From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: lockdep and threaded IRQs Date: Mon, 2 Mar 2009 14:57:57 -0800 Message-ID: <20090302145757.38a44307.akpm@linux-foundation.org> References: <1236030106.5330.1553.camel@laptop> <200903021409.21344.david-b@pacbell.net> <1236032371.5330.1654.camel@laptop> <20090302.144647.116847598.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:36810 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755273AbZCBX71 (ORCPT ); Mon, 2 Mar 2009 18:59:27 -0500 In-Reply-To: <20090302.144647.116847598.davem@davemloft.net> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: David Miller Cc: a.p.zijlstra@chello.nl, dbrownell@users.sourceforge.net, tglx@linutronix.de, me@felipebalbi.com, linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, felipe.balbi@nokia.com, dmitry.torokhov@gmail.com, sameo@openedhand.com On Mon, 02 Mar 2009 14:46:47 -0800 (PST) David Miller wrote: > From: Peter Zijlstra > Date: Mon, 02 Mar 2009 23:19:31 +0100 > > > I state that every !IRQF_DISABLED usage is a bug, either due to broken > > hardware or broken drivers. > > We'll send you the bill to have everyone's hardware > replaced :-) yes, but with what? No matter how fast all our interrupt handlers are, running them with local interrupts disabled has to worsen the worst-case interrupt latency. I don't see how removing !IRQF_DISABLED improves the kernel - in fact there's a latency argument for making !IRQF_DISABLED the default.