From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756459Ab1GFVMm (ORCPT ); Wed, 6 Jul 2011 17:12:42 -0400 Received: from palinux.external.hp.com ([192.25.206.14]:33136 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756345Ab1GFVMl (ORCPT ); Wed, 6 Jul 2011 17:12:41 -0400 Date: Wed, 6 Jul 2011 15:12:39 -0600 From: Matthew Wilcox To: Linus Torvalds Cc: Miklos Szeredi , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, stable@kernel.org Subject: Re: [PATCH] fs: fix lock initialization Message-ID: <20110706211239.GC389@parisc-linux.org> References: <87iprf3dgs.fsf@tucsk.pomaz.szeredi.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 06, 2011 at 10:40:44AM -0700, Linus Torvalds wrote: > Ugh. Code that depends on SLAB initializers is broken. > > The reason for those initializers are traditionally "better cache > behavior" where you don't need to initialize everything at allocation > time, but the whole concept is almost invariably a disaster. This is a > prime example of it. It'd be good to have that documented somewhere. When I wrote this code (a decade ago), that wasn't my understanding. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."