1 files changed, 14 insertions, 81 deletions

diff --git a/mm/vmstat.c b/mm/vmstat.c
index b916a43a6b37..f42745e65780 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -14,7 +14,6 @@
 #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>
@@ -433,12 +432,11 @@ EXPORT_SYMBOL(dec_zone_page_state);
  * with the global counters. These could cause remote node cache line
  * bouncing and will have to be only done when necessary.
  */
-bool refresh_cpu_vm_stats(int cpu)
+void 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;
@@ -485,21 +483,14 @@ bool refresh_cpu_vm_stats(int cpu)
 		if (p->expire)
 			continue;
 
-		if (p->pcp.count) {
-			vm_activity = true;
+		if (p->pcp.count)
 			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;
-
 }
 
 /*
@@ -1183,70 +1174,20 @@ static const struct file_operations proc_vmstat_file_operations = {
 #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 inline bool need_vmstat(int cpu)
-{
-	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 vmstat_update(struct work_struct *w);
-
-static void start_cpu_timer(int cpu)
+static void vmstat_update(struct work_struct *w)
 {
-	struct delayed_work *work = &per_cpu(vmstat_work, cpu);
-
-	cpumask_clear_cpu(cpu, &vmstat_off_cpus);
-	schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
+	refresh_cpu_vm_stats(smp_processor_id());
+	schedule_delayed_work(&__get_cpu_var(vmstat_work),
+		round_jiffies_relative(sysctl_stat_interval));
 }
 
-static void __cpuinit setup_cpu_timer(int cpu)
+static void __cpuinit start_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);
+	schedule_delayed_work_on(cpu, work, __round_jiffies_relative(HZ, cpu));
 }
 
 /*
@@ -1263,19 +1204,17 @@ static int __cpuinit vmstat_cpuup_callback(struct notifier_block *nfb,
 	case CPU_ONLINE:
 	case CPU_ONLINE_FROZEN:
 		refresh_zone_stat_thresholds();
-		setup_cpu_timer(cpu);
+		start_cpu_timer(cpu);
 		node_set_state(cpu_to_node(cpu), N_CPU);
 		break;
 	case CPU_DOWN_PREPARE:
 	case CPU_DOWN_PREPARE_FROZEN:
-		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;
-		}
+		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:
-		setup_cpu_timer(cpu);
+		start_cpu_timer(cpu);
 		break;
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN:
@@ -1298,14 +1237,8 @@ static int __init setup_vmstat(void)
 
 	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)
-		setup_cpu_timer(cpu);
+		start_cpu_timer(cpu);
 #endif
 #ifdef CONFIG_PROC_FS
 	proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);