From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756121AbYEROcD (ORCPT ); Sun, 18 May 2008 10:32:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752985AbYEROby (ORCPT ); Sun, 18 May 2008 10:31:54 -0400 Received: from ozlabs.org ([203.10.76.45]:33049 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751731AbYERObx (ORCPT ); Sun, 18 May 2008 10:31:53 -0400 From: Rusty Russell To: Eric Dumazet Subject: Re: [PATCH] modules: Use a better scheme for refcounting Date: Mon, 19 May 2008 00:31:44 +1000 User-Agent: KMail/1.9.9 Cc: Mike Travis , Andrew Morton , linux kernel , Christoph Lameter References: <482C9FC5.2070508@cosmosbay.com> <200805171533.46295.rusty@rustcorp.com.au> <482E8AF5.9050804@cosmosbay.com> In-Reply-To: <482E8AF5.9050804@cosmosbay.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200805190031.45136.rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 17 May 2008 17:36:21 Eric Dumazet wrote: > Christoph Lameter made good work last year and apparently the path is to : > > 1) Put pda at the begining of percpu section. Well, we killed the pda on i386: it's basically a limited arch-specific percpu section. Unfortunately, ISTR that doing so kills -fstack-protector on x86-64 (gcc was explicitly patched to support the kernel doing this, but it nailed us to a fixed offset off %fs). But the PDA is a redundant idea which should be removed. > 2) Relocate percpu variables to begin at zero > 3) Use %gs (or %fs) register to address pda AND percpu section. Thanks for the prod Eric. ISTR acking those patches; Christoph, what happened to them? Cheers, Rusty.