tag 4755587e53c6e50a58c96d5b0d5fdf187c227e1d
tagger Darrick J. Wong <darrick.wong@oracle.com> Mon Oct 23 18:32:07 2017 -0700
object 942491c9e6d631c012f3c4ea8e7777b0b02edeab

Changes since last time:
- Rework nowait locking code to reduce locking overhead penalty

commit 942491c9e6d631c012f3c4ea8e7777b0b02edeab
author Christoph Hellwig <hch@lst.de> Mon Oct 23 18:31:50 2017 -0700
committer Darrick J. Wong <darrick.wong@oracle.com> Mon Oct 23 18:31:50 2017 -0700
tree b316042eb963aaede79c0ce3aa1ac8772a38f4db
parent 785545c8982604fe3ba79d16409e83993be77d5e

xfs: fix AIM7 regression

Apparently our current rwsem code doesn't like doing the trylock, then
lock for real scheme.  So change our read/write methods to just do the
trylock for the RWF_NOWAIT case.  This fixes a ~25% regression in
AIM7.

Fixes: 91f9943e ("fs: support RWF_NOWAIT for buffered reads")
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>