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>
21 #include <linux/compaction.h>
23 #ifdef CONFIG_VM_EVENT_COUNTERS
24 DEFINE_PER_CPU(struct vm_event_state
, vm_event_states
) = {{0}};
25 EXPORT_PER_CPU_SYMBOL(vm_event_states
);
27 static void sum_vm_events(unsigned long *ret
)
32 memset(ret
, 0, NR_VM_EVENT_ITEMS
* sizeof(unsigned long));
34 for_each_online_cpu(cpu
) {
35 struct vm_event_state
*this = &per_cpu(vm_event_states
, cpu
);
37 for (i
= 0; i
< NR_VM_EVENT_ITEMS
; i
++)
38 ret
[i
] += this->event
[i
];
43 * Accumulate the vm event counters across all CPUs.
44 * The result is unavoidably approximate - it can change
45 * during and after execution of this function.
47 void all_vm_events(unsigned long *ret
)
53 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;
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
] __cacheline_aligned_in_smp
;
80 EXPORT_SYMBOL(vm_stat
);
84 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 int calculate_normal_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
->managed_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 void refresh_zone_stat_thresholds(void)
164 for_each_populated_zone(zone
) {
165 unsigned long max_drift
, tolerate_drift
;
167 threshold
= calculate_normal_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 set_pgdat_percpu_threshold(pg_data_t
*pgdat
,
187 int (*calculate_pressure
)(struct zone
*))
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
)(zone
);
200 for_each_possible_cpu(cpu
)
201 per_cpu_ptr(zone
->pageset
, cpu
)->stat_threshold
207 * For use when we know that interrupts are disabled.
209 void __mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
212 struct per_cpu_pageset __percpu
*pcp
= zone
->pageset
;
213 s8 __percpu
*p
= pcp
->vm_stat_diff
+ item
;
217 x
= delta
+ __this_cpu_read(*p
);
219 t
= __this_cpu_read(pcp
->stat_threshold
);
221 if (unlikely(x
> t
|| x
< -t
)) {
222 zone_page_state_add(x
, zone
, item
);
225 __this_cpu_write(*p
, x
);
227 EXPORT_SYMBOL(__mod_zone_page_state
);
230 * Optimized increment and decrement functions.
232 * These are only for a single page and therefore can take a struct page *
233 * argument instead of struct zone *. This allows the inclusion of the code
234 * generated for page_zone(page) into the optimized functions.
236 * No overflow check is necessary and therefore the differential can be
237 * incremented or decremented in place which may allow the compilers to
238 * generate better code.
239 * The increment or decrement is known and therefore one boundary check can
242 * NOTE: These functions are very performance sensitive. Change only
245 * Some processors have inc/dec instructions that are atomic vs an interrupt.
246 * However, the code must first determine the differential location in a zone
247 * based on the processor number and then inc/dec the counter. There is no
248 * guarantee without disabling preemption that the processor will not change
249 * in between and therefore the atomicity vs. interrupt cannot be exploited
250 * in a useful way here.
252 void __inc_zone_state(struct zone
*zone
, enum zone_stat_item item
)
254 struct per_cpu_pageset __percpu
*pcp
= zone
->pageset
;
255 s8 __percpu
*p
= pcp
->vm_stat_diff
+ item
;
258 v
= __this_cpu_inc_return(*p
);
259 t
= __this_cpu_read(pcp
->stat_threshold
);
260 if (unlikely(v
> t
)) {
261 s8 overstep
= t
>> 1;
263 zone_page_state_add(v
+ overstep
, zone
, item
);
264 __this_cpu_write(*p
, -overstep
);
268 void __inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
270 __inc_zone_state(page_zone(page
), item
);
272 EXPORT_SYMBOL(__inc_zone_page_state
);
274 void __dec_zone_state(struct zone
*zone
, enum zone_stat_item item
)
276 struct per_cpu_pageset __percpu
*pcp
= zone
->pageset
;
277 s8 __percpu
*p
= pcp
->vm_stat_diff
+ item
;
280 v
= __this_cpu_dec_return(*p
);
281 t
= __this_cpu_read(pcp
->stat_threshold
);
282 if (unlikely(v
< - t
)) {
283 s8 overstep
= t
>> 1;
285 zone_page_state_add(v
- overstep
, zone
, item
);
286 __this_cpu_write(*p
, overstep
);
290 void __dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
292 __dec_zone_state(page_zone(page
), item
);
294 EXPORT_SYMBOL(__dec_zone_page_state
);
296 #ifdef CONFIG_HAVE_CMPXCHG_LOCAL
298 * If we have cmpxchg_local support then we do not need to incur the overhead
299 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
301 * mod_state() modifies the zone counter state through atomic per cpu
304 * Overstep mode specifies how overstep should handled:
306 * 1 Overstepping half of threshold
307 * -1 Overstepping minus half of threshold
309 static inline void mod_state(struct zone
*zone
,
310 enum zone_stat_item item
, int delta
, int overstep_mode
)
312 struct per_cpu_pageset __percpu
*pcp
= zone
->pageset
;
313 s8 __percpu
*p
= pcp
->vm_stat_diff
+ item
;
317 z
= 0; /* overflow to zone counters */
320 * The fetching of the stat_threshold is racy. We may apply
321 * a counter threshold to the wrong the cpu if we get
322 * rescheduled while executing here. However, the next
323 * counter update will apply the threshold again and
324 * therefore bring the counter under the threshold again.
326 * Most of the time the thresholds are the same anyways
327 * for all cpus in a zone.
329 t
= this_cpu_read(pcp
->stat_threshold
);
331 o
= this_cpu_read(*p
);
334 if (n
> t
|| n
< -t
) {
335 int os
= overstep_mode
* (t
>> 1) ;
337 /* Overflow must be added to zone counters */
341 } while (this_cpu_cmpxchg(*p
, o
, n
) != o
);
344 zone_page_state_add(z
, zone
, item
);
347 void mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
350 mod_state(zone
, item
, delta
, 0);
352 EXPORT_SYMBOL(mod_zone_page_state
);
354 void inc_zone_state(struct zone
*zone
, enum zone_stat_item item
)
356 mod_state(zone
, item
, 1, 1);
359 void inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
361 mod_state(page_zone(page
), item
, 1, 1);
363 EXPORT_SYMBOL(inc_zone_page_state
);
365 void dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
367 mod_state(page_zone(page
), item
, -1, -1);
369 EXPORT_SYMBOL(dec_zone_page_state
);
372 * Use interrupt disable to serialize counter updates
374 void mod_zone_page_state(struct zone
*zone
, enum zone_stat_item item
,
379 local_irq_save(flags
);
380 __mod_zone_page_state(zone
, item
, delta
);
381 local_irq_restore(flags
);
383 EXPORT_SYMBOL(mod_zone_page_state
);
385 void inc_zone_state(struct zone
*zone
, enum zone_stat_item item
)
389 local_irq_save(flags
);
390 __inc_zone_state(zone
, item
);
391 local_irq_restore(flags
);
394 void inc_zone_page_state(struct page
*page
, enum zone_stat_item item
)
399 zone
= page_zone(page
);
400 local_irq_save(flags
);
401 __inc_zone_state(zone
, item
);
402 local_irq_restore(flags
);
404 EXPORT_SYMBOL(inc_zone_page_state
);
406 void dec_zone_page_state(struct page
*page
, enum zone_stat_item item
)
410 local_irq_save(flags
);
411 __dec_zone_page_state(page
, item
);
412 local_irq_restore(flags
);
414 EXPORT_SYMBOL(dec_zone_page_state
);
417 static inline void fold_diff(int *diff
)
421 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
423 atomic_long_add(diff
[i
], &vm_stat
[i
]);
427 * Update the zone counters for the current cpu.
429 * Note that refresh_cpu_vm_stats strives to only access
430 * node local memory. The per cpu pagesets on remote zones are placed
431 * in the memory local to the processor using that pageset. So the
432 * loop over all zones will access a series of cachelines local to
435 * The call to zone_page_state_add updates the cachelines with the
436 * statistics in the remote zone struct as well as the global cachelines
437 * with the global counters. These could cause remote node cache line
438 * bouncing and will have to be only done when necessary.
440 static void refresh_cpu_vm_stats(void)
444 int global_diff
[NR_VM_ZONE_STAT_ITEMS
] = { 0, };
446 for_each_populated_zone(zone
) {
447 struct per_cpu_pageset __percpu
*p
= zone
->pageset
;
449 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++) {
452 v
= this_cpu_xchg(p
->vm_stat_diff
[i
], 0);
455 atomic_long_add(v
, &zone
->vm_stat
[i
]);
458 /* 3 seconds idle till flush */
459 __this_cpu_write(p
->expire
, 3);
466 * Deal with draining the remote pageset of this
469 * Check if there are pages remaining in this pageset
470 * if not then there is nothing to expire.
472 if (!__this_cpu_read(p
->expire
) ||
473 !__this_cpu_read(p
->pcp
.count
))
477 * We never drain zones local to this processor.
479 if (zone_to_nid(zone
) == numa_node_id()) {
480 __this_cpu_write(p
->expire
, 0);
485 if (__this_cpu_dec_return(p
->expire
))
488 if (__this_cpu_read(p
->pcp
.count
))
489 drain_zone_pages(zone
, __this_cpu_ptr(&p
->pcp
));
492 fold_diff(global_diff
);
496 * Fold the data for an offline cpu into the global array.
497 * There cannot be any access by the offline cpu and therefore
498 * synchronization is simplified.
500 void cpu_vm_stats_fold(int cpu
)
504 int global_diff
[NR_VM_ZONE_STAT_ITEMS
] = { 0, };
506 for_each_populated_zone(zone
) {
507 struct per_cpu_pageset
*p
;
509 p
= per_cpu_ptr(zone
->pageset
, cpu
);
511 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
512 if (p
->vm_stat_diff
[i
]) {
515 v
= p
->vm_stat_diff
[i
];
516 p
->vm_stat_diff
[i
] = 0;
517 atomic_long_add(v
, &zone
->vm_stat
[i
]);
522 fold_diff(global_diff
);
526 * this is only called if !populated_zone(zone), which implies no other users of
527 * pset->vm_stat_diff[] exsist.
529 void drain_zonestat(struct zone
*zone
, struct per_cpu_pageset
*pset
)
533 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
534 if (pset
->vm_stat_diff
[i
]) {
535 int v
= pset
->vm_stat_diff
[i
];
536 pset
->vm_stat_diff
[i
] = 0;
537 atomic_long_add(v
, &zone
->vm_stat
[i
]);
538 atomic_long_add(v
, &vm_stat
[i
]);
545 * zonelist = the list of zones passed to the allocator
546 * z = the zone from which the allocation occurred.
548 * Must be called with interrupts disabled.
550 * When __GFP_OTHER_NODE is set assume the node of the preferred
551 * zone is the local node. This is useful for daemons who allocate
552 * memory on behalf of other processes.
554 void zone_statistics(struct zone
*preferred_zone
, struct zone
*z
, gfp_t flags
)
556 if (z
->zone_pgdat
== preferred_zone
->zone_pgdat
) {
557 __inc_zone_state(z
, NUMA_HIT
);
559 __inc_zone_state(z
, NUMA_MISS
);
560 __inc_zone_state(preferred_zone
, NUMA_FOREIGN
);
562 if (z
->node
== ((flags
& __GFP_OTHER_NODE
) ?
563 preferred_zone
->node
: numa_node_id()))
564 __inc_zone_state(z
, NUMA_LOCAL
);
566 __inc_zone_state(z
, NUMA_OTHER
);
570 #ifdef CONFIG_COMPACTION
572 struct contig_page_info
{
573 unsigned long free_pages
;
574 unsigned long free_blocks_total
;
575 unsigned long free_blocks_suitable
;
579 * Calculate the number of free pages in a zone, how many contiguous
580 * pages are free and how many are large enough to satisfy an allocation of
581 * the target size. Note that this function makes no attempt to estimate
582 * how many suitable free blocks there *might* be if MOVABLE pages were
583 * migrated. Calculating that is possible, but expensive and can be
584 * figured out from userspace
586 static void fill_contig_page_info(struct zone
*zone
,
587 unsigned int suitable_order
,
588 struct contig_page_info
*info
)
592 info
->free_pages
= 0;
593 info
->free_blocks_total
= 0;
594 info
->free_blocks_suitable
= 0;
596 for (order
= 0; order
< MAX_ORDER
; order
++) {
597 unsigned long blocks
;
599 /* Count number of free blocks */
600 blocks
= zone
->free_area
[order
].nr_free
;
601 info
->free_blocks_total
+= blocks
;
603 /* Count free base pages */
604 info
->free_pages
+= blocks
<< order
;
606 /* Count the suitable free blocks */
607 if (order
>= suitable_order
)
608 info
->free_blocks_suitable
+= blocks
<<
609 (order
- suitable_order
);
614 * A fragmentation index only makes sense if an allocation of a requested
615 * size would fail. If that is true, the fragmentation index indicates
616 * whether external fragmentation or a lack of memory was the problem.
617 * The value can be used to determine if page reclaim or compaction
620 static int __fragmentation_index(unsigned int order
, struct contig_page_info
*info
)
622 unsigned long requested
= 1UL << order
;
624 if (!info
->free_blocks_total
)
627 /* Fragmentation index only makes sense when a request would fail */
628 if (info
->free_blocks_suitable
)
632 * Index is between 0 and 1 so return within 3 decimal places
634 * 0 => allocation would fail due to lack of memory
635 * 1 => allocation would fail due to fragmentation
637 return 1000 - div_u64( (1000+(div_u64(info
->free_pages
* 1000ULL, requested
))), info
->free_blocks_total
);
640 /* Same as __fragmentation index but allocs contig_page_info on stack */
641 int fragmentation_index(struct zone
*zone
, unsigned int order
)
643 struct contig_page_info info
;
645 fill_contig_page_info(zone
, order
, &info
);
646 return __fragmentation_index(order
, &info
);
650 #if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
651 #include <linux/proc_fs.h>
652 #include <linux/seq_file.h>
654 static char * const migratetype_names
[MIGRATE_TYPES
] = {
662 #ifdef CONFIG_MEMORY_ISOLATION
667 static void *frag_start(struct seq_file
*m
, loff_t
*pos
)
671 for (pgdat
= first_online_pgdat();
673 pgdat
= next_online_pgdat(pgdat
))
679 static void *frag_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
681 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
684 return next_online_pgdat(pgdat
);
687 static void frag_stop(struct seq_file
*m
, void *arg
)
691 /* Walk all the zones in a node and print using a callback */
692 static void walk_zones_in_node(struct seq_file
*m
, pg_data_t
*pgdat
,
693 void (*print
)(struct seq_file
*m
, pg_data_t
*, struct zone
*))
696 struct zone
*node_zones
= pgdat
->node_zones
;
699 for (zone
= node_zones
; zone
- node_zones
< MAX_NR_ZONES
; ++zone
) {
700 if (!populated_zone(zone
))
703 spin_lock_irqsave(&zone
->lock
, flags
);
704 print(m
, pgdat
, zone
);
705 spin_unlock_irqrestore(&zone
->lock
, flags
);
710 #if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
711 #ifdef CONFIG_ZONE_DMA
712 #define TEXT_FOR_DMA(xx) xx "_dma",
714 #define TEXT_FOR_DMA(xx)
717 #ifdef CONFIG_ZONE_DMA32
718 #define TEXT_FOR_DMA32(xx) xx "_dma32",
720 #define TEXT_FOR_DMA32(xx)
723 #ifdef CONFIG_HIGHMEM
724 #define TEXT_FOR_HIGHMEM(xx) xx "_high",
726 #define TEXT_FOR_HIGHMEM(xx)
729 #define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
730 TEXT_FOR_HIGHMEM(xx) xx "_movable",
732 const char * const vmstat_text
[] = {
733 /* Zoned VM counters */
747 "nr_slab_reclaimable",
748 "nr_slab_unreclaimable",
749 "nr_page_table_pages",
754 "nr_vmscan_immediate_reclaim",
770 "nr_anon_transparent_hugepages",
772 "nr_dirty_threshold",
773 "nr_dirty_background_threshold",
775 #ifdef CONFIG_VM_EVENT_COUNTERS
781 TEXTS_FOR_ZONES("pgalloc")
790 TEXTS_FOR_ZONES("pgrefill")
791 TEXTS_FOR_ZONES("pgsteal_kswapd")
792 TEXTS_FOR_ZONES("pgsteal_direct")
793 TEXTS_FOR_ZONES("pgscan_kswapd")
794 TEXTS_FOR_ZONES("pgscan_direct")
795 "pgscan_direct_throttle",
798 "zone_reclaim_failed",
803 "kswapd_low_wmark_hit_quickly",
804 "kswapd_high_wmark_hit_quickly",
810 #ifdef CONFIG_NUMA_BALANCING
813 "numa_hint_faults_local",
814 "numa_pages_migrated",
816 #ifdef CONFIG_MIGRATION
820 #ifdef CONFIG_COMPACTION
821 "compact_migrate_scanned",
822 "compact_free_scanned",
829 #ifdef CONFIG_HUGETLB_PAGE
830 "htlb_buddy_alloc_success",
831 "htlb_buddy_alloc_fail",
833 "unevictable_pgs_culled",
834 "unevictable_pgs_scanned",
835 "unevictable_pgs_rescued",
836 "unevictable_pgs_mlocked",
837 "unevictable_pgs_munlocked",
838 "unevictable_pgs_cleared",
839 "unevictable_pgs_stranded",
841 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
843 "thp_fault_fallback",
844 "thp_collapse_alloc",
845 "thp_collapse_alloc_failed",
847 "thp_zero_page_alloc",
848 "thp_zero_page_alloc_failed",
851 "nr_tlb_remote_flush",
852 "nr_tlb_remote_flush_received",
854 "nr_tlb_local_flush_all",
855 "nr_tlb_local_flush_one",
857 #endif /* CONFIG_VM_EVENTS_COUNTERS */
859 #endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
862 #ifdef CONFIG_PROC_FS
863 static void frag_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
868 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
869 for (order
= 0; order
< MAX_ORDER
; ++order
)
870 seq_printf(m
, "%6lu ", zone
->free_area
[order
].nr_free
);
875 * This walks the free areas for each zone.
877 static int frag_show(struct seq_file
*m
, void *arg
)
879 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
880 walk_zones_in_node(m
, pgdat
, frag_show_print
);
884 static void pagetypeinfo_showfree_print(struct seq_file
*m
,
885 pg_data_t
*pgdat
, struct zone
*zone
)
889 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++) {
890 seq_printf(m
, "Node %4d, zone %8s, type %12s ",
893 migratetype_names
[mtype
]);
894 for (order
= 0; order
< MAX_ORDER
; ++order
) {
895 unsigned long freecount
= 0;
896 struct free_area
*area
;
897 struct list_head
*curr
;
899 area
= &(zone
->free_area
[order
]);
901 list_for_each(curr
, &area
->free_list
[mtype
])
903 seq_printf(m
, "%6lu ", freecount
);
909 /* Print out the free pages at each order for each migatetype */
910 static int pagetypeinfo_showfree(struct seq_file
*m
, void *arg
)
913 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
916 seq_printf(m
, "%-43s ", "Free pages count per migrate type at order");
917 for (order
= 0; order
< MAX_ORDER
; ++order
)
918 seq_printf(m
, "%6d ", order
);
921 walk_zones_in_node(m
, pgdat
, pagetypeinfo_showfree_print
);
926 static void pagetypeinfo_showblockcount_print(struct seq_file
*m
,
927 pg_data_t
*pgdat
, struct zone
*zone
)
931 unsigned long start_pfn
= zone
->zone_start_pfn
;
932 unsigned long end_pfn
= zone_end_pfn(zone
);
933 unsigned long count
[MIGRATE_TYPES
] = { 0, };
935 for (pfn
= start_pfn
; pfn
< end_pfn
; pfn
+= pageblock_nr_pages
) {
941 page
= pfn_to_page(pfn
);
943 /* Watch for unexpected holes punched in the memmap */
944 if (!memmap_valid_within(pfn
, page
, zone
))
947 mtype
= get_pageblock_migratetype(page
);
949 if (mtype
< MIGRATE_TYPES
)
954 seq_printf(m
, "Node %d, zone %8s ", pgdat
->node_id
, zone
->name
);
955 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
956 seq_printf(m
, "%12lu ", count
[mtype
]);
960 /* Print out the free pages at each order for each migratetype */
961 static int pagetypeinfo_showblockcount(struct seq_file
*m
, void *arg
)
964 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
966 seq_printf(m
, "\n%-23s", "Number of blocks type ");
967 for (mtype
= 0; mtype
< MIGRATE_TYPES
; mtype
++)
968 seq_printf(m
, "%12s ", migratetype_names
[mtype
]);
970 walk_zones_in_node(m
, pgdat
, pagetypeinfo_showblockcount_print
);
976 * This prints out statistics in relation to grouping pages by mobility.
977 * It is expensive to collect so do not constantly read the file.
979 static int pagetypeinfo_show(struct seq_file
*m
, void *arg
)
981 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
983 /* check memoryless node */
984 if (!node_state(pgdat
->node_id
, N_MEMORY
))
987 seq_printf(m
, "Page block order: %d\n", pageblock_order
);
988 seq_printf(m
, "Pages per block: %lu\n", pageblock_nr_pages
);
990 pagetypeinfo_showfree(m
, pgdat
);
991 pagetypeinfo_showblockcount(m
, pgdat
);
996 static const struct seq_operations fragmentation_op
= {
1003 static int fragmentation_open(struct inode
*inode
, struct file
*file
)
1005 return seq_open(file
, &fragmentation_op
);
1008 static const struct file_operations fragmentation_file_operations
= {
1009 .open
= fragmentation_open
,
1011 .llseek
= seq_lseek
,
1012 .release
= seq_release
,
1015 static const struct seq_operations pagetypeinfo_op
= {
1016 .start
= frag_start
,
1019 .show
= pagetypeinfo_show
,
1022 static int pagetypeinfo_open(struct inode
*inode
, struct file
*file
)
1024 return seq_open(file
, &pagetypeinfo_op
);
1027 static const struct file_operations pagetypeinfo_file_ops
= {
1028 .open
= pagetypeinfo_open
,
1030 .llseek
= seq_lseek
,
1031 .release
= seq_release
,
1034 static void zoneinfo_show_print(struct seq_file
*m
, pg_data_t
*pgdat
,
1038 seq_printf(m
, "Node %d, zone %8s", pgdat
->node_id
, zone
->name
);
1048 zone_page_state(zone
, NR_FREE_PAGES
),
1049 min_wmark_pages(zone
),
1050 low_wmark_pages(zone
),
1051 high_wmark_pages(zone
),
1052 zone
->pages_scanned
,
1053 zone
->spanned_pages
,
1054 zone
->present_pages
,
1055 zone
->managed_pages
);
1057 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
1058 seq_printf(m
, "\n %-12s %lu", vmstat_text
[i
],
1059 zone_page_state(zone
, i
));
1062 "\n protection: (%lu",
1063 zone
->lowmem_reserve
[0]);
1064 for (i
= 1; i
< ARRAY_SIZE(zone
->lowmem_reserve
); i
++)
1065 seq_printf(m
, ", %lu", zone
->lowmem_reserve
[i
]);
1069 for_each_online_cpu(i
) {
1070 struct per_cpu_pageset
*pageset
;
1072 pageset
= per_cpu_ptr(zone
->pageset
, i
);
1081 pageset
->pcp
.batch
);
1083 seq_printf(m
, "\n vm stats threshold: %d",
1084 pageset
->stat_threshold
);
1088 "\n all_unreclaimable: %u"
1090 "\n inactive_ratio: %u",
1091 zone
->all_unreclaimable
,
1092 zone
->zone_start_pfn
,
1093 zone
->inactive_ratio
);
1098 * Output information about zones in @pgdat.
1100 static int zoneinfo_show(struct seq_file
*m
, void *arg
)
1102 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1103 walk_zones_in_node(m
, pgdat
, zoneinfo_show_print
);
1107 static const struct seq_operations zoneinfo_op
= {
1108 .start
= frag_start
, /* iterate over all zones. The same as in
1112 .show
= zoneinfo_show
,
1115 static int zoneinfo_open(struct inode
*inode
, struct file
*file
)
1117 return seq_open(file
, &zoneinfo_op
);
1120 static const struct file_operations proc_zoneinfo_file_operations
= {
1121 .open
= zoneinfo_open
,
1123 .llseek
= seq_lseek
,
1124 .release
= seq_release
,
1127 enum writeback_stat_item
{
1129 NR_DIRTY_BG_THRESHOLD
,
1130 NR_VM_WRITEBACK_STAT_ITEMS
,
1133 static void *vmstat_start(struct seq_file
*m
, loff_t
*pos
)
1136 int i
, stat_items_size
;
1138 if (*pos
>= ARRAY_SIZE(vmstat_text
))
1140 stat_items_size
= NR_VM_ZONE_STAT_ITEMS
* sizeof(unsigned long) +
1141 NR_VM_WRITEBACK_STAT_ITEMS
* sizeof(unsigned long);
1143 #ifdef CONFIG_VM_EVENT_COUNTERS
1144 stat_items_size
+= sizeof(struct vm_event_state
);
1147 v
= kmalloc(stat_items_size
, GFP_KERNEL
);
1150 return ERR_PTR(-ENOMEM
);
1151 for (i
= 0; i
< NR_VM_ZONE_STAT_ITEMS
; i
++)
1152 v
[i
] = global_page_state(i
);
1153 v
+= NR_VM_ZONE_STAT_ITEMS
;
1155 global_dirty_limits(v
+ NR_DIRTY_BG_THRESHOLD
,
1156 v
+ NR_DIRTY_THRESHOLD
);
1157 v
+= NR_VM_WRITEBACK_STAT_ITEMS
;
1159 #ifdef CONFIG_VM_EVENT_COUNTERS
1161 v
[PGPGIN
] /= 2; /* sectors -> kbytes */
1164 return (unsigned long *)m
->private + *pos
;
1167 static void *vmstat_next(struct seq_file
*m
, void *arg
, loff_t
*pos
)
1170 if (*pos
>= ARRAY_SIZE(vmstat_text
))
1172 return (unsigned long *)m
->private + *pos
;
1175 static int vmstat_show(struct seq_file
*m
, void *arg
)
1177 unsigned long *l
= arg
;
1178 unsigned long off
= l
- (unsigned long *)m
->private;
1180 seq_printf(m
, "%s %lu\n", vmstat_text
[off
], *l
);
1184 static void vmstat_stop(struct seq_file
*m
, void *arg
)
1190 static const struct seq_operations vmstat_op
= {
1191 .start
= vmstat_start
,
1192 .next
= vmstat_next
,
1193 .stop
= vmstat_stop
,
1194 .show
= vmstat_show
,
1197 static int vmstat_open(struct inode
*inode
, struct file
*file
)
1199 return seq_open(file
, &vmstat_op
);
1202 static const struct file_operations proc_vmstat_file_operations
= {
1203 .open
= vmstat_open
,
1205 .llseek
= seq_lseek
,
1206 .release
= seq_release
,
1208 #endif /* CONFIG_PROC_FS */
1211 static DEFINE_PER_CPU(struct delayed_work
, vmstat_work
);
1212 int sysctl_stat_interval __read_mostly
= HZ
;
1214 static void vmstat_update(struct work_struct
*w
)
1216 refresh_cpu_vm_stats();
1217 schedule_delayed_work(&__get_cpu_var(vmstat_work
),
1218 round_jiffies_relative(sysctl_stat_interval
));
1221 static void start_cpu_timer(int cpu
)
1223 struct delayed_work
*work
= &per_cpu(vmstat_work
, cpu
);
1225 INIT_DEFERRABLE_WORK(work
, vmstat_update
);
1226 schedule_delayed_work_on(cpu
, work
, __round_jiffies_relative(HZ
, cpu
));
1230 * Use the cpu notifier to insure that the thresholds are recalculated
1233 static int vmstat_cpuup_callback(struct notifier_block
*nfb
,
1234 unsigned long action
,
1237 long cpu
= (long)hcpu
;
1241 case CPU_ONLINE_FROZEN
:
1242 refresh_zone_stat_thresholds();
1243 start_cpu_timer(cpu
);
1244 node_set_state(cpu_to_node(cpu
), N_CPU
);
1246 case CPU_DOWN_PREPARE
:
1247 case CPU_DOWN_PREPARE_FROZEN
:
1248 cancel_delayed_work_sync(&per_cpu(vmstat_work
, cpu
));
1249 per_cpu(vmstat_work
, cpu
).work
.func
= NULL
;
1251 case CPU_DOWN_FAILED
:
1252 case CPU_DOWN_FAILED_FROZEN
:
1253 start_cpu_timer(cpu
);
1256 case CPU_DEAD_FROZEN
:
1257 refresh_zone_stat_thresholds();
1265 static struct notifier_block vmstat_notifier
=
1266 { &vmstat_cpuup_callback
, NULL
, 0 };
1269 static int __init
setup_vmstat(void)
1274 register_cpu_notifier(&vmstat_notifier
);
1276 for_each_online_cpu(cpu
)
1277 start_cpu_timer(cpu
);
1279 #ifdef CONFIG_PROC_FS
1280 proc_create("buddyinfo", S_IRUGO
, NULL
, &fragmentation_file_operations
);
1281 proc_create("pagetypeinfo", S_IRUGO
, NULL
, &pagetypeinfo_file_ops
);
1282 proc_create("vmstat", S_IRUGO
, NULL
, &proc_vmstat_file_operations
);
1283 proc_create("zoneinfo", S_IRUGO
, NULL
, &proc_zoneinfo_file_operations
);
1287 module_init(setup_vmstat
)
1289 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1290 #include <linux/debugfs.h>
1294 * Return an index indicating how much of the available free memory is
1295 * unusable for an allocation of the requested size.
1297 static int unusable_free_index(unsigned int order
,
1298 struct contig_page_info
*info
)
1300 /* No free memory is interpreted as all free memory is unusable */
1301 if (info
->free_pages
== 0)
1305 * Index should be a value between 0 and 1. Return a value to 3
1308 * 0 => no fragmentation
1309 * 1 => high fragmentation
1311 return div_u64((info
->free_pages
- (info
->free_blocks_suitable
<< order
)) * 1000ULL, info
->free_pages
);
1315 static void unusable_show_print(struct seq_file
*m
,
1316 pg_data_t
*pgdat
, struct zone
*zone
)
1320 struct contig_page_info info
;
1322 seq_printf(m
, "Node %d, zone %8s ",
1325 for (order
= 0; order
< MAX_ORDER
; ++order
) {
1326 fill_contig_page_info(zone
, order
, &info
);
1327 index
= unusable_free_index(order
, &info
);
1328 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
1335 * Display unusable free space index
1337 * The unusable free space index measures how much of the available free
1338 * memory cannot be used to satisfy an allocation of a given size and is a
1339 * value between 0 and 1. The higher the value, the more of free memory is
1340 * unusable and by implication, the worse the external fragmentation is. This
1341 * can be expressed as a percentage by multiplying by 100.
1343 static int unusable_show(struct seq_file
*m
, void *arg
)
1345 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1347 /* check memoryless node */
1348 if (!node_state(pgdat
->node_id
, N_MEMORY
))
1351 walk_zones_in_node(m
, pgdat
, unusable_show_print
);
1356 static const struct seq_operations unusable_op
= {
1357 .start
= frag_start
,
1360 .show
= unusable_show
,
1363 static int unusable_open(struct inode
*inode
, struct file
*file
)
1365 return seq_open(file
, &unusable_op
);
1368 static const struct file_operations unusable_file_ops
= {
1369 .open
= unusable_open
,
1371 .llseek
= seq_lseek
,
1372 .release
= seq_release
,
1375 static void extfrag_show_print(struct seq_file
*m
,
1376 pg_data_t
*pgdat
, struct zone
*zone
)
1381 /* Alloc on stack as interrupts are disabled for zone walk */
1382 struct contig_page_info info
;
1384 seq_printf(m
, "Node %d, zone %8s ",
1387 for (order
= 0; order
< MAX_ORDER
; ++order
) {
1388 fill_contig_page_info(zone
, order
, &info
);
1389 index
= __fragmentation_index(order
, &info
);
1390 seq_printf(m
, "%d.%03d ", index
/ 1000, index
% 1000);
1397 * Display fragmentation index for orders that allocations would fail for
1399 static int extfrag_show(struct seq_file
*m
, void *arg
)
1401 pg_data_t
*pgdat
= (pg_data_t
*)arg
;
1403 walk_zones_in_node(m
, pgdat
, extfrag_show_print
);
1408 static const struct seq_operations extfrag_op
= {
1409 .start
= frag_start
,
1412 .show
= extfrag_show
,
1415 static int extfrag_open(struct inode
*inode
, struct file
*file
)
1417 return seq_open(file
, &extfrag_op
);
1420 static const struct file_operations extfrag_file_ops
= {
1421 .open
= extfrag_open
,
1423 .llseek
= seq_lseek
,
1424 .release
= seq_release
,
1427 static int __init
extfrag_debug_init(void)
1429 struct dentry
*extfrag_debug_root
;
1431 extfrag_debug_root
= debugfs_create_dir("extfrag", NULL
);
1432 if (!extfrag_debug_root
)
1435 if (!debugfs_create_file("unusable_index", 0444,
1436 extfrag_debug_root
, NULL
, &unusable_file_ops
))
1439 if (!debugfs_create_file("extfrag_index", 0444,
1440 extfrag_debug_root
, NULL
, &extfrag_file_ops
))
1445 debugfs_remove_recursive(extfrag_debug_root
);
1449 module_init(extfrag_debug_init
);