From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754481AbYJCPVg (ORCPT ); Fri, 3 Oct 2008 11:21:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754177AbYJCPVR (ORCPT ); Fri, 3 Oct 2008 11:21:17 -0400 Received: from mtagate7.uk.ibm.com ([195.212.29.140]:50343 "EHLO mtagate7.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754157AbYJCPVQ (ORCPT ); Fri, 3 Oct 2008 11:21:16 -0400 From: Christian Borntraeger To: Linus Torvalds Subject: Re: [regression] Latest git has WARN_ON storm with e1000e driver Date: Fri, 3 Oct 2008 17:20:53 +0200 User-Agent: KMail/1.9.9 Cc: Thomas Gleixner , linux-kernel@vger.kernel.org, Jesse Brandeburg References: <200810031041.49350.borntraeger@de.ibm.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200810031720.53923.borntraeger@de.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Freitag, 3. Oktober 2008 schrieben Sie: > Which spinlock is it? It sure shouldn't be anything in the generic drievr > layer: __driver_attach takes a lock, but it's a semaphore (dev->sem), not > a spinlock. In fact, al lot of drivers will sleep or do allocations, so if > the driver layer were to call the probe function with a spinlock held, > things would be really broken. > > The callchain has "spin_lock_irqsave" in it, but that's stale stack data. Very good point indeed. Seems my analysis was wrong. I made a short test and preempt_count() returns 1 when the WARN_ON triggers. So its either a spinlock or something else that increased my preempt_count.