Make vm statistics update interval configurable
Make it configurable. Code in mm makes the vm statistics intervals
independent from the cache reaper use that opportunity to make it
configurable.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index f0664bd..4073353 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -77,6 +77,7 @@
extern int percpu_pagelist_fraction;
extern int compat_log;
extern int maps_protect;
+extern int sysctl_stat_interval;
/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
static int maxolduid = 65535;
@@ -857,6 +858,17 @@
.extra2 = &one_hundred,
},
#endif
+#ifdef CONFIG_SMP
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "stat_interval",
+ .data = &sysctl_stat_interval,
+ .maxlen = sizeof(sysctl_stat_interval),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_jiffies,
+ .strategy = &sysctl_jiffies,
+ },
+#endif
#if defined(CONFIG_X86_32) || \
(defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
{
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 9d82464..006eb76 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -641,11 +641,13 @@
#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), HZ);
+ schedule_delayed_work(&__get_cpu_var(vmstat_work),
+ sysctl_stat_interval);
}
static void __devinit start_cpu_timer(int cpu)