Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755849AbYGKA6x (ORCPT ); Thu, 10 Jul 2008 20:58:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755287AbYGKA6p (ORCPT ); Thu, 10 Jul 2008 20:58:45 -0400 Received: from relay2.sgi.com ([192.48.171.30]:42467 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752186AbYGKA6o (ORCPT ); Thu, 10 Jul 2008 20:58:44 -0400 Message-ID: <4876B043.7040304@sgi.com> Date: Thu, 10 Jul 2008 17:58:43 -0700 From: Mike Travis User-Agent: Thunderbird 2.0.0.6 (X11/20070801) MIME-Version: 1.0 To: "H. Peter Anvin" CC: Christoph Lameter , Jeremy Fitzhardinge , "Eric W. Biederman" , Ingo Molnar , Andrew Morton , Jack Steiner , linux-kernel@vger.kernel.org, Arjan van de Ven Subject: Re: [RFC 00/15] x86_64: Optimize percpu accesses References: <20080709165129.292635000@polaris-admin.engr.sgi.com> <20080709200757.GD14009@elte.hu> <48751B57.8030605@goop.org> <48751CF9.4020901@linux-foundation.org> <4875209D.8010603@goop.org> <48752CCD.30507@linux-foundation.org> <48753C99.5050408@goop.org> <487555A8.2050007@zytor.com> <487556A5.5090907@goop.org> <4876194E.4080205@linux-foundation.org> <48761C06.3020003@zytor.com> <48762A3B.5050104@linux-foundation.org> <48762DD2.5090802@zytor.com> <487637A1.4080403@linux-foundation.org> <487639ED.7000502@zytor.com> <48763CA6.9030802@linux-foundation.org> <487647EF.5010609@goop.org> <48764A01.1070402@linux-foundation.org> <48764C7C.5010309@goop.org> <48767692.4080504@linux-foundation.org> <487677F0.4000404@goop.org> <4876799B.7010204@linux-foundation.org> <48767F4F.1010209@zytor.com> <4876A56C.3050707@sgi.com> <4876A5CA.7020109@zytor.com> In-Reply-To: <4876A5CA.7020109@zytor.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1151 Lines: 33 H. Peter Anvin wrote: > Mike Travis wrote: >> >> Hmm, that might be the way to go.... At boot up time determine the >> size of the system in terms of cpu count and memory available and >> attempt to do the right thing, with startup options to override the >> internal choices... ? >> >> (Surely a system that has a "gazillion ip tunnels" could modify it's >> kernel start options... ;-) >> >> Unfortunately, we can't use a MODULE to support different options unless >> we change how the kernel starts up (would need to mount the root fs >> before starting secondary cpus.) >> > > Using a module doesn't make any sense anyway. This is more what the > kernel command line is for. > > -hpa I was thinking that supporting virtual percpu addresses would take a fair amount of code that, if living in a MODULE, wouldn't impact small systems. But it seems to be not worth the effort... ;-) Thanks, Mike -- 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/