From: Dave Chinner <dchinner@xxxxxxxxxx>
Avoid an extra atomic operation in the non-trylock case by only
doing a trylock if the XBF_TRYLOCK flag is set. This follows the
pattern in the IO path with NOWAIT semantics where the
"trylock-fail-lock" path showed 5-10% reduced throughput compared to
just using single lock call when not under NOWAIT conditions. So
make that same change here, too.
See commit 942491c9e6d6 ("xfs: fix AIM7 regression") for details.
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
fs/xfs/xfs_buf.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 81ca951b451a..374c4e508b12 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -534,11 +534,12 @@ xfs_buf_find_lock(
struct xfs_buf *bp,
xfs_buf_flags_t flags)
{
- if (!xfs_buf_trylock(bp)) {
- if (flags & XBF_TRYLOCK) {
+ if (flags & XBF_TRYLOCK) {
+ if (!xfs_buf_trylock(bp)) {
XFS_STATS_INC(bp->b_mount, xb_busy_locked);
return -EAGAIN;
}
+ } else {
xfs_buf_lock(bp);
XFS_STATS_INC(bp->b_mount, xb_get_locked_waited);
}
--
2.36.1
