From owner-freebsd-stable@FreeBSD.ORG Tue Oct 30 15:45:43 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 82C92202 for ; Tue, 30 Oct 2012 15:45:43 +0000 (UTC) (envelope-from steven_nikkel@ertyu.org) Received: from idcmail-mo2no.shaw.ca (idcmail-mo2no.shaw.ca [64.59.134.9]) by mx1.freebsd.org (Postfix) with ESMTP id 48DF28FC12 for ; Tue, 30 Oct 2012 15:45:42 +0000 (UTC) Received: from lb7f8hsrpno-svcs.dcs.int.inet (HELO pd5ml2no-ssvc.prod.shaw.ca) ([10.0.144.222]) by pd7mo1no-svcs.prod.shaw.ca with ESMTP; 30 Oct 2012 09:45:42 -0600 X-Cloudmark-SP-Filtered: true X-Cloudmark-SP-Result: v=1.1 cv=+lz5uX4xiInwtrymCIFxsZpC13k2qgqBCqxhxbRs02Y= c=1 sm=1 a=UGu_2VojXwwA:10 a=1fWRePjM8PAA:10 a=BLceEmwcHowA:10 a=8nJEP1OIZ-IA:10 a=gn0rv3KfuWpWgkKhuBHlTQ==:17 a=QASXUrwb0TYg6-wgdpoA:9 a=wPNLvfGTeEIA:10 a=HpAAvcLHHh0Zw7uRqdWCyQ==:117 Received: from unknown (HELO ertyu.org) ([24.79.195.167]) by pd5ml2no-dmz.prod.shaw.ca with ESMTP; 30 Oct 2012 09:45:42 -0600 Message-ID: <52c0ed4c284d09009a886a09321f477b.squirrel@www2.ertyu.org> In-Reply-To: <508FC3D8.8030800@ShaneWare.Biz> References: <508F9671.3060501@FreeBSD.org> <508FC3D8.8030800@ShaneWare.Biz> Date: Tue, 30 Oct 2012 10:45:41 -0500 Subject: Re: CPU Competition Issue From: steven_nikkel@ertyu.org To: freebsd-stable@freebsd.org User-Agent: SquirrelMail/1.4.22 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal 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 15:45:43 -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? I am running ZFS. I've tried with doing the I/O on a UFS volume instead of ZFS and the behaviour is the same.