From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932353AbeCEUip (ORCPT ); Mon, 5 Mar 2018 15:38:45 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:52966 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751275AbeCEUin (ORCPT ); Mon, 5 Mar 2018 15:38:43 -0500 Subject: Re: [PATCH v12 08/11] mm: Clear arch specific VM flags on protection change To: Dave Hansen , akpm@linux-foundation.org, davem@davemloft.net Cc: mhocko@suse.com, jack@suse.cz, kirill.shutemov@linux.intel.com, ross.zwisler@linux.intel.com, willy@infradead.org, hughd@google.com, n-horiguchi@ah.jp.nec.com, mgorman@suse.de, jglisse@redhat.com, dave.jiang@intel.com, dan.j.williams@intel.com, anthony.yznaga@oracle.com, nadav.amit@gmail.com, zi.yan@cs.rutgers.edu, aarcange@redhat.com, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, henry.willard@oracle.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, Khalid Aziz References: From: Khalid Aziz Organization: Oracle Corp Message-ID: Date: Mon, 5 Mar 2018 13:38:02 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8823 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=626 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1803050236 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/05/2018 12:23 PM, Dave Hansen wrote: > On 02/21/2018 09:15 AM, Khalid Aziz wrote: >> +/* Arch-specific flags to clear when updating VM flags on protection change */ >> +#ifndef VM_ARCH_CLEAR >> +# define VM_ARCH_CLEAR VM_NONE >> +#endif >> +#define VM_FLAGS_CLEAR (ARCH_VM_PKEY_FLAGS | VM_ARCH_CLEAR) > > Shouldn't this be defining > > # define VM_ARCH_CLEAR ARCH_VM_PKEY_FLAGS > > on x86? ARCH_VM_PKEY_FLAGS is used by x86 as well as powerpc. On those two architectures VM_FLAGS_CLEAR will end up being ARCH_VM_PKEY_FLAGS and thus current behavior will be retained. Defining VM_ARCH_CLEAR to be ARCH_VM_PKEY_FLAGS on x86 will just result in VM_FLAGS_CLEAR to be (ARCH_VM_PKEY_FLAGS | ARCH_VM_PKEY_FLAGS) which is superfluous. -- Khalid