*
* Manages VM statistics
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ *
+ * zoned VM statistics
+ * Copyright (C) 2006 Silicon Graphics, Inc.,
+ * Christoph Lameter <christoph@lameter.com>
*/
#include <linux/config.h>
#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/cpu.h>
+
+void __get_zone_counts(unsigned long *active, unsigned long *inactive,
+ unsigned long *free, struct pglist_data *pgdat)
+{
+ struct zone *zones = pgdat->node_zones;
+ int i;
+
+ *active = 0;
+ *inactive = 0;
+ *free = 0;
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ *active += zones[i].nr_active;
+ *inactive += zones[i].nr_inactive;
+ *free += zones[i].free_pages;
+ }
+}
+
+void get_zone_counts(unsigned long *active,
+ unsigned long *inactive, unsigned long *free)
+{
+ struct pglist_data *pgdat;
+
+ *active = 0;
+ *inactive = 0;
+ *free = 0;
+ for_each_online_pgdat(pgdat) {
+ unsigned long l, m, n;
+ __get_zone_counts(&l, &m, &n, pgdat);
+ *active += l;
+ *inactive += m;
+ *free += n;
+ }
+}
+
+#ifdef CONFIG_VM_EVENT_COUNTERS
+DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
+EXPORT_PER_CPU_SYMBOL(vm_event_states);
+
+static void sum_vm_events(unsigned long *ret, cpumask_t *cpumask)
+{
+ int cpu = 0;
+ int i;
+
+ memset(ret, 0, NR_VM_EVENT_ITEMS * sizeof(unsigned long));
+
+ cpu = first_cpu(*cpumask);
+ while (cpu < NR_CPUS) {
+ struct vm_event_state *this = &per_cpu(vm_event_states, cpu);
+
+ cpu = next_cpu(cpu, *cpumask);
+
+ if (cpu < NR_CPUS)
+ prefetch(&per_cpu(vm_event_states, cpu));
+
+
+ for (i = 0; i < NR_VM_EVENT_ITEMS; i++)
+ ret[i] += this->event[i];
+ }
+}
/*
- * Accumulate the page_state information across all CPUs.
+ * 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)
+{
+ sum_vm_events(ret, &cpu_online_map);
+}
+EXPORT_SYMBOL_GPL(all_vm_events);
+
+#ifdef CONFIG_HOTPLUG
+/*
+ * Fold the foreign cpu events into our own.
+ *
+ * This is adding to the events on one processor
+ * but keeps the global counts constant.
*/
-DEFINE_PER_CPU(struct page_state, page_states) = {0};
+void vm_events_fold_cpu(int cpu)
+{
+ struct vm_event_state *fold_state = &per_cpu(vm_event_states, cpu);
+ int i;
+
+ for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
+ count_vm_events(i, fold_state->event[i]);
+ fold_state->event[i] = 0;
+ }
+}
+#endif /* CONFIG_HOTPLUG */
+
+#endif /* CONFIG_VM_EVENT_COUNTERS */
+
+/*
+ * Manage combined zone based / global counters
+ *
+ * vm_stat contains the global counters
+ */
+atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
+EXPORT_SYMBOL(vm_stat);
-atomic_t nr_pagecache = ATOMIC_INIT(0);
-EXPORT_SYMBOL(nr_pagecache);
#ifdef CONFIG_SMP
-DEFINE_PER_CPU(long, nr_pagecache_local) = 0;
-#endif
-static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
+static int calculate_threshold(struct zone *zone)
{
- unsigned cpu;
+ int threshold;
+ int mem; /* memory in 128 MB units */
+
+ /*
+ * The threshold scales with the number of processors and the amount
+ * of memory per zone. More memory means that we can defer updates for
+ * longer, more processors could lead to more contention.
+ * fls() is used to have a cheap way of logarithmic scaling.
+ *
+ * Some sample thresholds:
+ *
+ * Threshold Processors (fls) Zonesize fls(mem+1)
+ * ------------------------------------------------------------------
+ * 8 1 1 0.9-1 GB 4
+ * 16 2 2 0.9-1 GB 4
+ * 20 2 2 1-2 GB 5
+ * 24 2 2 2-4 GB 6
+ * 28 2 2 4-8 GB 7
+ * 32 2 2 8-16 GB 8
+ * 4 2 2 <128M 1
+ * 30 4 3 2-4 GB 5
+ * 48 4 3 8-16 GB 8
+ * 32 8 4 1-2 GB 4
+ * 32 8 4 0.9-1GB 4
+ * 10 16 5 <128M 1
+ * 40 16 5 900M 4
+ * 70 64 7 2-4 GB 5
+ * 84 64 7 4-8 GB 6
+ * 108 512 9 4-8 GB 6
+ * 125 1024 10 8-16 GB 8
+ * 125 1024 10 16-32 GB 9
+ */
+
+ mem = zone->present_pages >> (27 - PAGE_SHIFT);
+
+ threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem));
+
+ /*
+ * Maximum threshold is 125
+ */
+ threshold = min(125, threshold);
+
+ return threshold;
+}
- memset(ret, 0, nr * sizeof(unsigned long));
- cpus_and(*cpumask, *cpumask, cpu_online_map);
+/*
+ * Refresh the thresholds for each zone.
+ */
+static void refresh_zone_stat_thresholds(void)
+{
+ struct zone *zone;
+ int cpu;
+ int threshold;
- for_each_cpu_mask(cpu, *cpumask) {
- unsigned long *in;
- unsigned long *out;
- unsigned off;
- unsigned next_cpu;
+ for_each_zone(zone) {
- in = (unsigned long *)&per_cpu(page_states, cpu);
+ if (!zone->present_pages)
+ continue;
- next_cpu = next_cpu(cpu, *cpumask);
- if (likely(next_cpu < NR_CPUS))
- prefetch(&per_cpu(page_states, next_cpu));
+ threshold = calculate_threshold(zone);
- out = (unsigned long *)ret;
- for (off = 0; off < nr; off++)
- *out++ += *in++;
+ for_each_online_cpu(cpu)
+ zone_pcp(zone, cpu)->stat_threshold = threshold;
}
}
-void get_page_state_node(struct page_state *ret, int node)
+/*
+ * For use when we know that interrupts are disabled.
+ */
+void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
+ int delta)
{
- int nr;
- cpumask_t mask = node_to_cpumask(node);
+ struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
+ s8 *p = pcp->vm_stat_diff + item;
+ long x;
- nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
- nr /= sizeof(unsigned long);
+ x = delta + *p;
- __get_page_state(ret, nr+1, &mask);
+ if (unlikely(x > pcp->stat_threshold || x < -pcp->stat_threshold)) {
+ zone_page_state_add(x, zone, item);
+ x = 0;
+ }
+ *p = x;
}
+EXPORT_SYMBOL(__mod_zone_page_state);
-void get_page_state(struct page_state *ret)
+/*
+ * For an unknown interrupt state
+ */
+void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
+ int delta)
{
- int nr;
- cpumask_t mask = CPU_MASK_ALL;
-
- nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
- nr /= sizeof(unsigned long);
+ unsigned long flags;
- __get_page_state(ret, nr + 1, &mask);
+ local_irq_save(flags);
+ __mod_zone_page_state(zone, item, delta);
+ local_irq_restore(flags);
}
+EXPORT_SYMBOL(mod_zone_page_state);
-void get_full_page_state(struct page_state *ret)
+/*
+ * 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.
+ *
+ * NOTE: These functions are very performance sensitive. Change only
+ * with care.
+ *
+ * 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.
+ */
+static void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
- cpumask_t mask = CPU_MASK_ALL;
+ struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
+ s8 *p = pcp->vm_stat_diff + item;
+
+ (*p)++;
+
+ if (unlikely(*p > pcp->stat_threshold)) {
+ int overstep = pcp->stat_threshold / 2;
- __get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask);
+ zone_page_state_add(*p + overstep, zone, item);
+ *p = -overstep;
+ }
}
-unsigned long read_page_state_offset(unsigned long offset)
+void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
- unsigned long ret = 0;
- int cpu;
+ __inc_zone_state(page_zone(page), item);
+}
+EXPORT_SYMBOL(__inc_zone_page_state);
+
+void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
+{
+ struct zone *zone = page_zone(page);
+ struct per_cpu_pageset *pcp = zone_pcp(zone, smp_processor_id());
+ s8 *p = pcp->vm_stat_diff + item;
+
+ (*p)--;
- for_each_online_cpu(cpu) {
- unsigned long in;
+ if (unlikely(*p < - pcp->stat_threshold)) {
+ int overstep = pcp->stat_threshold / 2;
- in = (unsigned long)&per_cpu(page_states, cpu) + offset;
- ret += *((unsigned long *)in);
+ zone_page_state_add(*p - overstep, zone, item);
+ *p = overstep;
}
- return ret;
}
+EXPORT_SYMBOL(__dec_zone_page_state);
-void __mod_page_state_offset(unsigned long offset, unsigned long delta)
+void inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
- void *ptr;
+ unsigned long flags;
- ptr = &__get_cpu_var(page_states);
- *(unsigned long *)(ptr + offset) += delta;
+ local_irq_save(flags);
+ __inc_zone_state(zone, item);
+ local_irq_restore(flags);
}
-EXPORT_SYMBOL(__mod_page_state_offset);
-void mod_page_state_offset(unsigned long offset, unsigned long delta)
+void inc_zone_page_state(struct page *page, enum zone_stat_item item)
{
unsigned long flags;
- void *ptr;
+ struct zone *zone;
+ zone = page_zone(page);
local_irq_save(flags);
- ptr = &__get_cpu_var(page_states);
- *(unsigned long *)(ptr + offset) += delta;
+ __inc_zone_state(zone, item);
local_irq_restore(flags);
}
-EXPORT_SYMBOL(mod_page_state_offset);
+EXPORT_SYMBOL(inc_zone_page_state);
-void __get_zone_counts(unsigned long *active, unsigned long *inactive,
- unsigned long *free, struct pglist_data *pgdat)
+void dec_zone_page_state(struct page *page, enum zone_stat_item item)
{
- struct zone *zones = pgdat->node_zones;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __dec_zone_page_state(page, item);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(dec_zone_page_state);
+
+/*
+ * Update the zone counters for one cpu.
+ */
+void refresh_cpu_vm_stats(int cpu)
+{
+ struct zone *zone;
int i;
+ unsigned long flags;
- *active = 0;
- *inactive = 0;
- *free = 0;
- for (i = 0; i < MAX_NR_ZONES; i++) {
- *active += zones[i].nr_active;
- *inactive += zones[i].nr_inactive;
- *free += zones[i].free_pages;
+ for_each_zone(zone) {
+ struct per_cpu_pageset *pcp;
+
+ pcp = zone_pcp(zone, cpu);
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ if (pcp->vm_stat_diff[i]) {
+ local_irq_save(flags);
+ zone_page_state_add(pcp->vm_stat_diff[i],
+ zone, i);
+ pcp->vm_stat_diff[i] = 0;
+ local_irq_restore(flags);
+ }
}
}
-void get_zone_counts(unsigned long *active,
- unsigned long *inactive, unsigned long *free)
+static void __refresh_cpu_vm_stats(void *dummy)
{
- struct pglist_data *pgdat;
+ refresh_cpu_vm_stats(smp_processor_id());
+}
- *active = 0;
- *inactive = 0;
- *free = 0;
- for_each_online_pgdat(pgdat) {
- unsigned long l, m, n;
- __get_zone_counts(&l, &m, &n, pgdat);
- *active += l;
- *inactive += m;
- *free += n;
+/*
+ * Consolidate all counters.
+ *
+ * Note that the result is less inaccurate but still inaccurate
+ * if concurrent processes are allowed to run.
+ */
+void refresh_vm_stats(void)
+{
+ on_each_cpu(__refresh_cpu_vm_stats, NULL, 0, 1);
+}
+EXPORT_SYMBOL(refresh_vm_stats);
+
+#endif
+
+#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.
+ */
+void zone_statistics(struct zonelist *zonelist, struct zone *z)
+{
+ if (z->zone_pgdat == zonelist->zones[0]->zone_pgdat) {
+ __inc_zone_state(z, NUMA_HIT);
+ } else {
+ __inc_zone_state(z, NUMA_MISS);
+ __inc_zone_state(zonelist->zones[0], NUMA_FOREIGN);
}
+ if (z->zone_pgdat == NODE_DATA(numa_node_id()))
+ __inc_zone_state(z, NUMA_LOCAL);
+ else
+ __inc_zone_state(z, NUMA_OTHER);
}
+#endif
#ifdef CONFIG_PROC_FS
};
static char *vmstat_text[] = {
+ /* Zoned VM counters */
+ "nr_anon_pages",
+ "nr_mapped",
+ "nr_file_pages",
+ "nr_slab",
+ "nr_page_table_pages",
"nr_dirty",
"nr_writeback",
"nr_unstable",
- "nr_page_table_pages",
- "nr_mapped",
- "nr_slab",
+ "nr_bounce",
+
+#ifdef CONFIG_NUMA
+ "numa_hit",
+ "numa_miss",
+ "numa_foreign",
+ "numa_interleave",
+ "numa_local",
+ "numa_other",
+#endif
+#ifdef CONFIG_VM_EVENT_COUNTERS
"pgpgin",
"pgpgout",
"pswpin",
"pswpout",
- "pgalloc_high",
- "pgalloc_normal",
- "pgalloc_dma32",
"pgalloc_dma",
+ "pgalloc_dma32",
+ "pgalloc_normal",
+ "pgalloc_high",
"pgfree",
"pgactivate",
"pgfault",
"pgmajfault",
- "pgrefill_high",
- "pgrefill_normal",
- "pgrefill_dma32",
"pgrefill_dma",
+ "pgrefill_dma32",
+ "pgrefill_normal",
+ "pgrefill_high",
- "pgsteal_high",
- "pgsteal_normal",
- "pgsteal_dma32",
"pgsteal_dma",
+ "pgsteal_dma32",
+ "pgsteal_normal",
+ "pgsteal_high",
- "pgscan_kswapd_high",
- "pgscan_kswapd_normal",
- "pgscan_kswapd_dma32",
"pgscan_kswapd_dma",
+ "pgscan_kswapd_dma32",
+ "pgscan_kswapd_normal",
+ "pgscan_kswapd_high",
- "pgscan_direct_high",
- "pgscan_direct_normal",
- "pgscan_direct_dma32",
"pgscan_direct_dma",
+ "pgscan_direct_dma32",
+ "pgscan_direct_normal",
+ "pgscan_direct_high",
"pginodesteal",
"slabs_scanned",
"allocstall",
"pgrotated",
- "nr_bounce",
+#endif
};
/*
zone->nr_scan_active, zone->nr_scan_inactive,
zone->spanned_pages,
zone->present_pages);
+
+ for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
+ seq_printf(m, "\n %-12s %lu", vmstat_text[i],
+ zone_page_state(zone, i));
+
seq_printf(m,
"\n protection: (%lu",
zone->lowmem_reserve[0]);
pageset->pcp[j].high,
pageset->pcp[j].batch);
}
-#ifdef CONFIG_NUMA
- seq_printf(m,
- "\n numa_hit: %lu"
- "\n numa_miss: %lu"
- "\n numa_foreign: %lu"
- "\n interleave_hit: %lu"
- "\n local_node: %lu"
- "\n other_node: %lu",
- pageset->numa_hit,
- pageset->numa_miss,
- pageset->numa_foreign,
- pageset->interleave_hit,
- pageset->local_node,
- pageset->other_node);
+#ifdef CONFIG_SMP
+ seq_printf(m, "\n vm stats threshold: %d",
+ pageset->stat_threshold);
#endif
}
seq_printf(m,
static void *vmstat_start(struct seq_file *m, loff_t *pos)
{
- struct page_state *ps;
+ unsigned long *v;
+#ifdef CONFIG_VM_EVENT_COUNTERS
+ unsigned long *e;
+#endif
+ int i;
if (*pos >= ARRAY_SIZE(vmstat_text))
return NULL;
- ps = kmalloc(sizeof(*ps), GFP_KERNEL);
- m->private = ps;
- if (!ps)
+#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);
- get_full_page_state(ps);
- ps->pgpgin /= 2; /* sectors -> kbytes */
- ps->pgpgout /= 2;
- return (unsigned long *)ps + *pos;
+ 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)
#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
git.openpandora.org / pandora-kernel.git / blobdiff