Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750985AbWEWRBL (ORCPT ); Tue, 23 May 2006 13:01:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751002AbWEWRBK (ORCPT ); Tue, 23 May 2006 13:01:10 -0400 Received: from ms-smtp-01.nyroc.rr.com ([24.24.2.55]:17064 "EHLO ms-smtp-01.nyroc.rr.com") by vger.kernel.org with ESMTP id S1750985AbWEWRBJ (ORCPT ); Tue, 23 May 2006 13:01:09 -0400 Subject: Re: Ingo's realtime_preempt patch causes kernel oops From: Steven Rostedt To: Yann.LEPROVOST@wavecom.fr Cc: Daniel Walker , linux-kernel@vger.kernel.org, Ingo Molnar , Thomas Gleixner In-Reply-To: References: Content-Type: text/plain Date: Tue, 23 May 2006 13:00:42 -0400 Message-Id: <1148403642.22855.12.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.4.2.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 869 Lines: 23 On Tue, 2006-05-23 at 18:27 +0200, Yann.LEPROVOST@wavecom.fr wrote: > I forgot to say that I let SA_SHIRQ as the IRQ line is shared... > It seems to work correctly... What shares it? Reason I ask, is that this irq is now running in true interrupt context, and that on PREEMPT_RT the spin_locks are mutexes and can schedule. So if another device is sharing this irq, then its interrupt handler will be running in interrupt context, and if it grabs a spin_lock than is not a raw_spinlock_t then you will have a crash. This won't be a problem if you only turn on Hard irqs as threads and don't do the PREEMPT_RT. -- Steve - 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/