From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755035AbcGZAZy (ORCPT ); Mon, 25 Jul 2016 20:25:54 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50236 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753623AbcGZAZv (ORCPT ); Mon, 25 Jul 2016 20:25:51 -0400 Date: Mon, 25 Jul 2016 17:25:49 -0700 From: Andrew Morton To: Tejun Heo Cc: Dou Liyang , cl@linux.com, mika.j.penttila@gmail.com, mingo@redhat.com, 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 v9 0/7] Make cpuid <-> nodeid mapping persistent Message-Id: <20160725172549.e5a23d495a356f026fbb28fa@linux-foundation.org> In-Reply-To: <20160726001151.GN19588@mtj.duckdns.org> References: <1469435749-19582-1-git-send-email-douly.fnst@cn.fujitsu.com> <20160725162022.e90e9c6c74a5d147e39e5945@linux-foundation.org> <20160726001151.GN19588@mtj.duckdns.org> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 25 Jul 2016 20:11:51 -0400 Tejun Heo wrote: > Hello, Andrew. > > On Mon, Jul 25, 2016 at 04:20:22PM -0700, Andrew Morton wrote: > > > When a pool workqueue is initialized, if its cpumask belongs to a node, its > > > pool->node will be mapped to that node. And memory used by this workqueue will > > > also be allocated on that node. > > > > Plan B is to hunt down and fix up all the workqueue structures at > > hotplug-time. Has that option been evaluated? > > > > Your fix is x86-only and this bug presumably affects other > > architectures, yes? I think a "Plan B" would fix all architectures? > > Yeah, that was one of the early approaches. The issue isn't limited > to wq. Any memory allocation can have similar issues of underlying > node association changing and we don't have any synchronization > mechanism around it. It doesn't make any sense to make NUMA > association dynamic when the consumer surface is vastly larger and > there's nothing inherently dynamic about the association itself. And other architectures?