From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3wYY614w0LzDqk7 for ; Fri, 26 May 2017 01:27:05 +1000 (AEST) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v4PFNcL4054735 for ; Thu, 25 May 2017 11:27:01 -0400 Received: from e13.ny.us.ibm.com (e13.ny.us.ibm.com [129.33.205.203]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ap1v4850d-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 25 May 2017 11:27:00 -0400 Received: from localhost by e13.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 25 May 2017 11:27:00 -0400 Subject: Re: [Patch 2/2]: powerpc/hotplug/mm: Fix hot-add memory node assoc To: Reza Arbab , Michael Ellerman , Balbir Singh References: <3bb44d92-b2ff-e197-4bdf-ec6d588d6dab@linux.vnet.ibm.com> <20170523155251.bqwc5mc4jpgzkqlm@arbab-laptop.localdomain> <1c1d70e3-4e45-b035-0e75-1b0f531c111b@linux.vnet.ibm.com> <20170523214922.bns675oqzqj4pkhc@arbab-laptop.localdomain> <87poeya4dt.fsf@concordia.ellerman.id.au> <8e2417d8-d108-2949-40f2-997d53a3f367@linux.vnet.ibm.com> <87a861a25y.fsf@concordia.ellerman.id.au> <20170525151011.m4ae4ipxbqsj3mn7@arbab-laptop.localdomain> Cc: linux-kernel@vger.kernel.org, Paul Mackerras , "Aneesh Kumar K.V" , Bharata B Rao , Shailendra Singh , Thomas Gleixner , linuxppc-dev@lists.ozlabs.org, Sebastian Andrzej Siewior From: Michael Bringmann Date: Thu, 25 May 2017 10:26:54 -0500 MIME-Version: 1.0 In-Reply-To: <20170525151011.m4ae4ipxbqsj3mn7@arbab-laptop.localdomain> Content-Type: text/plain; charset=windows-1252 Message-Id: <16fa033f-4641-9a91-2b6e-ca5ff50037f3@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 05/25/2017 10:10 AM, Reza Arbab wrote: > On Thu, May 25, 2017 at 04:19:53PM +1000, Michael Ellerman wrote: >> The commit message for 3af229f2071f says: >> >> In practice, we never see a system with 256 NUMA nodes, and in fact, we >> do not support node hotplug on power in the first place, so the nodes >> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >> that are online when we come up are the nodes that will be present for >> the lifetime of this kernel. >> >> Is that no longer true? > > I don't know what the reasoning behind that statement was at the time, but as far as I can tell, the only thing missing for node hotplug now is Balbir's patchset [1]. He fixes the resource issue which motivated 3af229f2071f and reverts it. > > With that set, I can instantiate a new numa node just by doing add_memory(nid, ...) where nid doesn't currently exist. > > [1] https://lkml.kernel.org/r/1479253501-26261-1-git-send-email-bsingharora@gmail.com > Yes, the change to 'numa.c' looks to be sufficient for my needs as well. -- 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