From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f198.google.com (mail-io0-f198.google.com [209.85.223.198]) by kanga.kvack.org (Postfix) with ESMTP id 1F6DC6B025E for ; Fri, 6 Jan 2017 12:08:54 -0500 (EST) Received: by mail-io0-f198.google.com with SMTP id p127so578661333iop.5 for ; Fri, 06 Jan 2017 09:08:54 -0800 (PST) Received: from userp1040.oracle.com (userp1040.oracle.com. [156.151.31.81]) by mx.google.com with ESMTPS id r72si56360366iod.59.2017.01.06.09.08.53 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 06 Jan 2017 09:08:53 -0800 (PST) Subject: Re: [RFC PATCH v3] sparc64: Add support for Application Data Integrity (ADI) References: <8612e7db-97c5-f757-0aae-24c3acedbc29@oracle.com> <2c0502d0-20ef-44ac-db5b-7f651a70b978@linux.intel.com> <5a0270ea-b29a-0751-a27f-2412a8588561@oracle.com> <7532a1d6-6562-b10b-dacd-931cb2a9e536@linux.intel.com> <92d55a69-b400-8461-53a1-d505de089700@oracle.com> <75c31c99-cff7-72dc-f593-012fe5acd405@linux.intel.com> <7fbc4ca1-22ef-8ef5-5c1b-dd075852e512@oracle.com> <20170106091934.GF5556@dhcp22.suse.cz> From: Khalid Aziz Message-ID: Date: Fri, 6 Jan 2017 10:08:27 -0700 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen , Michal Hocko Cc: Rob Gardner , davem@davemloft.net, corbet@lwn.net, arnd@arndb.de, akpm@linux-foundation.org, hpa@zytor.com, viro@zeniv.linux.org.uk, nitin.m.gupta@oracle.com, chris.hyser@oracle.com, tushar.n.dave@oracle.com, sowmini.varadhan@oracle.com, mike.kravetz@oracle.com, adam.buchbinder@gmail.com, minchan@kernel.org, hughd@google.com, kirill.shutemov@linux.intel.com, keescook@chromium.org, allen.pais@oracle.com, aryabinin@virtuozzo.com, atish.patra@oracle.com, joe@perches.com, pmladek@suse.com, jslaby@suse.cz, cmetcalf@mellanox.com, paul.gortmaker@windriver.com, jmarchan@redhat.com, lstoakes@gmail.com, 0x7f454c46@gmail.com, vbabka@suse.cz, tglx@linutronix.de, mingo@redhat.com, dan.j.williams@intel.com, iamjoonsoo.kim@lge.com, mgorman@techsingularity.net, vdavydov.dev@gmail.com, hannes@cmpxchg.org, namit@vmware.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org, Khalid Aziz On 01/06/2017 09:55 AM, Dave Hansen wrote: > On 01/06/2017 08:22 AM, Khalid Aziz wrote: >> On 01/06/2017 08:36 AM, Dave Hansen wrote: >>> On 01/06/2017 07:32 AM, Khalid Aziz wrote: >>>> I agree with you on simplicity first. Subpage granularity is complex, >>>> but the architecture allows for subpage granularity. Maybe the right >>>> approach is to support this at page granularity first for swappable >>>> pages and then expand to subpage granularity in a subsequent patch? >>>> Pages locked in memory can already use subpage granularity with my >>>> patch. >>> >>> What do you mean by "locked in memory"? mlock()'d memory can still be >>> migrated around and still requires "swap" ptes, for instance. >> >> You are right. Page migration can invalidate subpage granularity even >> for locked pages. Is it possible to use cpusets to keep a task and its >> memory locked on a single node? > > It's going to be hard to impossible to guarantee. mlock() doesn't > guarantee that things won't change physical addresses. You'd have to > change that guarantee or chase all the things in the kernel that might > change physical addresses (compaction, ksm, etc...). > > Actually, that reminds me... How does your code interface with ksm? Or > is there no interaction needed since you're always working on virtual > addresses? > Yes, version tags are interpreted at virtual address level. -- Khalid -- 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