From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel Becker Date: Tue, 4 Jan 2011 14:15:17 -0800 Subject: [Ocfs2-devel] [PATCH 00/34] OCFS2: Add trace event and replace mlog(0). In-Reply-To: <4D22E32D.40406@tao.ma> References: <4D12F7E7.1090204@tao.ma> <20101231125217.GC21179@mail.oracle.com> <4D1DF2A3.9090106@tao.ma> <20101231223951.GC20521@mail.oracle.com> <4D22E32D.40406@tao.ma> Message-ID: <20110104221517.GB30671@mail.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 On Tue, Jan 04, 2011 at 05:06:53PM +0800, Tao Ma wrote: > On 01/01/2011 06:39 AM, Joel Becker wrote: > >On Fri, Dec 31, 2010 at 11:11:31PM +0800, Tao Ma wrote: > >>On 12/31/2010 08:52 PM, Joel Becker wrote: > >>> Overall this seems pretty straightforward. There wasn't a lot > >>>of editing of masklog entries; we still have a million tracepoints. I > >>>wonder how much memory that will use. Have you checked the space usage > >>>of all the sysfs files for all of our tracepoints? > >>Sorry, I don't know how to check the space usage of these files. any tips? > > > > Just count the number of files and directories added to sysfs. > >I believe the files disappear when not open, but the directories > >I think have inode and dentry structures around permanently.. > OK, so > #find /sys/kernel/debug/tracing/events/ocfs2 -type d|wc -l > give me 319. Every trace event dir has 4 > members(enable,filter,format and id). So it contains about > 1600(dir+files). I think what matters to count is dirs, because files disappear when you're not using them. If you have 319 trace event directories, that's 319 inodes. On my x86, a vanilla struct inode is 360 bytes and a dentry is 136 bytes. That's 154K always in RAM for these knobs. I gotta say that I'm not too worried about 154K. On x86_64 (ca-build24) this grows to 241K. I imagine it will double when cluster and dlm are moved to similar trace events. Are we OK with 300K on x86 and 500K on x86_64 always used up by these tracing entries? Joel -- Life's Little Instruction Book #464 "Don't miss the magic of the moment by focusing on what's to come." Joel Becker Senior Development Manager Oracle E-mail: joel.becker at oracle.com Phone: (650) 506-8127