Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932240AbbLCCoQ (ORCPT ); Wed, 2 Dec 2015 21:44:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55464 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932141AbbLCCoN (ORCPT ); Wed, 2 Dec 2015 21:44:13 -0500 Subject: Re: [PATCH] sched/core: Clear the root_domain cpumasks in init_rootdomain() To: Peter Zijlstra References: <1449057179-29321-1-git-send-email-xlpang@redhat.com> <20151202123414.GB9928@worktop.ger.corp.intel.com> <565EEE3E.30301@redhat.com> <20151202162542.GT3816@twins.programming.kicks-ass.net> Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Steven Rostedt From: Xunlei Pang Message-ID: <565FAC78.3030205@redhat.com> Date: Thu, 3 Dec 2015 10:44:08 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151202162542.GT3816@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1253 Lines: 33 Hi Peter, On 12/03/2015 at 12:25 AM, Peter Zijlstra wrote: > On Wed, Dec 02, 2015 at 09:12:30PM +0800, Xunlei Pang wrote: >> Hi Peter, >> >> On 12/02/2015 at 08:34 PM, Peter Zijlstra wrote: >>> On Wed, Dec 02, 2015 at 07:52:59PM +0800, Xunlei Pang wrote: >>>> The patch cleans the garbage by using zalloc_cpumask_var() >>>> instead of alloc_cpumask_var() for root_domain::rto_mask >>>> allocation, thereby addressing the issues. >>> How did you notice this? Also do we want to do the same for the kmalloc >> When doing review. > Nice, will you be looking for similar issues elsewhere in the scheduler > too? Sure :-) >>> in alloc_rootdomain() ? >> There is a "memset(rd, 0, sizeof(*rd))" in init_rootdomain(), >> so I don't think we need to do this in alloc_rootdomain(). > Ah, right there is. Which also clears the mask for small systems. Yeah, maybe we can improve it using alloc_cpumask_var() with __GFP_ZERO instead of zalloc_cpumask_var() to avoid duplicate clean for small systems. Regards, Xunlei -- 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/