Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261950AbVDCXJF (ORCPT ); Sun, 3 Apr 2005 19:09:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261955AbVDCXJF (ORCPT ); Sun, 3 Apr 2005 19:09:05 -0400 Received: from zeus.kernel.org ([204.152.189.113]:27836 "EHLO zeus.kernel.org") by vger.kernel.org with ESMTP id S261950AbVDCXIo (ORCPT ); Sun, 3 Apr 2005 19:08:44 -0400 Date: Sun, 3 Apr 2005 16:08:07 -0700 From: Paul Jackson To: Ingo Molnar Cc: kenneth.w.chen@intel.com, torvalds@osdl.org, nickpiggin@yahoo.com.au, akpm@osdl.org, linux-kernel@vger.kernel.org Subject: Re: [patch] sched: auto-tune migration costs [was: Re: Industry db benchmark result on recent 2.6 kernels] Message-Id: <20050403160807.35381385.pj@engr.sgi.com> In-Reply-To: <20050403152413.GA26631@elte.hu> References: <200504020100.j3210fg04870@unix-os.sc.intel.com> <20050402145351.GA11601@elte.hu> <20050402215332.79ff56cc.pj@engr.sgi.com> <20050403070415.GA18893@elte.hu> <20050403043420.212290a8.pj@engr.sgi.com> <20050403071227.666ac33d.pj@engr.sgi.com> <20050403152413.GA26631@elte.hu> Organization: SGI X-Mailer: Sylpheed version 1.0.0 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1464 Lines: 38 Ingo wrote: > if you create a sched-domains hierarchy (based on the SLIT tables, or in > whatever other way) that matches the CPU hierarchy then you'll > automatically get the proper distances detected. Yes - agreed. I should push in the direction of improving the SN2 sched domain hierarchy. Would be a good idea to rename 'cpu_distance()' to something more specific, like 'cpu_dist_ndx()', and reserve the generic name 'cpu_distance()' for later use to return a scaled integer distance, rather like 'node_distance()' does now. For example, 'cpu_distance()' might, someday, return integer values such as: 40 217 252 253 as are displayed (in tenths) in the debug line: --------------------- cacheflush times [4]: 4.0 (4080540) 21.7 (21781380) 25.2 (25259428) 25.3 (25372682) --------------------- (that is, the integer (long)cost / 100000 - one less zero). I don't know that we have any use, yet, for this 'cpu_distance()' as a scaled integer value. But I'd be more comfortable reserving that name for that purpose. -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.650.933.1373, 1.925.600.0401 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/