From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id E389EDDE1D for ; Fri, 25 Jan 2008 18:04:09 +1100 (EST) Subject: Re: ppc32: Weird process scheduling behaviour with 2.6.24-rc From: Benjamin Herrenschmidt To: Peter Zijlstra 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 Date: Fri, 25 Jan 2008 18:03:38 +1100 Message-Id: <1201244618.6815.130.camel@pasglop> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, Ingo Molnar , Michel =?ISO-8859-1?Q?D=E4nzer?= Reply-To: benh@kernel.crashing.org 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: > > 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. FYI. This is a 4 way G5 (ppc64) Ben.