From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bob Peterson Date: Mon, 16 Nov 2015 13:14:33 -0500 (EST) Subject: [Cluster-devel] [PATCH 2/2] gfs2: Extended attribute readahead optimization In-Reply-To: References: <1446404579-5211-1-git-send-email-agruenba@redhat.com> <1446404579-5211-3-git-send-email-agruenba@redhat.com> <564497B6.7060105@redhat.com> <1447359346-11402-1-git-send-email-agruenba@redhat.com> <5644F78E.60205@redhat.com> Message-ID: <887170668.12201825.1447697673364.JavaMail.zimbra@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit ----- Original Message ----- > On Thu, Nov 12, 2015 at 9:33 PM, Steven Whitehouse > wrote: > > That looks good to me, and I assume that it should be faster too? > > I did some tests with a directory tree with 3439 directories and 51556 > files in it. > > In that tree, 47313 or 86% of the 54995 files and directories ended up > with readahead enabled, while 7682 didn't. > > On a slow SATA magnetic disc, I compared the time required for running > "find", then "find | xargs stat", then "find | xargs getfattr". I > booted with selinux=0 for these measurements, so "find" and "find | > xargs stat" didn't use the xattrs. > > The results are attached as a spreadsheet. They show that xattr > readahead can save quite some time (here, about -75%). The optimized > version of xattr readahead is about 3% faster than the simple version > in this test, so I'll leave it up to you whether that's worth it for > you. > > It makes no difference whether the scheduler is "noop" or "deadline" > here; the "noop" scheduler still seems to merge adjacent I/O requests > (which makes sense). > > Andreas > Hi, Thanks. Both patches are now applied to the for-next branch of the linux-gfs2 tree: https://git.kernel.org/cgit/linux/kernel/git/gfs2/linux-gfs2.git/commit/fs/gfs2?h=for-next&id=c8d577038449a718ad0027d1790b6ef4441715d4 https://git.kernel.org/cgit/linux/kernel/git/gfs2/linux-gfs2.git/commit/fs/gfs2?h=for-next&id=843396ad9886458bddbc7d07137b2975876b029e Regards, Bob Peterson Red Hat File Systems