From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fg-out-1718.google.com (fg-out-1718.google.com [72.14.220.153]) by ozlabs.org (Postfix) with ESMTP id 5ACE2DDE36 for ; Fri, 25 Jan 2008 22:34:35 +1100 (EST) Received: by fg-out-1718.google.com with SMTP id 16so551756fgg.39 for ; Fri, 25 Jan 2008 03:34:34 -0800 (PST) Subject: Re: ppc32: Weird process scheduling behaviour with 2.6.24-rc From: Michel =?ISO-8859-1?Q?D=E4nzer?= To: benh@kernel.crashing.org In-Reply-To: <1201244082.6815.128.camel@pasglop> References: <1200659696.23161.81.camel@thor.sulgenrain.local> <1201013786.4726.28.camel@thor.sulgenrain.local> <1201090699.9052.39.camel@thor.sulgenrain.local> <1201092131.6341.51.camel@lappy> <1201244082.6815.128.camel@pasglop> Content-Type: text/plain; charset=utf-8 Date: Fri, 25 Jan 2008 12:34:27 +0100 Message-Id: <1201260867.6293.38.camel@thor.sulgenrain.local> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, Ingo Molnar , Peter Zijlstra List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2008-01-25 at 17:54 +1100, Benjamin Herrenschmidt wrote: > On Wed, 2008-01-23 at 13:42 +0100, Peter Zijlstra wrote: > > Another question, do you have: > > CONFIG_FAIR_GROUP_SCHED=y > > > > if so, does flipping that off have any effect? > > Yes. > > Here, I do the test of running 4 times the repro-case provided by Michel > with nice 19 and a dd eating CPU with nice 0. > > Without this option, I get the dd at 100% and the nice 19 shells down > below it with whatever is left of the CPUs. > > With this option, dd gets about 50% of one CPU and the niced processes > still get most of the time. Hmm, interesting. As I said before, I thought I had tested with this disabled and not seen a difference, but I'll try again to confirm. -- Earthling Michel Dänzer | http://tungstengraphics.com Libre software enthusiast | Debian, X and DRI developer