From owner-freebsd-current@FreeBSD.ORG Mon Oct 18 22:56:14 2010 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: by hub.freebsd.org (Postfix, from userid 1233) id 8562A1065670; Mon, 18 Oct 2010 22:56:14 +0000 (UTC) Date: Mon, 18 Oct 2010 22:56:14 +0000 From: Alexander Best To: David Xu Message-ID: <20101018225614.GA77926@freebsd.org> References: <4C961009.6080609@freebsd.org> <20100920141023.GA27509@freebsd.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100920141023.GA27509@freebsd.org> Cc: freebsd-current@freebsd.org Subject: Re: sysctl -a is slow X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 18 Oct 2010 22:56:14 -0000 On Mon Sep 20 10, Alexander Best wrote: > On Sun Sep 19 10, David Xu wrote: > > just typed sysctl -a on keyboard, and found it is slow, sometimes > > it has been stuck for a few seconds, further studied,I found it is > > stucked at sysctl kern.geom: > > > > %/usr/bin/time sysctl -a kern.geom > > kern.geom.collectstats: 1 > > kern.geom.debugflags: 0 > > kern.geom.label.debug: 0 > > kern.geom.label.ext2fs.enable: 1 > > kern.geom.label.iso9660.enable: 1 > > kern.geom.label.msdosfs.enable: 1 > > kern.geom.label.ntfs.enable: 1 > > kern.geom.label.reiserfs.enable: 1 > > kern.geom.label.ufs.enable: 1 > > kern.geom.label.ufsid.enable: 1 > > kern.geom.label.gptid.enable: 1 > > kern.geom.label.gpt.enable: 1 > > 2.01 real 0.00 user 0.00 sys > > > > it seems it needs more than 2 seconds to complete. > > have you had a look at the bug database? just noticed a few sysctl reports > there which describe issues similar to yours. these are the results from the following script: #!/bin/sh TESTS="kern vm vfs net debug hw user p1003_1b compat security dev" for i in $TESTS; do echo $i:; time sysctl $i > /dev/null; done kern: 0,09 real 0,00 user 0,07 sys vm: 0,05 real 0,00 user 0,05 sys vfs: 0,00 real 0,00 user 0,00 sys net: 0,01 real 0,01 user 0,00 sys debug: 0,36 real 0,00 user 0,35 sys hw: 0,01 real 0,00 user 0,00 sys user: 0,00 real 0,00 user 0,00 sys p1003_1b: 0,00 real 0,00 user 0,00 sys compat: 0,00 real 0,00 user 0,00 sys security: 0,00 real 0,00 user 0,00 sys dev: 0,04 real 0,00 user 0,04 sys ...that's on a very recent HEAD. cheers. alex ps: debug.witness.fullgraph is producing quite a lot of output. also debug.witness.badstacks. i think most of cpu time can be blamed on those two options. also: otaku% /usr/bin/time sysctl -a kern.geom kern.geom.debugflags: 0 kern.geom.collectstats: 1 kern.geom.label.debug: 0 kern.geom.label.ext2fs.enable: 1 kern.geom.label.iso9660.enable: 1 kern.geom.label.msdosfs.enable: 1 kern.geom.label.ntfs.enable: 1 kern.geom.label.reiserfs.enable: 1 kern.geom.label.ufsid.enable: 1 kern.geom.label.ufs.enable: 1 kern.geom.label.gpt.enable: 1 kern.geom.label.gptid.enable: 1 0,01 real 0,00 user 0,00 sys however i ran the test app from PR 134231 and 8.1-PRELEASE (freefall) performed far worse than 7.3-STABLE (hub). 8.1 (freefall): 0.037u 28.304s 0:28.35 99.9% 5+175k 0+0io 0pf+0w 7.3 (hub): 0.007u 8.991s 0:08.99 100.0% 5+175k 0+0io 0pf+0w > > #134231 e.g. > > cheers. > alex > > > > > -- > a13x -- a13x