From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752076AbbCZCgv (ORCPT ); Wed, 25 Mar 2015 22:36:51 -0400 Received: from cn.fujitsu.com ([59.151.112.132]:26353 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751220AbbCZCgu (ORCPT ); Wed, 25 Mar 2015 22:36:50 -0400 X-IronPort-AV: E=Sophos;i="5.04,848,1406563200"; d="scan'208";a="89352319" From: Gu Zheng To: CC: , , , , , , Subject: [PATCH 0/2] workqueue: fix a bug when numa mapping is changed Date: Thu, 26 Mar 2015 10:17:53 +0800 Message-ID: <1427336275-32066-1-git-send-email-guz.fnst@cn.fujitsu.com> X-Mailer: git-send-email 1.7.7 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.167.226.100] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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 arch/x86/kernel/apic/apic.c | 31 ++++++++++++++++++++++++++++++- kernel/workqueue.c | 1 + 2 files changed, 31 insertions(+), 1 deletions(-) -- 1.7.7