From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161020AbXAaUWL (ORCPT ); Wed, 31 Jan 2007 15:22:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161027AbXAaUWL (ORCPT ); Wed, 31 Jan 2007 15:22:11 -0500 Received: from mx1.redhat.com ([66.187.233.31]:35650 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161020AbXAaUWJ (ORCPT ); Wed, 31 Jan 2007 15:22:09 -0500 Message-ID: <45C0FA11.1060303@redhat.com> Date: Wed, 31 Jan 2007 15:20:33 -0500 From: Chuck Ebbert Organization: Red Hat User-Agent: Thunderbird 1.5.0.9 (X11/20061219) MIME-Version: 1.0 To: Arjan van de Ven CC: "Linda W." , LKML Subject: Re: linux scheduler and "cache-mate" processors References: <45B7F567.7020100@tlinx.org> <1170238640.2865.4.camel@laptopd505.fenrus.org> In-Reply-To: <1170238640.2865.4.camel@laptopd505.fenrus.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Arjan van de Ven wrote: >> 1) does the scheduler know enough to try to spread tasks >> equally over both the pairs to make best use of the 16MB total >> cache? (i.e. given cpu bound processes "1" and "2", if they >> are both on CPU "A", then the "C-D" cache remains unused, but >> keeping "1" on "a" and "2" on "C" would tend to minimize >> their caches being consumed by each other. >> > > yes this works just fine > > > >> 2) Since either A&B both have access to the 8MB cache, then >> if a process was running on "A", it seems it would have a >> low migration cost to be scheduled on "B" -- i.e. shouldn't >> the process, if it were migrated to "A"'s "cache-mate", "B", >> be able to benefit by any previous caching done on "A"? >> If that's true, does the scheduler give preference, when >> migrating a process, to a CPU's "cache-mate"? >> > > afaik yes as well > > You do have to enable "Multi-core scheduler support" in the kernel .config, though.