From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751093AbcDBWFf (ORCPT ); Sat, 2 Apr 2016 18:05:35 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:34329 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750766AbcDBWFd (ORCPT ); Sat, 2 Apr 2016 18:05:33 -0400 Date: Sun, 3 Apr 2016 01:05:28 +0300 From: "Kirill A. Shutemov" To: Konstantin Khlebnikov Cc: linux-mm@kvack.org, Andrew Morton , Dmitry Vyukov , Andrea Arcangeli , linux-kernel@vger.kernel.org, stable Subject: Re: [PATCH] mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check Message-ID: <20160402220528.GA7977@node.shutemov.name> References: <145961146490.28194.16019687861681349309.stgit@zurg> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <145961146490.28194.16019687861681349309.stgit@zurg> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Apr 02, 2016 at 06:37:44PM +0300, Konstantin Khlebnikov wrote: > Khugepaged detects own VMAs by checking vm_file and vm_ops but this > way it cannot distinguish private /dev/zero mappings from other special > mappings like /dev/hpet which has no vm_ops and popultes PTEs in mmap. > > This fixes false-positive VM_BUG_ON and prevents installing THP where > they are not expected. > > Signed-off-by: Konstantin Khlebnikov > Reported-by: Dmitry Vyukov > Link: http://lkml.kernel.org/r/CACT4Y+ZmuZMV5CjSFOeXviwQdABAgT7T+StKfTqan9YDtgEi5g@mail.gmail.com > Fixes: 78f11a255749 ("mm: thp: fix /dev/zero MAP_PRIVATE and vm_flags cleanups") > Cc: stable Looks good to me. Acked-by: Kirill A. Shutemov -- Kirill A. Shutemov