Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932200AbWA3KbT (ORCPT ); Mon, 30 Jan 2006 05:31:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932203AbWA3KbT (ORCPT ); Mon, 30 Jan 2006 05:31:19 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:27776 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S932200AbWA3KbS (ORCPT ); Mon, 30 Jan 2006 05:31:18 -0500 Subject: Re: [PATCH 2.6.16-rc1-git4] accessfs: a permission managing filesystem From: Arjan van de Ven To: Jan Engelhardt Cc: Andrew Morton , olaf+list.linux-kernel@olafdietsche.de, eike-kernel@sf-tec.de, linux-kernel@vger.kernel.org In-Reply-To: References: <87ek3a8qpy.fsf@goat.bogus.local> <200601231257.28796@bilbo.math.uni-mannheim.de> <87mzhgyomh.fsf@goat.bogus.local> <20060128150137.5ba5af04.akpm@osdl.org> <20060130011630.60f402d8.akpm@osdl.org> <1138614388.2977.10.camel@laptopd505.fenrus.org> <1138614856.2977.16.camel@laptopd505.fenrus.org> Content-Type: text/plain Date: Mon, 30 Jan 2006 11:31:12 +0100 Message-Id: <1138617073.2977.21.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 916 Lines: 25 On Mon, 2006-01-30 at 11:25 +0100, Jan Engelhardt wrote: > >> You can't do that. > > > >Exactly why not? Assuming there are zero users left in the kernel..... > >(which highly obviously is a prerequisite for even thinking about such a > >step) > > Documentation/mutex-design.txt: > * - mutexes may not be used in irq contexts > > I need some locking strategy within irq contexts, and that suggests > semaphores do the job. well... maybe. If you need to mess inside irq context, spinlocks sound more the right thing. Or if you need to do a "I'm done" in the irq and a "sleep until done" thing in process context, then you really should use completions instead. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/