From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f71.google.com (mail-pa0-f71.google.com [209.85.220.71]) by kanga.kvack.org (Postfix) with ESMTP id 6E2D46B026E for ; Wed, 21 Sep 2016 12:32:12 -0400 (EDT) Received: by mail-pa0-f71.google.com with SMTP id wk8so100785481pab.3 for ; Wed, 21 Sep 2016 09:32:12 -0700 (PDT) Received: from mga05.intel.com (mga05.intel.com. [192.55.52.43]) by mx.google.com with ESMTPS id n79si76403432pfb.225.2016.09.21.09.32.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 21 Sep 2016 09:32:11 -0700 (PDT) Subject: Re: [PATCH] memory-hotplug: Fix bad area access on dissolve_free_huge_pages() References: <57D97CAF.7080005@linux.intel.com> <566c04af-c937-cbe0-5646-2cc2c816cc3f@linux.vnet.ibm.com> <57DC1CE0.5070400@linux.intel.com> <7e642622-72ee-87f6-ceb0-890ce9c28382@linux.vnet.ibm.com> <57E14D64.6090609@linux.intel.com> <57E17531.6050008@linux.intel.com> <20160921120507.GG10300@dhcp22.suse.cz> <57E2AF8F.6030202@linux.intel.com> <20160921162715.GC24210@dhcp22.suse.cz> From: Dave Hansen Message-ID: <57E2B60A.2060200@linux.intel.com> Date: Wed, 21 Sep 2016 09:32:10 -0700 MIME-Version: 1.0 In-Reply-To: <20160921162715.GC24210@dhcp22.suse.cz> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Rui Teng , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Naoya Horiguchi , "Kirill A . Shutemov" , Vlastimil Babka , Mike Kravetz , "Aneesh Kumar K . V" , Paul Gortmaker , Santhosh G On 09/21/2016 09:27 AM, Michal Hocko wrote: > That was not my point. I wasn't very clear probably. Offlining can fail > which shouldn't be really surprising. There might be a kernel allocation > in the particular block which cannot be migrated so failures are to be > expected. I just do not see how offlining in the middle of a gigantic > page is any different from having any other unmovable allocation in a > block. That being said, why don't we simply refuse to offline a block > which is in the middle of a gigantic page. Don't we want to minimize the things that can cause an offline to fail? The code to fix it here doesn't seem too bad. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org