From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965050AbWFHXAH (ORCPT ); Thu, 8 Jun 2006 19:00:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965051AbWFHXAH (ORCPT ); Thu, 8 Jun 2006 19:00:07 -0400 Received: from ozlabs.org ([203.10.76.45]:21889 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S965050AbWFHXAF (ORCPT ); Thu, 8 Jun 2006 19:00:05 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17544.44013.299585.169274@cargo.ozlabs.ibm.com> Date: Fri, 9 Jun 2006 08:59:57 +1000 From: Paul Mackerras To: Ingo Molnar Cc: Benjamin Herrenschmidt , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: mutex vs. local irqs (Was: 2.6.18 -mm merge plans) In-Reply-To: <20060607132155.GB14425@elte.hu> References: <20060604135011.decdc7c9.akpm@osdl.org> <1149652378.27572.109.camel@localhost.localdomain> <20060606212930.364b43fa.akpm@osdl.org> <1149656647.27572.128.camel@localhost.localdomain> <20060606222942.43ed6437.akpm@osdl.org> <1149662671.27572.158.camel@localhost.localdomain> <20060607132155.GB14425@elte.hu> X-Mailer: VM 7.19 under Emacs 21.4.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar writes: > a better solution would be to install boot-time IRQ vectors that just do > nothing but return. They dont mask, they dont ACK nor EOI - they just > return. How would that help? We'd just end up taking the interrupt over and over again. We have to either poke the PIC to tell it to shut up somehow (which we can't do before ioremap is available) or arrange for interrupts to be disabled after the return (which means that might_sleep() will scream at us). Paul.