#include <linux/module.h>
#include <linux/slab.h>
#include <linux/cpu.h>
+#include <linux/cpumask.h>
#include <linux/vmstat.h>
#include <linux/sched.h>
#include <linux/math64.h>
* 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)
+bool refresh_cpu_vm_stats(int cpu)
{
struct zone *zone;
int i;
int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+ bool vm_activity = false;
for_each_populated_zone(zone) {
struct per_cpu_pageset *p;
if (p->expire)
continue;
- if (p->pcp.count)
+ if (p->pcp.count) {
+ vm_activity = true;
drain_zone_pages(zone, &p->pcp);
+ }
#endif
}
for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
- if (global_diff[i])
+ if (global_diff[i]) {
atomic_long_add(global_diff[i], &vm_stat[i]);
+ vm_activity = true;
+ }
+
+ return vm_activity;
+
}
/*
#ifdef CONFIG_NUMA_BALANCING
"numa_pte_updates",
+ "numa_huge_pte_updates",
"numa_hint_faults",
"numa_hint_faults_local",
"numa_pages_migrated",
#ifdef CONFIG_SMP
static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
int sysctl_stat_interval __read_mostly = HZ;
+static struct cpumask vmstat_off_cpus;
+struct delayed_work vmstat_monitor_work;
-static void vmstat_update(struct work_struct *w)
+static inline bool need_vmstat(int cpu)
{
- refresh_cpu_vm_stats(smp_processor_id());
- schedule_delayed_work(&__get_cpu_var(vmstat_work),
- round_jiffies_relative(sysctl_stat_interval));
+ struct zone *zone;
+ int i;
+
+ 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])
+ return true;
+
+ if (zone_to_nid(zone) != numa_node_id() && p->pcp.count)
+ return true;
+ }
+
+ return false;
}
-static void __cpuinit start_cpu_timer(int cpu)
+static void vmstat_update(struct work_struct *w);
+
+static void start_cpu_timer(int cpu)
{
struct delayed_work *work = &per_cpu(vmstat_work, cpu);
- INIT_DEFERRABLE_WORK(work, vmstat_update);
+ cpumask_clear_cpu(cpu, &vmstat_off_cpus);
schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
}
+static void __cpuinit setup_cpu_timer(int cpu)
+{
+ struct delayed_work *work = &per_cpu(vmstat_work, cpu);
+
+ INIT_DEFERRABLE_WORK(work, vmstat_update);
+ start_cpu_timer(cpu);
+}
+
+static void vmstat_update_monitor(struct work_struct *w)
+{
+ int cpu;
+
+ for_each_cpu_and(cpu, &vmstat_off_cpus, cpu_online_mask)
+ if (need_vmstat(cpu))
+ start_cpu_timer(cpu);
+
+ queue_delayed_work(system_unbound_wq, &vmstat_monitor_work,
+ round_jiffies_relative(sysctl_stat_interval));
+}
+
+
+static void vmstat_update(struct work_struct *w)
+{
+ int cpu = smp_processor_id();
+
+ if (likely(refresh_cpu_vm_stats(cpu)))
+ schedule_delayed_work(&__get_cpu_var(vmstat_work),
+ round_jiffies_relative(sysctl_stat_interval));
+ else
+ cpumask_set_cpu(cpu, &vmstat_off_cpus);
+}
+
/*
* Use the cpu notifier to insure that the thresholds are recalculated
* when necessary.
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
refresh_zone_stat_thresholds();
- start_cpu_timer(cpu);
+ setup_cpu_timer(cpu);
node_set_state(cpu_to_node(cpu), N_CPU);
break;
case CPU_DOWN_PREPARE:
case CPU_DOWN_PREPARE_FROZEN:
- cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu));
- per_cpu(vmstat_work, cpu).work.func = NULL;
+ if (!cpumask_test_cpu(cpu, &vmstat_off_cpus)) {
+ cancel_delayed_work_sync(&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);
+ setup_cpu_timer(cpu);
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
register_cpu_notifier(&vmstat_notifier);
+ INIT_DEFERRABLE_WORK(&vmstat_monitor_work,
+ vmstat_update_monitor);
+ queue_delayed_work(system_unbound_wq,
+ &vmstat_monitor_work,
+ round_jiffies_relative(HZ));
+
for_each_online_cpu(cpu)
- start_cpu_timer(cpu);
+ setup_cpu_timer(cpu);
#endif
#ifdef CONFIG_PROC_FS
proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);