Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752400AbbGOAW0 (ORCPT ); Tue, 14 Jul 2015 20:22:26 -0400 Received: from ozlabs.org ([103.22.144.67]:57914 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751595AbbGOAWZ (ORCPT ); Tue, 14 Jul 2015 20:22:25 -0400 Message-ID: <1436919743.10956.2.camel@ellerman.id.au> Subject: Re: [RFC,1/2] powerpc/numa: fix cpu_to_node() usage during boot From: Michael Ellerman To: Nishanth Aravamudan Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, Paul Mackerras , Anton Blanchard , David Rientjes , linuxppc-dev@lists.ozlabs.org Date: Wed, 15 Jul 2015 10:22:23 +1000 In-Reply-To: <20150708231623.GB44862@linux.vnet.ibm.com> References: <20150702230202.GA2807@linux.vnet.ibm.com> <20150708040056.948A1140770@ozlabs.org> <20150708231623.GB44862@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.10-0ubuntu1~14.10.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1460 Lines: 40 On Wed, 2015-07-08 at 16:16 -0700, Nishanth Aravamudan wrote: > On 08.07.2015 [14:00:56 +1000], Michael Ellerman wrote: > > On Thu, 2015-02-07 at 23:02:02 UTC, Nishanth Aravamudan wrote: > > > > > > we currently emit at boot: > > > > > > [ 0.000000] pcpu-alloc: [0] 0 1 2 3 [0] 4 5 6 7 > > > > > > After this commit, we correctly emit: > > > > > > [ 0.000000] pcpu-alloc: [0] 0 1 2 3 [1] 4 5 6 7 > > > > > > So it looks fairly sane, and I guess it's a bug fix. > > > > But I'm a bit reluctant to put it in straight away without some time in next. > > I'm fine with that -- it could use some more extensive testing, > admittedly (I only have been able to verify the pcpu areas are being > correctly allocated on the right node so far). > > I still need to test with hotplug and things like that. Hence the RFC. > > > It looks like the symptom is that the per-cpu areas are all allocated on node > > 0, is that all that goes wrong? > > Yes, that's the symptom. I cc'd a few folks to see if they could help > indicate the performance implications of such a setup -- sorry, I should > have been more explicit about that. OK cool. I'm happy to put it in next if you send a non-RFC version. cheers -- 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/