From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752550AbZK0CDJ (ORCPT ); Thu, 26 Nov 2009 21:03:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751577AbZK0CDI (ORCPT ); Thu, 26 Nov 2009 21:03:08 -0500 Received: from hera.kernel.org ([140.211.167.34]:60323 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751491AbZK0CDG (ORCPT ); Thu, 26 Nov 2009 21:03:06 -0500 Message-ID: <4B0F3331.3070107@kernel.org> Date: Fri, 27 Nov 2009 11:02:25 +0900 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; ko-KR; rv:1.9.1.4pre) Gecko/20090915 SUSE/3.0b4-3.6 Thunderbird/3.0b4 MIME-Version: 1.0 To: Andy Walls CC: Peter Ujfalusi , Stephen Rothwell , "linux-next@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Takashi Iwai , Mark Brown Subject: Re: linux-next: workqueues tree build failure References: <20091126190050.3f9d7fef.sfr@canb.auug.org.au> <4B0E3677.6000603@kernel.org> <200911261016.58810.peter.ujfalusi@nokia.com> <4B0E467A.8080201@kernel.org> <1259239225.3062.16.camel@palomino.walls.org> In-Reply-To: <1259239225.3062.16.camel@palomino.walls.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, 11/26/2009 09:40 PM, Andy Walls wrote: >> * If you need to respond fast, wouldn't you be doing that from IRQ >> handler or softirq? Do you need task context? > > I'm not sure doing things like I2C transactions in the in the top half > of the IRQ handler is generally viable. On shared IRQ lines, wouldn't > this hold off the interrupt for another device for too long? > > For example, I already ran across the case of an error path in the ahci > disk controller driver interrupt handler holding off interrupts from the > cx18 driver longer than the CX23418 firmware would tolerate on a shared > interrupt line. Sounds like it should be using bottom half tasklet not workqueue. Tasklet is exactly designed to handle situations like this. Is there any reason tasklet can't be used? Thanks. -- tejun