From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753906AbcAHBOA (ORCPT ); Thu, 7 Jan 2016 20:14:00 -0500 Received: from mga04.intel.com ([192.55.52.120]:56084 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752189AbcAHBN7 (ORCPT ); Thu, 7 Jan 2016 20:13:59 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,535,1444719600"; d="scan'208";a="856025775" Subject: Re: [PATCH v4] memory-hotplug: Fix kernel warning during memory hotplug on ppc64 To: John Allen , gregkh@linuxfoundation.org References: <568D9568.1010808@linux.vnet.ibm.com> Cc: Nathan Fontenot , akpm@linux-foundation.org, Michael Ellerman , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Linux-MM , Andrew Morton From: Dave Hansen Message-ID: <568F0D56.5010908@intel.com> Date: Thu, 7 Jan 2016 17:13:58 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <568D9568.1010808@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/06/2016 02:30 PM, John Allen wrote: > On any architecture that uses memory_probe_store to reserve memory, the > udev rule will be triggered after the first section of the block is > reserved and will subsequently attempt to online the entire block, > interrupting the memory reservation process and causing the warning. > This patch modifies memory_probe_store to add a block of memory with > a single call to add_memory as opposed to looping through and adding > each section individually. A single call to add_memory is protected by > the mem_hotplug mutex which will prevent the udev rule from onlining > memory until the reservation of the entire block is complete. Seems sane to me. Makes the code simpler too, so win win. Acked-by: Dave Hansen