From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srinivas Eeda Date: Mon, 07 May 2012 18:26:58 -0700 Subject: [Ocfs2-devel] ocfs2 discontiguous localalloc patches In-Reply-To: <20120508000100.GB4713@dhcp-172-17-9-228.mtv.corp.google.com> References: <1336432890-18638-1-git-send-email-srinivas.eeda@oracle.com> <20120508000100.GB4713@dhcp-172-17-9-228.mtv.corp.google.com> Message-ID: <4FA87662.9040006@oracle.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com Joel Becker wrote: > On Mon, May 07, 2012 at 04:21:27PM -0700, Srinivas Eeda wrote: > >> can you please review following 3 patches that implement discontiguous >> localalloc bitmap support for ocfs2 file system. This feature helps >> applications that significantly fragment the filesystem. >> > > Hi Srini. Have you some performance numbers backing this? That > is, I believe that the described filesystem turned off local alloc. Do > you have proof that these patches, turning it back on, improved the > customer's performance? > > Joel > Hi Joel, thanks a lot for the quick reply. I have some stat_sysdir.sh snapshots at http://oss.oracle.com/~seeda/diag/stat_sysdir/ collected from a system. It has 4 snapshots collected when the file system usage is at 8%, 19%, 21% and 52%. In file stat_sysdir_52_percent_usage_slow_del.out, for the filesystem that has UUID: 3A6F54DF288C4AF2ABD1E00FC49BE7ED you could see that local_alloc:0000 bitmap total is 38 and is 0(disabled) for local_alloc:0001, and local_alloc:0002. for the filesystem that has uuid AC444DB162AE427C899BA89E076DD479, all localalloc appears to be disabled. Sorry I didn't collect /sys/kernel/debug/fs//fs_state. But, given the file system state, even if localalloc is not disabled localalloc need to be refilled every 40 clusters. Thanks, --Srini