From 821e6b62e6833b54eca6f131d2c507f7661a1a8e Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Thu, 11 May 2017 05:07:34 -0400 Subject: [PATCH] dm cache policy smq: only demote entries in bottom half of the clean multiqueue Heavy IO load may mean there are very few clean blocks in the cache, and we risk demoting entries that get hit a lot. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- drivers/md/dm-cache-policy-smq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/dm-cache-policy-smq.c b/drivers/md/dm-cache-policy-smq.c index 72479bd61e118..a177559f2049f 100644 --- a/drivers/md/dm-cache-policy-smq.c +++ b/drivers/md/dm-cache-policy-smq.c @@ -1190,7 +1190,7 @@ static void queue_demotion(struct smq_policy *mq) if (unlikely(WARN_ON_ONCE(!mq->migrations_allowed))) return; - e = q_peek(&mq->clean, mq->clean.nr_levels, true); + e = q_peek(&mq->clean, mq->clean.nr_levels / 2, true); if (!e) { if (!clean_target_met(mq, false)) queue_writeback(mq); -- 2.39.5