From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753346AbYC1NSS (ORCPT ); Fri, 28 Mar 2008 09:18:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752126AbYC1NSI (ORCPT ); Fri, 28 Mar 2008 09:18:08 -0400 Received: from palinux.external.hp.com ([192.25.206.14]:38139 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752109AbYC1NSH (ORCPT ); Fri, 28 Mar 2008 09:18:07 -0400 Date: Fri, 28 Mar 2008 07:17:50 -0600 From: Matthew Wilcox To: Jens Axboe Cc: "Luck, Tony" , Stephen Rothwell , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: down_spin() implementation Message-ID: <20080328131750.GT16721@parisc-linux.org> References: <1FE6DD409037234FAB833C420AA843ECE9DF60@orsmsx424.amr.corp.intel.com> <20080326123239.GG16721@parisc-linux.org> <1FE6DD409037234FAB833C420AA843ECE9EB1C@orsmsx424.amr.corp.intel.com> <20080327141508.GL16721@parisc-linux.org> <20080328125104.GK12346@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080328125104.GK12346@kernel.dk> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 28, 2008 at 01:51:04PM +0100, Jens Axboe wrote: > It used to be illegal to pass flags as parameters. IIRC, sparc did some > trickery with it. That may still be the case, I haven't checked in a > long time. That problem was removed before 2.6 started, iirc. At least the chapter on 'The Fucked Up Sparc' [1] was removed before 2.6.12-rc2 (the beginning of git history and I can't be bothered to pinpoint it more precisely). > Why not just fold __down_spin() into down_spin() and get rid of that > nasty anyway? Could have done. It's moot now that Nick's pointed out how unsafe it is to mix down_spin() with plain down(). [1] http://www.kernel.org/pub/linux/kernel/people/rusty/kernel-locking/x467.html -- Intel are signing my paycheques ... these opinions are still mine "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."