From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750745AbWFNSs2 (ORCPT ); Wed, 14 Jun 2006 14:48:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750751AbWFNSs2 (ORCPT ); Wed, 14 Jun 2006 14:48:28 -0400 Received: from mtagate5.uk.ibm.com ([195.212.29.138]:51655 "EHLO mtagate5.uk.ibm.com") by vger.kernel.org with ESMTP id S1750745AbWFNSs1 (ORCPT ); Wed, 14 Jun 2006 14:48:27 -0400 Date: Wed, 14 Jun 2006 20:47:57 +0200 From: Heiko Carstens To: Ingo Molnar Cc: Arjan van de Ven , Andrew Morton , linux-kernel@vger.kernel.org, Martin Schwidefsky Subject: Re: [patch 7/8] lock validator: s390 use raw_spinlock in mcck handler Message-ID: <20060614184757.GA10391@osiris.ibm.com> References: <20060614142318.GH1241@osiris.boeblingen.de.ibm.com> <20060614182516.GB31243@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060614182516.GB31243@elte.hu> User-Agent: mutt-ng/devel-r802 (Linux) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 14, 2006 at 09:25:16PM +0200, Ingo Molnar wrote: > > * Heiko Carstens wrote: > > > From: Heiko Carstens > > > > Machine checks on s390 are always enabled (except in the machine check > > handler itself). Therefore use a raw_spinlock in the machine check > > handler to avoid deadlocks in the lock validator. > > hm, couldnt you use the ->lockdep_recursion mechanism to take care of > such cases? Just call lockdep_off() when entering a machine exception > handler, and lockdep_on() when exiting it. Ah, sure. Wasn't aware that there is such an interface. Will do.