dm cache: wake the worker thread every time we free a migration object
When the cache is idle, writeback work was only being issued every
second. With this change outstanding writebacks are streamed
constantly. This offers a writeback performance improvement.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 7829d94..6d36ed3 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -418,10 +418,13 @@
static void free_migration(struct dm_cache_migration *mg)
{
- if (atomic_dec_and_test(&mg->cache->nr_allocated_migrations))
- wake_up(&mg->cache->migration_wait);
+ struct cache *cache = mg->cache;
- mempool_free(mg, mg->cache->migration_pool);
+ if (atomic_dec_and_test(&cache->nr_allocated_migrations))
+ wake_up(&cache->migration_wait);
+
+ mempool_free(mg, cache->migration_pool);
+ wake_worker(cache);
}
static int prealloc_data_structs(struct cache *cache, struct prealloc *p)