From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757673AbcFAJkF (ORCPT ); Wed, 1 Jun 2016 05:40:05 -0400 Received: from mail-lf0-f51.google.com ([209.85.215.51]:36099 "EHLO mail-lf0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751415AbcFAJkC (ORCPT ); Wed, 1 Jun 2016 05:40:02 -0400 Date: Wed, 1 Jun 2016 12:39:57 +0300 From: "Kirill A. Shutemov" To: Naoya Horiguchi Cc: Andrew Morton , Hugh Dickins , Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Naoya Horiguchi Subject: Re: [PATCH v1] mm: thp: check pmd_trans_unstable() after split_huge_pmd() Message-ID: <20160601093957.GA8493@node.shutemov.name> References: <1464741400-12143-1-git-send-email-n-horiguchi@ah.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1464741400-12143-1-git-send-email-n-horiguchi@ah.jp.nec.com> 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 Wed, Jun 01, 2016 at 09:36:40AM +0900, Naoya Horiguchi wrote: > split_huge_pmd() doesn't guarantee that the pmd is normal pmd pointing to > pte entries, which can be checked with pmd_trans_unstable(). Could you be more specific on when we don't have normal ptes after split_huge_pmd? Race with other thread? DAX? I guess we can modify split_huge_pmd() to return if the pmd was split or not. -- Kirill A. Shutemov