On Mon, Jun 27, 2022 at 04:08:39PM +1000, Dave Chinner wrote:
> 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>
LGTM
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> ---
> 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 469e84fe21aa..3bcb691c6d95 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
>
