From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f71.google.com (mail-pa0-f71.google.com [209.85.220.71]) by kanga.kvack.org (Postfix) with ESMTP id 3D7F36B0005 for ; Mon, 25 Jul 2016 20:31:43 -0400 (EDT) Received: by mail-pa0-f71.google.com with SMTP id ag5so259943038pad.2 for ; Mon, 25 Jul 2016 17:31:43 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id bl8si36048723pad.42.2016.07.25.17.26.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 25 Jul 2016 17:26:11 -0700 (PDT) Date: Mon, 25 Jul 2016 17:25:49 -0700 From: Andrew Morton 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> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: 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 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? -- 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