Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760368Ab2EDWaJ (ORCPT ); Fri, 4 May 2012 18:30:09 -0400 Received: from casper.infradead.org ([85.118.1.10]:34493 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754292Ab2EDWaI convert rfc822-to-8bit (ORCPT ); Fri, 4 May 2012 18:30:08 -0400 Message-ID: <1336170586.16236.11.camel@twins> Subject: RE: [PATCH] sched: Enable arch-specific asym packing option in sched domain From: Peter Zijlstra To: Diwakar Tundlam Cc: "'Ingo Molnar'" , "'Andrew Morton'" , "'Christoph Lameter'" , "'Michael Neuling'" , "'Stephen Rothwell'" , "'Benjamin Herrenschmidt'" , "'David Rientjes'" , "'linux-kernel@vger.kernel.org'" , Peter De Schrijver Date: Sat, 05 May 2012 00:29:46 +0200 In-Reply-To: <1DD7BFEDD3147247B1355BEFEFE46652379C3DF102@HQMAIL04.nvidia.com> References: <1DD7BFEDD3147247B1355BEFEFE46652379C3DF0FF@HQMAIL04.nvidia.com> <1DD7BFEDD3147247B1355BEFEFE46652379C3DF101@HQMAIL04.nvidia.com> <1336169422.16236.1.camel@twins> <1DD7BFEDD3147247B1355BEFEFE46652379C3DF102@HQMAIL04.nvidia.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1601 Lines: 39 On Fri, 2012-05-04 at 15:18 -0700, Diwakar Tundlam wrote: > > arch_sd_sibling_asym_packing() is already present under ifdef CONFIG_SMT. > I didn't touch that. I only added it to SD_CPU_INIT for all cpu's. > I assumed Power7 shouldn't use SD_CPU_INIT. All archs use SD_CPU_INIT, its the default topology level for a package/socket. So now you've made Power7 prefer lower numbered sockets over higher numbered sockets.. not fatal, but not really nice either. [ power7 is the only one that implements arch_sd_sibling_asym_packing ] > Maybe I should define a separate weak symbol, say arch_sd_bias_to_lower_num_cpu()? > Then Power7 can define arch_sd_sibling_asym_packing() to be '1' and it will not > break all-cpu init. A slightly saner name would be: arch_sd_package_asym_packing() FWIW, I suspect you're wanting to use this for some ARM chip (nvidia doesn't do much else -- aside from this graphics stuff) so that if there's hardly anything it runs on cpu0. Now, last time I checked, these ARM things had only 1 package, so I still don't see the point :-) I suspect you want to modify SD_MC_INIT() with something like: arch_sd_mc_asym_packing() Or is this the big-little thing and you're representing them as separate packages? See how a little extra information avoids me having to endlessly second guess wtf you're actually wanting to do? -- 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/