blk-throttle: Avoid getting the current time if tg->last_finish_time is 0
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>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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;