vmstat.c 31.3 KB
Newer Older
1 2 3 4 5
/*
 *  linux/mm/vmstat.c
 *
 *  Manages VM statistics
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
6 7 8 9
 *
 *  zoned VM statistics
 *  Copyright (C) 2006 Silicon Graphics, Inc.,
 *		Christoph Lameter <christoph@lameter.com>
10
 */
11
#include <linux/fs.h>
12
#include <linux/mm.h>
Alexey Dobriyan's avatar
Alexey Dobriyan committed
13
#include <linux/err.h>
14
#include <linux/module.h>
15
#include <linux/slab.h>
16
#include <linux/cpu.h>
Adrian Bunk's avatar
Adrian Bunk committed
17
#include <linux/vmstat.h>
Alexey Dobriyan's avatar
Alexey Dobriyan committed
18
#include <linux/sched.h>
19
#include <linux/math64.h>
20
#include <linux/writeback.h>
21
#include <linux/compaction.h>
22

23 24 25 26
#ifdef CONFIG_VM_EVENT_COUNTERS
DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
EXPORT_PER_CPU_SYMBOL(vm_event_states);

27
static void sum_vm_events(unsigned long *ret)
28
{
Christoph Lameter's avatar
Christoph Lameter committed
29
	int cpu;
30 31 32 33
	int i;

	memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));

34
	for_each_online_cpu(cpu) {
35 36 37 38 39 40 41 42 43 44 45 46 47 48
		struct vm_event_state *this = &per_cpu(vm_event_states, cpu);

		for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
			ret[i] += this->event[i];
	}
}

/*
 * Accumulate the vm event counters across all CPUs.
 * The result is unavoidably approximate - it can change
 * during and after execution of this function.
*/
void all_vm_events(unsigned long *ret)
{
KOSAKI Motohiro's avatar
KOSAKI Motohiro committed
49
	get_online_cpus();
50
	sum_vm_events(ret);
KOSAKI Motohiro's avatar
KOSAKI Motohiro committed
51
	put_online_cpus();
52
}
53
EXPORT_SYMBOL_GPL(all_vm_events);
54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75

#ifdef CONFIG_HOTPLUG
/*
 * Fold the foreign cpu events into our own.
 *
 * This is adding to the events on one processor
 * but keeps the global counts constant.
 */
void vm_events_fold_cpu(int cpu)
{
	struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
	int i;

	for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
		count_vm_events(i, fold_state->event[i]);
		fold_state->event[i] = 0;
	}
}
#endif /* CONFIG_HOTPLUG */

#endif /* CONFIG_VM_EVENT_COUNTERS */

76 77 78 79 80 81 82 83 84 85
/*
 * Manage combined zone based / global counters
 *
 * vm_stat contains the global counters
 */
atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
EXPORT_SYMBOL(vm_stat);

#ifdef CONFIG_SMP

86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131
static int calculate_threshold(struct zone *zone)
{
	int threshold;
	int mem;	/* memory in 128 MB units */

	/*
	 * The threshold scales with the number of processors and the amount
	 * of memory per zone. More memory means that we can defer updates for
	 * longer, more processors could lead to more contention.
 	 * fls() is used to have a cheap way of logarithmic scaling.
	 *
	 * Some sample thresholds:
	 *
	 * Threshold	Processors	(fls)	Zonesize	fls(mem+1)
	 * ------------------------------------------------------------------
	 * 8		1		1	0.9-1 GB	4
	 * 16		2		2	0.9-1 GB	4
	 * 20 		2		2	1-2 GB		5
	 * 24		2		2	2-4 GB		6
	 * 28		2		2	4-8 GB		7
	 * 32		2		2	8-16 GB		8
	 * 4		2		2	<128M		1
	 * 30		4		3	2-4 GB		5
	 * 48		4		3	8-16 GB		8
	 * 32		8		4	1-2 GB		4
	 * 32		8		4	0.9-1GB		4
	 * 10		16		5	<128M		1
	 * 40		16		5	900M		4
	 * 70		64		7	2-4 GB		5
	 * 84		64		7	4-8 GB		6
	 * 108		512		9	4-8 GB		6
	 * 125		1024		10	8-16 GB		8
	 * 125		1024		10	16-32 GB	9
	 */

	mem = zone->present_pages >> (27 - PAGE_SHIFT);

	threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));

	/*
	 * Maximum threshold is 125
	 */
	threshold = min(125, threshold);

	return threshold;
}
132 133

/*
134
 * Refresh the thresholds for each zone.
135
 */
136
static void refresh_zone_stat_thresholds(void)
137
{
138 139 140 141
	struct zone *zone;
	int cpu;
	int threshold;

142
	for_each_populated_zone(zone) {
143 144
		unsigned long max_drift, tolerate_drift;

145 146 147
		threshold = calculate_threshold(zone);

		for_each_online_cpu(cpu)
148 149
			per_cpu_ptr(zone->pageset, cpu)->stat_threshold
							= threshold;
150 151 152 153 154 155 156 157 158 159 160

		/*
		 * Only set percpu_drift_mark if there is a danger that
		 * NR_FREE_PAGES reports the low watermark is ok when in fact
		 * the min watermark could be breached by an allocation
		 */
		tolerate_drift = low_wmark_pages(zone) - min_wmark_pages(zone);
		max_drift = num_online_cpus() * threshold;
		if (max_drift > tolerate_drift)
			zone->percpu_drift_mark = high_wmark_pages(zone) +
					max_drift;
161
	}
162 163 164 165 166 167 168 169
}

/*
 * For use when we know that interrupts are disabled.
 */
void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
				int delta)
{
170 171
	struct per_cpu_pageset __percpu *pcp = zone->pageset;
	s8 __percpu *p = pcp->vm_stat_diff + item;
172
	long x;
173 174 175
	long t;

	x = delta + __this_cpu_read(*p);
176

177
	t = __this_cpu_read(pcp->stat_threshold);
178

179
	if (unlikely(x > t || x < -t)) {
180 181 182
		zone_page_state_add(x, zone, item);
		x = 0;
	}
183
	__this_cpu_write(*p, x);
184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199
}
EXPORT_SYMBOL(__mod_zone_page_state);

/*
 * Optimized increment and decrement functions.
 *
 * These are only for a single page and therefore can take a struct page *
 * argument instead of struct zone *. This allows the inclusion of the code
 * generated for page_zone(page) into the optimized functions.
 *
 * No overflow check is necessary and therefore the differential can be
 * incremented or decremented in place which may allow the compilers to
 * generate better code.
 * The increment or decrement is known and therefore one boundary check can
 * be omitted.
 *
200 201 202
 * NOTE: These functions are very performance sensitive. Change only
 * with care.
 *
203 204 205 206 207 208 209
 * Some processors have inc/dec instructions that are atomic vs an interrupt.
 * However, the code must first determine the differential location in a zone
 * based on the processor number and then inc/dec the counter. There is no
 * guarantee without disabling preemption that the processor will not change
 * in between and therefore the atomicity vs. interrupt cannot be exploited
 * in a useful way here.
 */
210
void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
211
{
212 213 214
	struct per_cpu_pageset __percpu *pcp = zone->pageset;
	s8 __percpu *p = pcp->vm_stat_diff + item;
	s8 v, t;
215

216
	v = __this_cpu_inc_return(*p);
217 218 219
	t = __this_cpu_read(pcp->stat_threshold);
	if (unlikely(v > t)) {
		s8 overstep = t >> 1;
220

221 222
		zone_page_state_add(v + overstep, zone, item);
		__this_cpu_write(*p, -overstep);
223 224
	}
}
225 226 227 228 229

void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
	__inc_zone_state(page_zone(page), item);
}
230 231
EXPORT_SYMBOL(__inc_zone_page_state);

232
void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
233
{
234 235 236
	struct per_cpu_pageset __percpu *pcp = zone->pageset;
	s8 __percpu *p = pcp->vm_stat_diff + item;
	s8 v, t;
237

238
	v = __this_cpu_dec_return(*p);
239 240 241
	t = __this_cpu_read(pcp->stat_threshold);
	if (unlikely(v < - t)) {
		s8 overstep = t >> 1;
242

243 244
		zone_page_state_add(v - overstep, zone, item);
		__this_cpu_write(*p, overstep);
245 246
	}
}
247 248 249 250 251

void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
	__dec_zone_state(page_zone(page), item);
}
252 253
EXPORT_SYMBOL(__dec_zone_page_state);

254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339
#ifdef CONFIG_CMPXCHG_LOCAL
/*
 * If we have cmpxchg_local support then we do not need to incur the overhead
 * that comes with local_irq_save/restore if we use this_cpu_cmpxchg.
 *
 * mod_state() modifies the zone counter state through atomic per cpu
 * operations.
 *
 * Overstep mode specifies how overstep should handled:
 *     0       No overstepping
 *     1       Overstepping half of threshold
 *     -1      Overstepping minus half of threshold
*/
static inline void mod_state(struct zone *zone,
       enum zone_stat_item item, int delta, int overstep_mode)
{
	struct per_cpu_pageset __percpu *pcp = zone->pageset;
	s8 __percpu *p = pcp->vm_stat_diff + item;
	long o, n, t, z;

	do {
		z = 0;  /* overflow to zone counters */

		/*
		 * The fetching of the stat_threshold is racy. We may apply
		 * a counter threshold to the wrong the cpu if we get
		 * rescheduled while executing here. However, the following
		 * will apply the threshold again and therefore bring the
		 * counter under the threshold.
		 */
		t = this_cpu_read(pcp->stat_threshold);

		o = this_cpu_read(*p);
		n = delta + o;

		if (n > t || n < -t) {
			int os = overstep_mode * (t >> 1) ;

			/* Overflow must be added to zone counters */
			z = n + os;
			n = -os;
		}
	} while (this_cpu_cmpxchg(*p, o, n) != o);

	if (z)
		zone_page_state_add(z, zone, item);
}

void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
					int delta)
{
	mod_state(zone, item, delta, 0);
}
EXPORT_SYMBOL(mod_zone_page_state);

void inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
	mod_state(zone, item, 1, 1);
}

void inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
	mod_state(page_zone(page), item, 1, 1);
}
EXPORT_SYMBOL(inc_zone_page_state);

void dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
	mod_state(page_zone(page), item, -1, -1);
}
EXPORT_SYMBOL(dec_zone_page_state);
#else
/*
 * Use interrupt disable to serialize counter updates
 */
void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
					int delta)
{
	unsigned long flags;

	local_irq_save(flags);
	__mod_zone_page_state(zone, item, delta);
	local_irq_restore(flags);
}
EXPORT_SYMBOL(mod_zone_page_state);

340 341 342 343 344 345 346 347 348
void inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
	unsigned long flags;

	local_irq_save(flags);
	__inc_zone_state(zone, item);
	local_irq_restore(flags);
}

349 350 351 352 353 354 355
void inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
	unsigned long flags;
	struct zone *zone;

	zone = page_zone(page);
	local_irq_save(flags);
356
	__inc_zone_state(zone, item);
357 358 359 360 361 362 363 364 365
	local_irq_restore(flags);
}
EXPORT_SYMBOL(inc_zone_page_state);

void dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
	unsigned long flags;

	local_irq_save(flags);
366
	__dec_zone_page_state(page, item);
367 368 369
	local_irq_restore(flags);
}
EXPORT_SYMBOL(dec_zone_page_state);
370
#endif
371 372 373

/*
 * Update the zone counters for one cpu.
374
 *
375 376 377 378
 * The cpu specified must be either the current cpu or a processor that
 * is not online. If it is the current cpu then the execution thread must
 * be pinned to the current cpu.
 *
379 380 381 382 383 384 385 386 387 388
 * Note that refresh_cpu_vm_stats strives to only access
 * node local memory. The per cpu pagesets on remote zones are placed
 * in the memory local to the processor using that pageset. So the
 * loop over all zones will access a series of cachelines local to
 * the processor.
 *
 * The call to zone_page_state_add updates the cachelines with the
 * statistics in the remote zone struct as well as the global cachelines
 * with the global counters. These could cause remote node cache line
 * bouncing and will have to be only done when necessary.
389 390 391 392 393
 */
void refresh_cpu_vm_stats(int cpu)
{
	struct zone *zone;
	int i;
394
	int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
395

396
	for_each_populated_zone(zone) {
397
		struct per_cpu_pageset *p;
398

399
		p = per_cpu_ptr(zone->pageset, cpu);
400 401

		for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
402
			if (p->vm_stat_diff[i]) {
403 404 405
				unsigned long flags;
				int v;

406
				local_irq_save(flags);
407
				v = p->vm_stat_diff[i];
408
				p->vm_stat_diff[i] = 0;
409 410 411
				local_irq_restore(flags);
				atomic_long_add(v, &zone->vm_stat[i]);
				global_diff[i] += v;
412 413 414 415
#ifdef CONFIG_NUMA
				/* 3 seconds idle till flush */
				p->expire = 3;
#endif
416
			}
417
		cond_resched();
418 419 420 421 422 423 424 425
#ifdef CONFIG_NUMA
		/*
		 * Deal with draining the remote pageset of this
		 * processor
		 *
		 * Check if there are pages remaining in this pageset
		 * if not then there is nothing to expire.
		 */
426
		if (!p->expire || !p->pcp.count)
427 428 429 430 431 432 433 434 435 436 437 438 439 440
			continue;

		/*
		 * We never drain zones local to this processor.
		 */
		if (zone_to_nid(zone) == numa_node_id()) {
			p->expire = 0;
			continue;
		}

		p->expire--;
		if (p->expire)
			continue;

441 442
		if (p->pcp.count)
			drain_zone_pages(zone, &p->pcp);
443
#endif
444
	}
445 446 447 448

	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
		if (global_diff[i])
			atomic_long_add(global_diff[i], &vm_stat[i]);
449 450 451 452
}

#endif

453 454 455 456 457 458 459
#ifdef CONFIG_NUMA
/*
 * zonelist = the list of zones passed to the allocator
 * z 	    = the zone from which the allocation occurred.
 *
 * Must be called with interrupts disabled.
 */
460
void zone_statistics(struct zone *preferred_zone, struct zone *z)
461
{
462
	if (z->zone_pgdat == preferred_zone->zone_pgdat) {
463 464 465
		__inc_zone_state(z, NUMA_HIT);
	} else {
		__inc_zone_state(z, NUMA_MISS);
466
		__inc_zone_state(preferred_zone, NUMA_FOREIGN);
467
	}
468
	if (z->node == numa_node_id())
469 470 471 472 473 474
		__inc_zone_state(z, NUMA_LOCAL);
	else
		__inc_zone_state(z, NUMA_OTHER);
}
#endif

475
#ifdef CONFIG_COMPACTION
476

477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516
struct contig_page_info {
	unsigned long free_pages;
	unsigned long free_blocks_total;
	unsigned long free_blocks_suitable;
};

/*
 * Calculate the number of free pages in a zone, how many contiguous
 * pages are free and how many are large enough to satisfy an allocation of
 * the target size. Note that this function makes no attempt to estimate
 * how many suitable free blocks there *might* be if MOVABLE pages were
 * migrated. Calculating that is possible, but expensive and can be
 * figured out from userspace
 */
static void fill_contig_page_info(struct zone *zone,
				unsigned int suitable_order,
				struct contig_page_info *info)
{
	unsigned int order;

	info->free_pages = 0;
	info->free_blocks_total = 0;
	info->free_blocks_suitable = 0;

	for (order = 0; order < MAX_ORDER; order++) {
		unsigned long blocks;

		/* Count number of free blocks */
		blocks = zone->free_area[order].nr_free;
		info->free_blocks_total += blocks;

		/* Count free base pages */
		info->free_pages += blocks << order;

		/* Count the suitable free blocks */
		if (order >= suitable_order)
			info->free_blocks_suitable += blocks <<
						(order - suitable_order);
	}
}
517 518 519 520 521 522 523 524

/*
 * A fragmentation index only makes sense if an allocation of a requested
 * size would fail. If that is true, the fragmentation index indicates
 * whether external fragmentation or a lack of memory was the problem.
 * The value can be used to determine if page reclaim or compaction
 * should be used
 */
525
static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543
{
	unsigned long requested = 1UL << order;

	if (!info->free_blocks_total)
		return 0;

	/* Fragmentation index only makes sense when a request would fail */
	if (info->free_blocks_suitable)
		return -1000;

	/*
	 * Index is between 0 and 1 so return within 3 decimal places
	 *
	 * 0 => allocation would fail due to lack of memory
	 * 1 => allocation would fail due to fragmentation
	 */
	return 1000 - div_u64( (1000+(div_u64(info->free_pages * 1000ULL, requested))), info->free_blocks_total);
}
544 545 546 547 548 549 550 551 552

/* Same as __fragmentation index but allocs contig_page_info on stack */
int fragmentation_index(struct zone *zone, unsigned int order)
{
	struct contig_page_info info;

	fill_contig_page_info(zone, order, &info);
	return __fragmentation_index(order, &info);
}
553 554 555
#endif

#if defined(CONFIG_PROC_FS) || defined(CONFIG_COMPACTION)
556
#include <linux/proc_fs.h>
557 558
#include <linux/seq_file.h>

559 560 561 562 563
static char * const migratetype_names[MIGRATE_TYPES] = {
	"Unmovable",
	"Reclaimable",
	"Movable",
	"Reserve",
564
	"Isolate",
565 566
};

567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590
static void *frag_start(struct seq_file *m, loff_t *pos)
{
	pg_data_t *pgdat;
	loff_t node = *pos;
	for (pgdat = first_online_pgdat();
	     pgdat && node;
	     pgdat = next_online_pgdat(pgdat))
		--node;

	return pgdat;
}

static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
{
	pg_data_t *pgdat = (pg_data_t *)arg;

	(*pos)++;
	return next_online_pgdat(pgdat);
}

static void frag_stop(struct seq_file *m, void *arg)
{
}

591 592 593
/* Walk all the zones in a node and print using a callback */
static void walk_zones_in_node(struct seq_file *m, pg_data_t *pgdat,
		void (*print)(struct seq_file *m, pg_data_t *, struct zone *))
594 595 596 597 598 599 600 601 602 603
{
	struct zone *zone;
	struct zone *node_zones = pgdat->node_zones;
	unsigned long flags;

	for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
		if (!populated_zone(zone))
			continue;

		spin_lock_irqsave(&zone->lock, flags);
604
		print(m, pgdat, zone);
605
		spin_unlock_irqrestore(&zone->lock, flags);
606 607
	}
}
608
#endif
609

610
#ifdef CONFIG_PROC_FS
611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652
static void frag_show_print(struct seq_file *m, pg_data_t *pgdat,
						struct zone *zone)
{
	int order;

	seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
	for (order = 0; order < MAX_ORDER; ++order)
		seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
	seq_putc(m, '\n');
}

/*
 * This walks the free areas for each zone.
 */
static int frag_show(struct seq_file *m, void *arg)
{
	pg_data_t *pgdat = (pg_data_t *)arg;
	walk_zones_in_node(m, pgdat, frag_show_print);
	return 0;
}

static void pagetypeinfo_showfree_print(struct seq_file *m,
					pg_data_t *pgdat, struct zone *zone)
{
	int order, mtype;

	for (mtype = 0; mtype < MIGRATE_TYPES; mtype++) {
		seq_printf(m, "Node %4d, zone %8s, type %12s ",
					pgdat->node_id,
					zone->name,
					migratetype_names[mtype]);
		for (order = 0; order < MAX_ORDER; ++order) {
			unsigned long freecount = 0;
			struct free_area *area;
			struct list_head *curr;

			area = &(zone->free_area[order]);

			list_for_each(curr, &area->free_list[mtype])
				freecount++;
			seq_printf(m, "%6lu ", freecount);
		}
653 654
		seq_putc(m, '\n');
	}
655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689
}

/* Print out the free pages at each order for each migatetype */
static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
{
	int order;
	pg_data_t *pgdat = (pg_data_t *)arg;

	/* Print header */
	seq_printf(m, "%-43s ", "Free pages count per migrate type at order");
	for (order = 0; order < MAX_ORDER; ++order)
		seq_printf(m, "%6d ", order);
	seq_putc(m, '\n');

	walk_zones_in_node(m, pgdat, pagetypeinfo_showfree_print);

	return 0;
}

static void pagetypeinfo_showblockcount_print(struct seq_file *m,
					pg_data_t *pgdat, struct zone *zone)
{
	int mtype;
	unsigned long pfn;
	unsigned long start_pfn = zone->zone_start_pfn;
	unsigned long end_pfn = start_pfn + zone->spanned_pages;
	unsigned long count[MIGRATE_TYPES] = { 0, };

	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
		struct page *page;

		if (!pfn_valid(pfn))
			continue;

		page = pfn_to_page(pfn);
690 691 692

		/* Watch for unexpected holes punched in the memmap */
		if (!memmap_valid_within(pfn, page, zone))
693
			continue;
694

695 696
		mtype = get_pageblock_migratetype(page);

697 698
		if (mtype < MIGRATE_TYPES)
			count[mtype]++;
699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730
	}

	/* Print counts */
	seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
	for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
		seq_printf(m, "%12lu ", count[mtype]);
	seq_putc(m, '\n');
}

/* Print out the free pages at each order for each migratetype */
static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
{
	int mtype;
	pg_data_t *pgdat = (pg_data_t *)arg;

	seq_printf(m, "\n%-23s", "Number of blocks type ");
	for (mtype = 0; mtype < MIGRATE_TYPES; mtype++)
		seq_printf(m, "%12s ", migratetype_names[mtype]);
	seq_putc(m, '\n');
	walk_zones_in_node(m, pgdat, pagetypeinfo_showblockcount_print);

	return 0;
}

/*
 * This prints out statistics in relation to grouping pages by mobility.
 * It is expensive to collect so do not constantly read the file.
 */
static int pagetypeinfo_show(struct seq_file *m, void *arg)
{
	pg_data_t *pgdat = (pg_data_t *)arg;

731 732 733 734
	/* check memoryless node */
	if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
		return 0;

735 736 737 738 739 740
	seq_printf(m, "Page block order: %d\n", pageblock_order);
	seq_printf(m, "Pages per block:  %lu\n", pageblock_nr_pages);
	seq_putc(m, '\n');
	pagetypeinfo_showfree(m, pgdat);
	pagetypeinfo_showblockcount(m, pgdat);

741 742 743
	return 0;
}

744
static const struct seq_operations fragmentation_op = {
745 746 747 748 749 750
	.start	= frag_start,
	.next	= frag_next,
	.stop	= frag_stop,
	.show	= frag_show,
};

751 752 753 754 755 756 757 758 759 760 761 762
static int fragmentation_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &fragmentation_op);
}

static const struct file_operations fragmentation_file_operations = {
	.open		= fragmentation_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

763
static const struct seq_operations pagetypeinfo_op = {
764 765 766 767 768 769
	.start	= frag_start,
	.next	= frag_next,
	.stop	= frag_stop,
	.show	= pagetypeinfo_show,
};

770 771 772 773 774 775 776 777 778 779 780 781
static int pagetypeinfo_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &pagetypeinfo_op);
}

static const struct file_operations pagetypeinfo_file_ops = {
	.open		= pagetypeinfo_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

782 783 784 785 786 787
#ifdef CONFIG_ZONE_DMA
#define TEXT_FOR_DMA(xx) xx "_dma",
#else
#define TEXT_FOR_DMA(xx)
#endif

788 789 790 791 792 793 794 795 796 797 798 799
#ifdef CONFIG_ZONE_DMA32
#define TEXT_FOR_DMA32(xx) xx "_dma32",
#else
#define TEXT_FOR_DMA32(xx)
#endif

#ifdef CONFIG_HIGHMEM
#define TEXT_FOR_HIGHMEM(xx) xx "_high",
#else
#define TEXT_FOR_HIGHMEM(xx)
#endif

800
#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
Mel Gorman's avatar
Mel Gorman committed
801
					TEXT_FOR_HIGHMEM(xx) xx "_movable",
802

803
static const char * const vmstat_text[] = {
804
	/* Zoned VM counters */
805
	"nr_free_pages",
806 807 808 809
	"nr_inactive_anon",
	"nr_active_anon",
	"nr_inactive_file",
	"nr_active_file",
810
	"nr_unevictable",
Nick Piggin's avatar
Nick Piggin committed
811
	"nr_mlock",
812
	"nr_anon_pages",
813
	"nr_mapped",
814
	"nr_file_pages",
815 816
	"nr_dirty",
	"nr_writeback",
817 818
	"nr_slab_reclaimable",
	"nr_slab_unreclaimable",
819
	"nr_page_table_pages",
820
	"nr_kernel_stack",
821
	"nr_unstable",
822
	"nr_bounce",
823
	"nr_vmscan_write",
824
	"nr_writeback_temp",
825 826
	"nr_isolated_anon",
	"nr_isolated_file",
827
	"nr_shmem",
828 829 830
	"nr_dirtied",
	"nr_written",

831 832 833 834 835 836 837 838
#ifdef CONFIG_NUMA
	"numa_hit",
	"numa_miss",
	"numa_foreign",
	"numa_interleave",
	"numa_local",
	"numa_other",
#endif
839 840
	"nr_dirty_threshold",
	"nr_dirty_background_threshold",
841

842
#ifdef CONFIG_VM_EVENT_COUNTERS
843 844 845 846 847
	"pgpgin",
	"pgpgout",
	"pswpin",
	"pswpout",

848
	TEXTS_FOR_ZONES("pgalloc")
849 850 851 852 853 854 855 856

	"pgfree",
	"pgactivate",
	"pgdeactivate",

	"pgfault",
	"pgmajfault",

857 858 859 860
	TEXTS_FOR_ZONES("pgrefill")
	TEXTS_FOR_ZONES("pgsteal")
	TEXTS_FOR_ZONES("pgscan_kswapd")
	TEXTS_FOR_ZONES("pgscan_direct")
861

862 863 864
#ifdef CONFIG_NUMA
	"zone_reclaim_failed",
#endif
865 866 867 868
	"pginodesteal",
	"slabs_scanned",
	"kswapd_steal",
	"kswapd_inodesteal",
869 870 871
	"kswapd_low_wmark_hit_quickly",
	"kswapd_high_wmark_hit_quickly",
	"kswapd_skip_congestion_wait",
872 873 874 875
	"pageoutrun",
	"allocstall",

	"pgrotated",
876 877 878 879 880

#ifdef CONFIG_COMPACTION
	"compact_blocks_moved",
	"compact_pages_moved",
	"compact_pagemigrate_failed",
881 882 883
	"compact_stall",
	"compact_fail",
	"compact_success",
884 885
#endif

886 887 888 889
#ifdef CONFIG_HUGETLB_PAGE
	"htlb_buddy_alloc_success",
	"htlb_buddy_alloc_fail",
#endif
890 891 892
	"unevictable_pgs_culled",
	"unevictable_pgs_scanned",
	"unevictable_pgs_rescued",
Nick Piggin's avatar
Nick Piggin committed
893 894 895 896
	"unevictable_pgs_mlocked",
	"unevictable_pgs_munlocked",
	"unevictable_pgs_cleared",
	"unevictable_pgs_stranded",
897
	"unevictable_pgs_mlockfreed",
898
#endif
899 900
};

901 902
static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
							struct zone *zone)
903
{
904 905 906 907 908 909 910
	int i;
	seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
	seq_printf(m,
		   "\n  pages free     %lu"
		   "\n        min      %lu"
		   "\n        low      %lu"
		   "\n        high     %lu"
911
		   "\n        scanned  %lu"
912 913
		   "\n        spanned  %lu"
		   "\n        present  %lu",
914
		   zone_nr_free_pages(zone),
915 916 917
		   min_wmark_pages(zone),
		   low_wmark_pages(zone),
		   high_wmark_pages(zone),
918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936
		   zone->pages_scanned,
		   zone->spanned_pages,
		   zone->present_pages);

	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
		seq_printf(m, "\n    %-12s %lu", vmstat_text[i],
				zone_page_state(zone, i));

	seq_printf(m,
		   "\n        protection: (%lu",
		   zone->lowmem_reserve[0]);
	for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
		seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
	seq_printf(m,
		   ")"
		   "\n  pagesets");
	for_each_online_cpu(i) {
		struct per_cpu_pageset *pageset;

937
		pageset = per_cpu_ptr(zone->pageset, i);
938 939 940 941 942 943 944 945 946
		seq_printf(m,
			   "\n    cpu: %i"
			   "\n              count: %i"
			   "\n              high:  %i"
			   "\n              batch: %i",
			   i,
			   pageset->pcp.count,
			   pageset->pcp.high,
			   pageset->pcp.batch);
947
#ifdef CONFIG_SMP
948 949
		seq_printf(m, "\n  vm stats threshold: %d",
				pageset->stat_threshold);
950
#endif
951
	}
952 953
	seq_printf(m,
		   "\n  all_unreclaimable: %u"
954 955
		   "\n  start_pfn:         %lu"
		   "\n  inactive_ratio:    %u",
956
		   zone->all_unreclaimable,
957 958
		   zone->zone_start_pfn,
		   zone->inactive_ratio);
959 960 961 962 963 964 965 966 967 968
	seq_putc(m, '\n');
}

/*
 * Output information about zones in @pgdat.
 */
static int zoneinfo_show(struct seq_file *m, void *arg)
{
	pg_data_t *pgdat = (pg_data_t *)arg;
	walk_zones_in_node(m, pgdat, zoneinfo_show_print);
969 970 971
	return 0;
}

972
static const struct seq_operations zoneinfo_op = {
973 974 975 976 977 978 979
	.start	= frag_start, /* iterate over all zones. The same as in
			       * fragmentation. */
	.next	= frag_next,
	.stop	= frag_stop,
	.show	= zoneinfo_show,
};

980 981 982 983 984 985 986 987 988 989 990 991
static int zoneinfo_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &zoneinfo_op);
}

static const struct file_operations proc_zoneinfo_file_operations = {
	.open		= zoneinfo_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

992 993 994 995 996 997
enum writeback_stat_item {
	NR_DIRTY_THRESHOLD,
	NR_DIRTY_BG_THRESHOLD,
	NR_VM_WRITEBACK_STAT_ITEMS,
};

998 999
static void *vmstat_start(struct seq_file *m, loff_t *pos)
{
1000
	unsigned long *v;
1001
	int i, stat_items_size;
1002 1003 1004

	if (*pos >= ARRAY_SIZE(vmstat_text))
		return NULL;
1005 1006
	stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
			  NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1007

1008
#ifdef CONFIG_VM_EVENT_COUNTERS
1009
	stat_items_size += sizeof(struct vm_event_state);
1010
#endif
1011 1012

	v = kmalloc(stat_items_size, GFP_KERNEL);
1013 1014
	m->private = v;
	if (!v)
1015
		return ERR_PTR(-ENOMEM);
1016 1017
	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
		v[i] = global_page_state(i);
1018 1019 1020 1021 1022 1023
	v += NR_VM_ZONE_STAT_ITEMS;

	global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
			    v + NR_DIRTY_THRESHOLD);
	v += NR_VM_WRITEBACK_STAT_ITEMS;

1024
#ifdef CONFIG_VM_EVENT_COUNTERS
1025 1026 1027
	all_vm_events(v);
	v[PGPGIN] /= 2;		/* sectors -> kbytes */
	v[PGPGOUT] /= 2;
1028
#endif
1029
	return (unsigned long *)m->private + *pos;
1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054
}

static void *vmstat_next(struct seq_file *m, void *arg, loff_t *pos)
{
	(*pos)++;
	if (*pos >= ARRAY_SIZE(vmstat_text))
		return NULL;
	return (unsigned long *)m->private + *pos;
}

static int vmstat_show(struct seq_file *m, void *arg)
{
	unsigned long *l = arg;
	unsigned long off = l - (unsigned long *)m->private;

	seq_printf(m, "%s %lu\n", vmstat_text[off], *l);
	return 0;
}

static void vmstat_stop(struct seq_file *m, void *arg)
{
	kfree(m->private);
	m->private = NULL;
}

1055
static const struct seq_operations vmstat_op = {
1056 1057 1058 1059 1060 1061
	.start	= vmstat_start,
	.next	= vmstat_next,
	.stop	= vmstat_stop,
	.show	= vmstat_show,
};

1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072
static int vmstat_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &vmstat_op);
}

static const struct file_operations proc_vmstat_file_operations = {
	.open		= vmstat_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};
1073 1074
#endif /* CONFIG_PROC_FS */

1075
#ifdef CONFIG_SMP
1076
static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1077
int sysctl_stat_interval __read_mostly = HZ;
1078 1079 1080 1081

static void vmstat_update(struct work_struct *w)
{
	refresh_cpu_vm_stats(smp_processor_id());
1082
	schedule_delayed_work(&__get_cpu_var(vmstat_work),
1083
		round_jiffies_relative(sysctl_stat_interval));
1084 1085
}

1086
static void __cpuinit start_cpu_timer(int cpu)
1087
{
1088
	struct delayed_work *work = &per_cpu(vmstat_work, cpu);
1089

1090 1091
	INIT_DELAYED_WORK_DEFERRABLE(work, vmstat_update);
	schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
1092 1093
}

1094 1095 1096 1097 1098 1099 1100 1101
/*
 * Use the cpu notifier to insure that the thresholds are recalculated
 * when necessary.
 */
static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
		unsigned long action,
		void *hcpu)
{
1102 1103
	long cpu = (long)hcpu;

1104
	switch (action) {
1105 1106
	case CPU_ONLINE:
	case CPU_ONLINE_FROZEN:
1107
		refresh_zone_stat_thresholds();
1108
		start_cpu_timer(cpu);
1109
		node_set_state(cpu_to_node(cpu), N_CPU);
1110 1111 1112
		break;
	case CPU_DOWN_PREPARE:
	case CPU_DOWN_PREPARE_FROZEN:
1113
		cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1114 1115 1116 1117 1118 1119
		per_cpu(vmstat_work, cpu).work.func = NULL;
		break;
	case CPU_DOWN_FAILED:
	case CPU_DOWN_FAILED_FROZEN:
		start_cpu_timer(cpu);
		break;
1120
	case CPU_DEAD:
1121
	case CPU_DEAD_FROZEN:
1122 1123 1124 1125
		refresh_zone_stat_thresholds();
		break;
	default:
		break;
1126 1127 1128 1129 1130 1131
	}
	return NOTIFY_OK;
}

static struct notifier_block __cpuinitdata vmstat_notifier =
	{ &vmstat_cpuup_callback, NULL, 0 };
1132
#endif
1133

Adrian Bunk's avatar
Adrian Bunk committed
1134
static int __init setup_vmstat(void)
1135
{
1136
#ifdef CONFIG_SMP
1137 1138
	int cpu;

1139 1140
	refresh_zone_stat_thresholds();
	register_cpu_notifier(&vmstat_notifier);
1141 1142 1143

	for_each_online_cpu(cpu)
		start_cpu_timer(cpu);
1144 1145 1146
#endif
#ifdef CONFIG_PROC_FS
	proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1147
	proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1148
	proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1149
	proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1150
#endif
1151 1152 1153
	return 0;
}
module_init(setup_vmstat)
1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241

#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)
#include <linux/debugfs.h>

static struct dentry *extfrag_debug_root;

/*
 * Return an index indicating how much of the available free memory is
 * unusable for an allocation of the requested size.
 */
static int unusable_free_index(unsigned int order,
				struct contig_page_info *info)
{
	/* No free memory is interpreted as all free memory is unusable */
	if (info->free_pages == 0)
		return 1000;

	/*
	 * Index should be a value between 0 and 1. Return a value to 3
	 * decimal places.
	 *
	 * 0 => no fragmentation
	 * 1 => high fragmentation
	 */
	return div_u64((info->free_pages - (info->free_blocks_suitable << order)) * 1000ULL, info->free_pages);

}

static void unusable_show_print(struct seq_file *m,
					pg_data_t *pgdat, struct zone *zone)
{
	unsigned int order;
	int index;
	struct contig_page_info info;

	seq_printf(m, "Node %d, zone %8s ",
				pgdat->node_id,
				zone->name);
	for (order = 0; order < MAX_ORDER; ++order) {
		fill_contig_page_info(zone, order, &info);
		index = unusable_free_index(order, &info);
		seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
	}

	seq_putc(m, '\n');
}

/*
 * Display unusable free space index
 *
 * The unusable free space index measures how much of the available free
 * memory cannot be used to satisfy an allocation of a given size and is a
 * value between 0 and 1. The higher the value, the more of free memory is
 * unusable and by implication, the worse the external fragmentation is. This
 * can be expressed as a percentage by multiplying by 100.
 */
static int unusable_show(struct seq_file *m, void *arg)
{
	pg_data_t *pgdat = (pg_data_t *)arg;

	/* check memoryless node */
	if (!node_state(pgdat->node_id, N_HIGH_MEMORY))
		return 0;

	walk_zones_in_node(m, pgdat, unusable_show_print);

	return 0;
}

static const struct seq_operations unusable_op = {
	.start	= frag_start,
	.next	= frag_next,
	.stop	= frag_stop,
	.show	= unusable_show,
};

static int unusable_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &unusable_op);
}

static const struct file_operations unusable_file_ops = {
	.open		= unusable_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255
static void extfrag_show_print(struct seq_file *m,
					pg_data_t *pgdat, struct zone *zone)
{
	unsigned int order;
	int index;

	/* Alloc on stack as interrupts are disabled for zone walk */
	struct contig_page_info info;

	seq_printf(m, "Node %d, zone %8s ",
				pgdat->node_id,
				zone->name);
	for (order = 0; order < MAX_ORDER; ++order) {
		fill_contig_page_info(zone, order, &info);
1256
		index = __fragmentation_index(order, &info);
1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293
		seq_printf(m, "%d.%03d ", index / 1000, index % 1000);
	}

	seq_putc(m, '\n');
}

/*
 * Display fragmentation index for orders that allocations would fail for
 */
static int extfrag_show(struct seq_file *m, void *arg)
{
	pg_data_t *pgdat = (pg_data_t *)arg;

	walk_zones_in_node(m, pgdat, extfrag_show_print);

	return 0;
}

static const struct seq_operations extfrag_op = {
	.start	= frag_start,
	.next	= frag_next,
	.stop	= frag_stop,
	.show	= extfrag_show,
};

static int extfrag_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &extfrag_op);
}

static const struct file_operations extfrag_file_ops = {
	.open		= extfrag_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

1294 1295 1296 1297 1298 1299 1300 1301 1302 1303
static int __init extfrag_debug_init(void)
{
	extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
	if (!extfrag_debug_root)
		return -ENOMEM;

	if (!debugfs_create_file("unusable_index", 0444,
			extfrag_debug_root, NULL, &unusable_file_ops))
		return -ENOMEM;

1304 1305 1306 1307
	if (!debugfs_create_file("extfrag_index", 0444,
			extfrag_debug_root, NULL, &extfrag_file_ops))
		return -ENOMEM;

1308 1309 1310 1311 1312
	return 0;
}

module_init(extfrag_debug_init);
#endif