)->stat_threshold
151 * Only set percpu_drift_mark if there is a danger that
152 * NR_FREE_PAGES reports the low watermark is ok when in fact
153 * the min watermark could be breached by an allocation
155 tolerate_drift
= low_wmark_pages(zone
) - min_wmark_pages(zone
);
156 max_drift
= num_online_cpus() * threshold
;
157 if (max_drift
> tolerate_drift
)
158 zone
->percpu_drift_mark
= high_wmark_pages(zone
) +
164 * For use when we know that interrupts are disabled.
166 void __mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
169 struct per_cpu_pageset
*pcp
= this_cpu_ptr(zone
->pageset
);
171 s8
*p
= pcp
->vm_stat_diff
+ item
;
176 if (unlikely(x
> pcp
->stat_threshold
|| x
< -pcp
->stat_threshold
)) {
177 zone_page_state_add(x
, zone
, item
);
182 EXPORT_SYMBOL(__mod_zone_page_state
);
185 * For an unknown interrupt state
187 void mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
192 local_irq_save(flags
);
193 __mod_zone_page_state(zone
, item
, delta
);
194 local_irq_restore(flags
);
196 EXPORT_SYMBOL(mod_zone_page_state
);
199 * Optimized increment and decrement functions.
201 * These are only for a single page and therefore can take a struct page *
202 * argument instead of struct zone *. This allows the inclusion of the code
203 * generated for page_zone(page) into the optimized functions.
205 * No overflow check is necessary and therefore the differential can be
206 * incremented or decremented in place which may allow the compilers to
207 * generate better code.
208 * The increment or decrement is known and therefore one boundary check can
211 * NOTE: These functions are very performance sensitive. Change only
214 * Some processors have inc/dec instructions that are atomic vs an interrupt.
215 * However, the code must first determine the differential location in a zone
216 * based on the processor number and then inc/dec the counter. There is no
217 * guarantee without disabling preemption that the processor will not change
218 * in between and therefore the atomicity vs. interrupt cannot be exploited
219 * in a useful way here.
221 void __inc_zone_state(struct zone
*zone
, enum zone_stat_item item
)
223 struct per_cpu_pageset
*pcp
= this_cpu_ptr(zone
->pageset
);
224 s8
*p
= pcp
->vm_stat_diff
+ item
;
228 if (unlikely(*p
> pcp
->stat_threshold
)) {
229 int overstep
= pcp
->stat_threshold
/ 2;
231 zone_page_state_add(*p
+ overstep
, zone
, item
);
236 void __inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
238 __inc_zone_state(page_zone(page
), item
);
240 EXPORT_SYMBOL(__inc_zone_page_state
);
242 void __dec_zone_state(struct zone
*zone
, enum zone_stat_item item
)
244 struct per_cpu_pageset
*pcp
= this_cpu_ptr(zone
->pageset
);
245 s8
*p
= pcp
->vm_stat_diff
+ item
;
249 if (unlikely(*p
< - pcp
->stat_threshold
)) {
250 int overstep
= pcp
->stat_threshold
/ 2;
252 zone_page_state_add(*p
- overstep
, zone
, item
);
257 void __dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
259 __dec_zone_state(page_zone(page
), item
);
261 EXPORT_SYMBOL(__dec_zone_page_state
);
263 void inc_zone_state(struct zone
*zone
, enum zone_stat_item item
)
267 local_irq_save(flags
);
268 __inc_zone_state(zone
, item
);
269 local_irq_restore(flags
);
272 void inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
277 zone
= page_zone(page
);
278 local_irq_save(flags
);
279 __inc_zone_state(zone
, item
);
280 local_irq_restore(flags
);
282 EXPORT_SYMBOL(inc_zone_page_state
);
284 void dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
288 local_irq_save(flags
);
289 __dec_zone_page_state(page
, item
);
290 local_irq_restore(flags
);
292 EXPORT_SYMBOL(dec_zone_page_state
);
295 * Update the zone counters for one cpu.
297 * The cpu specified must be either the current cpu or a processor that
298 * is not online. If it is the current cpu then the execution thread must
299 * be pinned to the current cpu.
301 * Note that refresh_cpu_vm_stats strives to only access
302 * node local memory. The per cpu pagesets on remote zones are placed
303 * in the memory local to the processor using that pageset. So the
304 * loop over all zones will access a series of cachelines local to
307 * The call to zone_page_state_add updates the cachelines with the
308 * statistics in the remote zone struct as well as the global cachelines
309 * with the global counters. These could cause remote node cache line
310 * bouncing and will have to be only done when necessary.
312 void refresh_cpu_vm_stats(int cpu
)
316 int global_diff
[NR_VM_ZONE_STAT_ITEMS
] = { 0, };
318 for_each_populated_zone(zone
) {
319 struct per_cpu_pageset
*p
;
321 p
= per_cpu_ptr(zone
->pageset
, cpu
);
323 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
324 if (p
->vm_stat_diff
[i
]) {
328 local_irq_save(flags
);
329 v
= p
->vm_stat_diff
[i
];
330 p
->vm_stat_diff
[i
] = 0;
331 local_irq_restore(flags
);
332 atomic_long_add(v
, &zone
->vm_stat
[i
]);
335 /* 3 seconds idle till flush */
342 * Deal with draining the remote pageset of this
345 * Check if there are pages remaining in this pageset
346 * if not then there is nothing to expire.
348 if (!p
->expire
|| !p
->pcp
.count
)
352 * We never drain zones local to this processor.
354 if (zone_to_nid(zone
) == numa_node_id()) {
364 drain_zone_pages(zone
, &p
->pcp
);
368 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
370 atomic_long_add(global_diff
[i
], &vm_stat
[i
]);
377 * zonelist = the list of zones passed to the allocator
378 * z = the zone from which the allocation occurred.
380 * Must be called with interrupts disabled.
382 void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
384 if (z
->zone_pgdat
== preferred_zone
->zone_pgdat
) {
385 __inc_zone_state(z
, NUMA_HIT
);
387 __inc_zone_state(z
, NUMA_MISS
);
388 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
390 if (z
->node
== numa_node_id())
391 __inc_zone_state(z
, NUMA_LOCAL
);
393 __inc_zone_state(z
, NUMA_OTHER
);
397 #ifdef CONFIG_COMPACTION
398 struct contig_page_info
{
399 unsigned long free_pages
;
400 unsigned long free_blocks_total
;
401 unsigned long free_blocks_suitable
;
405 * Calculate the number of free pages in a zone, how many contiguous
406 * pages are free and how many are large enough to satisfy an allocation of
407 * the target size. Note that this function makes no attempt to estimate
408 * how many suitable free blocks there *might* be if MOVABLE pages were
409 * migrated. Calculating that is possible, but expensive and can be
410 * figured out from userspace
412 static void fill_contig_page_info(struct zone
*zone
,
413 unsigned int suitable_order
,
414 struct contig_page_info
*info
)
418 info
->free_pages
= 0;
419 info
->free_blocks_total
= 0;
420 info
->free_blocks_suitable
= 0;
422 for (order
= 0; order
< MAX_ORDER
; order
++) {
423 unsigned long blocks
;
425 /* Count number of free blocks */
426 blocks
= zone
->free_area
[order
].nr_free
;
427 info
->free_blocks_total
+= blocks
;
429 /* Count free base pages */
430 info
->free_pages
+= blocks
<< order
;
432 /* Count the suitable free blocks */
433 if (order
>= suitable_order
)
434 info
->free_blocks_suitable
+= blocks
<<
435 (order
- suitable_order
);
440 * A fragmentation index only makes sense if an allocation of a requested
441 * size would fail. If that is true, the fragmentation index indicates
442 * whether external fragmentation or a lack of memory was the problem.
443 * The value can be used to determine if page reclaim or compaction
446 static int __fragmentation_index(unsigned int order
, struct contig_page_info
*info
)
448 unsigned long requested
= 1UL << order
;
450 if (!info
->free_blocks_total
)
453 /* Fragmentation index only makes sense when a request would fail */
454 if (info
->free_blocks_suitable
)
458 * Index is between 0 and 1 so return within 3 decimal places
460 * 0 => allocation would fail due to lack of memory
461 * 1 => allocation would fail due to fragmentation
463 return 1000 - div_u64( (1000+(div_u64(info
->free_pages
* 1000ULL, requested
))), info
->free_blocks_total
);
466 /* Same as __fragmentation index but allocs contig_page_info on stack */
467 int fragmentation_index(struct zone
*zone
, unsigned int order
)
469 struct contig_page_info info
;
471 fill_contig_page_info(zone
, order
, &info
);
472 return __fragmentation_index(order
, &info
);
476 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
477 #include <linux/proc_fs.h>
478 #include <linux/seq_file.h>
480 static char * const migratetype_names
[MIGRATE_TYPES
] = {
488 static void *frag_start(struct seq_file
*m
, loff_t
*pos
)
492 for (pgdat
= first_online_pgdat();
494 pgdat
= next_online_pgdat(pgdat
))
500 static void *frag_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
502 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
505 return next_online_pgdat(pgdat
);
508 static void frag_stop(struct seq_file
*m
, void *arg
)
512 /* Walk all the zones in a node and print using a callback */
513 static void walk_zones_in_node(struct seq_file
*m
, pg_data_t
*pgdat
,
514 void (*print
)(struct seq_file
*m
, pg_data_t
*, struct zone
*))
517 struct zone
*node_zones
= pgdat
->node_zones
;
520 for (zone
= node_zones
; zone
- node_zones
< MAX_NR_ZONES
; ++zone
) {
521 if (!populated_zone(zone
))
524 spin_lock_irqsave(&zone
->lock
, flags
);
525 print(m
, pgdat
, zone
);
526 spin_unlock_irqrestore(&zone
->lock
, flags
);
531 #ifdef CONFIG_PROC_FS
532 static void frag_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
537 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
538 for (order
= 0; order
< MAX_ORDER
; ++order
)
539 seq_printf(m
, "%6lu ", zone
->free_area
[order
].nr_free
);
544 * This walks the free areas for each zone.
546 static int frag_show(struct seq_file
*m
, void *arg
)
548 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
549 walk_zones_in_node(m
, pgdat
, frag_show_print
);
553 static void pagetypeinfo_showfree_print(struct seq_file
*m
,
554 pg_data_t
*pgdat
, struct zone
*zone
)
558 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++) {
559 seq_printf(m
, "Node %4d, zone %8s, type %12s ",
562 migratetype_names
[mtype
]);
563 for (order
= 0; order
< MAX_ORDER
; ++order
) {
564 unsigned long freecount
= 0;
565 struct free_area
*area
;
566 struct list_head
*curr
;
568 area
= &(zone
->free_area
[order
]);
570 list_for_each(curr
, &area
->free_list
[mtype
])
572 seq_printf(m
, "%6lu ", freecount
);
578 /* Print out the free pages at each order for each migatetype */
579 static int pagetypeinfo_showfree(struct seq_file
*m
, void *arg
)
582 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
585 seq_printf(m
, "%-43s ", "Free pages count per migrate type at order");
586 for (order
= 0; order
< MAX_ORDER
; ++order
)
587 seq_printf(m
, "%6d ", order
);
590 walk_zones_in_node(m
, pgdat
, pagetypeinfo_showfree_print
);
595 static void pagetypeinfo_showblockcount_print(struct seq_file
*m
,
596 pg_data_t
*pgdat
, struct zone
*zone
)
600 unsigned long start_pfn
= zone
->zone_start_pfn
;
601 unsigned long end_pfn
= start_pfn
+ zone
->spanned_pages
;
602 unsigned long count
[MIGRATE_TYPES
] = { 0, };
604 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
610 page
= pfn_to_page(pfn
);
612 /* Watch for unexpected holes punched in the memmap */
613 if (!memmap_valid_within(pfn
, page
, zone
))
616 mtype
= get_pageblock_migratetype(page
);
618 if (mtype
< MIGRATE_TYPES
)
623 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
624 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
625 seq_printf(m
, "%12lu ", count
[mtype
]);
629 /* Print out the free pages at each order for each migratetype */
630 static int pagetypeinfo_showblockcount(struct seq_file
*m
, void *arg
)
633 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
635 seq_printf(m
, "\n%-23s", "Number of blocks type ");
636 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
637 seq_printf(m
, "%12s ", migratetype_names
[mtype
]);
639 walk_zones_in_node(m
, pgdat
, pagetypeinfo_showblockcount_print
);
645 * This prints out statistics in relation to grouping pages by mobility.
646 * It is expensive to collect so do not constantly read the file.
648 static int pagetypeinfo_show(struct seq_file
*m
, void *arg
)
650 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
652 /* check memoryless node */
653 if (!node_state(pgdat
->node_id
, N_HIGH_MEMORY
))
656 seq_printf(m
, "Page block order: %d\n", pageblock_order
);
657 seq_printf(m
, "Pages per block: %lu\n", pageblock_nr_pages
);
659 pagetypeinfo_showfree(m
, pgdat
);
660 pagetypeinfo_showblockcount(m
, pgdat
);
665 static const struct seq_operations fragmentation_op
= {
672 static int fragmentation_open(struct inode
*inode
, struct file
*file
)
674 return seq_open(file
, &fragmentation_op
);
677 static const struct file_operations fragmentation_file_operations
= {
678 .open
= fragmentation_open
,
681 .release
= seq_release
,
684 static const struct seq_operations pagetypeinfo_op
= {
688 .show
= pagetypeinfo_show
,
691 static int pagetypeinfo_open(struct inode
*inode
, struct file
*file
)
693 return seq_open(file
, &pagetypeinfo_op
);
696 static const struct file_operations pagetypeinfo_file_ops
= {
697 .open
= pagetypeinfo_open
,
700 .release
= seq_release
,
703 #ifdef CONFIG_ZONE_DMA
704 #define TEXT_FOR_DMA(xx) xx "_dma",
706 #define TEXT_FOR_DMA(xx)
709 #ifdef CONFIG_ZONE_DMA32
710 #define TEXT_FOR_DMA32(xx) xx "_dma32",
712 #define TEXT_FOR_DMA32(xx)
715 #ifdef CONFIG_HIGHMEM
716 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
718 #define TEXT_FOR_HIGHMEM(xx)
721 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
722 TEXT_FOR_HIGHMEM(xx) xx "_movable",
724 static const char * const vmstat_text
[] = {
725 /* Zoned VM counters */
738 "nr_slab_reclaimable",
739 "nr_slab_unreclaimable",
740 "nr_page_table_pages",
751 "nr_dirty_threshold",
752 "nr_dirty_background_threshold",
763 #ifdef CONFIG_VM_EVENT_COUNTERS
769 TEXTS_FOR_ZONES("pgalloc")
778 TEXTS_FOR_ZONES("pgrefill")
779 TEXTS_FOR_ZONES("pgsteal")
780 TEXTS_FOR_ZONES("pgscan_kswapd")
781 TEXTS_FOR_ZONES("pgscan_direct")
784 "zone_reclaim_failed",
790 "kswapd_low_wmark_hit_quickly",
791 "kswapd_high_wmark_hit_quickly",
792 "kswapd_skip_congestion_wait",
798 #ifdef CONFIG_COMPACTION
799 "compact_blocks_moved",
800 "compact_pages_moved",
801 "compact_pagemigrate_failed",
807 #ifdef CONFIG_HUGETLB_PAGE
808 "htlb_buddy_alloc_success",
809 "htlb_buddy_alloc_fail",
811 "unevictable_pgs_culled",
812 "unevictable_pgs_scanned",
813 "unevictable_pgs_rescued",
814 "unevictable_pgs_mlocked",
815 "unevictable_pgs_munlocked",
816 "unevictable_pgs_cleared",
817 "unevictable_pgs_stranded",
818 "unevictable_pgs_mlockfreed",
822 static void zoneinfo_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
826 seq_printf(m
, "Node %d, zone %8s", pgdat
->node_id
, zone
->name
);
835 zone_nr_free_pages(zone
),
836 min_wmark_pages(zone
),
837 low_wmark_pages(zone
),
838 high_wmark_pages(zone
),
841 zone
->present_pages
);
843 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
844 seq_printf(m
, "\n %-12s %lu", vmstat_text
[i
],
845 zone_page_state(zone
, i
));
848 "\n protection: (%lu",
849 zone
->lowmem_reserve
[0]);
850 for (i
= 1; i
< ARRAY_SIZE(zone
->lowmem_reserve
); i
++)
851 seq_printf(m
, ", %lu", zone
->lowmem_reserve
[i
]);
855 for_each_online_cpu(i
) {
856 struct per_cpu_pageset
*pageset
;
858 pageset
= per_cpu_ptr(zone
->pageset
, i
);
869 seq_printf(m
, "\n vm stats threshold: %d",
870 pageset
->stat_threshold
);
874 "\n all_unreclaimable: %u"
876 "\n inactive_ratio: %u",
877 zone
->all_unreclaimable
,
878 zone
->zone_start_pfn
,
879 zone
->inactive_ratio
);
884 * Output information about zones in @pgdat.
886 static int zoneinfo_show(struct seq_file
*m
, void *arg
)
888 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
889 walk_zones_in_node(m
, pgdat
, zoneinfo_show_print
);
893 static const struct seq_operations zoneinfo_op
= {
894 .start
= frag_start
, /* iterate over all zones. The same as in
898 .show
= zoneinfo_show
,
901 static int zoneinfo_open(struct inode
*inode
, struct file
*file
)
903 return seq_open(file
, &zoneinfo_op
);
906 static const struct file_operations proc_zoneinfo_file_operations
= {
907 .open
= zoneinfo_open
,
910 .release
= seq_release
,
913 enum writeback_stat_item
{
915 NR_DIRTY_BG_THRESHOLD
,
916 NR_VM_WRITEBACK_STAT_ITEMS
,
919 static void *vmstat_start(struct seq_file
*m
, loff_t
*pos
)
922 int i
, stat_items_size
;
924 if (*pos
>= ARRAY_SIZE(vmstat_text
))
926 stat_items_size
= NR_VM_ZONE_STAT_ITEMS
* sizeof(unsigned long) +
927 NR_VM_WRITEBACK_STAT_ITEMS
* sizeof(unsigned long);
929 #ifdef CONFIG_VM_EVENT_COUNTERS
930 stat_items_size
+= sizeof(struct vm_event_state
);
933 v
= kmalloc(stat_items_size
, GFP_KERNEL
);
936 return ERR_PTR(-ENOMEM
);
937 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
938 v
[i
] = global_page_state(i
);
939 v
+= NR_VM_ZONE_STAT_ITEMS
;
941 global_dirty_limits(v
+ NR_DIRTY_BG_THRESHOLD
,
942 v
+ NR_DIRTY_THRESHOLD
);
943 v
+= NR_VM_WRITEBACK_STAT_ITEMS
;
945 #ifdef CONFIG_VM_EVENT_COUNTERS
947 v
[PGPGIN
] /= 2; /* sectors -> kbytes */
950 return m
->private + *pos
;
953 static void *vmstat_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
956 if (*pos
>= ARRAY_SIZE(vmstat_text
))
958 return (unsigned long *)m
->private + *pos
;
961 static int vmstat_show(struct seq_file
*m
, void *arg
)
963 unsigned long *l
= arg
;
964 unsigned long off
= l
- (unsigned long *)m
->private;
966 seq_printf(m
, "%s %lu\n", vmstat_text
[off
], *l
);
970 static void vmstat_stop(struct seq_file
*m
, void *arg
)
976 static const struct seq_operations vmstat_op
= {
977 .start
= vmstat_start
,
983 static int vmstat_open(struct inode
*inode
, struct file
*file
)
985 return seq_open(file
, &vmstat_op
);
988 static const struct file_operations proc_vmstat_file_operations
= {
992 .release
= seq_release
,
994 #endif /* CONFIG_PROC_FS */
997 static DEFINE_PER_CPU(struct delayed_work
, vmstat_work
);
998 int sysctl_stat_interval __read_mostly
= HZ
;
1000 static void vmstat_update(struct work_struct
*w
)
1002 refresh_cpu_vm_stats(smp_processor_id());
1003 schedule_delayed_work(&__get_cpu_var(vmstat_work
),
1004 round_jiffies_relative(sysctl_stat_interval
));
1007 static void __cpuinit
start_cpu_timer(int cpu
)
1009 struct delayed_work
*work
= &per_cpu(vmstat_work
, cpu
);
1011 INIT_DELAYED_WORK_DEFERRABLE(work
, vmstat_update
);
1012 schedule_delayed_work_on(cpu
, work
, __round_jiffies_relative(HZ
, cpu
));
1016 * Use the cpu notifier to insure that the thresholds are recalculated
1019 static int __cpuinit
vmstat_cpuup_callback(struct notifier_block
*nfb
,
1020 unsigned long action
,
1023 long cpu
= (long)hcpu
;
1027 case CPU_ONLINE_FROZEN
:
1028 refresh_zone_stat_thresholds();
1029 start_cpu_timer(cpu
);
1030 node_set_state(cpu_to_node(cpu
), N_CPU
);
1032 case CPU_DOWN_PREPARE
:
1033 case CPU_DOWN_PREPARE_FROZEN
:
1034 cancel_rearming_delayed_work(&per_cpu(vmstat_work
, cpu
));
1035 per_cpu(vmstat_work
, cpu
).work
.func
= NULL
;
1037 case CPU_DOWN_FAILED
:
1038 case CPU_DOWN_FAILED_FROZEN
:
1039 start_cpu_timer(cpu
);
1042 case CPU_DEAD_FROZEN
:
1043 refresh_zone_stat_thresholds();
1051 static struct notifier_block __cpuinitdata vmstat_notifier
=
1052 { &vmstat_cpuup_callback
, NULL
, 0 };
1055 static int __init
setup_vmstat(void)
1060 refresh_zone_stat_thresholds();
1061 register_cpu_notifier(&vmstat_notifier
);
1063 for_each_online_cpu(cpu
)
1064 start_cpu_timer(cpu
);
1066 #ifdef CONFIG_PROC_FS
1067 proc_create("buddyinfo", S_IRUGO
, NULL
, &fragmentation_file_operations
);
1068 proc_create("pagetypeinfo", S_IRUGO
, NULL
, &pagetypeinfo_file_ops
);
1069 proc_create("vmstat", S_IRUGO
, NULL
, &proc_vmstat_file_operations
);
1070 proc_create("zoneinfo", S_IRUGO
, NULL
, &proc_zoneinfo_file_operations
);
1074 module_init(setup_vmstat
)
1076 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1077 #include <linux/debugfs.h>
1079 static struct dentry
*extfrag_debug_root
;
1082 * Return an index indicating how much of the available free memory is
1083 * unusable for an allocation of the requested size.
1085 static int unusable_free_index(unsigned int order
,
1086 struct contig_page_info
*info
)
1088 /* No free memory is interpreted as all free memory is unusable */
1089 if (info
->free_pages
== 0)
1093 * Index should be a value between 0 and 1. Return a value to 3
1096 * 0 => no fragmentation
1097 * 1 => high fragmentation
1099 return div_u64((info
->free_pages
- (info
->free_blocks_suitable
<< order
)) * 1000ULL, info
->free_pages
);
1103 static void unusable_show_print(struct seq_file
*m
,
1104 pg_data_t
*pgdat
, struct zone
*zone
)
1108 struct contig_page_info info
;
1110 seq_printf(m
, "Node %d, zone %8s ",
1113 for (order
= 0; order
< MAX_ORDER
; ++order
) {
1114 fill_contig_page_info(zone
, order
, &info
);
1115 index
= unusable_free_index(order
, &info
);
1116 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
1123 * Display unusable free space index
1125 * The unusable free space index measures how much of the available free
1126 * memory cannot be used to satisfy an allocation of a given size and is a
1127 * value between 0 and 1. The higher the value, the more of free memory is
1128 * unusable and by implication, the worse the external fragmentation is. This
1129 * can be expressed as a percentage by multiplying by 100.
1131 static int unusable_show(struct seq_file
*m
, void *arg
)
1133 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1135 /* check memoryless node */
1136 if (!node_state(pgdat
->node_id
, N_HIGH_MEMORY
))
1139 walk_zones_in_node(m
, pgdat
, unusable_show_print
);
1144 static const struct seq_operations unusable_op
= {
1145 .start
= frag_start
,
1148 .show
= unusable_show
,
1151 static int unusable_open(struct inode
*inode
, struct file
*file
)
1153 return seq_open(file
, &unusable_op
);
1156 static const struct file_operations unusable_file_ops
= {
1157 .open
= unusable_open
,
1159 .llseek
= seq_lseek
,
1160 .release
= seq_release
,
1163 static void extfrag_show_print(struct seq_file
*m
,
1164 pg_data_t
*pgdat
, struct zone
*zone
)
1169 /* Alloc on stack as interrupts are disabled for zone walk */
1170 struct contig_page_info info
;
1172 seq_printf(m
, "Node %d, zone %8s ",
1175 for (order
= 0; order
< MAX_ORDER
; ++order
) {
1176 fill_contig_page_info(zone
, order
, &info
);
1177 index
= __fragmentation_index(order
, &info
);
1178 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
1185 * Display fragmentation index for orders that allocations would fail for
1187 static int extfrag_show(struct seq_file
*m
, void *arg
)
1189 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1191 walk_zones_in_node(m
, pgdat
, extfrag_show_print
);
1196 static const struct seq_operations extfrag_op
= {
1197 .start
= frag_start
,
1200 .show
= extfrag_show
,
1203 static int extfrag_open(struct inode
*inode
, struct file
*file
)
1205 return seq_open(file
, &extfrag_op
);
1208 static const struct file_operations extfrag_file_ops
= {
1209 .open
= extfrag_open
,
1211 .llseek
= seq_lseek
,
1212 .release
= seq_release
,
1215 static int __init
extfrag_debug_init(void)
1217 extfrag_debug_root
= debugfs_create_dir("extfrag", NULL
);
1218 if (!extfrag_debug_root
)
1221 if (!debugfs_create_file("unusable_index", 0444,
1222 extfrag_debug_root
, NULL
, &unusable_file_ops
))
1225 if (!debugfs_create_file("extfrag_index", 0444,
1226 extfrag_debug_root
, NULL
, &extfrag_file_ops
))
1232 module_init(extfrag_debug_init
);