diff options
| author | Joe Thornber <ejt@redhat.com> | 2014-09-12 11:34:01 +0100 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2014-11-10 15:25:27 -0500 |
| commit | 7a7e97ca580b944d2c89b59bc74a7b9ddd044705 (patch) | |
| tree | 93ce0a65769205e6330ccf0691777eeaf51011fa | |
| parent | 36f12aeb714fc04752997d6c07b6afb2fa0ac947 (diff) | |
dm thin: performance improvement to discard processing
When processing a discard bio, if the block is already quiesced do the
discard immediately rather than adding the mapping to a list for the
next iteration of the worker thread.
Discarding a fully provisioned 100G thin volume with 64k block size goes
from 860s to 95s with this change.
Clearly there's something wrong with the worker architecture, more
investigation needed.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| -rw-r--r-- | drivers/md/dm-thin.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 06860782869..8c3d048dd31 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -1194,7 +1194,6 @@ static void retry_bios_on_resume(struct pool *pool, struct dm_bio_prison_cell *c static void process_discard(struct thin_c *tc, struct bio *bio) { int r; - unsigned long flags; struct pool *pool = tc->pool; struct dm_bio_prison_cell *cell, *cell2; struct dm_cell_key key, key2; @@ -1235,12 +1234,9 @@ static void process_discard(struct thin_c *tc, struct bio *bio) m->cell2 = cell2; m->bio = bio; - if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) { - spin_lock_irqsave(&pool->lock, flags); - list_add_tail(&m->list, &pool->prepared_discards); - spin_unlock_irqrestore(&pool->lock, flags); - wake_worker(pool); - } + if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list)) + pool->process_prepared_discard(m); + } else { inc_all_io_entry(pool, bio); cell_defer_no_holder(tc, cell); |