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Christoph Lameterf6ac2352006-06-30 01:55:32 -07001/*
2 * linux/mm/vmstat.c
3 *
4 * Manages VM statistics
5 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
Christoph Lameter2244b952006-06-30 01:55:33 -07006 *
7 * zoned VM statistics
8 * Copyright (C) 2006 Silicon Graphics, Inc.,
9 * Christoph Lameter <christoph@lameter.com>
Christoph Lameterf6ac2352006-06-30 01:55:32 -070010 */
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +040011#include <linux/fs.h>
Christoph Lameterf6ac2352006-06-30 01:55:32 -070012#include <linux/mm.h>
Alexey Dobriyan4e950f62007-07-30 02:36:13 +040013#include <linux/err.h>
Christoph Lameter2244b952006-06-30 01:55:33 -070014#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090015#include <linux/slab.h>
Christoph Lameterdf9ecab2006-08-31 21:27:35 -070016#include <linux/cpu.h>
Adrian Bunkc748e132008-07-23 21:27:03 -070017#include <linux/vmstat.h>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +040018#include <linux/sched.h>
Mel Gormanf1a5ab12010-05-24 14:32:26 -070019#include <linux/math64.h>
Michael Rubin79da8262010-10-26 14:21:36 -070020#include <linux/writeback.h>
Namhyung Kim36deb0b2010-10-26 14:22:04 -070021#include <linux/compaction.h>
Christoph Lameterf6ac2352006-06-30 01:55:32 -070022
Christoph Lameterf8891e52006-06-30 01:55:45 -070023#ifdef CONFIG_VM_EVENT_COUNTERS
24DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
25EXPORT_PER_CPU_SYMBOL(vm_event_states);
26
Minchan Kim31f961a2010-08-09 17:18:59 -070027static void sum_vm_events(unsigned long *ret)
Christoph Lameterf8891e52006-06-30 01:55:45 -070028{
Christoph Lameter9eccf2a2008-02-04 22:29:22 -080029 int cpu;
Christoph Lameterf8891e52006-06-30 01:55:45 -070030 int i;
31
32 memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
33
Minchan Kim31f961a2010-08-09 17:18:59 -070034 for_each_online_cpu(cpu) {
Christoph Lameterf8891e52006-06-30 01:55:45 -070035 struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
36
Christoph Lameterf8891e52006-06-30 01:55:45 -070037 for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
38 ret[i] += this->event[i];
39 }
40}
41
42/*
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.
46*/
47void all_vm_events(unsigned long *ret)
48{
KOSAKI Motohirob5be1132008-05-12 14:02:06 -070049 get_online_cpus();
Minchan Kim31f961a2010-08-09 17:18:59 -070050 sum_vm_events(ret);
KOSAKI Motohirob5be1132008-05-12 14:02:06 -070051 put_online_cpus();
Christoph Lameterf8891e52006-06-30 01:55:45 -070052}
Heiko Carstens32dd66f2006-07-10 04:44:31 -070053EXPORT_SYMBOL_GPL(all_vm_events);
Christoph Lameterf8891e52006-06-30 01:55:45 -070054
55#ifdef CONFIG_HOTPLUG
56/*
57 * Fold the foreign cpu events into our own.
58 *
59 * This is adding to the events on one processor
60 * but keeps the global counts constant.
61 */
62void vm_events_fold_cpu(int cpu)
63{
64 struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
65 int i;
66
67 for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
68 count_vm_events(i, fold_state->event[i]);
69 fold_state->event[i] = 0;
70 }
71}
72#endif /* CONFIG_HOTPLUG */
73
74#endif /* CONFIG_VM_EVENT_COUNTERS */
75
Christoph Lameter2244b952006-06-30 01:55:33 -070076/*
77 * Manage combined zone based / global counters
78 *
79 * vm_stat contains the global counters
80 */
Dimitri Sivanicha1cb2c62011-10-31 17:09:46 -070081atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
Christoph Lameter2244b952006-06-30 01:55:33 -070082EXPORT_SYMBOL(vm_stat);
83
84#ifdef CONFIG_SMP
85
Mel Gormanb44129b2011-01-13 15:45:43 -080086int calculate_pressure_threshold(struct zone *zone)
Mel Gorman88f5acf2011-01-13 15:45:41 -080087{
88 int threshold;
89 int watermark_distance;
90
91 /*
92 * As vmstats are not up to date, there is drift between the estimated
93 * and real values. For high thresholds and a high number of CPUs, it
94 * is possible for the min watermark to be breached while the estimated
95 * value looks fine. The pressure threshold is a reduced value such
96 * that even the maximum amount of drift will not accidentally breach
97 * the min watermark
98 */
99 watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
100 threshold = max(1, (int)(watermark_distance / num_online_cpus()));
101
102 /*
103 * Maximum threshold is 125
104 */
105 threshold = min(125, threshold);
106
107 return threshold;
108}
109
Mel Gormanb44129b2011-01-13 15:45:43 -0800110int calculate_normal_threshold(struct zone *zone)
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700111{
112 int threshold;
113 int mem; /* memory in 128 MB units */
114
115 /*
116 * The threshold scales with the number of processors and the amount
117 * of memory per zone. More memory means that we can defer updates for
118 * longer, more processors could lead to more contention.
119 * fls() is used to have a cheap way of logarithmic scaling.
120 *
121 * Some sample thresholds:
122 *
123 * Threshold Processors (fls) Zonesize fls(mem+1)
124 * ------------------------------------------------------------------
125 * 8 1 1 0.9-1 GB 4
126 * 16 2 2 0.9-1 GB 4
127 * 20 2 2 1-2 GB 5
128 * 24 2 2 2-4 GB 6
129 * 28 2 2 4-8 GB 7
130 * 32 2 2 8-16 GB 8
131 * 4 2 2 <128M 1
132 * 30 4 3 2-4 GB 5
133 * 48 4 3 8-16 GB 8
134 * 32 8 4 1-2 GB 4
135 * 32 8 4 0.9-1GB 4
136 * 10 16 5 <128M 1
137 * 40 16 5 900M 4
138 * 70 64 7 2-4 GB 5
139 * 84 64 7 4-8 GB 6
140 * 108 512 9 4-8 GB 6
141 * 125 1024 10 8-16 GB 8
142 * 125 1024 10 16-32 GB 9
143 */
144
145 mem = zone->present_pages >> (27 - PAGE_SHIFT);
146
147 threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
148
149 /*
150 * Maximum threshold is 125
151 */
152 threshold = min(125, threshold);
153
154 return threshold;
155}
Christoph Lameter2244b952006-06-30 01:55:33 -0700156
157/*
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700158 * Refresh the thresholds for each zone.
Christoph Lameter2244b952006-06-30 01:55:33 -0700159 */
KOSAKI Motohiroa6cccdc2011-05-24 17:11:33 -0700160void refresh_zone_stat_thresholds(void)
Christoph Lameter2244b952006-06-30 01:55:33 -0700161{
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700162 struct zone *zone;
163 int cpu;
164 int threshold;
165
KOSAKI Motohiroee99c712009-03-31 15:19:31 -0700166 for_each_populated_zone(zone) {
Christoph Lameteraa454842010-09-09 16:38:17 -0700167 unsigned long max_drift, tolerate_drift;
168
Mel Gormanb44129b2011-01-13 15:45:43 -0800169 threshold = calculate_normal_threshold(zone);
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700170
171 for_each_online_cpu(cpu)
Christoph Lameter99dcc3e2010-01-05 15:34:51 +0900172 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
173 = threshold;
Christoph Lameteraa454842010-09-09 16:38:17 -0700174
175 /*
176 * Only set percpu_drift_mark if there is a danger that
177 * NR_FREE_PAGES reports the low watermark is ok when in fact
178 * the min watermark could be breached by an allocation
179 */
180 tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
181 max_drift = num_online_cpus() * threshold;
182 if (max_drift > tolerate_drift)
183 zone->percpu_drift_mark = high_wmark_pages(zone) +
184 max_drift;
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700185 }
Christoph Lameter2244b952006-06-30 01:55:33 -0700186}
187
Mel Gormanb44129b2011-01-13 15:45:43 -0800188void set_pgdat_percpu_threshold(pg_data_t *pgdat,
189 int (*calculate_pressure)(struct zone *))
Mel Gorman88f5acf2011-01-13 15:45:41 -0800190{
191 struct zone *zone;
192 int cpu;
193 int threshold;
194 int i;
195
Mel Gorman88f5acf2011-01-13 15:45:41 -0800196 for (i = 0; i < pgdat->nr_zones; i++) {
197 zone = &pgdat->node_zones[i];
198 if (!zone->percpu_drift_mark)
199 continue;
200
Mel Gormanb44129b2011-01-13 15:45:43 -0800201 threshold = (*calculate_pressure)(zone);
202 for_each_possible_cpu(cpu)
Mel Gorman88f5acf2011-01-13 15:45:41 -0800203 per_cpu_ptr(zone->pageset, cpu)->stat_threshold
204 = threshold;
205 }
Mel Gorman88f5acf2011-01-13 15:45:41 -0800206}
207
Christoph Lameter2244b952006-06-30 01:55:33 -0700208/*
209 * For use when we know that interrupts are disabled.
210 */
211void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
212 int delta)
213{
Christoph Lameter12938a92010-12-06 11:16:20 -0600214 struct per_cpu_pageset __percpu *pcp = zone->pageset;
215 s8 __percpu *p = pcp->vm_stat_diff + item;
Christoph Lameter2244b952006-06-30 01:55:33 -0700216 long x;
Christoph Lameter12938a92010-12-06 11:16:20 -0600217 long t;
Christoph Lameter2244b952006-06-30 01:55:33 -0700218
Christoph Lameter12938a92010-12-06 11:16:20 -0600219 x = delta + __this_cpu_read(*p);
Christoph Lameter2244b952006-06-30 01:55:33 -0700220
Christoph Lameter12938a92010-12-06 11:16:20 -0600221 t = __this_cpu_read(pcp->stat_threshold);
222
223 if (unlikely(x > t || x < -t)) {
Christoph Lameter2244b952006-06-30 01:55:33 -0700224 zone_page_state_add(x, zone, item);
225 x = 0;
226 }
Christoph Lameter12938a92010-12-06 11:16:20 -0600227 __this_cpu_write(*p, x);
Christoph Lameter2244b952006-06-30 01:55:33 -0700228}
229EXPORT_SYMBOL(__mod_zone_page_state);
230
231/*
Christoph Lameter2244b952006-06-30 01:55:33 -0700232 * Optimized increment and decrement functions.
233 *
234 * These are only for a single page and therefore can take a struct page *
235 * argument instead of struct zone *. This allows the inclusion of the code
236 * generated for page_zone(page) into the optimized functions.
237 *
238 * No overflow check is necessary and therefore the differential can be
239 * incremented or decremented in place which may allow the compilers to
240 * generate better code.
Christoph Lameter2244b952006-06-30 01:55:33 -0700241 * The increment or decrement is known and therefore one boundary check can
242 * be omitted.
243 *
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700244 * NOTE: These functions are very performance sensitive. Change only
245 * with care.
246 *
Christoph Lameter2244b952006-06-30 01:55:33 -0700247 * Some processors have inc/dec instructions that are atomic vs an interrupt.
248 * However, the code must first determine the differential location in a zone
249 * based on the processor number and then inc/dec the counter. There is no
250 * guarantee without disabling preemption that the processor will not change
251 * in between and therefore the atomicity vs. interrupt cannot be exploited
252 * in a useful way here.
253 */
Christoph Lameterc8785382007-02-10 01:43:01 -0800254void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
Christoph Lameter2244b952006-06-30 01:55:33 -0700255{
Christoph Lameter12938a92010-12-06 11:16:20 -0600256 struct per_cpu_pageset __percpu *pcp = zone->pageset;
257 s8 __percpu *p = pcp->vm_stat_diff + item;
258 s8 v, t;
Christoph Lameter2244b952006-06-30 01:55:33 -0700259
Christoph Lameter908ee0f2010-12-06 11:40:02 -0600260 v = __this_cpu_inc_return(*p);
Christoph Lameter12938a92010-12-06 11:16:20 -0600261 t = __this_cpu_read(pcp->stat_threshold);
262 if (unlikely(v > t)) {
263 s8 overstep = t >> 1;
Christoph Lameter2244b952006-06-30 01:55:33 -0700264
Christoph Lameter12938a92010-12-06 11:16:20 -0600265 zone_page_state_add(v + overstep, zone, item);
266 __this_cpu_write(*p, -overstep);
Christoph Lameter2244b952006-06-30 01:55:33 -0700267 }
268}
Christoph Lameterca889e62006-06-30 01:55:44 -0700269
270void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
271{
272 __inc_zone_state(page_zone(page), item);
273}
Christoph Lameter2244b952006-06-30 01:55:33 -0700274EXPORT_SYMBOL(__inc_zone_page_state);
275
Christoph Lameterc8785382007-02-10 01:43:01 -0800276void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
Christoph Lameter2244b952006-06-30 01:55:33 -0700277{
Christoph Lameter12938a92010-12-06 11:16:20 -0600278 struct per_cpu_pageset __percpu *pcp = zone->pageset;
279 s8 __percpu *p = pcp->vm_stat_diff + item;
280 s8 v, t;
Christoph Lameter2244b952006-06-30 01:55:33 -0700281
Christoph Lameter908ee0f2010-12-06 11:40:02 -0600282 v = __this_cpu_dec_return(*p);
Christoph Lameter12938a92010-12-06 11:16:20 -0600283 t = __this_cpu_read(pcp->stat_threshold);
284 if (unlikely(v < - t)) {
285 s8 overstep = t >> 1;
Christoph Lameter2244b952006-06-30 01:55:33 -0700286
Christoph Lameter12938a92010-12-06 11:16:20 -0600287 zone_page_state_add(v - overstep, zone, item);
288 __this_cpu_write(*p, overstep);
Christoph Lameter2244b952006-06-30 01:55:33 -0700289 }
290}
Christoph Lameterc8785382007-02-10 01:43:01 -0800291
292void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
293{
294 __dec_zone_state(page_zone(page), item);
295}
Christoph Lameter2244b952006-06-30 01:55:33 -0700296EXPORT_SYMBOL(__dec_zone_page_state);
297
Heiko Carstens41561532012-01-12 17:17:30 -0800298#ifdef CONFIG_HAVE_CMPXCHG_LOCAL
Christoph Lameter7c839122010-12-14 10:28:46 -0600299/*
300 * If we have cmpxchg_local support then we do not need to incur the overhead
301 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
302 *
303 * mod_state() modifies the zone counter state through atomic per cpu
304 * operations.
305 *
306 * Overstep mode specifies how overstep should handled:
307 * 0 No overstepping
308 * 1 Overstepping half of threshold
309 * -1 Overstepping minus half of threshold
310*/
311static inline void mod_state(struct zone *zone,
312 enum zone_stat_item item, int delta, int overstep_mode)
313{
314 struct per_cpu_pageset __percpu *pcp = zone->pageset;
315 s8 __percpu *p = pcp->vm_stat_diff + item;
316 long o, n, t, z;
317
318 do {
319 z = 0; /* overflow to zone counters */
320
321 /*
322 * The fetching of the stat_threshold is racy. We may apply
323 * a counter threshold to the wrong the cpu if we get
Christoph Lameterd3bc2362011-04-14 15:21:58 -0700324 * rescheduled while executing here. However, the next
325 * counter update will apply the threshold again and
326 * therefore bring the counter under the threshold again.
327 *
328 * Most of the time the thresholds are the same anyways
329 * for all cpus in a zone.
Christoph Lameter7c839122010-12-14 10:28:46 -0600330 */
331 t = this_cpu_read(pcp->stat_threshold);
332
333 o = this_cpu_read(*p);
334 n = delta + o;
335
336 if (n > t || n < -t) {
337 int os = overstep_mode * (t >> 1) ;
338
339 /* Overflow must be added to zone counters */
340 z = n + os;
341 n = -os;
342 }
343 } while (this_cpu_cmpxchg(*p, o, n) != o);
344
345 if (z)
346 zone_page_state_add(z, zone, item);
347}
348
349void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
350 int delta)
351{
352 mod_state(zone, item, delta, 0);
353}
354EXPORT_SYMBOL(mod_zone_page_state);
355
356void inc_zone_state(struct zone *zone, enum zone_stat_item item)
357{
358 mod_state(zone, item, 1, 1);
359}
360
361void inc_zone_page_state(struct page *page, enum zone_stat_item item)
362{
363 mod_state(page_zone(page), item, 1, 1);
364}
365EXPORT_SYMBOL(inc_zone_page_state);
366
367void dec_zone_page_state(struct page *page, enum zone_stat_item item)
368{
369 mod_state(page_zone(page), item, -1, -1);
370}
371EXPORT_SYMBOL(dec_zone_page_state);
372#else
373/*
374 * Use interrupt disable to serialize counter updates
375 */
376void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
377 int delta)
378{
379 unsigned long flags;
380
381 local_irq_save(flags);
382 __mod_zone_page_state(zone, item, delta);
383 local_irq_restore(flags);
384}
385EXPORT_SYMBOL(mod_zone_page_state);
386
Christoph Lameterca889e62006-06-30 01:55:44 -0700387void inc_zone_state(struct zone *zone, enum zone_stat_item item)
388{
389 unsigned long flags;
390
391 local_irq_save(flags);
392 __inc_zone_state(zone, item);
393 local_irq_restore(flags);
394}
395
Christoph Lameter2244b952006-06-30 01:55:33 -0700396void inc_zone_page_state(struct page *page, enum zone_stat_item item)
397{
398 unsigned long flags;
399 struct zone *zone;
Christoph Lameter2244b952006-06-30 01:55:33 -0700400
401 zone = page_zone(page);
402 local_irq_save(flags);
Christoph Lameterca889e62006-06-30 01:55:44 -0700403 __inc_zone_state(zone, item);
Christoph Lameter2244b952006-06-30 01:55:33 -0700404 local_irq_restore(flags);
405}
406EXPORT_SYMBOL(inc_zone_page_state);
407
408void dec_zone_page_state(struct page *page, enum zone_stat_item item)
409{
410 unsigned long flags;
Christoph Lameter2244b952006-06-30 01:55:33 -0700411
Christoph Lameter2244b952006-06-30 01:55:33 -0700412 local_irq_save(flags);
Christoph Lametera302eb42006-08-31 21:27:34 -0700413 __dec_zone_page_state(page, item);
Christoph Lameter2244b952006-06-30 01:55:33 -0700414 local_irq_restore(flags);
415}
416EXPORT_SYMBOL(dec_zone_page_state);
Christoph Lameter7c839122010-12-14 10:28:46 -0600417#endif
Christoph Lameter2244b952006-06-30 01:55:33 -0700418
419/*
420 * Update the zone counters for one cpu.
Christoph Lameter4037d452007-05-09 02:35:14 -0700421 *
Christoph Lametera7f75e22008-02-04 22:29:16 -0800422 * The cpu specified must be either the current cpu or a processor that
423 * is not online. If it is the current cpu then the execution thread must
424 * be pinned to the current cpu.
425 *
Christoph Lameter4037d452007-05-09 02:35:14 -0700426 * Note that refresh_cpu_vm_stats strives to only access
427 * node local memory. The per cpu pagesets on remote zones are placed
428 * in the memory local to the processor using that pageset. So the
429 * loop over all zones will access a series of cachelines local to
430 * the processor.
431 *
432 * The call to zone_page_state_add updates the cachelines with the
433 * statistics in the remote zone struct as well as the global cachelines
434 * with the global counters. These could cause remote node cache line
435 * bouncing and will have to be only done when necessary.
Christoph Lameter2244b952006-06-30 01:55:33 -0700436 */
437void refresh_cpu_vm_stats(int cpu)
438{
439 struct zone *zone;
440 int i;
Christoph Lametera7f75e22008-02-04 22:29:16 -0800441 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
Christoph Lameter2244b952006-06-30 01:55:33 -0700442
KOSAKI Motohiroee99c712009-03-31 15:19:31 -0700443 for_each_populated_zone(zone) {
Christoph Lameter4037d452007-05-09 02:35:14 -0700444 struct per_cpu_pageset *p;
Christoph Lameter2244b952006-06-30 01:55:33 -0700445
Christoph Lameter99dcc3e2010-01-05 15:34:51 +0900446 p = per_cpu_ptr(zone->pageset, cpu);
Christoph Lameter2244b952006-06-30 01:55:33 -0700447
448 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
Christoph Lameter4037d452007-05-09 02:35:14 -0700449 if (p->vm_stat_diff[i]) {
Christoph Lametera7f75e22008-02-04 22:29:16 -0800450 unsigned long flags;
451 int v;
452
Christoph Lameter2244b952006-06-30 01:55:33 -0700453 local_irq_save(flags);
Christoph Lametera7f75e22008-02-04 22:29:16 -0800454 v = p->vm_stat_diff[i];
Christoph Lameter4037d452007-05-09 02:35:14 -0700455 p->vm_stat_diff[i] = 0;
Christoph Lametera7f75e22008-02-04 22:29:16 -0800456 local_irq_restore(flags);
457 atomic_long_add(v, &zone->vm_stat[i]);
458 global_diff[i] += v;
Christoph Lameter4037d452007-05-09 02:35:14 -0700459#ifdef CONFIG_NUMA
460 /* 3 seconds idle till flush */
461 p->expire = 3;
462#endif
Christoph Lameter2244b952006-06-30 01:55:33 -0700463 }
Dimitri Sivanich468fd622008-04-28 02:13:37 -0700464 cond_resched();
Christoph Lameter4037d452007-05-09 02:35:14 -0700465#ifdef CONFIG_NUMA
466 /*
467 * Deal with draining the remote pageset of this
468 * processor
469 *
470 * Check if there are pages remaining in this pageset
471 * if not then there is nothing to expire.
472 */
Christoph Lameter3dfa5722008-02-04 22:29:19 -0800473 if (!p->expire || !p->pcp.count)
Christoph Lameter4037d452007-05-09 02:35:14 -0700474 continue;
475
476 /*
477 * We never drain zones local to this processor.
478 */
479 if (zone_to_nid(zone) == numa_node_id()) {
480 p->expire = 0;
481 continue;
482 }
483
484 p->expire--;
485 if (p->expire)
486 continue;
487
Christoph Lameter3dfa5722008-02-04 22:29:19 -0800488 if (p->pcp.count)
489 drain_zone_pages(zone, &p->pcp);
Christoph Lameter4037d452007-05-09 02:35:14 -0700490#endif
Christoph Lameter2244b952006-06-30 01:55:33 -0700491 }
Christoph Lametera7f75e22008-02-04 22:29:16 -0800492
493 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
494 if (global_diff[i])
495 atomic_long_add(global_diff[i], &vm_stat[i]);
Christoph Lameter2244b952006-06-30 01:55:33 -0700496}
497
Christoph Lameter2244b952006-06-30 01:55:33 -0700498#endif
499
Christoph Lameterca889e62006-06-30 01:55:44 -0700500#ifdef CONFIG_NUMA
501/*
502 * zonelist = the list of zones passed to the allocator
503 * z = the zone from which the allocation occurred.
504 *
505 * Must be called with interrupts disabled.
Andi Kleen78afd562011-03-22 16:33:12 -0700506 *
507 * When __GFP_OTHER_NODE is set assume the node of the preferred
508 * zone is the local node. This is useful for daemons who allocate
509 * memory on behalf of other processes.
Christoph Lameterca889e62006-06-30 01:55:44 -0700510 */
Andi Kleen78afd562011-03-22 16:33:12 -0700511void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
Christoph Lameterca889e62006-06-30 01:55:44 -0700512{
Mel Gorman18ea7e72008-04-28 02:12:14 -0700513 if (z->zone_pgdat == preferred_zone->zone_pgdat) {
Christoph Lameterca889e62006-06-30 01:55:44 -0700514 __inc_zone_state(z, NUMA_HIT);
515 } else {
516 __inc_zone_state(z, NUMA_MISS);
Mel Gorman18ea7e72008-04-28 02:12:14 -0700517 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
Christoph Lameterca889e62006-06-30 01:55:44 -0700518 }
Andi Kleen78afd562011-03-22 16:33:12 -0700519 if (z->node == ((flags & __GFP_OTHER_NODE) ?
520 preferred_zone->node : numa_node_id()))
Christoph Lameterca889e62006-06-30 01:55:44 -0700521 __inc_zone_state(z, NUMA_LOCAL);
522 else
523 __inc_zone_state(z, NUMA_OTHER);
524}
525#endif
526
Mel Gormand7a57522010-05-24 14:32:25 -0700527#ifdef CONFIG_COMPACTION
Namhyung Kim36deb0b2010-10-26 14:22:04 -0700528
Mel Gormand7a57522010-05-24 14:32:25 -0700529struct contig_page_info {
530 unsigned long free_pages;
531 unsigned long free_blocks_total;
532 unsigned long free_blocks_suitable;
533};
534
535/*
536 * Calculate the number of free pages in a zone, how many contiguous
537 * pages are free and how many are large enough to satisfy an allocation of
538 * the target size. Note that this function makes no attempt to estimate
539 * how many suitable free blocks there *might* be if MOVABLE pages were
540 * migrated. Calculating that is possible, but expensive and can be
541 * figured out from userspace
542 */
543static void fill_contig_page_info(struct zone *zone,
544 unsigned int suitable_order,
545 struct contig_page_info *info)
546{
547 unsigned int order;
548
549 info->free_pages = 0;
550 info->free_blocks_total = 0;
551 info->free_blocks_suitable = 0;
552
553 for (order = 0; order < MAX_ORDER; order++) {
554 unsigned long blocks;
555
556 /* Count number of free blocks */
557 blocks = zone->free_area[order].nr_free;
558 info->free_blocks_total += blocks;
559
560 /* Count free base pages */
561 info->free_pages += blocks << order;
562
563 /* Count the suitable free blocks */
564 if (order >= suitable_order)
565 info->free_blocks_suitable += blocks <<
566 (order - suitable_order);
567 }
568}
Mel Gormanf1a5ab12010-05-24 14:32:26 -0700569
570/*
571 * A fragmentation index only makes sense if an allocation of a requested
572 * size would fail. If that is true, the fragmentation index indicates
573 * whether external fragmentation or a lack of memory was the problem.
574 * The value can be used to determine if page reclaim or compaction
575 * should be used
576 */
Mel Gorman56de7262010-05-24 14:32:30 -0700577static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
Mel Gormanf1a5ab12010-05-24 14:32:26 -0700578{
579 unsigned long requested = 1UL << order;
580
581 if (!info->free_blocks_total)
582 return 0;
583
584 /* Fragmentation index only makes sense when a request would fail */
585 if (info->free_blocks_suitable)
586 return -1000;
587
588 /*
589 * Index is between 0 and 1 so return within 3 decimal places
590 *
591 * 0 => allocation would fail due to lack of memory
592 * 1 => allocation would fail due to fragmentation
593 */
594 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
595}
Mel Gorman56de7262010-05-24 14:32:30 -0700596
597/* Same as __fragmentation index but allocs contig_page_info on stack */
598int fragmentation_index(struct zone *zone, unsigned int order)
599{
600 struct contig_page_info info;
601
602 fill_contig_page_info(zone, order, &info);
603 return __fragmentation_index(order, &info);
604}
Mel Gormand7a57522010-05-24 14:32:25 -0700605#endif
606
607#if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +0400608#include <linux/proc_fs.h>
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700609#include <linux/seq_file.h>
610
Mel Gorman467c9962007-10-16 01:26:02 -0700611static char * const migratetype_names[MIGRATE_TYPES] = {
612 "Unmovable",
613 "Reclaimable",
614 "Movable",
615 "Reserve",
Michal Nazarewiczd4158d22011-12-29 13:09:50 +0100616#ifdef CONFIG_CMA
617 "CMA",
618#endif
KOSAKI Motohiro91446b02008-04-15 14:34:42 -0700619 "Isolate",
Mel Gorman467c9962007-10-16 01:26:02 -0700620};
621
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700622static void *frag_start(struct seq_file *m, loff_t *pos)
623{
624 pg_data_t *pgdat;
625 loff_t node = *pos;
626 for (pgdat = first_online_pgdat();
627 pgdat && node;
628 pgdat = next_online_pgdat(pgdat))
629 --node;
630
631 return pgdat;
632}
633
634static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
635{
636 pg_data_t *pgdat = (pg_data_t *)arg;
637
638 (*pos)++;
639 return next_online_pgdat(pgdat);
640}
641
642static void frag_stop(struct seq_file *m, void *arg)
643{
644}
645
Mel Gorman467c9962007-10-16 01:26:02 -0700646/* Walk all the zones in a node and print using a callback */
647static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
648 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700649{
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700650 struct zone *zone;
651 struct zone *node_zones = pgdat->node_zones;
652 unsigned long flags;
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700653
654 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
655 if (!populated_zone(zone))
656 continue;
657
658 spin_lock_irqsave(&zone->lock, flags);
Mel Gorman467c9962007-10-16 01:26:02 -0700659 print(m, pgdat, zone);
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700660 spin_unlock_irqrestore(&zone->lock, flags);
Mel Gorman467c9962007-10-16 01:26:02 -0700661 }
662}
Mel Gormand7a57522010-05-24 14:32:25 -0700663#endif
Mel Gorman467c9962007-10-16 01:26:02 -0700664
David Rientjes0d6617c2011-09-14 16:21:05 -0700665#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
KOSAKI Motohirofa25c502011-05-24 17:11:28 -0700666#ifdef CONFIG_ZONE_DMA
667#define TEXT_FOR_DMA(xx) xx "_dma",
668#else
669#define TEXT_FOR_DMA(xx)
670#endif
671
672#ifdef CONFIG_ZONE_DMA32
673#define TEXT_FOR_DMA32(xx) xx "_dma32",
674#else
675#define TEXT_FOR_DMA32(xx)
676#endif
677
678#ifdef CONFIG_HIGHMEM
679#define TEXT_FOR_HIGHMEM(xx) xx "_high",
680#else
681#define TEXT_FOR_HIGHMEM(xx)
682#endif
683
684#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
685 TEXT_FOR_HIGHMEM(xx) xx "_movable",
686
687const char * const vmstat_text[] = {
688 /* Zoned VM counters */
689 "nr_free_pages",
690 "nr_inactive_anon",
691 "nr_active_anon",
692 "nr_inactive_file",
693 "nr_active_file",
694 "nr_unevictable",
695 "nr_mlock",
696 "nr_anon_pages",
697 "nr_mapped",
698 "nr_file_pages",
699 "nr_dirty",
700 "nr_writeback",
701 "nr_slab_reclaimable",
702 "nr_slab_unreclaimable",
703 "nr_page_table_pages",
704 "nr_kernel_stack",
705 "nr_unstable",
706 "nr_bounce",
707 "nr_vmscan_write",
Mel Gorman49ea7eb2011-10-31 17:07:59 -0700708 "nr_vmscan_immediate_reclaim",
KOSAKI Motohirofa25c502011-05-24 17:11:28 -0700709 "nr_writeback_temp",
710 "nr_isolated_anon",
711 "nr_isolated_file",
712 "nr_shmem",
713 "nr_dirtied",
714 "nr_written",
715
716#ifdef CONFIG_NUMA
717 "numa_hit",
718 "numa_miss",
719 "numa_foreign",
720 "numa_interleave",
721 "numa_local",
722 "numa_other",
723#endif
724 "nr_anon_transparent_hugepages",
725 "nr_dirty_threshold",
726 "nr_dirty_background_threshold",
727
728#ifdef CONFIG_VM_EVENT_COUNTERS
729 "pgpgin",
730 "pgpgout",
731 "pswpin",
732 "pswpout",
733
734 TEXTS_FOR_ZONES("pgalloc")
735
736 "pgfree",
737 "pgactivate",
738 "pgdeactivate",
739
740 "pgfault",
741 "pgmajfault",
742
743 TEXTS_FOR_ZONES("pgrefill")
Ying Han904249a2012-04-25 16:01:48 -0700744 TEXTS_FOR_ZONES("pgsteal_kswapd")
745 TEXTS_FOR_ZONES("pgsteal_direct")
KOSAKI Motohirofa25c502011-05-24 17:11:28 -0700746 TEXTS_FOR_ZONES("pgscan_kswapd")
747 TEXTS_FOR_ZONES("pgscan_direct")
748
749#ifdef CONFIG_NUMA
750 "zone_reclaim_failed",
751#endif
752 "pginodesteal",
753 "slabs_scanned",
KOSAKI Motohirofa25c502011-05-24 17:11:28 -0700754 "kswapd_inodesteal",
755 "kswapd_low_wmark_hit_quickly",
756 "kswapd_high_wmark_hit_quickly",
757 "kswapd_skip_congestion_wait",
758 "pageoutrun",
759 "allocstall",
760
761 "pgrotated",
762
763#ifdef CONFIG_COMPACTION
764 "compact_blocks_moved",
765 "compact_pages_moved",
766 "compact_pagemigrate_failed",
767 "compact_stall",
768 "compact_fail",
769 "compact_success",
770#endif
771
772#ifdef CONFIG_HUGETLB_PAGE
773 "htlb_buddy_alloc_success",
774 "htlb_buddy_alloc_fail",
775#endif
776 "unevictable_pgs_culled",
777 "unevictable_pgs_scanned",
778 "unevictable_pgs_rescued",
779 "unevictable_pgs_mlocked",
780 "unevictable_pgs_munlocked",
781 "unevictable_pgs_cleared",
782 "unevictable_pgs_stranded",
783 "unevictable_pgs_mlockfreed",
784
785#ifdef CONFIG_TRANSPARENT_HUGEPAGE
786 "thp_fault_alloc",
787 "thp_fault_fallback",
788 "thp_collapse_alloc",
789 "thp_collapse_alloc_failed",
790 "thp_split",
791#endif
792
793#endif /* CONFIG_VM_EVENTS_COUNTERS */
794};
David Rientjes0d6617c2011-09-14 16:21:05 -0700795#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
KOSAKI Motohirofa25c502011-05-24 17:11:28 -0700796
797
Mel Gormand7a57522010-05-24 14:32:25 -0700798#ifdef CONFIG_PROC_FS
Mel Gorman467c9962007-10-16 01:26:02 -0700799static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
800 struct zone *zone)
801{
802 int order;
803
804 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
805 for (order = 0; order < MAX_ORDER; ++order)
806 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
807 seq_putc(m, '\n');
808}
809
810/*
811 * This walks the free areas for each zone.
812 */
813static int frag_show(struct seq_file *m, void *arg)
814{
815 pg_data_t *pgdat = (pg_data_t *)arg;
816 walk_zones_in_node(m, pgdat, frag_show_print);
817 return 0;
818}
819
820static void pagetypeinfo_showfree_print(struct seq_file *m,
821 pg_data_t *pgdat, struct zone *zone)
822{
823 int order, mtype;
824
825 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
826 seq_printf(m, "Node %4d, zone %8s, type %12s ",
827 pgdat->node_id,
828 zone->name,
829 migratetype_names[mtype]);
830 for (order = 0; order < MAX_ORDER; ++order) {
831 unsigned long freecount = 0;
832 struct free_area *area;
833 struct list_head *curr;
834
835 area = &(zone->free_area[order]);
836
837 list_for_each(curr, &area->free_list[mtype])
838 freecount++;
839 seq_printf(m, "%6lu ", freecount);
840 }
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700841 seq_putc(m, '\n');
842 }
Mel Gorman467c9962007-10-16 01:26:02 -0700843}
844
845/* Print out the free pages at each order for each migatetype */
846static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
847{
848 int order;
849 pg_data_t *pgdat = (pg_data_t *)arg;
850
851 /* Print header */
852 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
853 for (order = 0; order < MAX_ORDER; ++order)
854 seq_printf(m, "%6d ", order);
855 seq_putc(m, '\n');
856
857 walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
858
859 return 0;
860}
861
862static void pagetypeinfo_showblockcount_print(struct seq_file *m,
863 pg_data_t *pgdat, struct zone *zone)
864{
865 int mtype;
866 unsigned long pfn;
867 unsigned long start_pfn = zone->zone_start_pfn;
868 unsigned long end_pfn = start_pfn + zone->spanned_pages;
869 unsigned long count[MIGRATE_TYPES] = { 0, };
870
871 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
872 struct page *page;
873
874 if (!pfn_valid(pfn))
875 continue;
876
877 page = pfn_to_page(pfn);
Mel Gormaneb335752009-05-13 17:34:48 +0100878
879 /* Watch for unexpected holes punched in the memmap */
880 if (!memmap_valid_within(pfn, page, zone))
Mel Gormane80d6a22008-08-14 11:10:14 +0100881 continue;
Mel Gormaneb335752009-05-13 17:34:48 +0100882
Mel Gorman467c9962007-10-16 01:26:02 -0700883 mtype = get_pageblock_migratetype(page);
884
Mel Gormane80d6a22008-08-14 11:10:14 +0100885 if (mtype < MIGRATE_TYPES)
886 count[mtype]++;
Mel Gorman467c9962007-10-16 01:26:02 -0700887 }
888
889 /* Print counts */
890 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
891 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
892 seq_printf(m, "%12lu ", count[mtype]);
893 seq_putc(m, '\n');
894}
895
896/* Print out the free pages at each order for each migratetype */
897static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
898{
899 int mtype;
900 pg_data_t *pgdat = (pg_data_t *)arg;
901
902 seq_printf(m, "\n%-23s", "Number of blocks type ");
903 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
904 seq_printf(m, "%12s ", migratetype_names[mtype]);
905 seq_putc(m, '\n');
906 walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
907
908 return 0;
909}
910
911/*
912 * This prints out statistics in relation to grouping pages by mobility.
913 * It is expensive to collect so do not constantly read the file.
914 */
915static int pagetypeinfo_show(struct seq_file *m, void *arg)
916{
917 pg_data_t *pgdat = (pg_data_t *)arg;
918
KOSAKI Motohiro41b25a32008-04-30 00:52:13 -0700919 /* check memoryless node */
920 if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
921 return 0;
922
Mel Gorman467c9962007-10-16 01:26:02 -0700923 seq_printf(m, "Page block order: %d\n", pageblock_order);
924 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
925 seq_putc(m, '\n');
926 pagetypeinfo_showfree(m, pgdat);
927 pagetypeinfo_showblockcount(m, pgdat);
928
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700929 return 0;
930}
931
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +0400932static const struct seq_operations fragmentation_op = {
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700933 .start = frag_start,
934 .next = frag_next,
935 .stop = frag_stop,
936 .show = frag_show,
937};
938
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +0400939static int fragmentation_open(struct inode *inode, struct file *file)
940{
941 return seq_open(file, &fragmentation_op);
942}
943
944static const struct file_operations fragmentation_file_operations = {
945 .open = fragmentation_open,
946 .read = seq_read,
947 .llseek = seq_lseek,
948 .release = seq_release,
949};
950
Alexey Dobriyan74e2e8e2008-10-06 04:15:36 +0400951static const struct seq_operations pagetypeinfo_op = {
Mel Gorman467c9962007-10-16 01:26:02 -0700952 .start = frag_start,
953 .next = frag_next,
954 .stop = frag_stop,
955 .show = pagetypeinfo_show,
956};
957
Alexey Dobriyan74e2e8e2008-10-06 04:15:36 +0400958static int pagetypeinfo_open(struct inode *inode, struct file *file)
959{
960 return seq_open(file, &pagetypeinfo_op);
961}
962
963static const struct file_operations pagetypeinfo_file_ops = {
964 .open = pagetypeinfo_open,
965 .read = seq_read,
966 .llseek = seq_lseek,
967 .release = seq_release,
968};
969
Mel Gorman467c9962007-10-16 01:26:02 -0700970static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
971 struct zone *zone)
972{
973 int i;
974 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
975 seq_printf(m,
976 "\n pages free %lu"
977 "\n min %lu"
978 "\n low %lu"
979 "\n high %lu"
Wu Fengguang08d9ae72009-06-16 15:32:30 -0700980 "\n scanned %lu"
Mel Gorman467c9962007-10-16 01:26:02 -0700981 "\n spanned %lu"
982 "\n present %lu",
Mel Gorman88f5acf2011-01-13 15:45:41 -0800983 zone_page_state(zone, NR_FREE_PAGES),
Mel Gorman41858962009-06-16 15:32:12 -0700984 min_wmark_pages(zone),
985 low_wmark_pages(zone),
986 high_wmark_pages(zone),
Mel Gorman467c9962007-10-16 01:26:02 -0700987 zone->pages_scanned,
Mel Gorman467c9962007-10-16 01:26:02 -0700988 zone->spanned_pages,
989 zone->present_pages);
990
991 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
992 seq_printf(m, "\n %-12s %lu", vmstat_text[i],
993 zone_page_state(zone, i));
994
995 seq_printf(m,
996 "\n protection: (%lu",
997 zone->lowmem_reserve[0]);
998 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
999 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
1000 seq_printf(m,
1001 ")"
1002 "\n pagesets");
1003 for_each_online_cpu(i) {
1004 struct per_cpu_pageset *pageset;
Mel Gorman467c9962007-10-16 01:26:02 -07001005
Christoph Lameter99dcc3e2010-01-05 15:34:51 +09001006 pageset = per_cpu_ptr(zone->pageset, i);
Christoph Lameter3dfa5722008-02-04 22:29:19 -08001007 seq_printf(m,
1008 "\n cpu: %i"
1009 "\n count: %i"
1010 "\n high: %i"
1011 "\n batch: %i",
1012 i,
1013 pageset->pcp.count,
1014 pageset->pcp.high,
1015 pageset->pcp.batch);
Mel Gorman467c9962007-10-16 01:26:02 -07001016#ifdef CONFIG_SMP
1017 seq_printf(m, "\n vm stats threshold: %d",
1018 pageset->stat_threshold);
1019#endif
1020 }
1021 seq_printf(m,
1022 "\n all_unreclaimable: %u"
Rik van Riel556adec2008-10-18 20:26:34 -07001023 "\n start_pfn: %lu"
1024 "\n inactive_ratio: %u",
KOSAKI Motohiro93e4a892010-03-05 13:41:55 -08001025 zone->all_unreclaimable,
Rik van Riel556adec2008-10-18 20:26:34 -07001026 zone->zone_start_pfn,
1027 zone->inactive_ratio);
Mel Gorman467c9962007-10-16 01:26:02 -07001028 seq_putc(m, '\n');
1029}
1030
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001031/*
1032 * Output information about zones in @pgdat.
1033 */
1034static int zoneinfo_show(struct seq_file *m, void *arg)
1035{
Mel Gorman467c9962007-10-16 01:26:02 -07001036 pg_data_t *pgdat = (pg_data_t *)arg;
1037 walk_zones_in_node(m, pgdat, zoneinfo_show_print);
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001038 return 0;
1039}
1040
Alexey Dobriyan5c9fe622008-10-06 04:19:42 +04001041static const struct seq_operations zoneinfo_op = {
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001042 .start = frag_start, /* iterate over all zones. The same as in
1043 * fragmentation. */
1044 .next = frag_next,
1045 .stop = frag_stop,
1046 .show = zoneinfo_show,
1047};
1048
Alexey Dobriyan5c9fe622008-10-06 04:19:42 +04001049static int zoneinfo_open(struct inode *inode, struct file *file)
1050{
1051 return seq_open(file, &zoneinfo_op);
1052}
1053
1054static const struct file_operations proc_zoneinfo_file_operations = {
1055 .open = zoneinfo_open,
1056 .read = seq_read,
1057 .llseek = seq_lseek,
1058 .release = seq_release,
1059};
1060
Michael Rubin79da8262010-10-26 14:21:36 -07001061enum writeback_stat_item {
1062 NR_DIRTY_THRESHOLD,
1063 NR_DIRTY_BG_THRESHOLD,
1064 NR_VM_WRITEBACK_STAT_ITEMS,
1065};
1066
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001067static void *vmstat_start(struct seq_file *m, loff_t *pos)
1068{
Christoph Lameter2244b952006-06-30 01:55:33 -07001069 unsigned long *v;
Michael Rubin79da8262010-10-26 14:21:36 -07001070 int i, stat_items_size;
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001071
1072 if (*pos >= ARRAY_SIZE(vmstat_text))
1073 return NULL;
Michael Rubin79da8262010-10-26 14:21:36 -07001074 stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1075 NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001076
Christoph Lameterf8891e52006-06-30 01:55:45 -07001077#ifdef CONFIG_VM_EVENT_COUNTERS
Michael Rubin79da8262010-10-26 14:21:36 -07001078 stat_items_size += sizeof(struct vm_event_state);
Christoph Lameterf8891e52006-06-30 01:55:45 -07001079#endif
Michael Rubin79da8262010-10-26 14:21:36 -07001080
1081 v = kmalloc(stat_items_size, GFP_KERNEL);
Christoph Lameter2244b952006-06-30 01:55:33 -07001082 m->private = v;
1083 if (!v)
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001084 return ERR_PTR(-ENOMEM);
Christoph Lameter2244b952006-06-30 01:55:33 -07001085 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1086 v[i] = global_page_state(i);
Michael Rubin79da8262010-10-26 14:21:36 -07001087 v += NR_VM_ZONE_STAT_ITEMS;
1088
1089 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1090 v + NR_DIRTY_THRESHOLD);
1091 v += NR_VM_WRITEBACK_STAT_ITEMS;
1092
Christoph Lameterf8891e52006-06-30 01:55:45 -07001093#ifdef CONFIG_VM_EVENT_COUNTERS
Michael Rubin79da8262010-10-26 14:21:36 -07001094 all_vm_events(v);
1095 v[PGPGIN] /= 2; /* sectors -> kbytes */
1096 v[PGPGOUT] /= 2;
Christoph Lameterf8891e52006-06-30 01:55:45 -07001097#endif
Wu Fengguangff8b16d2010-11-04 01:56:49 +08001098 return (unsigned long *)m->private + *pos;
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001099}
1100
1101static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1102{
1103 (*pos)++;
1104 if (*pos >= ARRAY_SIZE(vmstat_text))
1105 return NULL;
1106 return (unsigned long *)m->private + *pos;
1107}
1108
1109static int vmstat_show(struct seq_file *m, void *arg)
1110{
1111 unsigned long *l = arg;
1112 unsigned long off = l - (unsigned long *)m->private;
1113
1114 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1115 return 0;
1116}
1117
1118static void vmstat_stop(struct seq_file *m, void *arg)
1119{
1120 kfree(m->private);
1121 m->private = NULL;
1122}
1123
Alexey Dobriyanb6aa44a2008-10-06 04:17:48 +04001124static const struct seq_operations vmstat_op = {
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001125 .start = vmstat_start,
1126 .next = vmstat_next,
1127 .stop = vmstat_stop,
1128 .show = vmstat_show,
1129};
1130
Alexey Dobriyanb6aa44a2008-10-06 04:17:48 +04001131static int vmstat_open(struct inode *inode, struct file *file)
1132{
1133 return seq_open(file, &vmstat_op);
1134}
1135
1136static const struct file_operations proc_vmstat_file_operations = {
1137 .open = vmstat_open,
1138 .read = seq_read,
1139 .llseek = seq_lseek,
1140 .release = seq_release,
1141};
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001142#endif /* CONFIG_PROC_FS */
1143
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001144#ifdef CONFIG_SMP
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001145static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
Christoph Lameter77461ab2007-05-09 02:35:13 -07001146int sysctl_stat_interval __read_mostly = HZ;
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001147
1148static void vmstat_update(struct work_struct *w)
1149{
1150 refresh_cpu_vm_stats(smp_processor_id());
Christoph Lameter77461ab2007-05-09 02:35:13 -07001151 schedule_delayed_work(&__get_cpu_var(vmstat_work),
Anton Blanchard98f4ebb2009-04-02 16:56:39 -07001152 round_jiffies_relative(sysctl_stat_interval));
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001153}
1154
Randy Dunlap42614fc2007-11-14 17:00:12 -08001155static void __cpuinit start_cpu_timer(int cpu)
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001156{
Tejun Heo1871e522009-10-29 22:34:13 +09001157 struct delayed_work *work = &per_cpu(vmstat_work, cpu);
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001158
Tejun Heo1871e522009-10-29 22:34:13 +09001159 INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
1160 schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001161}
1162
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001163/*
1164 * Use the cpu notifier to insure that the thresholds are recalculated
1165 * when necessary.
1166 */
1167static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
1168 unsigned long action,
1169 void *hcpu)
1170{
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001171 long cpu = (long)hcpu;
1172
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001173 switch (action) {
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001174 case CPU_ONLINE:
1175 case CPU_ONLINE_FROZEN:
KAMEZAWA Hiroyuki5ee28a42010-09-09 16:38:14 -07001176 refresh_zone_stat_thresholds();
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001177 start_cpu_timer(cpu);
Christoph Lameterad596922010-01-05 15:34:51 +09001178 node_set_state(cpu_to_node(cpu), N_CPU);
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001179 break;
1180 case CPU_DOWN_PREPARE:
1181 case CPU_DOWN_PREPARE_FROZEN:
Tejun Heoafe2c512010-12-14 16:21:17 +01001182 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001183 per_cpu(vmstat_work, cpu).work.func = NULL;
1184 break;
1185 case CPU_DOWN_FAILED:
1186 case CPU_DOWN_FAILED_FROZEN:
1187 start_cpu_timer(cpu);
1188 break;
Andy Whitcroftce421c72006-12-06 20:33:08 -08001189 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001190 case CPU_DEAD_FROZEN:
Andy Whitcroftce421c72006-12-06 20:33:08 -08001191 refresh_zone_stat_thresholds();
1192 break;
1193 default:
1194 break;
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001195 }
1196 return NOTIFY_OK;
1197}
1198
1199static struct notifier_block __cpuinitdata vmstat_notifier =
1200 { &vmstat_cpuup_callback, NULL, 0 };
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +04001201#endif
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001202
Adrian Bunke2fc88d2007-10-16 01:26:27 -07001203static int __init setup_vmstat(void)
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001204{
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +04001205#ifdef CONFIG_SMP
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001206 int cpu;
1207
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001208 register_cpu_notifier(&vmstat_notifier);
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001209
1210 for_each_online_cpu(cpu)
1211 start_cpu_timer(cpu);
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +04001212#endif
1213#ifdef CONFIG_PROC_FS
1214 proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
Alexey Dobriyan74e2e8e2008-10-06 04:15:36 +04001215 proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
Alexey Dobriyanb6aa44a2008-10-06 04:17:48 +04001216 proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
Alexey Dobriyan5c9fe622008-10-06 04:19:42 +04001217 proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +04001218#endif
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001219 return 0;
1220}
1221module_init(setup_vmstat)
Mel Gormand7a57522010-05-24 14:32:25 -07001222
1223#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1224#include <linux/debugfs.h>
1225
1226static struct dentry *extfrag_debug_root;
1227
1228/*
1229 * Return an index indicating how much of the available free memory is
1230 * unusable for an allocation of the requested size.
1231 */
1232static int unusable_free_index(unsigned int order,
1233 struct contig_page_info *info)
1234{
1235 /* No free memory is interpreted as all free memory is unusable */
1236 if (info->free_pages == 0)
1237 return 1000;
1238
1239 /*
1240 * Index should be a value between 0 and 1. Return a value to 3
1241 * decimal places.
1242 *
1243 * 0 => no fragmentation
1244 * 1 => high fragmentation
1245 */
1246 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1247
1248}
1249
1250static void unusable_show_print(struct seq_file *m,
1251 pg_data_t *pgdat, struct zone *zone)
1252{
1253 unsigned int order;
1254 int index;
1255 struct contig_page_info info;
1256
1257 seq_printf(m, "Node %d, zone %8s ",
1258 pgdat->node_id,
1259 zone->name);
1260 for (order = 0; order < MAX_ORDER; ++order) {
1261 fill_contig_page_info(zone, order, &info);
1262 index = unusable_free_index(order, &info);
1263 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1264 }
1265
1266 seq_putc(m, '\n');
1267}
1268
1269/*
1270 * Display unusable free space index
1271 *
1272 * The unusable free space index measures how much of the available free
1273 * memory cannot be used to satisfy an allocation of a given size and is a
1274 * value between 0 and 1. The higher the value, the more of free memory is
1275 * unusable and by implication, the worse the external fragmentation is. This
1276 * can be expressed as a percentage by multiplying by 100.
1277 */
1278static int unusable_show(struct seq_file *m, void *arg)
1279{
1280 pg_data_t *pgdat = (pg_data_t *)arg;
1281
1282 /* check memoryless node */
1283 if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
1284 return 0;
1285
1286 walk_zones_in_node(m, pgdat, unusable_show_print);
1287
1288 return 0;
1289}
1290
1291static const struct seq_operations unusable_op = {
1292 .start = frag_start,
1293 .next = frag_next,
1294 .stop = frag_stop,
1295 .show = unusable_show,
1296};
1297
1298static int unusable_open(struct inode *inode, struct file *file)
1299{
1300 return seq_open(file, &unusable_op);
1301}
1302
1303static const struct file_operations unusable_file_ops = {
1304 .open = unusable_open,
1305 .read = seq_read,
1306 .llseek = seq_lseek,
1307 .release = seq_release,
1308};
1309
Mel Gormanf1a5ab12010-05-24 14:32:26 -07001310static void extfrag_show_print(struct seq_file *m,
1311 pg_data_t *pgdat, struct zone *zone)
1312{
1313 unsigned int order;
1314 int index;
1315
1316 /* Alloc on stack as interrupts are disabled for zone walk */
1317 struct contig_page_info info;
1318
1319 seq_printf(m, "Node %d, zone %8s ",
1320 pgdat->node_id,
1321 zone->name);
1322 for (order = 0; order < MAX_ORDER; ++order) {
1323 fill_contig_page_info(zone, order, &info);
Mel Gorman56de7262010-05-24 14:32:30 -07001324 index = __fragmentation_index(order, &info);
Mel Gormanf1a5ab12010-05-24 14:32:26 -07001325 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1326 }
1327
1328 seq_putc(m, '\n');
1329}
1330
1331/*
1332 * Display fragmentation index for orders that allocations would fail for
1333 */
1334static int extfrag_show(struct seq_file *m, void *arg)
1335{
1336 pg_data_t *pgdat = (pg_data_t *)arg;
1337
1338 walk_zones_in_node(m, pgdat, extfrag_show_print);
1339
1340 return 0;
1341}
1342
1343static const struct seq_operations extfrag_op = {
1344 .start = frag_start,
1345 .next = frag_next,
1346 .stop = frag_stop,
1347 .show = extfrag_show,
1348};
1349
1350static int extfrag_open(struct inode *inode, struct file *file)
1351{
1352 return seq_open(file, &extfrag_op);
1353}
1354
1355static const struct file_operations extfrag_file_ops = {
1356 .open = extfrag_open,
1357 .read = seq_read,
1358 .llseek = seq_lseek,
1359 .release = seq_release,
1360};
1361
Mel Gormand7a57522010-05-24 14:32:25 -07001362static int __init extfrag_debug_init(void)
1363{
1364 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1365 if (!extfrag_debug_root)
1366 return -ENOMEM;
1367
1368 if (!debugfs_create_file("unusable_index", 0444,
1369 extfrag_debug_root, NULL, &unusable_file_ops))
1370 return -ENOMEM;
1371
Mel Gormanf1a5ab12010-05-24 14:32:26 -07001372 if (!debugfs_create_file("extfrag_index", 0444,
1373 extfrag_debug_root, NULL, &extfrag_file_ops))
1374 return -ENOMEM;
1375
Mel Gormand7a57522010-05-24 14:32:25 -07001376 return 0;
1377}
1378
1379module_init(extfrag_debug_init);
1380#endif