From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 3C81D6B0005 for ; Thu, 19 May 2016 10:47:45 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id 4so160779802pfw.0 for ; Thu, 19 May 2016 07:47:45 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id aj1si20529774pad.84.2016.05.19.07.47.44 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 19 May 2016 07:47:44 -0700 (PDT) Date: Thu, 19 May 2016 16:46:57 +0200 From: Peter Zijlstra Subject: Re: [PATCH v7 0/5] Make cpuid <-> nodeid mapping persistent Message-ID: <20160519144657.GK3206@twins.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Zhu Guihua 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 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. 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