xfs: reduce the number of atomic when locking a buffer after lookup

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 <[email protected]>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>

0 files changed, 0 insertions, 0 deletions