+#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),
+ round_jiffies_relative(sysctl_stat_interval));
+}
+
+static void __cpuinit 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,
+ __round_jiffies_relative(HZ, cpu));
+}
+
+/*
+ * 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)
+{
+ long cpu = (long)hcpu;
+
+ switch (action) {
+ 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:
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata vmstat_notifier =
+ { &vmstat_cpuup_callback, NULL, 0 };
+#endif
+
+static int __init setup_vmstat(void)
+{
+#ifdef CONFIG_SMP
+ int cpu;
+
+ refresh_zone_stat_thresholds();
+ register_cpu_notifier(&vmstat_notifier);
+
+ for_each_online_cpu(cpu)
+ start_cpu_timer(cpu);
+#endif
+#ifdef CONFIG_PROC_FS
+ proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations);
+ proc_create("pagetypeinfo", S_IRUGO, NULL, &pagetypeinfo_file_ops);
+ proc_create("vmstat", S_IRUGO, NULL, &proc_vmstat_file_operations);
+ proc_create("zoneinfo", S_IRUGO, NULL, &proc_zoneinfo_file_operations);
+#endif
+ return 0;
+}
+module_init(setup_vmstat)