diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2025-08-11 15:23:03 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-08-25 14:09:25 +0200 |
| commit | ec6f613ef376410753173f8236bad5f07a86503a (patch) | |
| tree | e387f1eecaa1d97ace96f25ef003267b05dfc4f3 | |
| parent | 14498ca7e0f18cd73ab0010cbfbf9413a9f0a96f (diff) | |
fs: Use try_cmpxchg() in sb_init_done_wq()
Use !try_cmpxchg() instead of cmpxchg(*ptr, old, new) != old.
The x86 CMPXCHG instruction returns success in the ZF flag,
so this change saves a compare after CMPXCHG.
No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Link: https://lore.kernel.org/20250811132326.620521-1-ubizjak@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | fs/super.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/fs/super.c b/fs/super.c index 7f876f32343a..e91718017701 100644 --- a/fs/super.c +++ b/fs/super.c @@ -2318,13 +2318,15 @@ int sb_init_dio_done_wq(struct super_block *sb) sb->s_id); if (!wq) return -ENOMEM; + + old = NULL; /* * This has to be atomic as more DIOs can race to create the workqueue */ - old = cmpxchg(&sb->s_dio_done_wq, NULL, wq); - /* Someone created workqueue before us? Free ours... */ - if (old) + if (!try_cmpxchg(&sb->s_dio_done_wq, &old, wq)) { + /* Someone created workqueue before us? Free ours... */ destroy_workqueue(wq); + } return 0; } EXPORT_SYMBOL_GPL(sb_init_dio_done_wq); |