dm cache: add cond_resched() to various workqueue loops

[ Upstream commit 76227f6dc805e9e960128bcc6276647361e0827c ]

Otherwise on resource constrained systems these workqueues may be too
greedy.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index abfe7e37b76f436f15232ca6b4f4f0942ac62a78..24cd28ea2c5957a463455f870027fd0092c44b5d 100644 (file)
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -1813,6 +1813,7 @@ static void process_deferred_bios(struct work_struct *ws)
 
                else
                        commit_needed = process_bio(cache, bio) || commit_needed;
+               cond_resched();
        }
 
        if (commit_needed)
@@ -1835,6 +1836,7 @@ static void requeue_deferred_bios(struct cache *cache)
        while ((bio = bio_list_pop(&bios))) {
                bio->bi_status = BLK_STS_DM_REQUEUE;
                bio_endio(bio);
+               cond_resched();
        }
 }
 
@@ -1875,6 +1877,8 @@ static void check_migrations(struct work_struct *ws)
                r = mg_start(cache, op, NULL);
                if (r)
                        break;
+
+               cond_resched();
        }
 }