From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752534AbdFUOZR (ORCPT ); Wed, 21 Jun 2017 10:25:17 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:36719 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752454AbdFUOZQ (ORCPT ); Wed, 21 Jun 2017 10:25:16 -0400 Subject: Re: [PATCH V6 1/2] powerpc/hotplug: Ensure enough nodes avail for operations To: Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: Benjamin Herrenschmidt , Paul Mackerras , David Gibson , Reza Arbab , John Allen , Thomas Gleixner , Bharata B Rao , Shailendra Singh , "Aneesh Kumar K.V" , Sebastian Andrzej Siewior , Rashmica Gupta , Ingo Molnar , Tyrel Datwyler , Michael Bringmann from Kernel Team , Nathan Fontenot References: <878tklu0pw.fsf@concordia.ellerman.id.au> From: Michael Bringmann Organization: IBM Linux Technology Center Date: Wed, 21 Jun 2017 09:24:59 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: <878tklu0pw.fsf@concordia.ellerman.id.au> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 17062114-8235-0000-0000-00000BC3F61D X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007266; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00877835; UDB=6.00437339; IPR=6.00657976; BA=6.00005434; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015909; XFM=3.00000015; UTC=2017-06-21 14:25:04 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17062114-8236-0000-0000-00003C629083 Message-Id: <75a86b88-ae0c-93c1-dade-85d5e8315610@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-06-21_03:,, 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-1706210244 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/21/2017 04:52 AM, Michael Ellerman wrote: > Michael Bringmann writes: > >> powerpc/hotplug: On systems like PowerPC which allow 'hot-add' of CPU >> or memory resources, it may occur that the new resources are to be >> inserted into nodes that were not used for these resources at bootup. >> In the kernel, any node that is used must be defined and initialized >> at boot. In order to meet both needs, this patch adds a new kernel >> command line option (numnodes=) for use by the PowerPC architecture- > > Sorry, that's a hack. It is an intermediate step pending the provision of the firmware properties under discussion that were mentioned by Nathan Fontenot last week. > I thought you were going to use firmware properties to find the set of > possible nodes. Did that not work? Inference based on the current set of firmware properties for associativity is insufficient. That is partly the reason for the properties mentioned by Nathan last week. The current firmware properties only cover what is known at boot time. They do not cover expansions from DLPAR / hot-add operations which can add up to everything else on the system. > cheers Regards, -- 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