From owner-freebsd-stable@FreeBSD.ORG Tue Nov 20 17:38:34 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 8FFF616A420 for ; Tue, 20 Nov 2007 17:38:34 +0000 (UTC) (envelope-from lol@chistydom.ru) Received: from comtv.ru (comtv.ru [217.10.32.17]) by mx1.freebsd.org (Postfix) with ESMTP id EA50B13C442 for ; Tue, 20 Nov 2007 17:38:33 +0000 (UTC) (envelope-from lol@chistydom.ru) X-UCL: actv Received: from yoda.org.ru ([83.167.98.162] verified) by comtv.ru (CommuniGate Pro SMTP 4.1.8) with ESMTP id 20951764; Tue, 20 Nov 2007 20:38:29 +0300 Received: from [192.168.102.10] (unknown [192.168.102.10]) (Authenticated sender: llp@soekris.ru) by yoda.org.ru (Postfix) with ESMTP id 5F88E28B5F; Tue, 20 Nov 2007 20:38:46 +0300 (MSK) Message-ID: <47431B75.4040601@chistydom.ru> Date: Tue, 20 Nov 2007 20:37:57 +0300 From: Alexey Popov User-Agent: Thunderbird 2.0.0.6 (X11/20070924) MIME-Version: 1.0 To: Ivan Voras References: <4741905E.8050300@chistydom.ru> <47419AB3.5030008@chistydom.ru> <4741B3DE.2000009@chistydom.ru> <47430AE8.7050408@chistydom.ru> <9bbcef730711200915n12e37efcs67cf260641b9baab@mail.gmail.com> In-Reply-To: <9bbcef730711200915n12e37efcs67cf260641b9baab@mail.gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org 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: Tue, 20 Nov 2007 17:38:34 -0000 Hi. Ivan Voras wrote: >> CPU states: 5.9% user, 0.0% nice, 81.3% system, 0.0% interrupt, 12.8% idle >> CPU states: 82.2% user, 0.0% nice, 13.8% system, 0.0% interrupt, 4.0% idle > Interesting coincidence: 1 CPU generates almost 8x less "sys time" then 8 CPUs. > But it seems that you have found something real. Inspired by your > problem I've done a simple measurement ("ab") on a 4-CPU (2x2 core > Opterons 2216 HE, PAE) machine I maintain, under these circumstances: > > - a "heavy" PHP application > - FastCGI > - in this case, load of 4 clients > - on 6-STABLE > > and I'm reporting similar findings: > CPU states: 38.8% user, 0.0% nice, 48.4% system, 3.2% interrupt, 9.6% idle > We are not so performance bound as you so I didn't do measurements > earlier. I cannot "play" with settings on this machine as it is in > production, but ~~50% sys time (the measurement changes around 45% +/- > 10%) seems too much. Thank you for your research. I think you can get more %sys with 4-core processors. For me 2xquad-core systems are now completely unusable as PHP backends. Anyway I'm happy that I'm not alone with this problem. But what can we do about it? With best regards, Alexey Popov