From owner-freebsd-stable@FreeBSD.ORG Tue Oct 30 23:33:34 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 CE924D2E; Tue, 30 Oct 2012 23:33:34 +0000 (UTC) (envelope-from steven_nikkel@ertyu.org) Received: from idcmail-mo1so.shaw.ca (idcmail-mo1so.shaw.ca [24.71.223.10]) by mx1.freebsd.org (Postfix) with ESMTP id 8E4588FC08; Tue, 30 Oct 2012 23:33:34 +0000 (UTC) Received: from pd2ml3so-ssvc.prod.shaw.ca ([10.0.141.148]) by pd3mo1so-svcs.prod.shaw.ca with ESMTP; 30 Oct 2012 17:33:28 -0600 X-Cloudmark-SP-Filtered: true X-Cloudmark-SP-Result: v=1.1 cv=SNukfclIDc7GjKe+LHtSoPUBJt/gHPuqMk7EpfoOdzs= c=1 sm=1 a=1fWRePjM8PAA:10 a=BLceEmwcHowA:10 a=kj9zAlcOel0A:10 a=gn0rv3KfuWpWgkKhuBHlTQ==:17 a=Egj1SV_zNB3GBmTDU5UA:9 a=CjuIK1q_8ugA:10 a=HpAAvcLHHh0Zw7uRqdWCyQ==:117 Received: from unknown (HELO ertyu.org) ([24.79.195.167]) by pd2ml3so-dmz.prod.shaw.ca with ESMTP; 30 Oct 2012 17:33:28 -0600 Date: Tue, 30 Oct 2012 18:33:27 -0500 (CDT) From: Steven Nikkel To: Andriy Gapon Subject: Re: CPU Competition Issue In-Reply-To: <508F9671.3060501@FreeBSD.org> Message-ID: References: <508F9671.3060501@FreeBSD.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: 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 23:33:34 -0000 On Tue, 30 Oct 2012, Andriy Gapon wrote: >> 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. > They seem to share in a much more reasonable manor after assigning the process to +10 instead of +20, which sounds like the fix you mentioned. The process hits priorities in the 120s when its competing. I think I'll continue with idle priority as that obtains the sharing behaviour I'm after.