From 9f233ffe02e5cef611100cd8c5bcf4de26ca7bef Mon Sep 17 00:00:00 2001 From: Kai Krakow Date: Wed, 10 Feb 2021 13:07:25 +0800 Subject: Revert "bcache: Kill btree_io_wq" This reverts commit 56b30770b27d54d68ad51eccc6d888282b568cee. With the btree using the `system_wq`, I seem to see a lot more desktop latency than I should. After some more investigation, it looks like the original assumption of 56b3077 no longer is true, and bcache has a very high potential of congesting the `system_wq`. In turn, this introduces laggy desktop performance, IO stalls (at least with btrfs), and input events may be delayed. So let's revert this. It's important to note that the semantics of using `system_wq` previously mean that `btree_io_wq` should be created before and destroyed after other bcache wqs to keep the same assumptions. Cc: Coly Li Cc: stable@vger.kernel.org # 5.4+ Signed-off-by: Kai Krakow Signed-off-by: Coly Li Signed-off-by: Jens Axboe --- drivers/md/bcache/bcache.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/md/bcache/bcache.h') diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index d7a84327b7f1..2b8c7dd2cfae 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -1046,5 +1046,7 @@ void bch_debug_exit(void); void bch_debug_init(void); void bch_request_exit(void); int bch_request_init(void); +void bch_btree_exit(void); +int bch_btree_init(void); #endif /* _BCACHE_H */ -- cgit v1.2.1