From a8cd1eba6135e086109e2b94bf96deb17456ede8 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 72479bd61e11..a177559f2049 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); -- 2.30.2