From owner-freebsd-stable@FreeBSD.ORG Tue Oct 30 12:19:40 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id B059E140; Tue, 30 Oct 2012 12:19:40 +0000 (UTC) (envelope-from FreeBSD@shaneware.biz) Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net [IPv6:2001:44b8:8060:ff02:300:1:6:5]) by mx1.freebsd.org (Postfix) with ESMTP id C2A6F8FC0A; Tue, 30 Oct 2012 12:19:39 +0000 (UTC) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Aq0IAE/Fj1DLevdH/2dsb2JhbABEv22CRASCCIIeAQEFOEEQCw4KCRMDDwkDAgECAUUGDQEHAQGIAaxJkDaLdWGFfAOmNoMC Received: from ppp247-71.static.internode.on.net (HELO leader.local) ([203.122.247.71]) by ipmail05.adl6.internode.on.net with ESMTP; 30 Oct 2012 22:49:38 +1030 Message-ID: <508FC3D8.8030800@ShaneWare.Biz> Date: Tue, 30 Oct 2012 22:41:04 +1030 From: Shane Ambler User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:16.0) Gecko/20121017 Thunderbird/16.0.1 MIME-Version: 1.0 To: Andriy Gapon Subject: Re: CPU Competition Issue References: <508F9671.3060501@FreeBSD.org> In-Reply-To: <508F9671.3060501@FreeBSD.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Steven Nikkel , freebsd-stable@FreeBSD.org X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.14 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, 30 Oct 2012 12:19:40 -0000 On 30/10/2012 19:27, Andriy Gapon wrote: > on 30/10/2012 03:33 Steven Nikkel said the following: >> I'm running a long duration CPU-centric process that will gobble up all >> available CPU time. I have it set to run at nice +20. While it's running I've >> noticed other processes have a hard time getting CPU time and run their >> activites very slowly. The processes I've noticed issues with are IO involved, >> but they don't appear to be IO blocked as they run dramatically faster and use >> much more CPU time when the CPU intensive process is not running. I haven't >> noticed issues with other processes, but I haven't been looking. If I push my >> CPU intensive process into idle priority 1, all the other processes return to >> their normal behaviour as if it's not running. >> >> This seems to be a specific behaviour on this one machine running 9.0-RELEASE-p4 >> on an Atom 330 dual core. I've tried with and without hyperthreading enabled >> with no noticeable change in behaviour. > > Can you try with lower nice value, like +10? > You want a fix from r228718. AFAIR, it is not in 9.0. > Could it be cache based? The atom's smaller cache causing more cache misses. Would you be running zfs?