From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754541AbaAFLY1 (ORCPT ); Mon, 6 Jan 2014 06:24:27 -0500 Received: from cantor2.suse.de ([195.135.220.15]:36739 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752857AbaAFLY0 (ORCPT ); Mon, 6 Jan 2014 06:24:26 -0500 Date: Mon, 6 Jan 2014 12:24:22 +0100 From: Michal Hocko To: Wanpeng Li Cc: Naoya Horiguchi , Bob Liu , linux-mm@kvack.org, LKML Subject: could you clarify mm/mempolicy: fix !vma in new_vma_page() Message-ID: <20140106112422.GA27602@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Wanpeng Li, I have just noticed 11c731e81bb0 (mm/mempolicy: fix !vma in new_vma_page()) and I am not sure I understand it. Your changelog claims " page_address_in_vma() may still return -EFAULT because of many other conditions in it. As a result the while loop in new_vma_page() may end with vma=NULL. " And the patch handles hugetlb case only. I was wondering what are those "other conditions" that failed in the BUG_ON mentioned in the changelog? Could you be more specific please? Thanks! -- Michal Hocko SUSE Labs