From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932806AbdIHUsE (ORCPT ); Fri, 8 Sep 2017 16:48:04 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:49252 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932786AbdIHUsC (ORCPT ); Fri, 8 Sep 2017 16:48:02 -0400 To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: Michael Bringmann , Nathan Fontenot , Michael Ellerman , John Allen In-Reply-To: <74fb879c-19bf-3abf-4491-1f0db162e7d8@linux.vnet.ibm.com> From: Michael Bringmann Subject: [PATCH V14 4/4] powerpc/vphn: Fix numa update end-loop bug Organization: IBM Linux Technology Center Date: Fri, 8 Sep 2017 15:47:56 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 17090820-0012-0000-0000-000014FAD412 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007691; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000227; SDB=6.00914193; UDB=6.00458905; IPR=6.00694451; BA=6.00005576; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017073; XFM=3.00000015; UTC=2017-09-08 20:48:00 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17090820-0013-0000-0000-00004F6952B3 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-09-08_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1709080310 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org powerpc/vphn: On Power systems with shared configurations of CPUs and memory, there are some issues with the association of additional CPUs and memory to nodes when hot-adding resources. This patch fixes an end-of-updates processing problem observed occasionally in numa_update_cpu_topology(). Signed-off-by: Michael Bringmann --- Changes in V14: -- More code cleanup --- arch/powerpc/mm/numa.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 32f5f8d..ec098b3 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1401,16 +1401,22 @@ int numa_update_cpu_topology(bool cpus_locked) for_each_cpu(sibling, cpu_sibling_mask(cpu)) { ud = &updates[i++]; + ud->next = &updates[i]; ud->cpu = sibling; ud->new_nid = new_nid; ud->old_nid = numa_cpu_lookup_table[sibling]; cpumask_set_cpu(sibling, &updated_cpus); - if (i < weight) - ud->next = &updates[i]; } cpu = cpu_last_thread_sibling(cpu); } + /* + * Prevent processing of 'updates' from overflowing array + * where last entry filled in a 'next' pointer. + */ + if (i) + updates[i-1].next = NULL; + pr_debug("Topology update for the following CPUs:\n"); if (cpumask_weight(&updated_cpus)) { for (ud = &updates[0]; ud; ud = ud->next) {