[PATCH v2 2/8] blk-throttle: Avoid getting the current time if tg->last_finish_time is 0
From: Baolin Wang <hidden>
Date: 2020-10-08 03:53:08
Also in:
linux-block, lkml
Subsystem:
block layer, control group - block io controller (blkio), the rest · Maintainers:
Jens Axboe, Tejun Heo, Josef Bacik, Linus Torvalds
We only update the tg->last_finish_time when the low limitaion is enabled, so we can move the tg->last_finish_time validation a little forward to avoid getting the unnecessary current time stamp if the the low limitation is not enabled. Signed-off-by: Baolin Wang <baolin.wang-KPsoFbNs7GizrGE5bRqYAgC/G2K4zDHf@public.gmane.org> --- block/blk-throttle.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 4007b26..7e72102 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c@@ -2077,10 +2077,14 @@ static void throtl_downgrade_check(struct throtl_grp *tg) static void blk_throtl_update_idletime(struct throtl_grp *tg) { - unsigned long now = ktime_get_ns() >> 10; + unsigned long now; unsigned long last_finish_time = tg->last_finish_time; - if (now <= last_finish_time || last_finish_time == 0 || + if (last_finish_time == 0) + return; + + now = ktime_get_ns() >> 10; + if (now <= last_finish_time || last_finish_time == tg->checked_last_finish_time) return;
--
1.8.3.1