Following the same idea, it occurs to me that we should only update
disk stat when "now" is different from disk->stamp. Otherwise, we
are again needlessly adding zero to the stats.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
index c42071f..4e2b1b0 100644
--- a/drivers/block/ll_rw_blk.c
+++ b/drivers/block/ll_rw_blk.c
@@ -2433,6 +2433,9 @@
{
unsigned long now = jiffies;
+ if (now == disk->stamp)
+ return;
+
if (disk->in_flight) {
__disk_stat_add(disk, time_in_queue,
disk->in_flight * (now - disk->stamp));