From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f52.google.com (mail-wm0-f52.google.com [74.125.82.52]) by kanga.kvack.org (Postfix) with ESMTP id 51D046B02A8 for ; Mon, 28 Dec 2015 07:58:08 -0500 (EST) Received: by mail-wm0-f52.google.com with SMTP id l126so263260239wml.0 for ; Mon, 28 Dec 2015 04:58:08 -0800 (PST) Received: from mail-wm0-x233.google.com (mail-wm0-x233.google.com. [2a00:1450:400c:c09::233]) by mx.google.com with ESMTPS id y7si29402799wmb.15.2015.12.28.04.58.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 28 Dec 2015 04:58:07 -0800 (PST) Received: by mail-wm0-x233.google.com with SMTP id l126so268220787wml.1 for ; Mon, 28 Dec 2015 04:58:06 -0800 (PST) Date: Mon, 28 Dec 2015 14:58:04 +0200 From: "Kirill A. Shutemov" Subject: Re: [PATCH 2/4] thp: fix regression in handling mlocked pages in __split_huge_pmd() Message-ID: <20151228125804.GA5284@node.shutemov.name> References: <1450957883-96356-1-git-send-email-kirill.shutemov@linux.intel.com> <1450957883-96356-3-git-send-email-kirill.shutemov@linux.intel.com> <567C978E.3090007@oracle.com> <567C991B.3000408@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <567C991B.3000408@oracle.com> Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: Dan Williams , "Kirill A. Shutemov" , Andrew Morton , Linux MM On Thu, Dec 24, 2015 at 08:17:15PM -0500, Sasha Levin wrote: > On 12/24/2015 08:12 PM, Dan Williams wrote: > > On Thu, Dec 24, 2015 at 5:10 PM, Sasha Levin wrote: > >> > On 12/24/2015 06:51 AM, Kirill A. Shutemov wrote: > >>> >> This patch fixes regression caused by patch > >>> >> "mm, dax: dax-pmd vs thp-pmd vs hugetlbfs-pmd" > >>> >> > >>> >> The patch makes pmd_trans_huge() check and "page = pmd_page(*pmd)" after > >>> >> __split_huge_pmd_locked(). It can never succeed, since the pmd already > >>> >> points to a page table. As result the page is never get munlocked. > >>> >> > >>> >> It causes crashes like this: > >>> >> http://lkml.kernel.org/r/5661FBB6.6050307@oracle.com > >> > > >> > So this patch didn't fix the issue for me. I've sent Kirill the trace > >> > off-list, but it's essentially the same thing. > > Can you send me the trace as well, and the reproducer? > > I don't have a simple reproducer, it reproduces rather quickly when running > under trinity within a KVM guest running a kernel I've attached the config > for. Is there a chance to get it reproduced with logs enabled in trinity? I failed to repoproduce it and code audit isn't fruitful so far. -- Kirill A. Shutemov -- 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