From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 85D176B0038 for ; Fri, 6 Jan 2017 04:19:43 -0500 (EST) Received: by mail-wm0-f69.google.com with SMTP id l2so2491812wml.5 for ; Fri, 06 Jan 2017 01:19:43 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id h194si2073903wmd.115.2017.01.06.01.19.41 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 06 Jan 2017 01:19:42 -0800 (PST) Date: Fri, 6 Jan 2017 10:19:34 +0100 From: Michal Hocko Subject: Re: [RFC PATCH v3] sparc64: Add support for Application Data Integrity (ADI) Message-ID: <20170106091934.GF5556@dhcp22.suse.cz> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7fbc4ca1-22ef-8ef5-5c1b-dd075852e512@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: Khalid Aziz Cc: Dave Hansen , 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 Thu 05-01-17 13:30:10, Khalid Aziz wrote: [...] > It is very tempting to restrict tags to PAGE_SIZE granularity since it makes > code noticeably simpler and that is indeed going to be the majority of > cases. Sooner or later somebody would want to use multiple tags per page > though. I didn't get to read the patch throughly yet but I am really confused by this statement. The api is mprotect based which makes it ineherently PAGE_SIZE granular. How do you want to achieve cache line granularity with this API? And I would really vote for simplicity first... Subpage granularity sounds way too tricky... -- Michal Hocko SUSE Labs -- 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