From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764934AbdEWUFS (ORCPT ); Tue, 23 May 2017 16:05:18 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:45772 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758664AbdEWUFP (ORCPT ); Tue, 23 May 2017 16:05:15 -0400 Subject: Re: [Patch 2/2]: powerpc/hotplug/mm: Fix hot-add memory node assoc To: Reza Arbab , Balbir Singh References: <3bb44d92-b2ff-e197-4bdf-ec6d588d6dab@linux.vnet.ibm.com> <20170523155251.bqwc5mc4jpgzkqlm@arbab-laptop.localdomain> Cc: Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, Paul Mackerras , "Aneesh Kumar K.V" , Bharata B Rao , Shailendra Singh , Thomas Gleixner , linuxppc-dev@lists.ozlabs.org From: Michael Bringmann Organization: IBM Linux Technology Center Date: Tue, 23 May 2017 15:05:08 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: <20170523155251.bqwc5mc4jpgzkqlm@arbab-laptop.localdomain> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 17052320-0024-0000-0000-0000167D0157 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007107; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000212; SDB=6.00864622; UDB=6.00429235; IPR=6.00644402; BA=6.00005369; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015555; XFM=3.00000015; UTC=2017-05-23 20:05:12 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17052320-0025-0000-0000-00004B0AEFF8 Message-Id: <1c1d70e3-4e45-b035-0e75-1b0f531c111b@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-05-23_07:,, 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=8.0.1-1703280000 definitions=main-1705230102 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/23/2017 10:52 AM, Reza Arbab wrote: > On Tue, May 23, 2017 at 10:15:44AM -0500, Michael Bringmann wrote: >> +static void setup_nodes(void) >> +{ >> + int i, l = 32 /* MAX_NUMNODES */; >> + >> + for (i = 0; i < l; i++) { >> + if (!node_possible(i)) { >> + setup_node_data(i, 0, 0); >> + node_set(i, node_possible_map); >> + } >> + } >> +} > > This seems to be a workaround for 3af229f2071f ("powerpc/numa: Reset node_possible_map to only node_online_map"). They may be related, but that commit is not a replacement. The above patch ensures that there are enough of the nodes initialized at startup to allow for memory hot-add into a node that was not used at boot. (See 'setup_node_data' function in 'numa.c'.) That and recording that the node was initialized. I didn't see where any part of commit 3af229f2071f would touch the 'node_possible_map' which is needed by 'numa.c' and 'workqueue.c'. The nodemask created and updated by 'mem_cgroup_may_update_nodemask()' does not appear to be the same mask. > > Balbir, you have a patchset which reverts it. Do you think that will be getting merged? > > http://lkml.kernel.org/r/1479253501-26261-1-git-send-email-bsingharora@gmail.com > (see patch 3/3) > -- Michael W. Bringmann Linux Technology Center IBM Corporation Tie-Line 363-5196 External: (512) 286-5196 Cell: (512) 466-0650 mwb@linux.vnet.ibm.com