From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752340Ab2BQMTo (ORCPT ); Fri, 17 Feb 2012 07:19:44 -0500 Received: from e28smtp05.in.ibm.com ([122.248.162.5]:50797 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751557Ab2BQMTm (ORCPT ); Fri, 17 Feb 2012 07:19:42 -0500 Message-ID: <4F3E45D2.5050100@linux.vnet.ibm.com> Date: Fri, 17 Feb 2012 17:49:30 +0530 From: "Srivatsa S. Bhat" User-Agent: Mozilla/5.0 (X11; Linux i686; rv:9.0) Gecko/20111222 Thunderbird/9.0 MIME-Version: 1.0 To: Rusty Russell CC: Eric Dumazet , akpm@linux-foundation.org, kosaki.motohiro@gmail.com, linux-kernel@vger.kernel.org, venki@google.com, Mike Travis Subject: Re: [PATCH] lib/cpumask.c: Optimize __any_online_cpu() calculation References: <20120215123208.15623.73499.stgit@srivatsabhat.in.ibm.com> <1329310627.2437.18.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <4F3BBED4.2090101@linux.vnet.ibm.com> <87pqdfbthw.fsf@rustcorp.com.au> In-Reply-To: <87pqdfbthw.fsf@rustcorp.com.au> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit x-cbid: 12021712-8256-0000-0000-0000014BAF89 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/16/2012 04:21 AM, Rusty Russell wrote: > On Wed, 15 Feb 2012 19:49:00 +0530, "Srivatsa S. Bhat" wrote: >> On 02/15/2012 06:27 PM, Eric Dumazet wrote: >> >>> Le mercredi 15 février 2012 à 18:05 +0530, Srivatsa S. Bhat a écrit : >>>> __any_online_cpu() uses a for loop at the moment. >>>> Instead, use cpumask_* operations to speed it up. >>>> >>>> Signed-off-by: Srivatsa S. Bhat >>>> --- >>>> Actually, the patch posted at https://lkml.org/lkml/2012/2/15/101 removed >>>> the last user of any_online_cpu() (and hence __any_online_cpu()). >>>> However, since this is an exported symbol, I refrained from removing this >>>> function altogether. >>> >>> Just remove the export/function and eventually leave the helper ? >>> >>> #define any_online_cpu(mask) cpumask_any_and(mask, cpu_online_mask) >>> >> >> >> That sounds good. Here is v2 of the patch. >> (Since this v2 touches include/linux/cpumask.h, I rebased it on top of the >> patch posted at: https://lkml.org/lkml/2012/2/15/2. Even without that >> patch it should apply with minor line number changes..) > > No. Just git rid of the only caller of any_online_cpu(): > > arch/ia64/kernel/smpboot.c:693: new_cpei_cpu = any_online_cpu(cpu_online_map); > My ia64 patch already got rid of that caller! So this patch should be fine as is. And it looks like Andrew Morton has taken this patch into -mm. So nothing more needs to be done about this :-) Regards, Srivatsa S. Bhat