[PATCH 3/5] vmevent: Refresh vmstats before sampling

[Anton Vorontsov <anton.vorontsov@linaro.org>]

On SMP, kernel updates vmstats only once per second, which makes vmevent
unusable. Let's fix it by updating vmstats before sampling.

Reported-by: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
---
 mm/vmevent.c |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mm/vmevent.c b/mm/vmevent.c
index 4ca2a04..35fd0d5 100644
--- a/mm/vmevent.c
+++ b/mm/vmevent.c
@@ -2,6 +2,7 @@
 #include <linux/atomic.h>
 #include <linux/compiler.h>
 #include <linux/vmevent.h>
+#include <linux/mm.h>
 #include <linux/syscalls.h>
 #include <linux/workqueue.h>
 #include <linux/file.h>
@@ -163,6 +164,9 @@ static void vmevent_sample(struct vmevent_watch *watch)
 
 	if (atomic_read(&watch->pending))
 		return;
+
+	refresh_vm_stats();
+
 	if (!vmevent_match(watch))
 		return;
 
-- 
1.7.9.2