From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755871AbZLINba (ORCPT ); Wed, 9 Dec 2009 08:31:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755848AbZLINb3 (ORCPT ); Wed, 9 Dec 2009 08:31:29 -0500 Received: from courier.cs.helsinki.fi ([128.214.9.1]:36018 "EHLO mail.cs.helsinki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755837AbZLINb2 (ORCPT ); Wed, 9 Dec 2009 08:31:28 -0500 Message-ID: <4B1FA6B6.8070701@cs.helsinki.fi> Date: Wed, 09 Dec 2009 15:31:34 +0200 From: Pekka Enberg User-Agent: Thunderbird 2.0.0.23 (Macintosh/20090812) MIME-Version: 1.0 To: Andrew Morton CC: Vegard Nossum , Eric Dumazet , linux-kernel@vger.kernel.org, stable@kernel.org Subject: Re: [PATCH] kmemcheck: make bitfield annotations truly no-ops when disabled References: <1260121333-19642-1-git-send-email-vegard.nossum@gmail.com> <20091207141356.9e83fd5b.akpm@linux-foundation.org> In-Reply-To: <20091207141356.9e83fd5b.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton kirjoitti: > On Sun, 6 Dec 2009 18:42:13 +0100 > Vegard Nossum wrote: > >> It turns out that even zero-sized struct members (int foo[0];) will affect >> the struct layout, causing us in particular to lose 4 bytes in struct sock. >> >> This patch fixes the regression in CONFIG_KMEMCHECK=n case. > > Which kernel version is the regression relative to? AFAICT, it dates back to 2.6.31 when kmemcheck was introduced in mainline. Vegard? > Should we backport this into 2.6.32.x? I guess so. Eric, how bad is the regression? Pekka