diff options
| author | GregorKopka <[email protected]> | 2013-09-19 16:42:17 +0200 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2013-09-25 15:29:45 -0700 |
| commit | f9f3f1ef983e987a2e09a49c3684405561fed634 (patch) | |
| tree | d7c90d355ed2cf4e6c5f7f1de5ce59669e7ca75e /module/zfs | |
| parent | 77831e17385ba822fe70436d862c0e14df5d67b2 (diff) | |
Removing unneeded mutex for reading vq_pending_tree size
Locking mutex &vq->vq_lock in vdev_mirror_pending is unneeded:
* no data is modified
* only vq_pending_tree is read
* in case garbage is returned (eg. vq_pending_tree being updated
while the read is made) the worst case would be that a single
read could be queued on a mirror side which more busy than thought
The benefit of this change is streamlining of the code path since
it is taken for *every* mirror member on *every* read.
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #1739
Diffstat (limited to 'module/zfs')
| -rw-r--r-- | module/zfs/vdev_mirror.c | 9 |
1 files changed, 1 insertions, 8 deletions
diff --git a/module/zfs/vdev_mirror.c b/module/zfs/vdev_mirror.c index e0884dc3c..e3d772ac2 100644 --- a/module/zfs/vdev_mirror.c +++ b/module/zfs/vdev_mirror.c @@ -89,14 +89,7 @@ static const zio_vsd_ops_t vdev_mirror_vsd_ops = { static int vdev_mirror_pending(vdev_t *vd) { - vdev_queue_t *vq = &vd->vdev_queue; - int pending; - - mutex_enter(&vq->vq_lock); - pending = avl_numnodes(&vq->vq_pending_tree); - mutex_exit(&vq->vq_lock); - - return (pending); + return avl_numnodes(&vd->vdev_queue.vq_pending_tree); } static mirror_map_t * |