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-rw-r--r--mm/vmstat.c96
1 files changed, 89 insertions, 7 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 6c488d6ac42..38254297a49 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -12,6 +12,7 @@
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/cpu.h>
+#include <linux/sched.h>
#ifdef CONFIG_VM_EVENT_COUNTERS
DEFINE_PER_CPU(struct vm_event_state, vm_event_states) = {{0}};
@@ -281,6 +282,17 @@ EXPORT_SYMBOL(dec_zone_page_state);
/*
* Update the zone counters for one cpu.
+ *
+ * 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.
*/
void refresh_cpu_vm_stats(int cpu)
{
@@ -289,21 +301,54 @@ void refresh_cpu_vm_stats(int cpu)
unsigned long flags;
for_each_zone(zone) {
- struct per_cpu_pageset *pcp;
+ struct per_cpu_pageset *p;
if (!populated_zone(zone))
continue;
- pcp = zone_pcp(zone, cpu);
+ p = zone_pcp(zone, cpu);
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
- if (pcp->vm_stat_diff[i]) {
+ if (p->vm_stat_diff[i]) {
local_irq_save(flags);
- zone_page_state_add(pcp->vm_stat_diff[i],
+ zone_page_state_add(p->vm_stat_diff[i],
zone, i);
- pcp->vm_stat_diff[i] = 0;
+ p->vm_stat_diff[i] = 0;
+#ifdef CONFIG_NUMA
+ /* 3 seconds idle till flush */
+ p->expire = 3;
+#endif
local_irq_restore(flags);
}
+#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.
+ */
+ if (!p->expire || (!p->pcp[0].count && !p->pcp[1].count))
+ continue;
+
+ /*
+ * We never drain zones local to this processor.
+ */
+ if (zone_to_nid(zone) == numa_node_id()) {
+ p->expire = 0;
+ continue;
+ }
+
+ p->expire--;
+ if (p->expire)
+ continue;
+
+ if (p->pcp[0].count)
+ drain_zone_pages(zone, p->pcp + 0);
+
+ if (p->pcp[1].count)
+ drain_zone_pages(zone, p->pcp + 1);
+#endif
}
}
@@ -640,6 +685,24 @@ const struct seq_operations vmstat_op = {
#endif /* CONFIG_PROC_FS */
#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
+int sysctl_stat_interval __read_mostly = HZ;
+
+static void vmstat_update(struct work_struct *w)
+{
+ refresh_cpu_vm_stats(smp_processor_id());
+ schedule_delayed_work(&__get_cpu_var(vmstat_work),
+ sysctl_stat_interval);
+}
+
+static void __devinit start_cpu_timer(int cpu)
+{
+ struct delayed_work *vmstat_work = &per_cpu(vmstat_work, cpu);
+
+ INIT_DELAYED_WORK_DEFERRABLE(vmstat_work, vmstat_update);
+ schedule_delayed_work_on(cpu, vmstat_work, HZ + cpu);
+}
+
/*
* Use the cpu notifier to insure that the thresholds are recalculated
* when necessary.
@@ -648,10 +711,24 @@ static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
unsigned long action,
void *hcpu)
{
+ long cpu = (long)hcpu;
+
switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_CANCELED:
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ start_cpu_timer(cpu);
+ break;
+ case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
+ cancel_rearming_delayed_work(&per_cpu(vmstat_work, cpu));
+ per_cpu(vmstat_work, cpu).work.func = NULL;
+ break;
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
+ start_cpu_timer(cpu);
+ break;
case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
refresh_zone_stat_thresholds();
break;
default:
@@ -665,8 +742,13 @@ static struct notifier_block __cpuinitdata vmstat_notifier =
int __init setup_vmstat(void)
{
+ int cpu;
+
refresh_zone_stat_thresholds();
register_cpu_notifier(&vmstat_notifier);
+
+ for_each_online_cpu(cpu)
+ start_cpu_timer(cpu);
return 0;
}
module_init(setup_vmstat)