From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755740AbZCCKER (ORCPT ); Tue, 3 Mar 2009 05:04:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751929AbZCCKED (ORCPT ); Tue, 3 Mar 2009 05:04:03 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:39888 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751524AbZCCKEA (ORCPT ); Tue, 3 Mar 2009 05:04:00 -0500 Date: Tue, 3 Mar 2009 11:03:29 +0100 From: Ingo Molnar To: Alan Cox Cc: Peter Zijlstra , David Brownell , Andrew Morton , me@felipebalbi.com, linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, felipe.balbi@nokia.com, dmitry.torokhov@gmail.com, sameo@openedhand.com, tglx@linutronix.de Subject: Re: lockdep and threaded IRQs (was: ...) Message-ID: <20090303100329.GA5050@elte.hu> References: <1235762883-20870-1-git-send-email-me@felipebalbi.com> <200903021633.08736.david-b@pacbell.net> <20090303004427.GA8638@elte.hu> <200903021837.08635.david-b@pacbell.net> <1236072446.18955.44.camel@twins> <20090303094743.030b2507@lxorguk.ukuu.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090303094743.030b2507@lxorguk.ukuu.org.uk> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Alan Cox wrote: > > Therefore IRQF_DISABLED _will_ be forced on everybody some > > day soon, and I'll provide an IRQF_ENABLED for use by broken > > hardware only (and make a TAINT flag for that too). > > I don't think you understand how the kernel project works. If > everyone thinks your change is inappropriate it won't get in. The change that people had a problem with was the immediate removal of IRQF_ENABLED, and that's not on the plate anymore. I dont think anyone offered any example where IRQF_ENABLED is used in a healthy way - they are all legacy or special hw quirks where we limp along with enabling IRQs in a hacky way. Furthermore, even these quirky cases can be supported cleanly _without_ IRQF_ENABLED: where an IRQ handler can take a long time to execute, the handler can be converted to a threaded IRQ handler - where it's fine to enable IRQs as there are no stack nesting issues. So there's no real technical problem here. Ingo