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| author | David Sterba <dsterba@suse.com> | 2015-02-16 19:39:00 +0100 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2015-10-10 18:40:33 +0200 |
| commit | 779adf0f647651f5a45eeee3442c881300ce989e (patch) | |
| tree | 4f9e555faf8ce150305cea076a31d509653205bb | |
| parent | a83342aa0c8f0ca90057d3837ae8d198186e5153 (diff) | |
btrfs: remove extra barrier before waitqueue_active
Removing barriers is scary, but a call to atomic_dec_and_test implies
a barrier, so we don't need to issue another one.
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | fs/btrfs/tree-log.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index d0deb4643502..63275594debd 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -229,7 +229,9 @@ int btrfs_pin_log_trans(struct btrfs_root *root) void btrfs_end_log_trans(struct btrfs_root *root) { if (atomic_dec_and_test(&root->log_writers)) { - smp_mb(); + /* + * Implicit memory barrier after atomic_dec_and_test + */ if (waitqueue_active(&root->log_writer_wait)) wake_up(&root->log_writer_wait); } @@ -2820,7 +2822,9 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans, mutex_lock(&log_root_tree->log_mutex); if (atomic_dec_and_test(&log_root_tree->log_writers)) { - smp_mb(); + /* + * Implicit memory barrier after atomic_dec_and_test + */ if (waitqueue_active(&log_root_tree->log_writer_wait)) wake_up(&log_root_tree->log_writer_wait); } |