vmstat.c 40.7 KB
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/*
 *  linux/mm/vmstat.c
 *
 *  Manages VM statistics
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
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 *
 *  zoned VM statistics
 *  Copyright (C) 2006 Silicon Graphics, Inc.,
 *		Christoph Lameter <christoph@lameter.com>
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 *  Copyright (C) 2008-2014 Christoph Lameter
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 */
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/cpu.h>
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#include <linux/cpumask.h>
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#include <linux/vmstat.h>
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#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
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#include <linux/sched.h>
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#include <linux/math64.h>
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#include <linux/writeback.h>
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#include <linux/compaction.h>
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#include <linux/mm_inline.h>
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#include <linux/page_ext.h>
#include <linux/page_owner.h>
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#include "internal.h"
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#ifdef CONFIG_VM_EVENT_COUNTERS
DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
EXPORT_PER_CPU_SYMBOL(vm_event_states);

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static void sum_vm_events(unsigned long *ret)
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{
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	int cpu;
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	int i;

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

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	for_each_online_cpu(cpu) {
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		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)
{
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	get_online_cpus();
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	sum_vm_events(ret);
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	put_online_cpus();
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}
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EXPORT_SYMBOL_GPL(all_vm_events);
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/*
 * 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_VM_EVENT_COUNTERS */

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/*
 * Manage combined zone based / global counters
 *
 * vm_stat contains the global counters
 */
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atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
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EXPORT_SYMBOL(vm_stat);

#ifdef CONFIG_SMP

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int calculate_pressure_threshold(struct zone *zone)
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{
	int threshold;
	int watermark_distance;

	/*
	 * As vmstats are not up to date, there is drift between the estimated
	 * and real values. For high thresholds and a high number of CPUs, it
	 * is possible for the min watermark to be breached while the estimated
	 * value looks fine. The pressure threshold is a reduced value such
	 * that even the maximum amount of drift will not accidentally breach
	 * the min watermark
	 */
	watermark_distance = low_wmark_pages(zone) - min_wmark_pages(zone);
	threshold = max(1, (int)(watermark_distance / num_online_cpus()));

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

	return threshold;
}

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int calculate_normal_threshold(struct zone *zone)
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{
	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
	 */

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	mem = zone->managed_pages >> (27 - PAGE_SHIFT);
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	threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));

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

	return threshold;
}
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/*
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 * Refresh the thresholds for each zone.
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 */
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void refresh_zone_stat_thresholds(void)
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{
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	struct zone *zone;
	int cpu;
	int threshold;

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	for_each_populated_zone(zone) {
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		unsigned long max_drift, tolerate_drift;

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		threshold = calculate_normal_threshold(zone);
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		for_each_online_cpu(cpu)
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			per_cpu_ptr(zone->pageset, cpu)->stat_threshold
							= threshold;
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		/*
		 * 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;
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	}
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}

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void set_pgdat_percpu_threshold(pg_data_t *pgdat,
				int (*calculate_pressure)(struct zone *))
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{
	struct zone *zone;
	int cpu;
	int threshold;
	int i;

	for (i = 0; i < pgdat->nr_zones; i++) {
		zone = &pgdat->node_zones[i];
		if (!zone->percpu_drift_mark)
			continue;

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		threshold = (*calculate_pressure)(zone);
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		for_each_online_cpu(cpu)
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			per_cpu_ptr(zone->pageset, cpu)->stat_threshold
							= threshold;
	}
}

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/*
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 * For use when we know that interrupts are disabled,
 * or when we know that preemption is disabled and that
 * particular counter cannot be updated from interrupt context.
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 */
void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
				int delta)
{
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	struct per_cpu_pageset __percpu *pcp = zone->pageset;
	s8 __percpu *p = pcp->vm_stat_diff + item;
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	long x;
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	long t;

	x = delta + __this_cpu_read(*p);
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	t = __this_cpu_read(pcp->stat_threshold);
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	if (unlikely(x > t || x < -t)) {
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		zone_page_state_add(x, zone, item);
		x = 0;
	}
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	__this_cpu_write(*p, x);
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}
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.
 *
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 * NOTE: These functions are very performance sensitive. Change only
 * with care.
 *
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 * 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.
 */
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void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
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{
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	struct per_cpu_pageset __percpu *pcp = zone->pageset;
	s8 __percpu *p = pcp->vm_stat_diff + item;
	s8 v, t;
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	v = __this_cpu_inc_return(*p);
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	t = __this_cpu_read(pcp->stat_threshold);
	if (unlikely(v > t)) {
		s8 overstep = t >> 1;
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		zone_page_state_add(v + overstep, zone, item);
		__this_cpu_write(*p, -overstep);
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	}
}
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void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
	__inc_zone_state(page_zone(page), item);
}
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EXPORT_SYMBOL(__inc_zone_page_state);

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void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
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{
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	struct per_cpu_pageset __percpu *pcp = zone->pageset;
	s8 __percpu *p = pcp->vm_stat_diff + item;
	s8 v, t;
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	v = __this_cpu_dec_return(*p);
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	t = __this_cpu_read(pcp->stat_threshold);
	if (unlikely(v < - t)) {
		s8 overstep = t >> 1;
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		zone_page_state_add(v - overstep, zone, item);
		__this_cpu_write(*p, overstep);
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	}
}
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void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
	__dec_zone_state(page_zone(page), item);
}
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EXPORT_SYMBOL(__dec_zone_page_state);

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#ifdef CONFIG_HAVE_CMPXCHG_LOCAL
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/*
 * 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
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		 * rescheduled while executing here. However, the next
		 * counter update will apply the threshold again and
		 * therefore bring the counter under the threshold again.
		 *
		 * Most of the time the thresholds are the same anyways
		 * for all cpus in a zone.
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		 */
		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);

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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);
}

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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);
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	__inc_zone_state(zone, item);
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	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);
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	__dec_zone_page_state(page, item);
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	local_irq_restore(flags);
}
EXPORT_SYMBOL(dec_zone_page_state);
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#endif
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/*
 * Fold a differential into the global counters.
 * Returns the number of counters updated.
 */
static int fold_diff(int *diff)
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{
	int i;
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	int changes = 0;
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	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
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		if (diff[i]) {
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			atomic_long_add(diff[i], &vm_stat[i]);
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			changes++;
	}
	return changes;
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}

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/*
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 * Update the zone counters for the current cpu.
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 *
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 * 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.
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 *
 * The function returns the number of global counters updated.
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 */
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static int refresh_cpu_vm_stats(void)
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{
	struct zone *zone;
	int i;
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	int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
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	int changes = 0;
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	for_each_populated_zone(zone) {
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		struct per_cpu_pageset __percpu *p = zone->pageset;
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		for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
			int v;
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			v = this_cpu_xchg(p->vm_stat_diff[i], 0);
			if (v) {
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				atomic_long_add(v, &zone->vm_stat[i]);
				global_diff[i] += v;
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#ifdef CONFIG_NUMA
				/* 3 seconds idle till flush */
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				__this_cpu_write(p->expire, 3);
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#endif
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			}
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		}
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		cond_resched();
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#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.
		 */
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		if (!__this_cpu_read(p->expire) ||
			       !__this_cpu_read(p->pcp.count))
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			continue;

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

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

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		if (__this_cpu_read(p->pcp.count)) {
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			drain_zone_pages(zone, this_cpu_ptr(&p->pcp));
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			changes++;
		}
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#endif
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	}
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	changes += fold_diff(global_diff);
	return changes;
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}

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/*
 * Fold the data for an offline cpu into the global array.
 * There cannot be any access by the offline cpu and therefore
 * synchronization is simplified.
 */
void cpu_vm_stats_fold(int cpu)
{
	struct zone *zone;
	int i;
	int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };

	for_each_populated_zone(zone) {
		struct per_cpu_pageset *p;

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

		for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
			if (p->vm_stat_diff[i]) {
				int v;

				v = p->vm_stat_diff[i];
				p->vm_stat_diff[i] = 0;
				atomic_long_add(v, &zone->vm_stat[i]);
				global_diff[i] += v;
			}
	}

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	fold_diff(global_diff);
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}

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/*
 * this is only called if !populated_zone(zone), which implies no other users of
 * pset->vm_stat_diff[] exsist.
 */
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void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
{
	int i;

	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
		if (pset->vm_stat_diff[i]) {
			int v = pset->vm_stat_diff[i];
			pset->vm_stat_diff[i] = 0;
			atomic_long_add(v, &zone->vm_stat[i]);
			atomic_long_add(v, &vm_stat[i]);
		}
}
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#endif

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#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.
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 *
 * When __GFP_OTHER_NODE is set assume the node of the preferred
 * zone is the local node. This is useful for daemons who allocate
 * memory on behalf of other processes.
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 */
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void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags)
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{
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	if (z->zone_pgdat == preferred_zone->zone_pgdat) {
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		__inc_zone_state(z, NUMA_HIT);
	} else {
		__inc_zone_state(z, NUMA_MISS);
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		__inc_zone_state(preferred_zone, NUMA_FOREIGN);
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	}
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	if (z->node == ((flags & __GFP_OTHER_NODE) ?
			preferred_zone->node : numa_node_id()))
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		__inc_zone_state(z, NUMA_LOCAL);
	else
		__inc_zone_state(z, NUMA_OTHER);
}
#endif

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#ifdef CONFIG_COMPACTION
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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);
	}
}
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/*
 * 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
 */
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static int __fragmentation_index(unsigned int order, struct contig_page_info *info)
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{
	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);
}
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/* 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);
}
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#endif

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#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
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#ifdef CONFIG_ZONE_DMA
#define TEXT_FOR_DMA(xx) xx "_dma",
#else
#define TEXT_FOR_DMA(xx)
#endif

#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

#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
					TEXT_FOR_HIGHMEM(xx) xx "_movable",

const char * const vmstat_text[] = {
699
	/* enum zone_stat_item countes */
700
	"nr_free_pages",
701
	"nr_alloc_batch",
702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719
	"nr_inactive_anon",
	"nr_active_anon",
	"nr_inactive_file",
	"nr_active_file",
	"nr_unevictable",
	"nr_mlock",
	"nr_anon_pages",
	"nr_mapped",
	"nr_file_pages",
	"nr_dirty",
	"nr_writeback",
	"nr_slab_reclaimable",
	"nr_slab_unreclaimable",
	"nr_page_table_pages",
	"nr_kernel_stack",
	"nr_unstable",
	"nr_bounce",
	"nr_vmscan_write",
720
	"nr_vmscan_immediate_reclaim",
721 722 723 724 725 726
	"nr_writeback_temp",
	"nr_isolated_anon",
	"nr_isolated_file",
	"nr_shmem",
	"nr_dirtied",
	"nr_written",
727
	"nr_pages_scanned",
728 729 730 731 732 733 734 735 736

#ifdef CONFIG_NUMA
	"numa_hit",
	"numa_miss",
	"numa_foreign",
	"numa_interleave",
	"numa_local",
	"numa_other",
#endif
737 738
	"workingset_refault",
	"workingset_activate",
739
	"workingset_nodereclaim",
740
	"nr_anon_transparent_hugepages",
741
	"nr_free_cma",
742 743

	/* enum writeback_stat_item counters */
744 745 746 747
	"nr_dirty_threshold",
	"nr_dirty_background_threshold",

#ifdef CONFIG_VM_EVENT_COUNTERS
748
	/* enum vm_event_item counters */
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	"pgpgin",
	"pgpgout",
	"pswpin",
	"pswpout",

	TEXTS_FOR_ZONES("pgalloc")

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

	"pgfault",
	"pgmajfault",

	TEXTS_FOR_ZONES("pgrefill")
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	TEXTS_FOR_ZONES("pgsteal_kswapd")
	TEXTS_FOR_ZONES("pgsteal_direct")
766 767
	TEXTS_FOR_ZONES("pgscan_kswapd")
	TEXTS_FOR_ZONES("pgscan_direct")
768
	"pgscan_direct_throttle",
769 770 771 772 773 774 775 776 777 778 779 780 781 782

#ifdef CONFIG_NUMA
	"zone_reclaim_failed",
#endif
	"pginodesteal",
	"slabs_scanned",
	"kswapd_inodesteal",
	"kswapd_low_wmark_hit_quickly",
	"kswapd_high_wmark_hit_quickly",
	"pageoutrun",
	"allocstall",

	"pgrotated",

783 784 785
	"drop_pagecache",
	"drop_slab",

786 787
#ifdef CONFIG_NUMA_BALANCING
	"numa_pte_updates",
788
	"numa_huge_pte_updates",
789 790 791 792
	"numa_hint_faults",
	"numa_hint_faults_local",
	"numa_pages_migrated",
#endif
793 794 795 796
#ifdef CONFIG_MIGRATION
	"pgmigrate_success",
	"pgmigrate_fail",
#endif
797
#ifdef CONFIG_COMPACTION
798 799 800
	"compact_migrate_scanned",
	"compact_free_scanned",
	"compact_isolated",
801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823
	"compact_stall",
	"compact_fail",
	"compact_success",
#endif

#ifdef CONFIG_HUGETLB_PAGE
	"htlb_buddy_alloc_success",
	"htlb_buddy_alloc_fail",
#endif
	"unevictable_pgs_culled",
	"unevictable_pgs_scanned",
	"unevictable_pgs_rescued",
	"unevictable_pgs_mlocked",
	"unevictable_pgs_munlocked",
	"unevictable_pgs_cleared",
	"unevictable_pgs_stranded",

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
	"thp_fault_alloc",
	"thp_fault_fallback",
	"thp_collapse_alloc",
	"thp_collapse_alloc_failed",
	"thp_split",
824 825
	"thp_zero_page_alloc",
	"thp_zero_page_alloc_failed",
826
#endif
827 828 829 830 831 832 833
#ifdef CONFIG_MEMORY_BALLOON
	"balloon_inflate",
	"balloon_deflate",
#ifdef CONFIG_BALLOON_COMPACTION
	"balloon_migrate",
#endif
#endif /* CONFIG_MEMORY_BALLOON */
834
#ifdef CONFIG_DEBUG_TLBFLUSH
835
#ifdef CONFIG_SMP
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	"nr_tlb_remote_flush",
	"nr_tlb_remote_flush_received",
838
#endif /* CONFIG_SMP */
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	"nr_tlb_local_flush_all",
	"nr_tlb_local_flush_one",
841
#endif /* CONFIG_DEBUG_TLBFLUSH */
842

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#ifdef CONFIG_DEBUG_VM_VMACACHE
	"vmacache_find_calls",
	"vmacache_find_hits",
846
	"vmacache_full_flushes",
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#endif
848 849
#endif /* CONFIG_VM_EVENTS_COUNTERS */
};
850
#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
851 852


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#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
     defined(CONFIG_PROC_FS)
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)
{
}

/* 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 *))
{
	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);
		print(m, pgdat, zone);
		spin_unlock_irqrestore(&zone->lock, flags);
	}
}
#endif

899
#ifdef CONFIG_PROC_FS
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static char * const migratetype_names[MIGRATE_TYPES] = {
	"Unmovable",
	"Reclaimable",
	"Movable",
	"Reserve",
#ifdef CONFIG_CMA
	"CMA",
#endif
#ifdef CONFIG_MEMORY_ISOLATION
	"Isolate",
#endif
};

913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954
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);
		}
955 956
		seq_putc(m, '\n');
	}
957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981
}

/* 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;
982
	unsigned long end_pfn = zone_end_pfn(zone);
983 984 985 986 987 988 989 990 991
	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);
992 993 994

		/* Watch for unexpected holes punched in the memmap */
		if (!memmap_valid_within(pfn, page, zone))
995
			continue;
996

997 998
		mtype = get_pageblock_migratetype(page);

999 1000
		if (mtype < MIGRATE_TYPES)
			count[mtype]++;
1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024
	}

	/* 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;
}

1025 1026 1027 1028 1029 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 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122
#ifdef CONFIG_PAGE_OWNER
static void pagetypeinfo_showmixedcount_print(struct seq_file *m,
							pg_data_t *pgdat,
							struct zone *zone)
{
	struct page *page;
	struct page_ext *page_ext;
	unsigned long pfn = zone->zone_start_pfn, block_end_pfn;
	unsigned long end_pfn = pfn + zone->spanned_pages;
	unsigned long count[MIGRATE_TYPES] = { 0, };
	int pageblock_mt, page_mt;
	int i;

	/* Scan block by block. First and last block may be incomplete */
	pfn = zone->zone_start_pfn;

	/*
	 * Walk the zone in pageblock_nr_pages steps. If a page block spans
	 * a zone boundary, it will be double counted between zones. This does
	 * not matter as the mixed block count will still be correct
	 */
	for (; pfn < end_pfn; ) {
		if (!pfn_valid(pfn)) {
			pfn = ALIGN(pfn + 1, MAX_ORDER_NR_PAGES);
			continue;
		}

		block_end_pfn = ALIGN(pfn + 1, pageblock_nr_pages);
		block_end_pfn = min(block_end_pfn, end_pfn);

		page = pfn_to_page(pfn);
		pageblock_mt = get_pfnblock_migratetype(page, pfn);

		for (; pfn < block_end_pfn; pfn++) {
			if (!pfn_valid_within(pfn))
				continue;

			page = pfn_to_page(pfn);
			if (PageBuddy(page)) {
				pfn += (1UL << page_order(page)) - 1;
				continue;
			}

			if (PageReserved(page))
				continue;

			page_ext = lookup_page_ext(page);

			if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags))
				continue;

			page_mt = gfpflags_to_migratetype(page_ext->gfp_mask);
			if (pageblock_mt != page_mt) {
				if (is_migrate_cma(pageblock_mt))
					count[MIGRATE_MOVABLE]++;
				else
					count[pageblock_mt]++;

				pfn = block_end_pfn;
				break;
			}
			pfn += (1UL << page_ext->order) - 1;
		}
	}

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

/*
 * Print out the number of pageblocks for each migratetype that contain pages
 * of other types. This gives an indication of how well fallbacks are being
 * contained by rmqueue_fallback(). It requires information from PAGE_OWNER
 * to determine what is going on
 */
static void pagetypeinfo_showmixedcount(struct seq_file *m, pg_data_t *pgdat)
{
#ifdef CONFIG_PAGE_OWNER
	int mtype;

	if (!page_owner_inited)
		return;

	drain_all_pages(NULL);

	seq_printf(m, "\n%-23s", "Number of mixed blocks ");
	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_showmixedcount_print);
#endif /* CONFIG_PAGE_OWNER */
}

1123 1124 1125 1126 1127 1128 1129 1130
/*
 * 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;

1131
	/* check memoryless node */
1132
	if (!node_state(pgdat->node_id, N_MEMORY))
1133 1134
		return 0;

1135 1136 1137 1138 1139
	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);
1140
	pagetypeinfo_showmixedcount(m, pgdat);
1141

1142 1143 1144
	return 0;
}

1145
static const struct seq_operations fragmentation_op = {
1146 1147 1148 1149 1150 1151
	.start	= frag_start,
	.next	= frag_next,
	.stop	= frag_stop,
	.show	= frag_show,
};

1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163
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,
};

1164
static const struct seq_operations pagetypeinfo_op = {
1165 1166 1167 1168 1169 1170
	.start	= frag_start,
	.next	= frag_next,
	.stop	= frag_stop,
	.show	= pagetypeinfo_show,
};

1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182
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,
};

1183 1184
static void zoneinfo_show_print(struct seq_file *m, pg_data_t *pgdat,
							struct zone *zone)
1185
{
1186 1187 1188 1189 1190 1191 1192
	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"
1193
		   "\n        scanned  %lu"
1194
		   "\n        spanned  %lu"
1195 1196
		   "\n        present  %lu"
		   "\n        managed  %lu",
1197
		   zone_page_state(zone, NR_FREE_PAGES),
1198 1199 1200
		   min_wmark_pages(zone),
		   low_wmark_pages(zone),
		   high_wmark_pages(zone),
1201
		   zone_page_state(zone, NR_PAGES_SCANNED),
1202
		   zone->spanned_pages,
1203 1204
		   zone->present_pages,
		   zone->managed_pages);
1205 1206 1207 1208 1209 1210

	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,
1211
		   "\n        protection: (%ld",
1212 1213
		   zone->lowmem_reserve[0]);
	for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
1214
		seq_printf(m, ", %ld", zone->lowmem_reserve[i]);
1215 1216 1217 1218 1219 1220
	seq_printf(m,
		   ")"
		   "\n  pagesets");
	for_each_online_cpu(i) {
		struct per_cpu_pageset *pageset;

1221
		pageset = per_cpu_ptr(zone->pageset, i);
1222 1223 1224 1225 1226 1227 1228 1229 1230
		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);
1231
#ifdef CONFIG_SMP
1232 1233
		seq_printf(m, "\n  vm stats threshold: %d",
				pageset->stat_threshold);
1234
#endif
1235
	}
1236 1237
	seq_printf(m,
		   "\n  all_unreclaimable: %u"
1238 1239
		   "\n  start_pfn:         %lu"
		   "\n  inactive_ratio:    %u",
1240
		   !zone_reclaimable(zone),
1241 1242
		   zone->zone_start_pfn,
		   zone->inactive_ratio);
1243 1244 1245 1246 1247 1248 1249 1250 1251 1252
	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);
1253 1254 1255
	return 0;
}

1256
static const struct seq_operations zoneinfo_op = {
1257 1258 1259 1260 1261 1262 1263
	.start	= frag_start, /* iterate over all zones. The same as in
			       * fragmentation. */
	.next	= frag_next,
	.stop	= frag_stop,
	.show	= zoneinfo_show,
};

1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275
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,
};

1276 1277 1278 1279 1280 1281
enum writeback_stat_item {
	NR_DIRTY_THRESHOLD,
	NR_DIRTY_BG_THRESHOLD,
	NR_VM_WRITEBACK_STAT_ITEMS,
};

1282 1283
static void *vmstat_start(struct seq_file *m, loff_t *pos)
{
1284
	unsigned long *v;
1285
	int i, stat_items_size;
1286 1287 1288

	if (*pos >= ARRAY_SIZE(vmstat_text))
		return NULL;
1289 1290
	stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
			  NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
1291

1292
#ifdef CONFIG_VM_EVENT_COUNTERS
1293
	stat_items_size += sizeof(struct vm_event_state);
1294
#endif
1295 1296

	v = kmalloc(stat_items_size, GFP_KERNEL);
1297 1298
	m->private = v;
	if (!v)
1299
		return ERR_PTR(-ENOMEM);
1300 1301
	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
		v[i] = global_page_state(i);
1302 1303 1304 1305 1306 1307
	v += NR_VM_ZONE_STAT_ITEMS;

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

1308
#ifdef CONFIG_VM_EVENT_COUNTERS
1309 1310 1311
	all_vm_events(v);
	v[PGPGIN] /= 2;		/* sectors -> kbytes */
	v[PGPGOUT] /= 2;
1312
#endif
1313
	return (unsigned long *)m->private + *pos;
1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338
}

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;
}

1339
static const struct seq_operations vmstat_op = {
1340 1341 1342 1343 1344 1345
	.start	= vmstat_start,
	.next	= vmstat_next,
	.stop	= vmstat_stop,
	.show	= vmstat_show,
};

1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356
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,
};
1357 1358
#endif /* CONFIG_PROC_FS */

1359
#ifdef CONFIG_SMP
1360
static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
1361
int sysctl_stat_interval __read_mostly = HZ;
1362
static cpumask_var_t cpu_stat_off;
1363 1364 1365

static void vmstat_update(struct work_struct *w)
{
1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445
	if (refresh_cpu_vm_stats())
		/*
		 * Counters were updated so we expect more updates
		 * to occur in the future. Keep on running the
		 * update worker thread.
		 */
		schedule_delayed_work(this_cpu_ptr(&vmstat_work),
			round_jiffies_relative(sysctl_stat_interval));
	else {
		/*
		 * We did not update any counters so the app may be in
		 * a mode where it does not cause counter updates.
		 * We may be uselessly running vmstat_update.
		 * Defer the checking for differentials to the
		 * shepherd thread on a different processor.
		 */
		int r;
		/*
		 * Shepherd work thread does not race since it never
		 * changes the bit if its zero but the cpu
		 * online / off line code may race if
		 * worker threads are still allowed during
		 * shutdown / startup.
		 */
		r = cpumask_test_and_set_cpu(smp_processor_id(),
			cpu_stat_off);
		VM_BUG_ON(r);
	}
}

/*
 * Check if the diffs for a certain cpu indicate that
 * an update is needed.
 */
static bool need_update(int cpu)
{
	struct zone *zone;

	for_each_populated_zone(zone) {
		struct per_cpu_pageset *p = per_cpu_ptr(zone->pageset, cpu);

		BUILD_BUG_ON(sizeof(p->vm_stat_diff[0]) != 1);
		/*
		 * The fast way of checking if there are any vmstat diffs.
		 * This works because the diffs are byte sized items.
		 */
		if (memchr_inv(p->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS))
			return true;

	}
	return false;
}


/*
 * Shepherd worker thread that checks the
 * differentials of processors that have their worker
 * threads for vm statistics updates disabled because of
 * inactivity.
 */
static void vmstat_shepherd(struct work_struct *w);

static DECLARE_DELAYED_WORK(shepherd, vmstat_shepherd);

static void vmstat_shepherd(struct work_struct *w)
{
	int cpu;

	get_online_cpus();
	/* Check processors whose vmstat worker threads have been disabled */
	for_each_cpu(cpu, cpu_stat_off)
		if (need_update(cpu) &&
			cpumask_test_and_clear_cpu(cpu, cpu_stat_off))

			schedule_delayed_work_on(cpu, &per_cpu(vmstat_work, cpu),
				__round_jiffies_relative(sysctl_stat_interval, cpu));

	put_online_cpus();

	schedule_delayed_work(&shepherd,
A
Anton Blanchard 已提交
1446
		round_jiffies_relative(sysctl_stat_interval));
1447

1448 1449
}

1450
static void __init start_shepherd_timer(void)
1451
{
1452 1453 1454
	int cpu;

	for_each_possible_cpu(cpu)
1455
		INIT_DELAYED_WORK(per_cpu_ptr(&vmstat_work, cpu),
1456 1457 1458 1459 1460
			vmstat_update);

	if (!alloc_cpumask_var(&cpu_stat_off, GFP_KERNEL))
		BUG();
	cpumask_copy(cpu_stat_off, cpu_online_mask);
1461

1462 1463
	schedule_delayed_work(&shepherd,
		round_jiffies_relative(sysctl_stat_interval));
1464 1465
}

1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479
static void vmstat_cpu_dead(int node)
{
	int cpu;

	get_online_cpus();
	for_each_online_cpu(cpu)
		if (cpu_to_node(cpu) == node)
			goto end;

	node_clear_state(node, N_CPU);
end:
	put_online_cpus();
}

1480 1481 1482 1483
/*
 * Use the cpu notifier to insure that the thresholds are recalculated
 * when necessary.
 */
1484
static int vmstat_cpuup_callback(struct notifier_block *nfb,
1485 1486 1487
		unsigned long action,
		void *hcpu)
{
1488 1489
	long cpu = (long)hcpu;

1490
	switch (action) {
1491 1492
	case CPU_ONLINE:
	case CPU_ONLINE_FROZEN:
1493
		refresh_zone_stat_thresholds();
1494
		node_set_state(cpu_to_node(cpu), N_CPU);
1495
		cpumask_set_cpu(cpu, cpu_stat_off);
1496 1497 1498
		break;
	case CPU_DOWN_PREPARE:
	case CPU_DOWN_PREPARE_FROZEN:
1499
		cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
1500
		cpumask_clear_cpu(cpu, cpu_stat_off);
1501 1502 1503
		break;
	case CPU_DOWN_FAILED:
	case CPU_DOWN_FAILED_FROZEN:
1504
		cpumask_set_cpu(cpu, cpu_stat_off);
1505
		break;
1506
	case CPU_DEAD:
1507
	case CPU_DEAD_FROZEN:
1508
		refresh_zone_stat_thresholds();
1509
		vmstat_cpu_dead(cpu_to_node(cpu));
1510 1511 1512
		break;
	default:
		break;
1513 1514 1515 1516
	}
	return NOTIFY_OK;
}

1517
static struct notifier_block vmstat_notifier =
1518
	{ &vmstat_cpuup_callback, NULL, 0 };
1519
#endif
1520

A
Adrian Bunk 已提交
1521
static int __init setup_vmstat(void)
1522
{
1523
#ifdef CONFIG_SMP
1524 1525
	cpu_notifier_register_begin();
	__register_cpu_notifier(&vmstat_notifier);
1526

1527
	start_shepherd_timer();
1528
	cpu_notifier_register_done();
1529 1530 1531
#endif
#ifdef CONFIG_PROC_FS
	proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
1532
	proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
1533
	proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
1534
	proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
1535
#endif
1536 1537 1538
	return 0;
}
module_init(setup_vmstat)
1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596

#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)

/*
 * 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 */
1597
	if (!node_state(pgdat->node_id, N_MEMORY))
1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623
		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,
};

1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637
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);
1638
		index = __fragmentation_index(order, &info);
1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675
		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,
};

1676 1677
static int __init extfrag_debug_init(void)
{
1678 1679
	struct dentry *extfrag_debug_root;

1680 1681 1682 1683 1684 1685
	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))
1686
		goto fail;
1687

1688 1689
	if (!debugfs_create_file("extfrag_index", 0444,
			extfrag_debug_root, NULL, &extfrag_file_ops))
1690
		goto fail;
1691

1692
	return 0;
1693 1694 1695
fail:
	debugfs_remove_recursive(extfrag_debug_root);
	return -ENOMEM;
1696 1697 1698 1699
}

module_init(extfrag_debug_init);
#endif