From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753911AbdA3Ry3 (ORCPT ); Mon, 30 Jan 2017 12:54:29 -0500 Received: from mga01.intel.com ([192.55.52.88]:35585 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751305AbdA3Ry2 (ORCPT ); Mon, 30 Jan 2017 12:54:28 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,312,1477983600"; d="scan'208";a="53816091" Subject: Re: [RFC V2 12/12] mm: Tag VMA with VM_CDM flag explicitly during mbind(MPOL_BIND) To: Anshuman Khandual , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20170130033602.12275-1-khandual@linux.vnet.ibm.com> <20170130033602.12275-13-khandual@linux.vnet.ibm.com> Cc: mhocko@suse.com, vbabka@suse.cz, mgorman@suse.de, minchan@kernel.org, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, srikar@linux.vnet.ibm.com, haren@linux.vnet.ibm.com, jglisse@redhat.com, dan.j.williams@intel.com From: Dave Hansen Message-ID: <26a17cd1-dd50-43b9-03b1-dd967466a273@intel.com> Date: Mon, 30 Jan 2017 09:54:27 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20170130033602.12275-13-khandual@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/29/2017 07:35 PM, Anshuman Khandual wrote: > + if ((new_pol->mode == MPOL_BIND) > + && nodemask_has_cdm(new_pol->v.nodes)) > + set_vm_cdm(vma); So, if you did: mbind(addr, PAGE_SIZE, MPOL_BIND, all_nodes, ...); mbind(addr, PAGE_SIZE, MPOL_BIND, one_non_cdm_node, ...); You end up with a VMA that can never have KSM done on it, etc... Even though there's no good reason for it. I guess /proc/$pid/smaps might be able to help us figure out what was going on here, but that still seems like an awful lot of damage.