705 lines
15 KiB
C
705 lines
15 KiB
C
/*
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* linux/mm/vmstat.c
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*
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* Manages VM statistics
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* zoned VM statistics
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* Copyright (C) 2006 Silicon Graphics, Inc.,
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* Christoph Lameter <christoph@lameter.com>
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*/
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#include <linux/config.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/cpu.h>
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void __get_zone_counts(unsigned long *active, unsigned long *inactive,
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unsigned long *free, struct pglist_data *pgdat)
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{
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struct zone *zones = pgdat->node_zones;
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int i;
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*active = 0;
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*inactive = 0;
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*free = 0;
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for (i = 0; i < MAX_NR_ZONES; i++) {
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*active += zones[i].nr_active;
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*inactive += zones[i].nr_inactive;
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*free += zones[i].free_pages;
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}
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}
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void get_zone_counts(unsigned long *active,
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unsigned long *inactive, unsigned long *free)
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{
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struct pglist_data *pgdat;
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*active = 0;
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*inactive = 0;
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*free = 0;
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for_each_online_pgdat(pgdat) {
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unsigned long l, m, n;
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__get_zone_counts(&l, &m, &n, pgdat);
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*active += l;
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*inactive += m;
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*free += n;
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}
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}
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#ifdef CONFIG_VM_EVENT_COUNTERS
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DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
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EXPORT_PER_CPU_SYMBOL(vm_event_states);
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static void sum_vm_events(unsigned long *ret, cpumask_t *cpumask)
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{
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int cpu = 0;
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int i;
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memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
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cpu = first_cpu(*cpumask);
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while (cpu < NR_CPUS) {
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struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
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cpu = next_cpu(cpu, *cpumask);
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if (cpu < NR_CPUS)
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prefetch(&per_cpu(vm_event_states, cpu));
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for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
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ret[i] += this->event[i];
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}
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}
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/*
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* Accumulate the vm event counters across all CPUs.
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* The result is unavoidably approximate - it can change
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* during and after execution of this function.
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*/
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void all_vm_events(unsigned long *ret)
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{
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sum_vm_events(ret, &cpu_online_map);
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}
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EXPORT_SYMBOL_GPL(all_vm_events);
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#ifdef CONFIG_HOTPLUG
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/*
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* Fold the foreign cpu events into our own.
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*
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* This is adding to the events on one processor
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* but keeps the global counts constant.
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*/
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void vm_events_fold_cpu(int cpu)
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{
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struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
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int i;
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for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
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count_vm_events(i, fold_state->event[i]);
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fold_state->event[i] = 0;
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}
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}
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#endif /* CONFIG_HOTPLUG */
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#endif /* CONFIG_VM_EVENT_COUNTERS */
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/*
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* Manage combined zone based / global counters
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*
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* vm_stat contains the global counters
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*/
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atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
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EXPORT_SYMBOL(vm_stat);
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#ifdef CONFIG_SMP
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static int calculate_threshold(struct zone *zone)
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{
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int threshold;
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int mem; /* memory in 128 MB units */
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/*
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* The threshold scales with the number of processors and the amount
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* of memory per zone. More memory means that we can defer updates for
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* longer, more processors could lead to more contention.
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* fls() is used to have a cheap way of logarithmic scaling.
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*
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* Some sample thresholds:
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*
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* Threshold Processors (fls) Zonesize fls(mem+1)
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* ------------------------------------------------------------------
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* 8 1 1 0.9-1 GB 4
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* 16 2 2 0.9-1 GB 4
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* 20 2 2 1-2 GB 5
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* 24 2 2 2-4 GB 6
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* 28 2 2 4-8 GB 7
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* 32 2 2 8-16 GB 8
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* 4 2 2 <128M 1
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* 30 4 3 2-4 GB 5
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* 48 4 3 8-16 GB 8
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* 32 8 4 1-2 GB 4
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* 32 8 4 0.9-1GB 4
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* 10 16 5 <128M 1
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* 40 16 5 900M 4
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* 70 64 7 2-4 GB 5
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* 84 64 7 4-8 GB 6
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* 108 512 9 4-8 GB 6
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* 125 1024 10 8-16 GB 8
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* 125 1024 10 16-32 GB 9
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*/
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mem = zone->present_pages >> (27 - PAGE_SHIFT);
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threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
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/*
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* Maximum threshold is 125
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*/
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threshold = min(125, threshold);
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return threshold;
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}
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/*
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* Refresh the thresholds for each zone.
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*/
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static void refresh_zone_stat_thresholds(void)
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{
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struct zone *zone;
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int cpu;
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int threshold;
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for_each_zone(zone) {
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if (!zone->present_pages)
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continue;
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threshold = calculate_threshold(zone);
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for_each_online_cpu(cpu)
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zone_pcp(zone, cpu)->stat_threshold = threshold;
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}
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}
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/*
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* For use when we know that interrupts are disabled.
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*/
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void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
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int delta)
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{
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struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
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s8 *p = pcp->vm_stat_diff + item;
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long x;
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x = delta + *p;
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if (unlikely(x > pcp->stat_threshold || x < -pcp->stat_threshold)) {
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zone_page_state_add(x, zone, item);
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x = 0;
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}
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*p = x;
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}
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EXPORT_SYMBOL(__mod_zone_page_state);
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/*
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* For an unknown interrupt state
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*/
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void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
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int delta)
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{
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unsigned long flags;
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local_irq_save(flags);
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__mod_zone_page_state(zone, item, delta);
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local_irq_restore(flags);
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}
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EXPORT_SYMBOL(mod_zone_page_state);
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/*
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* Optimized increment and decrement functions.
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*
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* These are only for a single page and therefore can take a struct page *
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* argument instead of struct zone *. This allows the inclusion of the code
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* generated for page_zone(page) into the optimized functions.
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*
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* No overflow check is necessary and therefore the differential can be
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* incremented or decremented in place which may allow the compilers to
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* generate better code.
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* The increment or decrement is known and therefore one boundary check can
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* be omitted.
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*
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* NOTE: These functions are very performance sensitive. Change only
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* with care.
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*
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* Some processors have inc/dec instructions that are atomic vs an interrupt.
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* However, the code must first determine the differential location in a zone
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* based on the processor number and then inc/dec the counter. There is no
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* guarantee without disabling preemption that the processor will not change
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* in between and therefore the atomicity vs. interrupt cannot be exploited
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* in a useful way here.
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*/
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static void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
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{
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struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
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s8 *p = pcp->vm_stat_diff + item;
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(*p)++;
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if (unlikely(*p > pcp->stat_threshold)) {
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int overstep = pcp->stat_threshold / 2;
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zone_page_state_add(*p + overstep, zone, item);
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*p = -overstep;
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}
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}
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void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
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{
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__inc_zone_state(page_zone(page), item);
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}
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EXPORT_SYMBOL(__inc_zone_page_state);
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void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
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{
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struct zone *zone = page_zone(page);
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struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
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s8 *p = pcp->vm_stat_diff + item;
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(*p)--;
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if (unlikely(*p < - pcp->stat_threshold)) {
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int overstep = pcp->stat_threshold / 2;
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zone_page_state_add(*p - overstep, zone, item);
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*p = overstep;
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}
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}
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EXPORT_SYMBOL(__dec_zone_page_state);
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void inc_zone_state(struct zone *zone, enum zone_stat_item item)
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{
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unsigned long flags;
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local_irq_save(flags);
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__inc_zone_state(zone, item);
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local_irq_restore(flags);
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}
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void inc_zone_page_state(struct page *page, enum zone_stat_item item)
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{
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unsigned long flags;
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struct zone *zone;
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zone = page_zone(page);
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local_irq_save(flags);
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__inc_zone_state(zone, item);
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local_irq_restore(flags);
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}
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EXPORT_SYMBOL(inc_zone_page_state);
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void dec_zone_page_state(struct page *page, enum zone_stat_item item)
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{
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unsigned long flags;
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local_irq_save(flags);
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__dec_zone_page_state(page, item);
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local_irq_restore(flags);
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}
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EXPORT_SYMBOL(dec_zone_page_state);
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/*
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* Update the zone counters for one cpu.
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*/
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void refresh_cpu_vm_stats(int cpu)
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{
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struct zone *zone;
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int i;
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unsigned long flags;
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for_each_zone(zone) {
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struct per_cpu_pageset *pcp;
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pcp = zone_pcp(zone, cpu);
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for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
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if (pcp->vm_stat_diff[i]) {
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local_irq_save(flags);
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zone_page_state_add(pcp->vm_stat_diff[i],
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zone, i);
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pcp->vm_stat_diff[i] = 0;
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local_irq_restore(flags);
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}
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}
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}
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static void __refresh_cpu_vm_stats(void *dummy)
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{
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refresh_cpu_vm_stats(smp_processor_id());
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}
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/*
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* Consolidate all counters.
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*
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* Note that the result is less inaccurate but still inaccurate
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* if concurrent processes are allowed to run.
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*/
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void refresh_vm_stats(void)
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{
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on_each_cpu(__refresh_cpu_vm_stats, NULL, 0, 1);
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}
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EXPORT_SYMBOL(refresh_vm_stats);
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#endif
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#ifdef CONFIG_NUMA
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/*
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* zonelist = the list of zones passed to the allocator
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* z = the zone from which the allocation occurred.
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*
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* Must be called with interrupts disabled.
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*/
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void zone_statistics(struct zonelist *zonelist, struct zone *z)
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{
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if (z->zone_pgdat == zonelist->zones[0]->zone_pgdat) {
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__inc_zone_state(z, NUMA_HIT);
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} else {
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__inc_zone_state(z, NUMA_MISS);
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__inc_zone_state(zonelist->zones[0], NUMA_FOREIGN);
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}
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if (z->zone_pgdat == NODE_DATA(numa_node_id()))
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__inc_zone_state(z, NUMA_LOCAL);
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else
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__inc_zone_state(z, NUMA_OTHER);
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}
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#endif
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#ifdef CONFIG_PROC_FS
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#include <linux/seq_file.h>
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static void *frag_start(struct seq_file *m, loff_t *pos)
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{
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pg_data_t *pgdat;
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loff_t node = *pos;
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for (pgdat = first_online_pgdat();
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pgdat && node;
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pgdat = next_online_pgdat(pgdat))
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--node;
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return pgdat;
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}
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static void *frag_next(struct seq_file *m, void *arg, loff_t *pos)
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{
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pg_data_t *pgdat = (pg_data_t *)arg;
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(*pos)++;
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return next_online_pgdat(pgdat);
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}
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static void frag_stop(struct seq_file *m, void *arg)
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{
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}
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/*
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* This walks the free areas for each zone.
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*/
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static int frag_show(struct seq_file *m, void *arg)
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{
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pg_data_t *pgdat = (pg_data_t *)arg;
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struct zone *zone;
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struct zone *node_zones = pgdat->node_zones;
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unsigned long flags;
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int order;
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for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; ++zone) {
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if (!populated_zone(zone))
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continue;
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spin_lock_irqsave(&zone->lock, flags);
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seq_printf(m, "Node %d, zone %8s ", pgdat->node_id, zone->name);
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for (order = 0; order < MAX_ORDER; ++order)
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seq_printf(m, "%6lu ", zone->free_area[order].nr_free);
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spin_unlock_irqrestore(&zone->lock, flags);
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seq_putc(m, '\n');
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}
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return 0;
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}
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struct seq_operations fragmentation_op = {
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.start = frag_start,
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.next = frag_next,
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.stop = frag_stop,
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.show = frag_show,
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};
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static char *vmstat_text[] = {
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/* Zoned VM counters */
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"nr_anon_pages",
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"nr_mapped",
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"nr_file_pages",
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"nr_slab",
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"nr_page_table_pages",
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"nr_dirty",
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"nr_writeback",
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"nr_unstable",
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"nr_bounce",
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#ifdef CONFIG_NUMA
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"numa_hit",
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"numa_miss",
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"numa_foreign",
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"numa_interleave",
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"numa_local",
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"numa_other",
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#endif
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#ifdef CONFIG_VM_EVENT_COUNTERS
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"pgpgin",
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"pgpgout",
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"pswpin",
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"pswpout",
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"pgalloc_dma",
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"pgalloc_dma32",
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"pgalloc_normal",
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"pgalloc_high",
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"pgfree",
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"pgactivate",
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"pgdeactivate",
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"pgfault",
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"pgmajfault",
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"pgrefill_dma",
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"pgrefill_dma32",
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"pgrefill_normal",
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"pgrefill_high",
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"pgsteal_dma",
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"pgsteal_dma32",
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"pgsteal_normal",
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"pgsteal_high",
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"pgscan_kswapd_dma",
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"pgscan_kswapd_dma32",
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"pgscan_kswapd_normal",
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"pgscan_kswapd_high",
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"pgscan_direct_dma",
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"pgscan_direct_dma32",
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"pgscan_direct_normal",
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"pgscan_direct_high",
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"pginodesteal",
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"slabs_scanned",
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"kswapd_steal",
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"kswapd_inodesteal",
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"pageoutrun",
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"allocstall",
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"pgrotated",
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#endif
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};
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/*
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* Output information about zones in @pgdat.
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*/
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static int zoneinfo_show(struct seq_file *m, void *arg)
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{
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pg_data_t *pgdat = arg;
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struct zone *zone;
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struct zone *node_zones = pgdat->node_zones;
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unsigned long flags;
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for (zone = node_zones; zone - node_zones < MAX_NR_ZONES; zone++) {
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int i;
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if (!populated_zone(zone))
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continue;
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spin_lock_irqsave(&zone->lock, flags);
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seq_printf(m, "Node %d, zone %8s", pgdat->node_id, zone->name);
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seq_printf(m,
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"\n pages free %lu"
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"\n min %lu"
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"\n low %lu"
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"\n high %lu"
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"\n active %lu"
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"\n inactive %lu"
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"\n scanned %lu (a: %lu i: %lu)"
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"\n spanned %lu"
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"\n present %lu",
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zone->free_pages,
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zone->pages_min,
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zone->pages_low,
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zone->pages_high,
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zone->nr_active,
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zone->nr_inactive,
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zone->pages_scanned,
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zone->nr_scan_active, zone->nr_scan_inactive,
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zone->spanned_pages,
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zone->present_pages);
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for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
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seq_printf(m, "\n %-12s %lu", vmstat_text[i],
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zone_page_state(zone, i));
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seq_printf(m,
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"\n protection: (%lu",
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zone->lowmem_reserve[0]);
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for (i = 1; i < ARRAY_SIZE(zone->lowmem_reserve); i++)
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seq_printf(m, ", %lu", zone->lowmem_reserve[i]);
|
|
seq_printf(m,
|
|
")"
|
|
"\n pagesets");
|
|
for_each_online_cpu(i) {
|
|
struct per_cpu_pageset *pageset;
|
|
int j;
|
|
|
|
pageset = zone_pcp(zone, i);
|
|
for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
|
|
if (pageset->pcp[j].count)
|
|
break;
|
|
}
|
|
if (j == ARRAY_SIZE(pageset->pcp))
|
|
continue;
|
|
for (j = 0; j < ARRAY_SIZE(pageset->pcp); j++) {
|
|
seq_printf(m,
|
|
"\n cpu: %i pcp: %i"
|
|
"\n count: %i"
|
|
"\n high: %i"
|
|
"\n batch: %i",
|
|
i, j,
|
|
pageset->pcp[j].count,
|
|
pageset->pcp[j].high,
|
|
pageset->pcp[j].batch);
|
|
}
|
|
#ifdef CONFIG_SMP
|
|
seq_printf(m, "\n vm stats threshold: %d",
|
|
pageset->stat_threshold);
|
|
#endif
|
|
}
|
|
seq_printf(m,
|
|
"\n all_unreclaimable: %u"
|
|
"\n prev_priority: %i"
|
|
"\n temp_priority: %i"
|
|
"\n start_pfn: %lu",
|
|
zone->all_unreclaimable,
|
|
zone->prev_priority,
|
|
zone->temp_priority,
|
|
zone->zone_start_pfn);
|
|
spin_unlock_irqrestore(&zone->lock, flags);
|
|
seq_putc(m, '\n');
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
struct seq_operations zoneinfo_op = {
|
|
.start = frag_start, /* iterate over all zones. The same as in
|
|
* fragmentation. */
|
|
.next = frag_next,
|
|
.stop = frag_stop,
|
|
.show = zoneinfo_show,
|
|
};
|
|
|
|
static void *vmstat_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
unsigned long *v;
|
|
#ifdef CONFIG_VM_EVENT_COUNTERS
|
|
unsigned long *e;
|
|
#endif
|
|
int i;
|
|
|
|
if (*pos >= ARRAY_SIZE(vmstat_text))
|
|
return NULL;
|
|
|
|
#ifdef CONFIG_VM_EVENT_COUNTERS
|
|
v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long)
|
|
+ sizeof(struct vm_event_state), GFP_KERNEL);
|
|
#else
|
|
v = kmalloc(NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long),
|
|
GFP_KERNEL);
|
|
#endif
|
|
m->private = v;
|
|
if (!v)
|
|
return ERR_PTR(-ENOMEM);
|
|
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
|
|
v[i] = global_page_state(i);
|
|
#ifdef CONFIG_VM_EVENT_COUNTERS
|
|
e = v + NR_VM_ZONE_STAT_ITEMS;
|
|
all_vm_events(e);
|
|
e[PGPGIN] /= 2; /* sectors -> kbytes */
|
|
e[PGPGOUT] /= 2;
|
|
#endif
|
|
return v + *pos;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
struct seq_operations vmstat_op = {
|
|
.start = vmstat_start,
|
|
.next = vmstat_next,
|
|
.stop = vmstat_stop,
|
|
.show = vmstat_show,
|
|
};
|
|
|
|
#endif /* CONFIG_PROC_FS */
|
|
|
|
#ifdef CONFIG_SMP
|
|
/*
|
|
* 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)
|
|
{
|
|
switch (action) {
|
|
case CPU_UP_PREPARE:
|
|
case CPU_UP_CANCELED:
|
|
case CPU_DEAD:
|
|
refresh_zone_stat_thresholds();
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block __cpuinitdata vmstat_notifier =
|
|
{ &vmstat_cpuup_callback, NULL, 0 };
|
|
|
|
int __init setup_vmstat(void)
|
|
{
|
|
refresh_zone_stat_thresholds();
|
|
register_cpu_notifier(&vmstat_notifier);
|
|
return 0;
|
|
}
|
|
module_init(setup_vmstat)
|
|
#endif
|