From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id 8318A6B0038 for ; Thu, 2 Feb 2017 22:12:36 -0500 (EST) Received: by mail-pg0-f71.google.com with SMTP id v184so8745356pgv.6 for ; Thu, 02 Feb 2017 19:12:36 -0800 (PST) Received: from out4434.biz.mail.alibaba.com (out4434.biz.mail.alibaba.com. [47.88.44.34]) by mx.google.com with ESMTP id j19si19462697pgn.187.2017.02.02.19.12.33 for ; Thu, 02 Feb 2017 19:12:35 -0800 (PST) Reply-To: "Hillf Danton" From: "Hillf Danton" References: <1478561517-4317-1-git-send-email-n-horiguchi@ah.jp.nec.com> <5890EB58.3050100@cs.rutgers.edu> In-Reply-To: <5890EB58.3050100@cs.rutgers.edu> Subject: Re: [PATCH v2 00/12] mm: page migration enhancement for thp Date: Fri, 03 Feb 2017 11:12:12 +0800 Message-ID: <004601d27dcb$509327a0$f1b976e0$@alibaba-inc.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Content-Language: zh-cn Sender: owner-linux-mm@kvack.org List-ID: To: 'Zi Yan' , 'Anshuman Khandual' , 'Andrew Morton' , 'Naoya Horiguchi' , "'Kirill A. Shutemov'" Cc: linux-mm@kvack.org, 'Hugh Dickins' , 'Dave Hansen' , 'Andrea Arcangeli' , 'Mel Gorman' , 'Michal Hocko' , 'Vlastimil Babka' , 'Pavel Emelyanov' , 'Balbir Singh' , linux-kernel@vger.kernel.org, 'Naoya Horiguchi' On February 01, 2017 3:54 AM Zi Yan wrote: > > I am also doing some tests on THP migration and discover that there are > some corner cases not handled in this patchset. > > For example, in handle_mm_fault, without taking pmd_lock, the kernel may > see pmd_none(*pmd) during THP migrations, which leads to > handle_pte_fault or even deeper in the code path. At that moment, > pmd_trans_unstable() will treat a pmd_migration_entry as pmd_bad and > clear it. This leads to application crashing and page table leaks, since > a deposited PTE page is not released when the application crashes. > > Even after I add is_pmd_migration_entry() into pmd_trans_unstable(), I > still see application data corruptions. > > I hope someone can shed some light on how to debug this. Should I also > look into pmd_trans_huge() call sites where pmd_migration_entry should > be handled differently? > Hm ... seems it helps more if you post your current works as RFC on top of the mm tree, and the relevant tests as well. Hillf > > Anshuman Khandual wrote: > > On 11/08/2016 05:01 AM, Naoya Horiguchi wrote: > >> Hi everyone, > >> > >> I've updated thp migration patches for v4.9-rc2-mmotm-2016-10-27-18-27 > >> with feedbacks for ver.1. > > > > Hello Noaya, > > > > I have been working with Zi Yan on the parallel huge page migration series > > (https://lkml.org/lkml/2016/11/22/457) and planning to post them on top of > > this THP migration enhancement series. Hence we were wondering if you have > > plans to post a new version of this series in near future ? > > > > Regards > > Anshuman > > > > -- > Best Regards, > Yan Zi -- 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