From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752110AbcEYUuF (ORCPT ); Wed, 25 May 2016 16:50:05 -0400 Received: from mail-yw0-f193.google.com ([209.85.161.193]:34127 "EHLO mail-yw0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751205AbcEYUuC (ORCPT ); Wed, 25 May 2016 16:50:02 -0400 Date: Wed, 25 May 2016 16:37:31 -0400 From: Tejun Heo To: Zhu Guihua Cc: Peter Zijlstra , cl@linux.com, 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 Subject: Re: [PATCH v7 0/5] Make cpuid <-> nodeid mapping persistent Message-ID: <20160525203731.GJ3354@mtj.duckdns.org> References: <20160519144657.GK3206@twins.programming.kicks-ass.net> <5742AAF6.3060901@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5742AAF6.3060901@cn.fujitsu.com> User-Agent: Mutt/1.6.1 (2016-04-27) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 23, 2016 at 03:02:14PM +0800, Zhu Guihua wrote: > 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? Workqueue is just one of symptoms. We have the same problem for memory allocation paths. It's either keeping cpu <-> node mapping persistent or hunting down every case which may be affected and build likely costly synchronization construct around it. It's not like we have a lot of archs which support CPU hotplug and NUMA. Thanks. -- tejun