Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934318AbZD3SAq (ORCPT ); Thu, 30 Apr 2009 14:00:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754699AbZD3SAc (ORCPT ); Thu, 30 Apr 2009 14:00:32 -0400 Received: from vpnflf.ccur.com ([12.192.68.2]:42327 "EHLO gamx.iccur.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755088AbZD3SAb (ORCPT ); Thu, 30 Apr 2009 14:00:31 -0400 Date: Thu, 30 Apr 2009 14:00:12 -0400 From: Joe Korty To: "Eric W. Biederman" Cc: "venkatesh.pallipadi@intel.com" , "mingo@elte.hu" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] clear irq pending when bypassing it Message-ID: <20090430180011.GB28139@tsunami.ccur.com> Reply-To: Joe Korty References: <20090430161506.GA2636@typhoon.ccur.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 909 Lines: 24 On Thu, Apr 30, 2009 at 12:49:39PM -0400, Eric W. Biederman wrote: > Joe Korty writes: > > > IRQ_MOVE_PENDING must be cleared whenever it is bypassed. > > > > Otherwise, we risk an old, pending affinity change > > overtaking and erasing a more recent affinity change that > > had been directly applied (eg, IRQ_MOVE_PCNTXT mode). > > When can this happen? Probably doesn't happen. AFAIK, each IRQ is either fully MSI or non-MSI. The MSI IRQs will always use IRQ_MOVE_PCNTXT and the non-MSI's will never use IRQ_MOVE_PCNTXT. Thus no collision. It could only happen if it was possible for a MSI and non-MSI device to share an IRQ. Joe -- 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/