btrfs: remove unlikely from data-dependent branches and slow paths
There are the branch hints that obviously depend on the data being
processed, the CPU predictor will do better job according to the actual
load. It also does not make sense to use the hints in slow paths that do
a lot of other operations like locking, waiting or IO.
Signed-off-by: David Sterba <dsterba@suse.cz>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 44d0497..ede740b 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -9694,7 +9694,7 @@
int btrfs_start_nocow_write(struct btrfs_root *root)
{
- if (unlikely(atomic_read(&root->will_be_snapshoted)))
+ if (atomic_read(&root->will_be_snapshoted))
return 0;
percpu_counter_inc(&root->subv_writers->counter);
@@ -9702,7 +9702,7 @@
* Make sure counter is updated before we check for snapshot creation.
*/
smp_mb();
- if (unlikely(atomic_read(&root->will_be_snapshoted))) {
+ if (atomic_read(&root->will_be_snapshoted)) {
btrfs_end_nocow_write(root);
return 0;
}