Btrfs: reduce calls to wake_up on uncontended locks
authorChris Mason <chris.mason@fusionio.com>
Mon, 23 Jul 2012 19:25:05 +0000 (15:25 -0400)
committerChris Mason <chris.mason@fusionio.com>
Mon, 23 Jul 2012 19:36:18 +0000 (15:36 -0400)
commitcbea5ac1ee03197354bd38caad3fcb798f185181
tree3d6b62c1fd163107ecb08d6489cf0bc159e6df12
parente39e64ac0cdeca3798a6bf186f873be20e2f57b4
Btrfs: reduce calls to wake_up on uncontended locks

The btrfs locks were unconditionally calling wake_up as the
locks were released.  This lead to extra thrashing on the waitqueue,
especially for locks that were dominated by readers.

Signed-off-by: Chris Mason <chris.mason@fusionio.com>
fs/btrfs/locking.c