diff mbox series

[2/4] blk-throttle: Avoid getting the current time if tg->last_finish_time is 0

Message ID 534c289866f74d1587806f7818baac789b49c484.1600592693.git.baolin.wang@linux.alibaba.com (mailing list archive)
State New, archived
Headers show
Series Some improvements for blk throttle | expand

Commit Message

Baolin Wang Sept. 20, 2020, 9:10 a.m. UTC 
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@linux.alibaba.com>
---
 block/blk-throttle.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
diff mbox series

Patch

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;