diff options
| author | Joe Thornber <ejt@redhat.com> | 2017-05-11 13:48:18 +0200 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2017-05-15 03:54:33 +0200 |
| commit | 6cf4cc8f8b3b7bc9e3c04a7eab44b985d50029fc (patch) | |
| tree | f9efea7081881af53eabb2f36d7aeafbfd44f71d /drivers/md | |
| parent | dm cache policy smq: put newly promoted entries at the top of the multiqueue (diff) | |
| download | linux-6cf4cc8f8b3b7bc9e3c04a7eab44b985d50029fc.tar.xz linux-6cf4cc8f8b3b7bc9e3c04a7eab44b985d50029fc.zip | |
dm cache policy smq: stop preemptively demoting blocks
It causes a lot of churn if the working set's size is close to the fast
device's size.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-cache-policy-smq.c | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/drivers/md/dm-cache-policy-smq.c b/drivers/md/dm-cache-policy-smq.c index 54421a846a0c..758480a1893d 100644 --- a/drivers/md/dm-cache-policy-smq.c +++ b/drivers/md/dm-cache-policy-smq.c @@ -1134,13 +1134,10 @@ static bool clean_target_met(struct smq_policy *mq, bool idle) percent_to_target(mq, CLEAN_TARGET); } -static bool free_target_met(struct smq_policy *mq, bool idle) +static bool free_target_met(struct smq_policy *mq) { unsigned nr_free; - if (!idle) - return true; - nr_free = from_cblock(mq->cache_size) - mq->cache_alloc.nr_allocated; return (nr_free + btracker_nr_demotions_queued(mq->bg_work)) >= percent_to_target(mq, FREE_TARGET); @@ -1220,7 +1217,7 @@ static void queue_promotion(struct smq_policy *mq, dm_oblock_t oblock, * We always claim to be 'idle' to ensure some demotions happen * with continuous loads. */ - if (!free_target_met(mq, true)) + if (!free_target_met(mq)) queue_demotion(mq); return; } @@ -1421,14 +1418,10 @@ static int smq_get_background_work(struct dm_cache_policy *p, bool idle, spin_lock_irqsave(&mq->lock, flags); r = btracker_issue(mq->bg_work, result); if (r == -ENODATA) { - /* find some writeback work to do */ - if (mq->migrations_allowed && !free_target_met(mq, idle)) - queue_demotion(mq); - - else if (!clean_target_met(mq, idle)) + if (!clean_target_met(mq, idle)) { queue_writeback(mq); - - r = btracker_issue(mq->bg_work, result); + r = btracker_issue(mq->bg_work, result); + } } spin_unlock_irqrestore(&mq->lock, flags); |