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_threshold(struct zone
*zone
)
87 int mem
; /* memory in 128 MB units */
90 * The threshold scales with the number of processors and the amount
91 * of memory per zone. More memory means that we can defer updates for
92 * longer, more processors could lead to more contention.
93 * fls() is used to have a cheap way of logarithmic scaling.
95 * Some sample thresholds:
97 * Threshold Processors (fls) Zonesize fls(mem+1)
98 * ------------------------------------------------------------------
115 * 125 1024 10 8-16 GB 8
116 * 125 1024 10 16-32 GB 9
119 mem
= zone
->present_pages
>> (27 - PAGE_SHIFT
);
121 threshold
= 2 * fls(num_online_cpus()) * (1 + fls(mem
));
124 * Maximum threshold is 125
126 threshold
= min(125, threshold
);
132 * Refresh the thresholds for each zone.
134 static void refresh_zone_stat_thresholds(void)
140 for_each_populated_zone(zone
) {
141 threshold
= calculate_threshold(zone
);
143 for_each_online_cpu(cpu
)
144 per_cpu_ptr(zone
->pageset
, cpu
)->stat_threshold
150 * For use when we know that interrupts are disabled.
152 void __mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
155 struct per_cpu_pageset
*pcp
= this_cpu_ptr(zone
->pageset
);
157 s8
*p
= pcp
->vm_stat_diff
+ item
;
162 if (unlikely(x
> pcp
->stat_threshold
|| x
< -pcp
->stat_threshold
)) {
163 zone_page_state_add(x
, zone
, item
);
168 EXPORT_SYMBOL(__mod_zone_page_state
);
171 * For an unknown interrupt state
173 void mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
178 local_irq_save(flags
);
179 __mod_zone_page_state(zone
, item
, delta
);
180 local_irq_restore(flags
);
182 EXPORT_SYMBOL(mod_zone_page_state
);
185 * Optimized increment and decrement functions.
187 * These are only for a single page and therefore can take a struct page *
188 * argument instead of struct zone *. This allows the inclusion of the code
189 * generated for page_zone(page) into the optimized functions.
191 * No overflow check is necessary and therefore the differential can be
192 * incremented or decremented in place which may allow the compilers to
193 * generate better code.
194 * The increment or decrement is known and therefore one boundary check can
197 * NOTE: These functions are very performance sensitive. Change only
200 * Some processors have inc/dec instructions that are atomic vs an interrupt.
201 * However, the code must first determine the differential location in a zone
202 * based on the processor number and then inc/dec the counter. There is no
203 * guarantee without disabling preemption that the processor will not change
204 * in between and therefore the atomicity vs. interrupt cannot be exploited
205 * in a useful way here.
207 void __inc_zone_state(struct zone
*zone
, enum zone_stat_item item
)
209 struct per_cpu_pageset
*pcp
= this_cpu_ptr(zone
->pageset
);
210 s8
*p
= pcp
->vm_stat_diff
+ item
;
214 if (unlikely(*p
> pcp
->stat_threshold
)) {
215 int overstep
= pcp
->stat_threshold
/ 2;
217 zone_page_state_add(*p
+ overstep
, zone
, item
);
222 void __inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
224 __inc_zone_state(page_zone(page
), item
);
226 EXPORT_SYMBOL(__inc_zone_page_state
);
228 void __dec_zone_state(struct zone
*zone
, enum zone_stat_item item
)
230 struct per_cpu_pageset
*pcp
= this_cpu_ptr(zone
->pageset
);
231 s8
*p
= pcp
->vm_stat_diff
+ item
;
235 if (unlikely(*p
< - pcp
->stat_threshold
)) {
236 int overstep
= pcp
->stat_threshold
/ 2;
238 zone_page_state_add(*p
- overstep
, zone
, item
);
243 void __dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
245 __dec_zone_state(page_zone(page
), item
);
247 EXPORT_SYMBOL(__dec_zone_page_state
);
249 void inc_zone_state(struct zone
*zone
, enum zone_stat_item item
)
253 local_irq_save(flags
);
254 __inc_zone_state(zone
, item
);
255 local_irq_restore(flags
);
258 void inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
263 zone
= page_zone(page
);
264 local_irq_save(flags
);
265 __inc_zone_state(zone
, item
);
266 local_irq_restore(flags
);
268 EXPORT_SYMBOL(inc_zone_page_state
);
270 void dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
274 local_irq_save(flags
);
275 __dec_zone_page_state(page
, item
);
276 local_irq_restore(flags
);
278 EXPORT_SYMBOL(dec_zone_page_state
);
281 * Update the zone counters for one cpu.
283 * The cpu specified must be either the current cpu or a processor that
284 * is not online. If it is the current cpu then the execution thread must
285 * be pinned to the current cpu.
287 * Note that refresh_cpu_vm_stats strives to only access
288 * node local memory. The per cpu pagesets on remote zones are placed
289 * in the memory local to the processor using that pageset. So the
290 * loop over all zones will access a series of cachelines local to
293 * The call to zone_page_state_add updates the cachelines with the
294 * statistics in the remote zone struct as well as the global cachelines
295 * with the global counters. These could cause remote node cache line
296 * bouncing and will have to be only done when necessary.
298 void refresh_cpu_vm_stats(int cpu
)
302 int global_diff
[NR_VM_ZONE_STAT_ITEMS
] = { 0, };
304 for_each_populated_zone(zone
) {
305 struct per_cpu_pageset
*p
;
307 p
= per_cpu_ptr(zone
->pageset
, cpu
);
309 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
310 if (p
->vm_stat_diff
[i
]) {
314 local_irq_save(flags
);
315 v
= p
->vm_stat_diff
[i
];
316 p
->vm_stat_diff
[i
] = 0;
317 local_irq_restore(flags
);
318 atomic_long_add(v
, &zone
->vm_stat
[i
]);
321 /* 3 seconds idle till flush */
328 * Deal with draining the remote pageset of this
331 * Check if there are pages remaining in this pageset
332 * if not then there is nothing to expire.
334 if (!p
->expire
|| !p
->pcp
.count
)
338 * We never drain zones local to this processor.
340 if (zone_to_nid(zone
) == numa_node_id()) {
350 drain_zone_pages(zone
, &p
->pcp
);
354 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
356 atomic_long_add(global_diff
[i
], &vm_stat
[i
]);
363 * zonelist = the list of zones passed to the allocator
364 * z = the zone from which the allocation occurred.
366 * Must be called with interrupts disabled.
368 void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
)
370 if (z
->zone_pgdat
== preferred_zone
->zone_pgdat
) {
371 __inc_zone_state(z
, NUMA_HIT
);
373 __inc_zone_state(z
, NUMA_MISS
);
374 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
376 if (z
->node
== numa_node_id())
377 __inc_zone_state(z
, NUMA_LOCAL
);
379 __inc_zone_state(z
, NUMA_OTHER
);
383 #ifdef CONFIG_COMPACTION
384 struct contig_page_info
{
385 unsigned long free_pages
;
386 unsigned long free_blocks_total
;
387 unsigned long free_blocks_suitable
;
391 * Calculate the number of free pages in a zone, how many contiguous
392 * pages are free and how many are large enough to satisfy an allocation of
393 * the target size. Note that this function makes no attempt to estimate
394 * how many suitable free blocks there *might* be if MOVABLE pages were
395 * migrated. Calculating that is possible, but expensive and can be
396 * figured out from userspace
398 static void fill_contig_page_info(struct zone
*zone
,
399 unsigned int suitable_order
,
400 struct contig_page_info
*info
)
404 info
->free_pages
= 0;
405 info
->free_blocks_total
= 0;
406 info
->free_blocks_suitable
= 0;
408 for (order
= 0; order
< MAX_ORDER
; order
++) {
409 unsigned long blocks
;
411 /* Count number of free blocks */
412 blocks
= zone
->free_area
[order
].nr_free
;
413 info
->free_blocks_total
+= blocks
;
415 /* Count free base pages */
416 info
->free_pages
+= blocks
<< order
;
418 /* Count the suitable free blocks */
419 if (order
>= suitable_order
)
420 info
->free_blocks_suitable
+= blocks
<<
421 (order
- suitable_order
);
426 * A fragmentation index only makes sense if an allocation of a requested
427 * size would fail. If that is true, the fragmentation index indicates
428 * whether external fragmentation or a lack of memory was the problem.
429 * The value can be used to determine if page reclaim or compaction
432 int fragmentation_index(unsigned int order
, struct contig_page_info
*info
)
434 unsigned long requested
= 1UL << order
;
436 if (!info
->free_blocks_total
)
439 /* Fragmentation index only makes sense when a request would fail */
440 if (info
->free_blocks_suitable
)
444 * Index is between 0 and 1 so return within 3 decimal places
446 * 0 => allocation would fail due to lack of memory
447 * 1 => allocation would fail due to fragmentation
449 return 1000 - div_u64( (1000+(div_u64(info
->free_pages
* 1000ULL, requested
))), info
->free_blocks_total
);
453 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
454 #include <linux/proc_fs.h>
455 #include <linux/seq_file.h>
457 static char * const migratetype_names
[MIGRATE_TYPES
] = {
465 static void *frag_start(struct seq_file
*m
, loff_t
*pos
)
469 for (pgdat
= first_online_pgdat();
471 pgdat
= next_online_pgdat(pgdat
))
477 static void *frag_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
479 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
482 return next_online_pgdat(pgdat
);
485 static void frag_stop(struct seq_file
*m
, void *arg
)
489 /* Walk all the zones in a node and print using a callback */
490 static void walk_zones_in_node(struct seq_file
*m
, pg_data_t
*pgdat
,
491 void (*print
)(struct seq_file
*m
, pg_data_t
*, struct zone
*))
494 struct zone
*node_zones
= pgdat
->node_zones
;
497 for (zone
= node_zones
; zone
- node_zones
< MAX_NR_ZONES
; ++zone
) {
498 if (!populated_zone(zone
))
501 spin_lock_irqsave(&zone
->lock
, flags
);
502 print(m
, pgdat
, zone
);
503 spin_unlock_irqrestore(&zone
->lock
, flags
);
508 #ifdef CONFIG_PROC_FS
509 static void frag_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
514 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
515 for (order
= 0; order
< MAX_ORDER
; ++order
)
516 seq_printf(m
, "%6lu ", zone
->free_area
[order
].nr_free
);
521 * This walks the free areas for each zone.
523 static int frag_show(struct seq_file
*m
, void *arg
)
525 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
526 walk_zones_in_node(m
, pgdat
, frag_show_print
);
530 static void pagetypeinfo_showfree_print(struct seq_file
*m
,
531 pg_data_t
*pgdat
, struct zone
*zone
)
535 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++) {
536 seq_printf(m
, "Node %4d, zone %8s, type %12s ",
539 migratetype_names
[mtype
]);
540 for (order
= 0; order
< MAX_ORDER
; ++order
) {
541 unsigned long freecount
= 0;
542 struct free_area
*area
;
543 struct list_head
*curr
;
545 area
= &(zone
->free_area
[order
]);
547 list_for_each(curr
, &area
->free_list
[mtype
])
549 seq_printf(m
, "%6lu ", freecount
);
555 /* Print out the free pages at each order for each migatetype */
556 static int pagetypeinfo_showfree(struct seq_file
*m
, void *arg
)
559 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
562 seq_printf(m
, "%-43s ", "Free pages count per migrate type at order");
563 for (order
= 0; order
< MAX_ORDER
; ++order
)
564 seq_printf(m
, "%6d ", order
);
567 walk_zones_in_node(m
, pgdat
, pagetypeinfo_showfree_print
);
572 static void pagetypeinfo_showblockcount_print(struct seq_file
*m
,
573 pg_data_t
*pgdat
, struct zone
*zone
)
577 unsigned long start_pfn
= zone
->zone_start_pfn
;
578 unsigned long end_pfn
= start_pfn
+ zone
->spanned_pages
;
579 unsigned long count
[MIGRATE_TYPES
] = { 0, };
581 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
587 page
= pfn_to_page(pfn
);
589 /* Watch for unexpected holes punched in the memmap */
590 if (!memmap_valid_within(pfn
, page
, zone
))
593 mtype
= get_pageblock_migratetype(page
);
595 if (mtype
< MIGRATE_TYPES
)
600 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
601 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
602 seq_printf(m
, "%12lu ", count
[mtype
]);
606 /* Print out the free pages at each order for each migratetype */
607 static int pagetypeinfo_showblockcount(struct seq_file
*m
, void *arg
)
610 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
612 seq_printf(m
, "\n%-23s", "Number of blocks type ");
613 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
614 seq_printf(m
, "%12s ", migratetype_names
[mtype
]);
616 walk_zones_in_node(m
, pgdat
, pagetypeinfo_showblockcount_print
);
622 * This prints out statistics in relation to grouping pages by mobility.
623 * It is expensive to collect so do not constantly read the file.
625 static int pagetypeinfo_show(struct seq_file
*m
, void *arg
)
627 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
629 /* check memoryless node */
630 if (!node_state(pgdat
->node_id
, N_HIGH_MEMORY
))
633 seq_printf(m
, "Page block order: %d\n", pageblock_order
);
634 seq_printf(m
, "Pages per block: %lu\n", pageblock_nr_pages
);
636 pagetypeinfo_showfree(m
, pgdat
);
637 pagetypeinfo_showblockcount(m
, pgdat
);
642 static const struct seq_operations fragmentation_op
= {
649 static int fragmentation_open(struct inode
*inode
, struct file
*file
)
651 return seq_open(file
, &fragmentation_op
);
654 static const struct file_operations fragmentation_file_operations
= {
655 .open
= fragmentation_open
,
658 .release
= seq_release
,
661 static const struct seq_operations pagetypeinfo_op
= {
665 .show
= pagetypeinfo_show
,
668 static int pagetypeinfo_open(struct inode
*inode
, struct file
*file
)
670 return seq_open(file
, &pagetypeinfo_op
);
673 static const struct file_operations pagetypeinfo_file_ops
= {
674 .open
= pagetypeinfo_open
,
677 .release
= seq_release
,
680 #ifdef CONFIG_ZONE_DMA
681 #define TEXT_FOR_DMA(xx) xx "_dma",
683 #define TEXT_FOR_DMA(xx)
686 #ifdef CONFIG_ZONE_DMA32
687 #define TEXT_FOR_DMA32(xx) xx "_dma32",
689 #define TEXT_FOR_DMA32(xx)
692 #ifdef CONFIG_HIGHMEM
693 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
695 #define TEXT_FOR_HIGHMEM(xx)
698 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
699 TEXT_FOR_HIGHMEM(xx) xx "_movable",
701 static const char * const vmstat_text
[] = {
702 /* Zoned VM counters */
715 "nr_slab_reclaimable",
716 "nr_slab_unreclaimable",
717 "nr_page_table_pages",
735 #ifdef CONFIG_VM_EVENT_COUNTERS
741 TEXTS_FOR_ZONES("pgalloc")
750 TEXTS_FOR_ZONES("pgrefill")
751 TEXTS_FOR_ZONES("pgsteal")
752 TEXTS_FOR_ZONES("pgscan_kswapd")
753 TEXTS_FOR_ZONES("pgscan_direct")
756 "zone_reclaim_failed",
762 "kswapd_low_wmark_hit_quickly",
763 "kswapd_high_wmark_hit_quickly",
764 "kswapd_skip_congestion_wait",
770 #ifdef CONFIG_COMPACTION
771 "compact_blocks_moved",
772 "compact_pages_moved",
773 "compact_pagemigrate_failed",
776 #ifdef CONFIG_HUGETLB_PAGE
777 "htlb_buddy_alloc_success",
778 "htlb_buddy_alloc_fail",
780 "unevictable_pgs_culled",
781 "unevictable_pgs_scanned",
782 "unevictable_pgs_rescued",
783 "unevictable_pgs_mlocked",
784 "unevictable_pgs_munlocked",
785 "unevictable_pgs_cleared",
786 "unevictable_pgs_stranded",
787 "unevictable_pgs_mlockfreed",
791 static void zoneinfo_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
795 seq_printf(m
, "Node %d, zone %8s", pgdat
->node_id
, zone
->name
);
804 zone_page_state(zone
, NR_FREE_PAGES
),
805 min_wmark_pages(zone
),
806 low_wmark_pages(zone
),
807 high_wmark_pages(zone
),
810 zone
->present_pages
);
812 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
813 seq_printf(m
, "\n %-12s %lu", vmstat_text
[i
],
814 zone_page_state(zone
, i
));
817 "\n protection: (%lu",
818 zone
->lowmem_reserve
[0]);
819 for (i
= 1; i
< ARRAY_SIZE(zone
->lowmem_reserve
); i
++)
820 seq_printf(m
, ", %lu", zone
->lowmem_reserve
[i
]);
824 for_each_online_cpu(i
) {
825 struct per_cpu_pageset
*pageset
;
827 pageset
= per_cpu_ptr(zone
->pageset
, i
);
838 seq_printf(m
, "\n vm stats threshold: %d",
839 pageset
->stat_threshold
);
843 "\n all_unreclaimable: %u"
844 "\n prev_priority: %i"
846 "\n inactive_ratio: %u",
847 zone
->all_unreclaimable
,
849 zone
->zone_start_pfn
,
850 zone
->inactive_ratio
);
855 * Output information about zones in @pgdat.
857 static int zoneinfo_show(struct seq_file
*m
, void *arg
)
859 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
860 walk_zones_in_node(m
, pgdat
, zoneinfo_show_print
);
864 static const struct seq_operations zoneinfo_op
= {
865 .start
= frag_start
, /* iterate over all zones. The same as in
869 .show
= zoneinfo_show
,
872 static int zoneinfo_open(struct inode
*inode
, struct file
*file
)
874 return seq_open(file
, &zoneinfo_op
);
877 static const struct file_operations proc_zoneinfo_file_operations
= {
878 .open
= zoneinfo_open
,
881 .release
= seq_release
,
884 static void *vmstat_start(struct seq_file
*m
, loff_t
*pos
)
887 #ifdef CONFIG_VM_EVENT_COUNTERS
892 if (*pos
>= ARRAY_SIZE(vmstat_text
))
895 #ifdef CONFIG_VM_EVENT_COUNTERS
896 v
= kmalloc(NR_VM_ZONE_STAT_ITEMS
* sizeof(unsigned long)
897 + sizeof(struct vm_event_state
), GFP_KERNEL
);
899 v
= kmalloc(NR_VM_ZONE_STAT_ITEMS
* sizeof(unsigned long),
904 return ERR_PTR(-ENOMEM
);
905 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
906 v
[i
] = global_page_state(i
);
907 #ifdef CONFIG_VM_EVENT_COUNTERS
908 e
= v
+ NR_VM_ZONE_STAT_ITEMS
;
910 e
[PGPGIN
] /= 2; /* sectors -> kbytes */
916 static void *vmstat_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
919 if (*pos
>= ARRAY_SIZE(vmstat_text
))
921 return (unsigned long *)m
->private + *pos
;
924 static int vmstat_show(struct seq_file
*m
, void *arg
)
926 unsigned long *l
= arg
;
927 unsigned long off
= l
- (unsigned long *)m
->private;
929 seq_printf(m
, "%s %lu\n", vmstat_text
[off
], *l
);
933 static void vmstat_stop(struct seq_file
*m
, void *arg
)
939 static const struct seq_operations vmstat_op
= {
940 .start
= vmstat_start
,
946 static int vmstat_open(struct inode
*inode
, struct file
*file
)
948 return seq_open(file
, &vmstat_op
);
951 static const struct file_operations proc_vmstat_file_operations
= {
955 .release
= seq_release
,
957 #endif /* CONFIG_PROC_FS */
960 static DEFINE_PER_CPU(struct delayed_work
, vmstat_work
);
961 int sysctl_stat_interval __read_mostly
= HZ
;
963 static void vmstat_update(struct work_struct
*w
)
965 refresh_cpu_vm_stats(smp_processor_id());
966 schedule_delayed_work(&__get_cpu_var(vmstat_work
),
967 round_jiffies_relative(sysctl_stat_interval
));
970 static void __cpuinit
start_cpu_timer(int cpu
)
972 struct delayed_work
*work
= &per_cpu(vmstat_work
, cpu
);
974 INIT_DELAYED_WORK_DEFERRABLE(work
, vmstat_update
);
975 schedule_delayed_work_on(cpu
, work
, __round_jiffies_relative(HZ
, cpu
));
979 * Use the cpu notifier to insure that the thresholds are recalculated
982 static int __cpuinit
vmstat_cpuup_callback(struct notifier_block
*nfb
,
983 unsigned long action
,
986 long cpu
= (long)hcpu
;
990 case CPU_ONLINE_FROZEN
:
991 start_cpu_timer(cpu
);
992 node_set_state(cpu_to_node(cpu
), N_CPU
);
994 case CPU_DOWN_PREPARE
:
995 case CPU_DOWN_PREPARE_FROZEN
:
996 cancel_rearming_delayed_work(&per_cpu(vmstat_work
, cpu
));
997 per_cpu(vmstat_work
, cpu
).work
.func
= NULL
;
999 case CPU_DOWN_FAILED
:
1000 case CPU_DOWN_FAILED_FROZEN
:
1001 start_cpu_timer(cpu
);
1004 case CPU_DEAD_FROZEN
:
1005 refresh_zone_stat_thresholds();
1013 static struct notifier_block __cpuinitdata vmstat_notifier
=
1014 { &vmstat_cpuup_callback
, NULL
, 0 };
1017 static int __init
setup_vmstat(void)
1022 refresh_zone_stat_thresholds();
1023 register_cpu_notifier(&vmstat_notifier
);
1025 for_each_online_cpu(cpu
)
1026 start_cpu_timer(cpu
);
1028 #ifdef CONFIG_PROC_FS
1029 proc_create("buddyinfo", S_IRUGO
, NULL
, &fragmentation_file_operations
);
1030 proc_create("pagetypeinfo", S_IRUGO
, NULL
, &pagetypeinfo_file_ops
);
1031 proc_create("vmstat", S_IRUGO
, NULL
, &proc_vmstat_file_operations
);
1032 proc_create("zoneinfo", S_IRUGO
, NULL
, &proc_zoneinfo_file_operations
);
1036 module_init(setup_vmstat
)
1038 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1039 #include <linux/debugfs.h>
1041 static struct dentry
*extfrag_debug_root
;
1044 * Return an index indicating how much of the available free memory is
1045 * unusable for an allocation of the requested size.
1047 static int unusable_free_index(unsigned int order
,
1048 struct contig_page_info
*info
)
1050 /* No free memory is interpreted as all free memory is unusable */
1051 if (info
->free_pages
== 0)
1055 * Index should be a value between 0 and 1. Return a value to 3
1058 * 0 => no fragmentation
1059 * 1 => high fragmentation
1061 return div_u64((info
->free_pages
- (info
->free_blocks_suitable
<< order
)) * 1000ULL, info
->free_pages
);
1065 static void unusable_show_print(struct seq_file
*m
,
1066 pg_data_t
*pgdat
, struct zone
*zone
)
1070 struct contig_page_info info
;
1072 seq_printf(m
, "Node %d, zone %8s ",
1075 for (order
= 0; order
< MAX_ORDER
; ++order
) {
1076 fill_contig_page_info(zone
, order
, &info
);
1077 index
= unusable_free_index(order
, &info
);
1078 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
1085 * Display unusable free space index
1087 * The unusable free space index measures how much of the available free
1088 * memory cannot be used to satisfy an allocation of a given size and is a
1089 * value between 0 and 1. The higher the value, the more of free memory is
1090 * unusable and by implication, the worse the external fragmentation is. This
1091 * can be expressed as a percentage by multiplying by 100.
1093 static int unusable_show(struct seq_file
*m
, void *arg
)
1095 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1097 /* check memoryless node */
1098 if (!node_state(pgdat
->node_id
, N_HIGH_MEMORY
))
1101 walk_zones_in_node(m
, pgdat
, unusable_show_print
);
1106 static const struct seq_operations unusable_op
= {
1107 .start
= frag_start
,
1110 .show
= unusable_show
,
1113 static int unusable_open(struct inode
*inode
, struct file
*file
)
1115 return seq_open(file
, &unusable_op
);
1118 static const struct file_operations unusable_file_ops
= {
1119 .open
= unusable_open
,
1121 .llseek
= seq_lseek
,
1122 .release
= seq_release
,
1125 static void extfrag_show_print(struct seq_file
*m
,
1126 pg_data_t
*pgdat
, struct zone
*zone
)
1131 /* Alloc on stack as interrupts are disabled for zone walk */
1132 struct contig_page_info info
;
1134 seq_printf(m
, "Node %d, zone %8s ",
1137 for (order
= 0; order
< MAX_ORDER
; ++order
) {
1138 fill_contig_page_info(zone
, order
, &info
);
1139 index
= fragmentation_index(order
, &info
);
1140 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
1147 * Display fragmentation index for orders that allocations would fail for
1149 static int extfrag_show(struct seq_file
*m
, void *arg
)
1151 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1153 walk_zones_in_node(m
, pgdat
, extfrag_show_print
);
1158 static const struct seq_operations extfrag_op
= {
1159 .start
= frag_start
,
1162 .show
= extfrag_show
,
1165 static int extfrag_open(struct inode
*inode
, struct file
*file
)
1167 return seq_open(file
, &extfrag_op
);
1170 static const struct file_operations extfrag_file_ops
= {
1171 .open
= extfrag_open
,
1173 .llseek
= seq_lseek
,
1174 .release
= seq_release
,
1177 static int __init
extfrag_debug_init(void)
1179 extfrag_debug_root
= debugfs_create_dir("extfrag", NULL
);
1180 if (!extfrag_debug_root
)
1183 if (!debugfs_create_file("unusable_index", 0444,
1184 extfrag_debug_root
, NULL
, &unusable_file_ops
))
1187 if (!debugfs_create_file("extfrag_index", 0444,
1188 extfrag_debug_root
, NULL
, &extfrag_file_ops
))
1194 module_init(extfrag_debug_init
);