From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759511AbZBFQhc (ORCPT ); Fri, 6 Feb 2009 11:37:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752645AbZBFQhY (ORCPT ); Fri, 6 Feb 2009 11:37:24 -0500 Received: from gw.goop.org ([64.81.55.164]:38473 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750936AbZBFQhX (ORCPT ); Fri, 6 Feb 2009 11:37:23 -0500 Message-ID: <498C6741.8000605@goop.org> Date: Fri, 06 Feb 2009 08:37:21 -0800 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Andi Kleen CC: Ingo Molnar , Zachary Amsden , Rusty Russell , Ian Campbell , the arch/x86 maintainers , linux-kernel@vger.kernel.org, Ravikiran Thirumalai , Xen-devel Subject: Re: [PATCH 5 of 7] x86/paravirt: add register-saving thunks to reduce caller register pressure References: <7d4a052c499dbfe5e816.1233182105@abulafia.goop.org> <87fxisvxb9.fsf@basil.nowhere.org> In-Reply-To: <87fxisvxb9.fsf@basil.nowhere.org> X-Enigmail-Version: 0.95.6 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 Andi Kleen wrote: > I had something like this (but not as generic) for the old pre > unification semaphores on x86-64 too. I think it's a generally useful > facility for lots of things (in fact I've been asking gcc developers > for providing this in a general way for some time). > What other users do you have in mind? > So I would suggest to move the necessary macros to do that outside > paravirt.h into a separate include so that it can be used independently > and not call it PV_*. That wouldn't be too hard to do, but I don't think its something we should do lightly. There are quite a few pitfalls, and the bugs can get pretty obscure. It would also mean bringing out a lot of the PV_CALL machinery, and I'm not sure we really want to give that too much exposure in the light of day. J