From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [RFC PATCH v3] sparc64: Add support for Application Data Integrity (ADI) Date: Wed, 4 Jan 2017 16:01:09 -0800 Message-ID: References: <1483569999-13543-1-git-send-email-khalid.aziz@oracle.com> <6fcaab9f-40fb-fdfb-2c7e-bf21a862ab7c@linux.intel.com> <8612e7db-97c5-f757-0aae-24c3acedbc29@oracle.com> <2c0502d0-20ef-44ac-db5b-7f651a70b978@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: owner-linux-mm@kvack.org To: Khalid Aziz , Rob Gardner , davem@davemloft.net, corbet@lwn.net, arnd@arndb.de, akpm@linux-foundation.org Cc: 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, mhocko@suse.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@kva List-Id: linux-arch.vger.kernel.org On 01/04/2017 03:58 PM, Khalid Aziz wrote: >> How does this all work with large pages? > > It works with large pages the same way as normal sized pages. The TTE > for a large page also will have the mcd bit set in it and tags are set > and referenced the same way. But does the user setting the tags need to know what the page size is? What if two different small pages have different tags and khugepaged comes along and tries to collapse them? Will the page be split if a user attempts to set two different tags inside two different small-page portions of a single THP? -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com ([192.55.52.120]:13985 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936417AbdAEAEW (ORCPT ); Wed, 4 Jan 2017 19:04:22 -0500 Subject: Re: [RFC PATCH v3] sparc64: Add support for Application Data Integrity (ADI) References: <1483569999-13543-1-git-send-email-khalid.aziz@oracle.com> <6fcaab9f-40fb-fdfb-2c7e-bf21a862ab7c@linux.intel.com> <8612e7db-97c5-f757-0aae-24c3acedbc29@oracle.com> <2c0502d0-20ef-44ac-db5b-7f651a70b978@linux.intel.com> From: Dave Hansen Message-ID: Date: Wed, 4 Jan 2017 16:01:09 -0800 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Khalid Aziz , Rob Gardner , davem@davemloft.net, corbet@lwn.net, arnd@arndb.de, akpm@linux-foundation.org Cc: 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, mhocko@suse.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 Message-ID: <20170105000109.fptxOlf0aMdTQ3WYJV3gjZ3lzC2HziUzV6gx46yoSAA@z> On 01/04/2017 03:58 PM, Khalid Aziz wrote: >> How does this all work with large pages? > > It works with large pages the same way as normal sized pages. The TTE > for a large page also will have the mcd bit set in it and tags are set > and referenced the same way. But does the user setting the tags need to know what the page size is? What if two different small pages have different tags and khugepaged comes along and tries to collapse them? Will the page be split if a user attempts to set two different tags inside two different small-page portions of a single THP?