From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751740AbbCZDNQ (ORCPT ); Wed, 25 Mar 2015 23:13:16 -0400 Received: from mgwkm04.jp.fujitsu.com ([202.219.69.171]:16097 "EHLO mgwkm04.jp.fujitsu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750789AbbCZDNN (ORCPT ); Wed, 25 Mar 2015 23:13:13 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v2.2.3 X-SHieldMailCheckerPolicyVersion: FJ-ISEC-20140219-2 Message-ID: <55137935.5080301@jp.fujitsu.com> Date: Thu, 26 Mar 2015 12:12:53 +0900 From: Kamezawa Hiroyuki User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Gu Zheng , CC: , , , , Subject: Re: [PATCH 0/2] workqueue: fix a bug when numa mapping is changed References: <1427336275-32066-1-git-send-email-guz.fnst@cn.fujitsu.com> In-Reply-To: <1427336275-32066-1-git-send-email-guz.fnst@cn.fujitsu.com> Content-Type: text/plain; charset="iso-2022-jp" Content-Transfer-Encoding: 7bit X-SecurityPolicyCheck-GC: OK by FENCE-Mail X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/03/26 11:17, Gu Zheng wrote: > Yasuaki Ishimatsu found that with node online/offline, cpu<->node > relationship is established. Because workqueue uses a info which was > established at boot time, but it may be changed by node hotpluging. > > Once pool->node points to a stale node, following allocation failure > happens. > == > SLUB: Unable to allocate memory on node 2 (gfp=0x80d0) > cache: kmalloc-192, object size: 192, buffer size: 192, default > order: > 1, min order: 0 > node 0: slabs: 6172, objs: 259224, free: 245741 > node 1: slabs: 3261, objs: 136962, free: 127656 > == > > As the apicid <--> node relationship is persistent, so the root cause is the 　　　　 ^^^^^^^ pxm. > cpu-id <-> lapicid mapping is not persistent (because the currently implementation > always choose the first free cpu id for the new added cpu), so if we can build > persistent cpu-id <-> lapicid relationship, this problem will be fixed. > > Please refer to https://lkml.org/lkml/2015/2/27/145 for the previous discussion. > > Gu Zheng (2): > x86/cpu hotplug: make lapicid <-> cpuid mapping persistent > workqueue: update per cpu workqueue's numa affinity when cpu > preparing online why patch(2/2) required ? Thanks, -Kame > > arch/x86/kernel/apic/apic.c | 31 ++++++++++++++++++++++++++++++- > kernel/workqueue.c | 1 + > 2 files changed, 31 insertions(+), 1 deletions(-) >