fs: push rcu_barrier() from deactivate_locked_super() to filesystems
There's no reason to call rcu_barrier() on every
deactivate_locked_super(). We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.
Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths. E.g. on my machine exit_group() of a last process in IPC
namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 19e2380..83d36e4 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1506,6 +1506,11 @@
STATIC void
xfs_destroy_zones(void)
{
+ /*
+ * Make sure all delayed rcu free are flushed before we
+ * destroy caches.
+ */
+ rcu_barrier();
kmem_zone_destroy(xfs_ili_zone);
kmem_zone_destroy(xfs_inode_zone);
kmem_zone_destroy(xfs_efi_zone);
