On Tue, Oct 15, 2013 at 04:39:28PM -0400, J. Bruce Fields wrote: > I tested performance with a script that creates an N-deep directory > tree, gets a filehandle for the bottom directory, writes 2 to > /proc/sys/vm/drop_caches, then times an open_by_handle_at() of the > filehandle. Code at > > git://linux-nfs.org/~bfields/fhtests.git > > For directories of various depths, some example observed times (median > results of 3 similar runs, in seconds), were: > > depth: 8000 2000 200 > no patches: 11 0.7 0.02 > first patch: 6 0.4 0.01 > all patches: 0.1 0.03 0.01 > > For depths < 2000 I used an ugly hack to shrink_slab_node() to force > drop_caches to free more dentries. Difference look lost in the noise > for much smaller depths. Btw, it would be good to get this wired up in xfstests - add xfs_io commands for the by handle ops and then just wire up the script driving them. I'd also really like to see a stress test for cold handle conversion vs various VFS ops based on that sort of infrastructure. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
