From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 9CCC46B0261 for ; Tue, 17 Oct 2017 09:55:16 -0400 (EDT) Received: by mail-pf0-f198.google.com with SMTP id x7so1330690pfa.19 for ; Tue, 17 Oct 2017 06:55:16 -0700 (PDT) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTPS id 1si812210pln.617.2017.10.17.06.55.15 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 17 Oct 2017 06:55:15 -0700 (PDT) From: "Huang\, Ying" Subject: Re: [PATCH -mm] mm, pagemap: Fix soft dirty marking for PMD migration entry References: <20171017081818.31795-1-ying.huang@intel.com> <20171017112100.pciya6pmo62owpht@node.shutemov.name> <874lqy7yks.fsf@yhuang-dev.intel.com> <59E5F881.20105@cs.rutgers.edu> Date: Tue, 17 Oct 2017 21:55:12 +0800 In-Reply-To: <59E5F881.20105@cs.rutgers.edu> (Zi Yan's message of "Tue, 17 Oct 2017 08:33:05 -0400") Message-ID: <87vajd7ubj.fsf@yhuang-dev.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Sender: owner-linux-mm@kvack.org List-ID: To: Zi Yan Cc: "Huang, Ying" , "Kirill A. Shutemov" , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , "Kirill A. Shutemov" , David Rientjes , Arnd Bergmann , Hugh Dickins , =?utf-8?B?Su+/vXLvv71tZQ==?= Glisse , Daniel Colascione , Naoya Horiguchi Zi Yan writes: > Huang, Ying wrote: >> "Kirill A. Shutemov" writes: >> >>> On Tue, Oct 17, 2017 at 04:18:18PM +0800, Huang, Ying wrote: >>>> From: Huang Ying >>>> >>>> Now, when the page table is walked in the implementation of >>>> /proc//pagemap, pmd_soft_dirty() is used for both the PMD huge >>>> page map and the PMD migration entries. That is wrong, >>>> pmd_swp_soft_dirty() should be used for the PMD migration entries >>>> instead because the different page table entry flag is used. >>>> >>>> Cc: Michal Hocko >>>> Cc: "Kirill A. Shutemov" >>>> Cc: David Rientjes >>>> Cc: Arnd Bergmann >>>> Cc: Hugh Dickins >>>> Cc: "J.r.me Glisse" >>>> Cc: Daniel Colascione >>>> Cc: Zi Yan >>>> Cc: Naoya Horiguchi >>>> Signed-off-by: "Huang, Ying" >>> What is effect of the misbehaviour? pagemap reports garbage? >> >> Yes. pagemap may report incorrect soft dirty information for PMD >> migration entries. > > Thanks for fixing it. > >> >>> Shoudn't it be in stable@? And maybe add Fixes: . >> >> Yes. Will do that in the next version. > > PMD migration is merged in 4.14, which is not final yet. Do we need to > split the patch, so that first hunk(for present PMD entries) goes into > stable and second hunk(for PMD migration entries) goes into 4.14? Oh, if so, I think we don't need to back port it to stable kernel. But we still need Fixes: tag. Best Regards, Huang, Ying -- 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