From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763569AbXJSBVM (ORCPT ); Thu, 18 Oct 2007 21:21:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754764AbXJSBVD (ORCPT ); Thu, 18 Oct 2007 21:21:03 -0400 Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:53174 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755772AbXJSBVB (ORCPT ); Thu, 18 Oct 2007 21:21:01 -0400 Date: Thu, 18 Oct 2007 18:21:00 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Nick Piggin cc: Linux Kernel Mailing List , akpm@linux-foundation.org, linux-mm@kvack.org Subject: Re: SLUB: Avoid atomic operation for slab_unlock In-Reply-To: <200710190949.01019.nickpiggin@yahoo.com.au> Message-ID: References: <200710190949.01019.nickpiggin@yahoo.com.au> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 19 Oct 2007, Nick Piggin wrote: > Ah, thanks, but can we just use my earlier patch that does the > proper __bit_spin_unlock which is provided by > bit_spin_lock-use-lock-bitops.patch Ok. > This primitive should have a better chance at being correct, and > also potentially be more optimised for each architecture (it > only has to provide release consistency). Yes that is what I attempted to do with the write barrier. To my knowledge there are no reads that could bleed out and I wanted to avoid a full fence instruction there. > I have attached the patch here just for reference, but actually > I am submitting it properly as part of a patch series today, now > that the base bit lock patches have been sent upstream. Good. Andrew: Drop my patch when this goes in.