From: Joe Thornber When discards are prepared it is best to directly wake the worker that will process them. The worker will be woken anyway, via periodic commit, but there is no reason to not wake_worker here. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-thin.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) Index: linux/drivers/md/dm-thin.c =================================================================== --- linux.orig/drivers/md/dm-thin.c +++ linux/drivers/md/dm-thin.c @@ -2676,10 +2676,13 @@ static int thin_endio(struct dm_target * if (h->all_io_entry) { INIT_LIST_HEAD(&work); dm_deferred_entry_dec(h->all_io_entry, &work); - spin_lock_irqsave(&pool->lock, flags); - list_for_each_entry_safe(m, tmp, &work, list) - list_add(&m->list, &pool->prepared_discards); - spin_unlock_irqrestore(&pool->lock, flags); + if (!list_empty(&work)) { + spin_lock_irqsave(&pool->lock, flags); + list_for_each_entry_safe(m, tmp, &work, list) + list_add(&m->list, &pool->prepared_discards); + spin_unlock_irqrestore(&pool->lock, flags); + wake_worker(pool); + } } mempool_free(h, pool->endio_hook_pool);