diff options
| author | Baokun Li <libaokun@linux.alibaba.com> | 2026-05-21 17:50:15 +0800 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2026-05-22 12:06:35 +0200 |
| commit | e90a6d668e26e00a72df2d09c173b563468f09c9 (patch) | |
| tree | d28269a1ce82a20b950b3d9febcb16d62c16141d | |
| parent | cba38ec4cbd3a7b8b942a8d52531a05be8a9ff0d (diff) | |
writeback: drop now-unnecessary rcu_barrier() in cgroup_writeback_umount()
Commit e1b849cfa6b6 ("writeback: Avoid contention on wb->list_lock when
switching inodes") replaced the queue_rcu_work() based scheduling of
inode wb switches with a plain queue_work(). Since then no switcher
goes through call_rcu(), so rcu_barrier() in cgroup_writeback_umount()
has no callbacks of its own to wait for. It still drains unrelated
call_rcu() callbacks from other subsystems on busy systems, which
incidentally slows umount down; drop it.
Fixes: e1b849cfa6b6 ("writeback: Avoid contention on wb->list_lock when switching inodes")
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun@linux.alibaba.com>
Link: https://patch.msgid.link/20260521095016.2791354-3-libaokun@linux.alibaba.com
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
| -rw-r--r-- | fs/fs-writeback.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 6766de9f9d75..325a30cc35bf 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1248,11 +1248,6 @@ void cgroup_writeback_umount(struct super_block *sb) * will then drain it. */ synchronize_rcu(); - /* - * Use rcu_barrier() to wait for all pending callbacks to - * ensure that all in-flight wb switches are in the workqueue. - */ - rcu_barrier(); flush_workqueue(isw_wq); } } |