From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755566AbaHFKRv (ORCPT ); Wed, 6 Aug 2014 06:17:51 -0400 Received: from mta-out1.inet.fi ([62.71.2.230]:33748 "EHLO jenni2.inet.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754703AbaHFKRt (ORCPT ); Wed, 6 Aug 2014 06:17:49 -0400 Date: Wed, 6 Aug 2014 13:17:18 +0300 From: "Kirill A. Shutemov" To: Oleg Nesterov Cc: Andrew Morton , Alexander Viro , Cyrill Gorcunov , David Howells , "David S. Miller" , "Eric W. Biederman" , "Kirill A. Shutemov" , Peter Zijlstra , Sasha Levin , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 6/7] fs/proc/task_mmu.c: cleanup the "tail_vma" horror in m_next() Message-ID: <20140806101718.GB30703@node.dhcp.inet.fi> References: <20140805194627.GA30693@redhat.com> <20140805194703.GA30739@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140805194703.GA30739@redhat.com> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 05, 2014 at 09:47:03PM +0200, Oleg Nesterov wrote: > 1. Kill the first "vma != NULL" check. Firstly this is not possible, > m_next() won't be called if ->start() or the previous ->next() > returns NULL. > > And if it was possible the 2nd "vma != tail_vma" check is buggy, > we should not wrongly return ->tail_vma. > > 2. Make this function readable. The logic is very simple, we should > return check "vma != tail" once and return "vm_next || tail_vma". > > Signed-off-by: Oleg Nesterov Acked-by: Kirill A. Shutemov -- Kirill A. Shutemov