From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759238AbZA2Pl6 (ORCPT ); Thu, 29 Jan 2009 10:41:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752466AbZA2Plt (ORCPT ); Thu, 29 Jan 2009 10:41:49 -0500 Received: from relay1.sgi.com ([192.48.179.29]:45933 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752118AbZA2Plt (ORCPT ); Thu, 29 Jan 2009 10:41:49 -0500 Date: Thu, 29 Jan 2009 09:41:46 -0600 From: Jack Steiner To: suresh.b.siddha@intel.com Cc: mingo@elte.hu, linux-kernel@vger.kernel.org Subject: Possible x2apic breakage Message-ID: <20090129154146.GA2694@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Suresh - This popped up in Ingo's x86 tree yesterday. This appears to be breaking on our simulator running in x2apic mode. If I understand the code, this is a real breakage and not a problem in our simulator: arch/x86/include/asm/genapic.h static inline unsigned int read_apic_id(void) { unsigned int reg; reg = *(u32 *)(APIC_BASE + APIC_ID); return apic->get_apic_id(reg); } As expected, the failure occurs right after: Enabling x2apic Enabled x2apic and interrupt-remapping The next reference to apicid tries to read from mem instead of MSRs. --- jack