Return-path: Received: from palinux.external.hp.com ([192.25.206.14]:33081 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752959AbYE0CPV (ORCPT ); Mon, 26 May 2008 22:15:21 -0400 Date: Mon, 26 May 2008 20:15:03 -0600 From: Matthew Wilcox To: Rusty Russell Cc: Michal Schmidt , Daniel Walker , linville@tuxdriver.com, mingo@elte.hu, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, arjan@infradead.org Subject: Re: [PATCH] net: wireless: airo semaphore to mutex Message-ID: <20080527021503.GH30894@parisc-linux.org> (sfid-20080527_041524_510284_7F34FF25) References: <20080522232103.120033152@mvista.com> <20080526192914.31045d09@brian.englab.brq.redhat.com> <200805271117.23051.rusty@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <200805271117.23051.rusty@rustcorp.com.au> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, May 27, 2008 at 11:17:22AM +1000, Rusty Russell wrote: > On Tuesday 27 May 2008 03:29:14 Michal Schmidt wrote: > > Mutexes are not allowed in interrupt context, not even mutex_trylock. > > As an aside, does anyone know why? I know the documentation says so, but it > wasn't immediately obvious to me. I asked before to no response... Because mutexes have an owner. In interrupt context, there is no owner. This owner is used to do priority boosts as well as debugging. -- 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."