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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 */
81atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
82EXPORT_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 */
Christoph Lameterdf9ecab2006-08-31 21:27:35 -0700160static void 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
Christoph Lameter7c839122010-12-14 10:28:46 -0600298#ifdef CONFIG_CMPXCHG_LOCAL
299/*
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
324 * rescheduled while executing here. However, the following
325 * will apply the threshold again and therefore bring the
326 * counter under the threshold.
327 */
328 t = this_cpu_read(pcp->stat_threshold);
329
330 o = this_cpu_read(*p);
331 n = delta + o;
332
333 if (n > t || n < -t) {
334 int os = overstep_mode * (t >> 1) ;
335
336 /* Overflow must be added to zone counters */
337 z = n + os;
338 n = -os;
339 }
340 } while (this_cpu_cmpxchg(*p, o, n) != o);
341
342 if (z)
343 zone_page_state_add(z, zone, item);
344}
345
346void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
347 int delta)
348{
349 mod_state(zone, item, delta, 0);
350}
351EXPORT_SYMBOL(mod_zone_page_state);
352
353void inc_zone_state(struct zone *zone, enum zone_stat_item item)
354{
355 mod_state(zone, item, 1, 1);
356}
357
358void inc_zone_page_state(struct page *page, enum zone_stat_item item)
359{
360 mod_state(page_zone(page), item, 1, 1);
361}
362EXPORT_SYMBOL(inc_zone_page_state);
363
364void dec_zone_page_state(struct page *page, enum zone_stat_item item)
365{
366 mod_state(page_zone(page), item, -1, -1);
367}
368EXPORT_SYMBOL(dec_zone_page_state);
369#else
370/*
371 * Use interrupt disable to serialize counter updates
372 */
373void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
374 int delta)
375{
376 unsigned long flags;
377
378 local_irq_save(flags);
379 __mod_zone_page_state(zone, item, delta);
380 local_irq_restore(flags);
381}
382EXPORT_SYMBOL(mod_zone_page_state);
383
Christoph Lameterca889e62006-06-30 01:55:44 -0700384void inc_zone_state(struct zone *zone, enum zone_stat_item item)
385{
386 unsigned long flags;
387
388 local_irq_save(flags);
389 __inc_zone_state(zone, item);
390 local_irq_restore(flags);
391}
392
Christoph Lameter2244b952006-06-30 01:55:33 -0700393void inc_zone_page_state(struct page *page, enum zone_stat_item item)
394{
395 unsigned long flags;
396 struct zone *zone;
Christoph Lameter2244b952006-06-30 01:55:33 -0700397
398 zone = page_zone(page);
399 local_irq_save(flags);
Christoph Lameterca889e62006-06-30 01:55:44 -0700400 __inc_zone_state(zone, item);
Christoph Lameter2244b952006-06-30 01:55:33 -0700401 local_irq_restore(flags);
402}
403EXPORT_SYMBOL(inc_zone_page_state);
404
405void dec_zone_page_state(struct page *page, enum zone_stat_item item)
406{
407 unsigned long flags;
Christoph Lameter2244b952006-06-30 01:55:33 -0700408
Christoph Lameter2244b952006-06-30 01:55:33 -0700409 local_irq_save(flags);
Christoph Lametera302eb42006-08-31 21:27:34 -0700410 __dec_zone_page_state(page, item);
Christoph Lameter2244b952006-06-30 01:55:33 -0700411 local_irq_restore(flags);
412}
413EXPORT_SYMBOL(dec_zone_page_state);
Christoph Lameter7c839122010-12-14 10:28:46 -0600414#endif
Christoph Lameter2244b952006-06-30 01:55:33 -0700415
416/*
417 * Update the zone counters for one cpu.
Christoph Lameter4037d452007-05-09 02:35:14 -0700418 *
Christoph Lametera7f75e22008-02-04 22:29:16 -0800419 * The cpu specified must be either the current cpu or a processor that
420 * is not online. If it is the current cpu then the execution thread must
421 * be pinned to the current cpu.
422 *
Christoph Lameter4037d452007-05-09 02:35:14 -0700423 * Note that refresh_cpu_vm_stats strives to only access
424 * node local memory. The per cpu pagesets on remote zones are placed
425 * in the memory local to the processor using that pageset. So the
426 * loop over all zones will access a series of cachelines local to
427 * the processor.
428 *
429 * The call to zone_page_state_add updates the cachelines with the
430 * statistics in the remote zone struct as well as the global cachelines
431 * with the global counters. These could cause remote node cache line
432 * bouncing and will have to be only done when necessary.
Christoph Lameter2244b952006-06-30 01:55:33 -0700433 */
434void refresh_cpu_vm_stats(int cpu)
435{
436 struct zone *zone;
437 int i;
Christoph Lametera7f75e22008-02-04 22:29:16 -0800438 int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
Christoph Lameter2244b952006-06-30 01:55:33 -0700439
KOSAKI Motohiroee99c712009-03-31 15:19:31 -0700440 for_each_populated_zone(zone) {
Christoph Lameter4037d452007-05-09 02:35:14 -0700441 struct per_cpu_pageset *p;
Christoph Lameter2244b952006-06-30 01:55:33 -0700442
Christoph Lameter99dcc3e2010-01-05 15:34:51 +0900443 p = per_cpu_ptr(zone->pageset, cpu);
Christoph Lameter2244b952006-06-30 01:55:33 -0700444
445 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
Christoph Lameter4037d452007-05-09 02:35:14 -0700446 if (p->vm_stat_diff[i]) {
Christoph Lametera7f75e22008-02-04 22:29:16 -0800447 unsigned long flags;
448 int v;
449
Christoph Lameter2244b952006-06-30 01:55:33 -0700450 local_irq_save(flags);
Christoph Lametera7f75e22008-02-04 22:29:16 -0800451 v = p->vm_stat_diff[i];
Christoph Lameter4037d452007-05-09 02:35:14 -0700452 p->vm_stat_diff[i] = 0;
Christoph Lametera7f75e22008-02-04 22:29:16 -0800453 local_irq_restore(flags);
454 atomic_long_add(v, &zone->vm_stat[i]);
455 global_diff[i] += v;
Christoph Lameter4037d452007-05-09 02:35:14 -0700456#ifdef CONFIG_NUMA
457 /* 3 seconds idle till flush */
458 p->expire = 3;
459#endif
Christoph Lameter2244b952006-06-30 01:55:33 -0700460 }
Dimitri Sivanich468fd622008-04-28 02:13:37 -0700461 cond_resched();
Christoph Lameter4037d452007-05-09 02:35:14 -0700462#ifdef CONFIG_NUMA
463 /*
464 * Deal with draining the remote pageset of this
465 * processor
466 *
467 * Check if there are pages remaining in this pageset
468 * if not then there is nothing to expire.
469 */
Christoph Lameter3dfa5722008-02-04 22:29:19 -0800470 if (!p->expire || !p->pcp.count)
Christoph Lameter4037d452007-05-09 02:35:14 -0700471 continue;
472
473 /*
474 * We never drain zones local to this processor.
475 */
476 if (zone_to_nid(zone) == numa_node_id()) {
477 p->expire = 0;
478 continue;
479 }
480
481 p->expire--;
482 if (p->expire)
483 continue;
484
Christoph Lameter3dfa5722008-02-04 22:29:19 -0800485 if (p->pcp.count)
486 drain_zone_pages(zone, &p->pcp);
Christoph Lameter4037d452007-05-09 02:35:14 -0700487#endif
Christoph Lameter2244b952006-06-30 01:55:33 -0700488 }
Christoph Lametera7f75e22008-02-04 22:29:16 -0800489
490 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
491 if (global_diff[i])
492 atomic_long_add(global_diff[i], &vm_stat[i]);
Christoph Lameter2244b952006-06-30 01:55:33 -0700493}
494
Christoph Lameter2244b952006-06-30 01:55:33 -0700495#endif
496
Christoph Lameterca889e62006-06-30 01:55:44 -0700497#ifdef CONFIG_NUMA
498/*
499 * zonelist = the list of zones passed to the allocator
500 * z = the zone from which the allocation occurred.
501 *
502 * Must be called with interrupts disabled.
503 */
Mel Gorman18ea7e72008-04-28 02:12:14 -0700504void zone_statistics(struct zone *preferred_zone, struct zone *z)
Christoph Lameterca889e62006-06-30 01:55:44 -0700505{
Mel Gorman18ea7e72008-04-28 02:12:14 -0700506 if (z->zone_pgdat == preferred_zone->zone_pgdat) {
Christoph Lameterca889e62006-06-30 01:55:44 -0700507 __inc_zone_state(z, NUMA_HIT);
508 } else {
509 __inc_zone_state(z, NUMA_MISS);
Mel Gorman18ea7e72008-04-28 02:12:14 -0700510 __inc_zone_state(preferred_zone, NUMA_FOREIGN);
Christoph Lameterca889e62006-06-30 01:55:44 -0700511 }
Christoph Lameter5d292342006-09-27 01:50:10 -0700512 if (z->node == numa_node_id())
Christoph Lameterca889e62006-06-30 01:55:44 -0700513 __inc_zone_state(z, NUMA_LOCAL);
514 else
515 __inc_zone_state(z, NUMA_OTHER);
516}
517#endif
518
Mel Gormand7a57522010-05-24 14:32:25 -0700519#ifdef CONFIG_COMPACTION
Namhyung Kim36deb0b2010-10-26 14:22:04 -0700520
Mel Gormand7a57522010-05-24 14:32:25 -0700521struct contig_page_info {
522 unsigned long free_pages;
523 unsigned long free_blocks_total;
524 unsigned long free_blocks_suitable;
525};
526
527/*
528 * Calculate the number of free pages in a zone, how many contiguous
529 * pages are free and how many are large enough to satisfy an allocation of
530 * the target size. Note that this function makes no attempt to estimate
531 * how many suitable free blocks there *might* be if MOVABLE pages were
532 * migrated. Calculating that is possible, but expensive and can be
533 * figured out from userspace
534 */
535static void fill_contig_page_info(struct zone *zone,
536 unsigned int suitable_order,
537 struct contig_page_info *info)
538{
539 unsigned int order;
540
541 info->free_pages = 0;
542 info->free_blocks_total = 0;
543 info->free_blocks_suitable = 0;
544
545 for (order = 0; order < MAX_ORDER; order++) {
546 unsigned long blocks;
547
548 /* Count number of free blocks */
549 blocks = zone->free_area[order].nr_free;
550 info->free_blocks_total += blocks;
551
552 /* Count free base pages */
553 info->free_pages += blocks << order;
554
555 /* Count the suitable free blocks */
556 if (order >= suitable_order)
557 info->free_blocks_suitable += blocks <<
558 (order - suitable_order);
559 }
560}
Mel Gormanf1a5ab12010-05-24 14:32:26 -0700561
562/*
563 * A fragmentation index only makes sense if an allocation of a requested
564 * size would fail. If that is true, the fragmentation index indicates
565 * whether external fragmentation or a lack of memory was the problem.
566 * The value can be used to determine if page reclaim or compaction
567 * should be used
568 */
Mel Gorman56de7262010-05-24 14:32:30 -0700569static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
Mel Gormanf1a5ab12010-05-24 14:32:26 -0700570{
571 unsigned long requested = 1UL << order;
572
573 if (!info->free_blocks_total)
574 return 0;
575
576 /* Fragmentation index only makes sense when a request would fail */
577 if (info->free_blocks_suitable)
578 return -1000;
579
580 /*
581 * Index is between 0 and 1 so return within 3 decimal places
582 *
583 * 0 => allocation would fail due to lack of memory
584 * 1 => allocation would fail due to fragmentation
585 */
586 return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
587}
Mel Gorman56de7262010-05-24 14:32:30 -0700588
589/* Same as __fragmentation index but allocs contig_page_info on stack */
590int fragmentation_index(struct zone *zone, unsigned int order)
591{
592 struct contig_page_info info;
593
594 fill_contig_page_info(zone, order, &info);
595 return __fragmentation_index(order, &info);
596}
Mel Gormand7a57522010-05-24 14:32:25 -0700597#endif
598
599#if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +0400600#include <linux/proc_fs.h>
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700601#include <linux/seq_file.h>
602
Mel Gorman467c9962007-10-16 01:26:02 -0700603static char * const migratetype_names[MIGRATE_TYPES] = {
604 "Unmovable",
605 "Reclaimable",
606 "Movable",
607 "Reserve",
KOSAKI Motohiro91446b02008-04-15 14:34:42 -0700608 "Isolate",
Mel Gorman467c9962007-10-16 01:26:02 -0700609};
610
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700611static void *frag_start(struct seq_file *m, loff_t *pos)
612{
613 pg_data_t *pgdat;
614 loff_t node = *pos;
615 for (pgdat = first_online_pgdat();
616 pgdat && node;
617 pgdat = next_online_pgdat(pgdat))
618 --node;
619
620 return pgdat;
621}
622
623static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
624{
625 pg_data_t *pgdat = (pg_data_t *)arg;
626
627 (*pos)++;
628 return next_online_pgdat(pgdat);
629}
630
631static void frag_stop(struct seq_file *m, void *arg)
632{
633}
634
Mel Gorman467c9962007-10-16 01:26:02 -0700635/* Walk all the zones in a node and print using a callback */
636static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
637 void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700638{
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700639 struct zone *zone;
640 struct zone *node_zones = pgdat->node_zones;
641 unsigned long flags;
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700642
643 for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
644 if (!populated_zone(zone))
645 continue;
646
647 spin_lock_irqsave(&zone->lock, flags);
Mel Gorman467c9962007-10-16 01:26:02 -0700648 print(m, pgdat, zone);
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700649 spin_unlock_irqrestore(&zone->lock, flags);
Mel Gorman467c9962007-10-16 01:26:02 -0700650 }
651}
Mel Gormand7a57522010-05-24 14:32:25 -0700652#endif
Mel Gorman467c9962007-10-16 01:26:02 -0700653
Mel Gormand7a57522010-05-24 14:32:25 -0700654#ifdef CONFIG_PROC_FS
Mel Gorman467c9962007-10-16 01:26:02 -0700655static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
656 struct zone *zone)
657{
658 int order;
659
660 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
661 for (order = 0; order < MAX_ORDER; ++order)
662 seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
663 seq_putc(m, '\n');
664}
665
666/*
667 * This walks the free areas for each zone.
668 */
669static int frag_show(struct seq_file *m, void *arg)
670{
671 pg_data_t *pgdat = (pg_data_t *)arg;
672 walk_zones_in_node(m, pgdat, frag_show_print);
673 return 0;
674}
675
676static void pagetypeinfo_showfree_print(struct seq_file *m,
677 pg_data_t *pgdat, struct zone *zone)
678{
679 int order, mtype;
680
681 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
682 seq_printf(m, "Node %4d, zone %8s, type %12s ",
683 pgdat->node_id,
684 zone->name,
685 migratetype_names[mtype]);
686 for (order = 0; order < MAX_ORDER; ++order) {
687 unsigned long freecount = 0;
688 struct free_area *area;
689 struct list_head *curr;
690
691 area = &(zone->free_area[order]);
692
693 list_for_each(curr, &area->free_list[mtype])
694 freecount++;
695 seq_printf(m, "%6lu ", freecount);
696 }
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700697 seq_putc(m, '\n');
698 }
Mel Gorman467c9962007-10-16 01:26:02 -0700699}
700
701/* Print out the free pages at each order for each migatetype */
702static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
703{
704 int order;
705 pg_data_t *pgdat = (pg_data_t *)arg;
706
707 /* Print header */
708 seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
709 for (order = 0; order < MAX_ORDER; ++order)
710 seq_printf(m, "%6d ", order);
711 seq_putc(m, '\n');
712
713 walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);
714
715 return 0;
716}
717
718static void pagetypeinfo_showblockcount_print(struct seq_file *m,
719 pg_data_t *pgdat, struct zone *zone)
720{
721 int mtype;
722 unsigned long pfn;
723 unsigned long start_pfn = zone->zone_start_pfn;
724 unsigned long end_pfn = start_pfn + zone->spanned_pages;
725 unsigned long count[MIGRATE_TYPES] = { 0, };
726
727 for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
728 struct page *page;
729
730 if (!pfn_valid(pfn))
731 continue;
732
733 page = pfn_to_page(pfn);
Mel Gormaneb335752009-05-13 17:34:48 +0100734
735 /* Watch for unexpected holes punched in the memmap */
736 if (!memmap_valid_within(pfn, page, zone))
Mel Gormane80d6a22008-08-14 11:10:14 +0100737 continue;
Mel Gormaneb335752009-05-13 17:34:48 +0100738
Mel Gorman467c9962007-10-16 01:26:02 -0700739 mtype = get_pageblock_migratetype(page);
740
Mel Gormane80d6a22008-08-14 11:10:14 +0100741 if (mtype < MIGRATE_TYPES)
742 count[mtype]++;
Mel Gorman467c9962007-10-16 01:26:02 -0700743 }
744
745 /* Print counts */
746 seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
747 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
748 seq_printf(m, "%12lu ", count[mtype]);
749 seq_putc(m, '\n');
750}
751
752/* Print out the free pages at each order for each migratetype */
753static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
754{
755 int mtype;
756 pg_data_t *pgdat = (pg_data_t *)arg;
757
758 seq_printf(m, "\n%-23s", "Number of blocks type ");
759 for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
760 seq_printf(m, "%12s ", migratetype_names[mtype]);
761 seq_putc(m, '\n');
762 walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);
763
764 return 0;
765}
766
767/*
768 * This prints out statistics in relation to grouping pages by mobility.
769 * It is expensive to collect so do not constantly read the file.
770 */
771static int pagetypeinfo_show(struct seq_file *m, void *arg)
772{
773 pg_data_t *pgdat = (pg_data_t *)arg;
774
KOSAKI Motohiro41b25a32008-04-30 00:52:13 -0700775 /* check memoryless node */
776 if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
777 return 0;
778
Mel Gorman467c9962007-10-16 01:26:02 -0700779 seq_printf(m, "Page block order: %d\n", pageblock_order);
780 seq_printf(m, "Pages per block: %lu\n", pageblock_nr_pages);
781 seq_putc(m, '\n');
782 pagetypeinfo_showfree(m, pgdat);
783 pagetypeinfo_showblockcount(m, pgdat);
784
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700785 return 0;
786}
787
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +0400788static const struct seq_operations fragmentation_op = {
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700789 .start = frag_start,
790 .next = frag_next,
791 .stop = frag_stop,
792 .show = frag_show,
793};
794
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +0400795static int fragmentation_open(struct inode *inode, struct file *file)
796{
797 return seq_open(file, &fragmentation_op);
798}
799
800static const struct file_operations fragmentation_file_operations = {
801 .open = fragmentation_open,
802 .read = seq_read,
803 .llseek = seq_lseek,
804 .release = seq_release,
805};
806
Alexey Dobriyan74e2e8e2008-10-06 04:15:36 +0400807static const struct seq_operations pagetypeinfo_op = {
Mel Gorman467c9962007-10-16 01:26:02 -0700808 .start = frag_start,
809 .next = frag_next,
810 .stop = frag_stop,
811 .show = pagetypeinfo_show,
812};
813
Alexey Dobriyan74e2e8e2008-10-06 04:15:36 +0400814static int pagetypeinfo_open(struct inode *inode, struct file *file)
815{
816 return seq_open(file, &pagetypeinfo_op);
817}
818
819static const struct file_operations pagetypeinfo_file_ops = {
820 .open = pagetypeinfo_open,
821 .read = seq_read,
822 .llseek = seq_lseek,
823 .release = seq_release,
824};
825
Christoph Lameter4b51d662007-02-10 01:43:10 -0800826#ifdef CONFIG_ZONE_DMA
827#define TEXT_FOR_DMA(xx) xx "_dma",
828#else
829#define TEXT_FOR_DMA(xx)
830#endif
831
Christoph Lameter27bf71c2006-09-25 23:31:15 -0700832#ifdef CONFIG_ZONE_DMA32
833#define TEXT_FOR_DMA32(xx) xx "_dma32",
834#else
835#define TEXT_FOR_DMA32(xx)
836#endif
837
838#ifdef CONFIG_HIGHMEM
839#define TEXT_FOR_HIGHMEM(xx) xx "_high",
840#else
841#define TEXT_FOR_HIGHMEM(xx)
842#endif
843
Christoph Lameter4b51d662007-02-10 01:43:10 -0800844#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
Mel Gorman2a1e2742007-07-17 04:03:12 -0700845 TEXT_FOR_HIGHMEM(xx) xx "_movable",
Christoph Lameter27bf71c2006-09-25 23:31:15 -0700846
Helge Deller15ad7cd2006-12-06 20:40:36 -0800847static const char * const vmstat_text[] = {
Christoph Lameter2244b952006-06-30 01:55:33 -0700848 /* Zoned VM counters */
Christoph Lameterd23ad422007-02-10 01:43:02 -0800849 "nr_free_pages",
Rik van Riel4f98a2f2008-10-18 20:26:32 -0700850 "nr_inactive_anon",
851 "nr_active_anon",
852 "nr_inactive_file",
853 "nr_active_file",
Lee Schermerhorn7b854122008-10-18 20:26:40 -0700854 "nr_unevictable",
Nick Piggin5344b7e2008-10-18 20:26:51 -0700855 "nr_mlock",
Christoph Lameterf3dbd342006-06-30 01:55:36 -0700856 "nr_anon_pages",
Christoph Lameter65ba55f2006-06-30 01:55:34 -0700857 "nr_mapped",
Christoph Lameter347ce432006-06-30 01:55:35 -0700858 "nr_file_pages",
Christoph Lameter51ed4492007-02-10 01:43:02 -0800859 "nr_dirty",
860 "nr_writeback",
Christoph Lameter972d1a72006-09-25 23:31:51 -0700861 "nr_slab_reclaimable",
862 "nr_slab_unreclaimable",
Christoph Lameterdf849a12006-06-30 01:55:38 -0700863 "nr_page_table_pages",
KOSAKI Motohiroc6a7f572009-09-21 17:01:32 -0700864 "nr_kernel_stack",
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700865 "nr_unstable",
Christoph Lameterd2c5e302006-06-30 01:55:41 -0700866 "nr_bounce",
Andrew Mortone129b5c2006-09-27 01:50:00 -0700867 "nr_vmscan_write",
Miklos Szeredifc3ba692008-04-30 00:54:38 -0700868 "nr_writeback_temp",
KOSAKI Motohiroa7312862009-09-21 17:01:37 -0700869 "nr_isolated_anon",
870 "nr_isolated_file",
KOSAKI Motohiro4b021082009-09-21 17:01:33 -0700871 "nr_shmem",
Michael Rubinea941f02010-10-26 14:21:35 -0700872 "nr_dirtied",
873 "nr_written",
874
Christoph Lameterca889e62006-06-30 01:55:44 -0700875#ifdef CONFIG_NUMA
876 "numa_hit",
877 "numa_miss",
878 "numa_foreign",
879 "numa_interleave",
880 "numa_local",
881 "numa_other",
882#endif
Andrea Arcangeli79134172011-01-13 15:46:58 -0800883 "nr_anon_transparent_hugepages",
Wu Fengguange1726622010-12-02 14:31:13 -0800884 "nr_dirty_threshold",
885 "nr_dirty_background_threshold",
Christoph Lameterca889e62006-06-30 01:55:44 -0700886
Christoph Lameterf8891e52006-06-30 01:55:45 -0700887#ifdef CONFIG_VM_EVENT_COUNTERS
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700888 "pgpgin",
889 "pgpgout",
890 "pswpin",
891 "pswpout",
892
Christoph Lameter27bf71c2006-09-25 23:31:15 -0700893 TEXTS_FOR_ZONES("pgalloc")
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700894
895 "pgfree",
896 "pgactivate",
897 "pgdeactivate",
898
899 "pgfault",
900 "pgmajfault",
901
Christoph Lameter27bf71c2006-09-25 23:31:15 -0700902 TEXTS_FOR_ZONES("pgrefill")
903 TEXTS_FOR_ZONES("pgsteal")
904 TEXTS_FOR_ZONES("pgscan_kswapd")
905 TEXTS_FOR_ZONES("pgscan_direct")
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700906
Mel Gorman24cf725182009-06-16 15:33:23 -0700907#ifdef CONFIG_NUMA
908 "zone_reclaim_failed",
909#endif
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700910 "pginodesteal",
911 "slabs_scanned",
912 "kswapd_steal",
913 "kswapd_inodesteal",
KOSAKI Motohirobb3ab592009-12-14 17:58:55 -0800914 "kswapd_low_wmark_hit_quickly",
915 "kswapd_high_wmark_hit_quickly",
916 "kswapd_skip_congestion_wait",
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700917 "pageoutrun",
918 "allocstall",
919
920 "pgrotated",
Mel Gorman748446b2010-05-24 14:32:27 -0700921
922#ifdef CONFIG_COMPACTION
923 "compact_blocks_moved",
924 "compact_pages_moved",
925 "compact_pagemigrate_failed",
Mel Gorman56de7262010-05-24 14:32:30 -0700926 "compact_stall",
927 "compact_fail",
928 "compact_success",
Mel Gorman748446b2010-05-24 14:32:27 -0700929#endif
930
Adam Litke3b116302008-04-28 02:13:06 -0700931#ifdef CONFIG_HUGETLB_PAGE
932 "htlb_buddy_alloc_success",
933 "htlb_buddy_alloc_fail",
934#endif
Lee Schermerhornbbfd28e2008-10-18 20:26:40 -0700935 "unevictable_pgs_culled",
936 "unevictable_pgs_scanned",
937 "unevictable_pgs_rescued",
Nick Piggin5344b7e2008-10-18 20:26:51 -0700938 "unevictable_pgs_mlocked",
939 "unevictable_pgs_munlocked",
940 "unevictable_pgs_cleared",
941 "unevictable_pgs_stranded",
Lee Schermerhorn985737c2008-10-18 20:26:53 -0700942 "unevictable_pgs_mlockfreed",
Lee Schermerhornbbfd28e2008-10-18 20:26:40 -0700943#endif
Christoph Lameterf6ac2352006-06-30 01:55:32 -0700944};
945
Mel Gorman467c9962007-10-16 01:26:02 -0700946static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
947 struct zone *zone)
948{
949 int i;
950 seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
951 seq_printf(m,
952 "\n pages free %lu"
953 "\n min %lu"
954 "\n low %lu"
955 "\n high %lu"
Wu Fengguang08d9ae72009-06-16 15:32:30 -0700956 "\n scanned %lu"
Mel Gorman467c9962007-10-16 01:26:02 -0700957 "\n spanned %lu"
958 "\n present %lu",
Mel Gorman88f5acf2011-01-13 15:45:41 -0800959 zone_page_state(zone, NR_FREE_PAGES),
Mel Gorman41858962009-06-16 15:32:12 -0700960 min_wmark_pages(zone),
961 low_wmark_pages(zone),
962 high_wmark_pages(zone),
Mel Gorman467c9962007-10-16 01:26:02 -0700963 zone->pages_scanned,
Mel Gorman467c9962007-10-16 01:26:02 -0700964 zone->spanned_pages,
965 zone->present_pages);
966
967 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
968 seq_printf(m, "\n %-12s %lu", vmstat_text[i],
969 zone_page_state(zone, i));
970
971 seq_printf(m,
972 "\n protection: (%lu",
973 zone->lowmem_reserve[0]);
974 for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
975 seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
976 seq_printf(m,
977 ")"
978 "\n pagesets");
979 for_each_online_cpu(i) {
980 struct per_cpu_pageset *pageset;
Mel Gorman467c9962007-10-16 01:26:02 -0700981
Christoph Lameter99dcc3e2010-01-05 15:34:51 +0900982 pageset = per_cpu_ptr(zone->pageset, i);
Christoph Lameter3dfa5722008-02-04 22:29:19 -0800983 seq_printf(m,
984 "\n cpu: %i"
985 "\n count: %i"
986 "\n high: %i"
987 "\n batch: %i",
988 i,
989 pageset->pcp.count,
990 pageset->pcp.high,
991 pageset->pcp.batch);
Mel Gorman467c9962007-10-16 01:26:02 -0700992#ifdef CONFIG_SMP
993 seq_printf(m, "\n vm stats threshold: %d",
994 pageset->stat_threshold);
995#endif
996 }
997 seq_printf(m,
998 "\n all_unreclaimable: %u"
Rik van Riel556adec2008-10-18 20:26:34 -0700999 "\n start_pfn: %lu"
1000 "\n inactive_ratio: %u",
KOSAKI Motohiro93e4a892010-03-05 13:41:55 -08001001 zone->all_unreclaimable,
Rik van Riel556adec2008-10-18 20:26:34 -07001002 zone->zone_start_pfn,
1003 zone->inactive_ratio);
Mel Gorman467c9962007-10-16 01:26:02 -07001004 seq_putc(m, '\n');
1005}
1006
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001007/*
1008 * Output information about zones in @pgdat.
1009 */
1010static int zoneinfo_show(struct seq_file *m, void *arg)
1011{
Mel Gorman467c9962007-10-16 01:26:02 -07001012 pg_data_t *pgdat = (pg_data_t *)arg;
1013 walk_zones_in_node(m, pgdat, zoneinfo_show_print);
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001014 return 0;
1015}
1016
Alexey Dobriyan5c9fe622008-10-06 04:19:42 +04001017static const struct seq_operations zoneinfo_op = {
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001018 .start = frag_start, /* iterate over all zones. The same as in
1019 * fragmentation. */
1020 .next = frag_next,
1021 .stop = frag_stop,
1022 .show = zoneinfo_show,
1023};
1024
Alexey Dobriyan5c9fe622008-10-06 04:19:42 +04001025static int zoneinfo_open(struct inode *inode, struct file *file)
1026{
1027 return seq_open(file, &zoneinfo_op);
1028}
1029
1030static const struct file_operations proc_zoneinfo_file_operations = {
1031 .open = zoneinfo_open,
1032 .read = seq_read,
1033 .llseek = seq_lseek,
1034 .release = seq_release,
1035};
1036
Michael Rubin79da8262010-10-26 14:21:36 -07001037enum writeback_stat_item {
1038 NR_DIRTY_THRESHOLD,
1039 NR_DIRTY_BG_THRESHOLD,
1040 NR_VM_WRITEBACK_STAT_ITEMS,
1041};
1042
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001043static void *vmstat_start(struct seq_file *m, loff_t *pos)
1044{
Christoph Lameter2244b952006-06-30 01:55:33 -07001045 unsigned long *v;
Michael Rubin79da8262010-10-26 14:21:36 -07001046 int i, stat_items_size;
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001047
1048 if (*pos >= ARRAY_SIZE(vmstat_text))
1049 return NULL;
Michael Rubin79da8262010-10-26 14:21:36 -07001050 stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
1051 NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001052
Christoph Lameterf8891e52006-06-30 01:55:45 -07001053#ifdef CONFIG_VM_EVENT_COUNTERS
Michael Rubin79da8262010-10-26 14:21:36 -07001054 stat_items_size += sizeof(struct vm_event_state);
Christoph Lameterf8891e52006-06-30 01:55:45 -07001055#endif
Michael Rubin79da8262010-10-26 14:21:36 -07001056
1057 v = kmalloc(stat_items_size, GFP_KERNEL);
Christoph Lameter2244b952006-06-30 01:55:33 -07001058 m->private = v;
1059 if (!v)
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001060 return ERR_PTR(-ENOMEM);
Christoph Lameter2244b952006-06-30 01:55:33 -07001061 for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
1062 v[i] = global_page_state(i);
Michael Rubin79da8262010-10-26 14:21:36 -07001063 v += NR_VM_ZONE_STAT_ITEMS;
1064
1065 global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
1066 v + NR_DIRTY_THRESHOLD);
1067 v += NR_VM_WRITEBACK_STAT_ITEMS;
1068
Christoph Lameterf8891e52006-06-30 01:55:45 -07001069#ifdef CONFIG_VM_EVENT_COUNTERS
Michael Rubin79da8262010-10-26 14:21:36 -07001070 all_vm_events(v);
1071 v[PGPGIN] /= 2; /* sectors -> kbytes */
1072 v[PGPGOUT] /= 2;
Christoph Lameterf8891e52006-06-30 01:55:45 -07001073#endif
Wu Fengguangff8b16d2010-11-04 01:56:49 +08001074 return (unsigned long *)m->private + *pos;
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001075}
1076
1077static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
1078{
1079 (*pos)++;
1080 if (*pos >= ARRAY_SIZE(vmstat_text))
1081 return NULL;
1082 return (unsigned long *)m->private + *pos;
1083}
1084
1085static int vmstat_show(struct seq_file *m, void *arg)
1086{
1087 unsigned long *l = arg;
1088 unsigned long off = l - (unsigned long *)m->private;
1089
1090 seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
1091 return 0;
1092}
1093
1094static void vmstat_stop(struct seq_file *m, void *arg)
1095{
1096 kfree(m->private);
1097 m->private = NULL;
1098}
1099
Alexey Dobriyanb6aa44a2008-10-06 04:17:48 +04001100static const struct seq_operations vmstat_op = {
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001101 .start = vmstat_start,
1102 .next = vmstat_next,
1103 .stop = vmstat_stop,
1104 .show = vmstat_show,
1105};
1106
Alexey Dobriyanb6aa44a2008-10-06 04:17:48 +04001107static int vmstat_open(struct inode *inode, struct file *file)
1108{
1109 return seq_open(file, &vmstat_op);
1110}
1111
1112static const struct file_operations proc_vmstat_file_operations = {
1113 .open = vmstat_open,
1114 .read = seq_read,
1115 .llseek = seq_lseek,
1116 .release = seq_release,
1117};
Christoph Lameterf6ac2352006-06-30 01:55:32 -07001118#endif /* CONFIG_PROC_FS */
1119
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001120#ifdef CONFIG_SMP
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001121static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
Christoph Lameter77461ab2007-05-09 02:35:13 -07001122int sysctl_stat_interval __read_mostly = HZ;
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001123
1124static void vmstat_update(struct work_struct *w)
1125{
1126 refresh_cpu_vm_stats(smp_processor_id());
Christoph Lameter77461ab2007-05-09 02:35:13 -07001127 schedule_delayed_work(&__get_cpu_var(vmstat_work),
Anton Blanchard98f4ebb2009-04-02 16:56:39 -07001128 round_jiffies_relative(sysctl_stat_interval));
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001129}
1130
Randy Dunlap42614fc2007-11-14 17:00:12 -08001131static void __cpuinit start_cpu_timer(int cpu)
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001132{
Tejun Heo1871e522009-10-29 22:34:13 +09001133 struct delayed_work *work = &per_cpu(vmstat_work, cpu);
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001134
Tejun Heo1871e522009-10-29 22:34:13 +09001135 INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
1136 schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001137}
1138
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001139/*
1140 * Use the cpu notifier to insure that the thresholds are recalculated
1141 * when necessary.
1142 */
1143static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
1144 unsigned long action,
1145 void *hcpu)
1146{
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001147 long cpu = (long)hcpu;
1148
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001149 switch (action) {
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001150 case CPU_ONLINE:
1151 case CPU_ONLINE_FROZEN:
KAMEZAWA Hiroyuki5ee28a42010-09-09 16:38:14 -07001152 refresh_zone_stat_thresholds();
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001153 start_cpu_timer(cpu);
Christoph Lameterad596922010-01-05 15:34:51 +09001154 node_set_state(cpu_to_node(cpu), N_CPU);
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001155 break;
1156 case CPU_DOWN_PREPARE:
1157 case CPU_DOWN_PREPARE_FROZEN:
Tejun Heoafe2c512010-12-14 16:21:17 +01001158 cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001159 per_cpu(vmstat_work, cpu).work.func = NULL;
1160 break;
1161 case CPU_DOWN_FAILED:
1162 case CPU_DOWN_FAILED_FROZEN:
1163 start_cpu_timer(cpu);
1164 break;
Andy Whitcroftce421c72006-12-06 20:33:08 -08001165 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001166 case CPU_DEAD_FROZEN:
Andy Whitcroftce421c72006-12-06 20:33:08 -08001167 refresh_zone_stat_thresholds();
1168 break;
1169 default:
1170 break;
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001171 }
1172 return NOTIFY_OK;
1173}
1174
1175static struct notifier_block __cpuinitdata vmstat_notifier =
1176 { &vmstat_cpuup_callback, NULL, 0 };
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +04001177#endif
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001178
Adrian Bunke2fc88d2007-10-16 01:26:27 -07001179static int __init setup_vmstat(void)
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001180{
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +04001181#ifdef CONFIG_SMP
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001182 int cpu;
1183
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001184 refresh_zone_stat_thresholds();
1185 register_cpu_notifier(&vmstat_notifier);
Christoph Lameterd1187ed2007-05-09 02:35:12 -07001186
1187 for_each_online_cpu(cpu)
1188 start_cpu_timer(cpu);
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +04001189#endif
1190#ifdef CONFIG_PROC_FS
1191 proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
Alexey Dobriyan74e2e8e2008-10-06 04:15:36 +04001192 proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
Alexey Dobriyanb6aa44a2008-10-06 04:17:48 +04001193 proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
Alexey Dobriyan5c9fe622008-10-06 04:19:42 +04001194 proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
Alexey Dobriyan8f32f7e2008-10-06 04:13:52 +04001195#endif
Christoph Lameterdf9ecab2006-08-31 21:27:35 -07001196 return 0;
1197}
1198module_init(setup_vmstat)
Mel Gormand7a57522010-05-24 14:32:25 -07001199
1200#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
1201#include <linux/debugfs.h>
1202
1203static struct dentry *extfrag_debug_root;
1204
1205/*
1206 * Return an index indicating how much of the available free memory is
1207 * unusable for an allocation of the requested size.
1208 */
1209static int unusable_free_index(unsigned int order,
1210 struct contig_page_info *info)
1211{
1212 /* No free memory is interpreted as all free memory is unusable */
1213 if (info->free_pages == 0)
1214 return 1000;
1215
1216 /*
1217 * Index should be a value between 0 and 1. Return a value to 3
1218 * decimal places.
1219 *
1220 * 0 => no fragmentation
1221 * 1 => high fragmentation
1222 */
1223 return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);
1224
1225}
1226
1227static void unusable_show_print(struct seq_file *m,
1228 pg_data_t *pgdat, struct zone *zone)
1229{
1230 unsigned int order;
1231 int index;
1232 struct contig_page_info info;
1233
1234 seq_printf(m, "Node %d, zone %8s ",
1235 pgdat->node_id,
1236 zone->name);
1237 for (order = 0; order < MAX_ORDER; ++order) {
1238 fill_contig_page_info(zone, order, &info);
1239 index = unusable_free_index(order, &info);
1240 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1241 }
1242
1243 seq_putc(m, '\n');
1244}
1245
1246/*
1247 * Display unusable free space index
1248 *
1249 * The unusable free space index measures how much of the available free
1250 * memory cannot be used to satisfy an allocation of a given size and is a
1251 * value between 0 and 1. The higher the value, the more of free memory is
1252 * unusable and by implication, the worse the external fragmentation is. This
1253 * can be expressed as a percentage by multiplying by 100.
1254 */
1255static int unusable_show(struct seq_file *m, void *arg)
1256{
1257 pg_data_t *pgdat = (pg_data_t *)arg;
1258
1259 /* check memoryless node */
1260 if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
1261 return 0;
1262
1263 walk_zones_in_node(m, pgdat, unusable_show_print);
1264
1265 return 0;
1266}
1267
1268static const struct seq_operations unusable_op = {
1269 .start = frag_start,
1270 .next = frag_next,
1271 .stop = frag_stop,
1272 .show = unusable_show,
1273};
1274
1275static int unusable_open(struct inode *inode, struct file *file)
1276{
1277 return seq_open(file, &unusable_op);
1278}
1279
1280static const struct file_operations unusable_file_ops = {
1281 .open = unusable_open,
1282 .read = seq_read,
1283 .llseek = seq_lseek,
1284 .release = seq_release,
1285};
1286
Mel Gormanf1a5ab12010-05-24 14:32:26 -07001287static void extfrag_show_print(struct seq_file *m,
1288 pg_data_t *pgdat, struct zone *zone)
1289{
1290 unsigned int order;
1291 int index;
1292
1293 /* Alloc on stack as interrupts are disabled for zone walk */
1294 struct contig_page_info info;
1295
1296 seq_printf(m, "Node %d, zone %8s ",
1297 pgdat->node_id,
1298 zone->name);
1299 for (order = 0; order < MAX_ORDER; ++order) {
1300 fill_contig_page_info(zone, order, &info);
Mel Gorman56de7262010-05-24 14:32:30 -07001301 index = __fragmentation_index(order, &info);
Mel Gormanf1a5ab12010-05-24 14:32:26 -07001302 seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
1303 }
1304
1305 seq_putc(m, '\n');
1306}
1307
1308/*
1309 * Display fragmentation index for orders that allocations would fail for
1310 */
1311static int extfrag_show(struct seq_file *m, void *arg)
1312{
1313 pg_data_t *pgdat = (pg_data_t *)arg;
1314
1315 walk_zones_in_node(m, pgdat, extfrag_show_print);
1316
1317 return 0;
1318}
1319
1320static const struct seq_operations extfrag_op = {
1321 .start = frag_start,
1322 .next = frag_next,
1323 .stop = frag_stop,
1324 .show = extfrag_show,
1325};
1326
1327static int extfrag_open(struct inode *inode, struct file *file)
1328{
1329 return seq_open(file, &extfrag_op);
1330}
1331
1332static const struct file_operations extfrag_file_ops = {
1333 .open = extfrag_open,
1334 .read = seq_read,
1335 .llseek = seq_lseek,
1336 .release = seq_release,
1337};
1338
Mel Gormand7a57522010-05-24 14:32:25 -07001339static int __init extfrag_debug_init(void)
1340{
1341 extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
1342 if (!extfrag_debug_root)
1343 return -ENOMEM;
1344
1345 if (!debugfs_create_file("unusable_index", 0444,
1346 extfrag_debug_root, NULL, &unusable_file_ops))
1347 return -ENOMEM;
1348
Mel Gormanf1a5ab12010-05-24 14:32:26 -07001349 if (!debugfs_create_file("extfrag_index", 0444,
1350 extfrag_debug_root, NULL, &extfrag_file_ops))
1351 return -ENOMEM;
1352
Mel Gormand7a57522010-05-24 14:32:25 -07001353 return 0;
1354}
1355
1356module_init(extfrag_debug_init);
1357#endif