From 62421b3880c71da7ecbf9c4072dc64ef3e65ad0a Mon Sep 17 00:00:00 2001 From: Huaisheng Ye Date: Sun, 25 Aug 2019 15:24:32 +0800 Subject: [PATCH] dm writecache: add unlikely for getting two block with same LBA In function writecache_writeback, entries g and f has same original sector only happens at entry f has been committed, but entry g has NOT yet. The probability of this happening is very low in the following 256 blocks at most of entry e. Signed-off-by: Huaisheng Ye Acked-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-writecache.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c index 5c7009d716d0..3643084f92e2 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -1628,8 +1628,8 @@ restart: if (unlikely(!next_node)) break; g = container_of(next_node, struct wc_entry, rb_node); - if (read_original_sector(wc, g) == - read_original_sector(wc, f)) { + if (unlikely(read_original_sector(wc, g) == + read_original_sector(wc, f))) { f = g; continue; }