On Tue, Jun 14, 2016 at 02:12:39PM -0400, Waiman Long wrote: > This patch enables reader optimistic spinning for inodes that are > under a DAX-based mount point. > > On a 4-socket Haswell machine running on a 4.7-rc1 tip-based kernel, > the fio test with multithreaded randrw and randwrite tests on the > same file on a XFS partition on top of a NVDIMM with DAX were run, > the aggregated bandwidths before and after the patch were as follows:
And why is this specific to DAX? Many I/O operations already never got out to disk, and ilock is mostly held for operations that have nothing to do with disk I/O.
