From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e2.ny.us.ibm.com (e2.ny.us.ibm.com [32.97.182.142]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e2.ny.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 35DDBDDE21 for ; Mon, 28 Jan 2008 23:57:53 +1100 (EST) Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e2.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m0SCvoap026556 for ; Mon, 28 Jan 2008 07:57:50 -0500 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m0SCvoJ1208868 for ; Mon, 28 Jan 2008 07:57:50 -0500 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m0SCvnwS003542 for ; Mon, 28 Jan 2008 07:57:50 -0500 Date: Mon, 28 Jan 2008 18:41:35 +0530 From: Srivatsa Vaddagiri To: Ingo Molnar Subject: Re: ppc32: Weird process scheduling behaviour with 2.6.24-rc Message-ID: <20080128131135.GJ1044@linux.vnet.ibm.com> References: <1201244082.6815.128.camel@pasglop> <1201244618.6815.130.camel@pasglop> <1201245901.6815.133.camel@pasglop> <1201251000.6341.108.camel@lappy> <20080126040734.GA21365@linux.vnet.ibm.com> <1201320834.6815.160.camel@pasglop> <20080126050757.GB14177@linux.vnet.ibm.com> <1201450409.1931.23.camel@thor.sulgenrain.local> <1201510236.6149.24.camel@lappy> <20080128123253.GA32496@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20080128123253.GA32496@elte.hu> Cc: linuxppc-dev@ozlabs.org, Peter Zijlstra , michel@tungstengraphics.com Reply-To: vatsa@linux.vnet.ibm.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Jan 28, 2008 at 01:32:53PM +0100, Ingo Molnar wrote: > * Peter Zijlstra wrote: > > > > * With CONFIG_FAIR_USER_SCHED disabled, there are severe > > > interactivity hickups with a niced CPU hog and top running. This > > > started with commit 810e95ccd58d91369191aa4ecc9e6d4a10d8d0c8. > > > > The revert at the bottom causes the wakeup granularity to shrink for + > > nice and to grow for - nice. That is, it becomes easier to preempt a + > > nice task, and harder to preempt a - nice task. > > i think it would be OK to do half of this: make it easier to preempt a > +nice task. Hmm .. I doubt whether that would help Michel's case, as he seems to be running +niced tasks and having problems getting control over his desktop. Something is basically wrong here .. > Michel, do you really need the -nice portion as well? It's > not a problem to super-preempt positively reniced tasks, but it can be > quite annoying if negatively reniced tasks have super-slices. -- Regards, vatsa