From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753311Ab0CZGKe (ORCPT ); Fri, 26 Mar 2010 02:10:34 -0400 Received: from one.firstfloor.org ([213.235.205.2]:48842 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752874Ab0CZGKd (ORCPT ); Fri, 26 Mar 2010 02:10:33 -0400 Date: Fri, 26 Mar 2010 07:10:29 +0100 From: Andi Kleen To: Linus Torvalds Cc: Peter Zijlstra , Thomas Gleixner , Andi Kleen , x86@kernel.org, LKML , jesse.brandeburg@intel.com Subject: Re: [PATCH] Prevent nested interrupts when the IRQ stack is near overflowing v2 Message-ID: <20100326061029.GU20695@one.firstfloor.org> References: <20100324190150.GA18803@basil.fritz.box> <20100325003652.GG20695@one.firstfloor.org> <20100325093744.GH20695@one.firstfloor.org> <1269539254.12097.100.camel@laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Now, I think (and sincerely) that the SCSI situation is likely long since > fixed, but we have thousands and thousands of drivers, and these kinds of > things are very hard to notice automatically. Are there any cases around > that still have busy-loop delays based on real-time in their irq handlers? > I simply don't know. This case was already broken back when the x86-64 port used to run with NMI watchdog on by default, because any IO exception handling with interrupts off would trigger the NMI watchdog eventually. I remember having to add bandaids to Fusion for this a long time ago. Of course ISA drivers might still do it. -Andi -- ak@linux.intel.com -- Speaking for myself only.