From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f199.google.com (mail-io0-f199.google.com [209.85.223.199]) by kanga.kvack.org (Postfix) with ESMTP id B1E766B025E for ; Mon, 23 May 2016 03:03:04 -0400 (EDT) Received: by mail-io0-f199.google.com with SMTP id 190so354544984iow.2 for ; Mon, 23 May 2016 00:03:04 -0700 (PDT) Received: from heian.cn.fujitsu.com ([59.151.112.132]) by mx.google.com with ESMTP id 13si8713008itq.12.2016.05.23.00.03.03 for ; Mon, 23 May 2016 00:03:03 -0700 (PDT) Message-ID: <5742AAF6.3060901@cn.fujitsu.com> Date: Mon, 23 May 2016 15:02:14 +0800 From: Zhu Guihua MIME-Version: 1.0 Subject: Re: [PATCH v7 0/5] Make cpuid <-> nodeid mapping persistent References: <20160519144657.GK3206@twins.programming.kicks-ass.net> In-Reply-To: <20160519144657.GK3206@twins.programming.kicks-ass.net> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: cl@linux.com, tj@kernel.org, mika.j.penttila@gmail.com, mingo@redhat.com, akpm@linux-foundation.org, rjw@rjwysocki.net, hpa@zytor.com, yasu.isimatu@gmail.com, isimatu.yasuaki@jp.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, gongzhaogang@inspur.com, len.brown@intel.com, lenb@kernel.org, tglx@linutronix.de, chen.tang@easystack.cn, rafael@kernel.org, x86@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Hi, On 05/19/2016 10:46 PM, Peter Zijlstra wrote: > On Thu, May 19, 2016 at 06:39:41PM +0800, Zhu Guihua wrote: >> [Problem] >> >> cpuid <-> nodeid mapping is firstly established at boot time. And workqueue caches >> the mapping in wq_numa_possible_cpumask in wq_numa_init() at boot time. >> >> When doing node online/offline, cpuid <-> nodeid mapping is established/destroyed, >> which means, cpuid <-> nodeid mapping will change if node hotplug happens. But >> workqueue does not update wq_numa_possible_cpumask. > So why are you not fixing up wq_numa_possible_cpumask instead? That > seems the far easier solution. We tried to do that. You can see our patch at http://www.gossamer-threads.com/lists/linux/kernel/2116748 But maintainer thought, we should establish persistent cpuid<->nodeid relationship, there is no need to change the map. Cc TJ, Could we return to workqueue to fix this? Thanks, Zhu > Do all the other archs that support NUMA and HOTPLUG have the mapping > stable, or will you now go fix each and every one of them? > > > . > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org