From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f44.google.com (mail-lf0-f44.google.com [209.85.215.44]) by kanga.kvack.org (Postfix) with ESMTP id 5055C6B0270 for ; Mon, 4 Apr 2016 08:36:38 -0400 (EDT) Received: by mail-lf0-f44.google.com with SMTP id c62so168384280lfc.1 for ; Mon, 04 Apr 2016 05:36:38 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id t19si13192444wme.63.2016.04.04.05.36.36 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 04 Apr 2016 05:36:37 -0700 (PDT) Subject: Re: [PATCH] mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check References: <145961146490.28194.16019687861681349309.stgit@zurg> From: Vlastimil Babka Message-ID: <57025FD3.4060004@suse.cz> Date: Mon, 4 Apr 2016 14:36:35 +0200 MIME-Version: 1.0 In-Reply-To: <145961146490.28194.16019687861681349309.stgit@zurg> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Konstantin Khlebnikov , linux-mm@kvack.org, Andrew Morton Cc: Dmitry Vyukov , Andrea Arcangeli , linux-kernel@vger.kernel.org, stable On 04/02/2016 05:37 PM, 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 Acked-by: Vlastimil Babka -- 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