From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f200.google.com (mail-pg1-f200.google.com [209.85.215.200]) by kanga.kvack.org (Postfix) with ESMTP id 267CE6B2F68 for ; Fri, 24 Aug 2018 07:35:34 -0400 (EDT) Received: by mail-pg1-f200.google.com with SMTP id r69-v6so4424689pgr.13 for ; Fri, 24 Aug 2018 04:35:34 -0700 (PDT) Received: from mga12.intel.com (mga12.intel.com. [192.55.52.136]) by mx.google.com with ESMTPS id 90-v6si6644053pla.466.2018.08.24.04.35.32 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 24 Aug 2018 04:35:33 -0700 (PDT) Date: Fri, 24 Aug 2018 14:35:29 +0300 From: "Kirill A. Shutemov" Subject: Re: [PATCH v6 0/2] huge_pmd_unshare migration and flushing Message-ID: <20180824113529.os4sx6ls5vbz4gwi@black.fi.intel.com> References: <20180823205917.16297-1-mike.kravetz@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180823205917.16297-1-mike.kravetz@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: Mike Kravetz Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, =?iso-8859-1?B?Suly9G1l?= Glisse , Vlastimil Babka , Naoya Horiguchi , Davidlohr Bueso , Michal Hocko , Andrew Morton On Thu, Aug 23, 2018 at 08:59:15PM +0000, Mike Kravetz wrote: > Correct a data corruption issue caused by improper handling of shared > huge PMDs during page migration. This issue was observed in a customer > environment and can be recreated fairly easily with a test program. > Patch 0001 addresses this issue only and is copied to stable with the > intention that this will go to stable releases. It has existed since > the addition of shared huge PMD support. > > While considering the issue above, Kirill Shutemov noticed that other > callers of huge_pmd_unshare have potential issues with cache and TLB > flushing. A separate patch (0002) takes advantage of the new routine > adjust_range_if_pmd_sharing_possible() to adjust flushing ranges in > the cases where huge PMD sharing is possible. There is no copy to > stable for this patch as it has not been reported as an issue and > discovered only via code inspection. Looks good to me. Acked-by: Kirill A. Shutemov -- Kirill A. Shutemov