From owner-freebsd-stable@FreeBSD.ORG Thu Nov 22 08:13:57 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0400016A474; Thu, 22 Nov 2007 08:13:57 +0000 (UTC) (envelope-from max@love2party.net) Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.126.183]) by mx1.freebsd.org (Postfix) with ESMTP id 8933513C457; Thu, 22 Nov 2007 08:13:56 +0000 (UTC) (envelope-from max@love2party.net) Received: from amd64.laiers.local (dslb-088-066-042-157.pools.arcor-ip.net [88.66.42.157]) by mrelayeu.kundenserver.de (node=mrelayeu8) with ESMTP (Nemesis) id 0ML31I-1IuzKP2JYF-0004cD; Thu, 22 Nov 2007 00:49:58 +0100 From: Max Laier Organization: FreeBSD To: freebsd-stable@freebsd.org Date: Thu, 22 Nov 2007 00:50:42 +0100 User-Agent: KMail/1.9.7 References: <4741905E.8050300@chistydom.ru> <474339E9.4080301@FreeBSD.org> <4743629B.9090408@FreeBSD.org> In-Reply-To: <4743629B.9090408@FreeBSD.org> X-Face: ,,8R(x[kmU]tKN@>gtH1yQE4aslGdu+2]; R]*pL,U>^H?)gW@49@wdJ`H<=?utf-8?q?=25=7D*=5FBD=0A=09U=5For=3D=5CmOZf764=26nYj=3DJYbR1PW0ud?=>|!~,,CPC.1-D$FG@0h3#'5"k{V]a~.<=?utf-8?q?mZ=7D44=23Se=7Em=0A=09Fe=7E=5C=5DX5B=5D=5Fxj?=(ykz9QKMw_l0C2AQ]}Ym8)fU MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart1663567.M1vWNXAkZY"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200711220050.51408.max@love2party.net> X-Provags-ID: V01U2FsdGVkX19K5eQDj+vmLeCvx26CRNaYpzdNyI9QFEkbL5b ic8hrqTSd3fhbxh35iE1zEM9WHeRvs4+23v5+9tud/u20MFjC9 /J4fd23mcQSPMklP4PWgN7HnnYh0ahU3aoc+i8e68Y= Cc: Attilio Rao , Kris Kennaway , Alexey Popov Subject: Re: 2 x quad-core system is slower that 2 x dual core on FreeBSD X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Nov 2007 08:13:57 -0000 --nextPart1663567.M1vWNXAkZY Content-Type: text/plain; charset="iso-8859-6" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Tuesday 20 November 2007, Kris Kennaway wrote: > Kris Kennaway wrote: > > Kris Kennaway wrote: > >> In the meantime there is unfortunately not a lot that can be done, > >> AFAICT. There is one hack that I will send you later but it is not > >> likely to help much. I will also think about how to track down the > >> cause of the contention further (the profiling trace only shows that > >> it comes mostly from vget/vput but doesn't show where these are > >> called from). > > > > Actually this patch might help. It doesn't replace lockmgr but it > > does fix a silly thundering herd behaviour. It probably needs some > > adjustment to get it to apply cleanly (it is about 7 months old), and > > I apparently stopped using it because I ran into deadlocks. It might > > be stable enough to at least see how much it helps. > > > > Set the vfs.lookup_shared=3D1 sysctl to enable the other half of the > > patch. > > > > Kris > > Try this one instead, it applies to HEAD. You'll need to manually > enter the paths though because of how p4 mangles diffs. I rolled a tiny, simple, possibly braindamaged benchmark (but then again=20 php code tends to be braindamaged): test.php includes 1000 different,=20 essential empty files and is strated over and over from a shell script=20 which counts the runs completed within 60seconds. 1-8,128 scripts are=20 started in parallel. On a 2x dual Opteron running amd64 I get: stock RELENG_7 w/o patch ULE: jobs sum runs gain 1 617 1 2 784 1.27 3 939 1.52 4 1015 1.65 5 658 1.07 6 642 1.04 7 666 1.08 8 696 1.13 128 726 1.18 RELENG_7 patched ULE vfs.lookup_shared=3D1: jobs sum runs gain 1 637 1 2 784 1.23 3 973 1.53 4 1104 1.73 5 708 1.11 6 733 1.15 7 776 1.22 8 840 1.32 128 936 1.47 So there is still a lot of room for improvement here. I'll rebuild with=20 lock profiling tomorrow and see what I can gather. Anything you'd like=20 to see in particular? =2D-=20 /"\ Best regards, | mlaier@freebsd.org \ / Max Laier | ICQ #67774661 X http://pf4freebsd.love2party.net/ | mlaier@EFnet / \ ASCII Ribbon Campaign | Against HTML Mail and News --nextPart1663567.M1vWNXAkZY Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQBHRMRbXyyEoT62BG0RAnQOAJ9a3antCCJXeVi0kWWOR3nsrru2+ACfaz3T 0eED8jBN1DCMR2OqjtBOqzs= =y37s -----END PGP SIGNATURE----- --nextPart1663567.M1vWNXAkZY--