From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753841Ab1LMAU1 (ORCPT ); Mon, 12 Dec 2011 19:20:27 -0500 Received: from mga01.intel.com ([192.55.52.88]:21702 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751970Ab1LMAU0 (ORCPT ); Mon, 12 Dec 2011 19:20:26 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="95407077" Subject: Re: x2apic boot failure on recent sandy bridge system From: Suresh Siddha Reply-To: Suresh Siddha To: "Berck E. Nash" Cc: Yinghai Lu , Ingo Molnar , "linux-kernel@vger.kernel.org" , "H. Peter Anvin" Date: Mon, 12 Dec 2011 16:25:02 -0800 In-Reply-To: <4EE68C80.7000408@gmail.com> References: <4EE2BC33.80902@gmail.com> <20111211075713.GA20790@elte.hu> <4EE5291C.1030302@gmail.com> <4EE68C80.7000408@gmail.com> Organization: Intel Corp Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.0.3 (3.0.3-1.fc15) Content-Transfer-Encoding: 7bit Message-ID: <1323735902.1984.165.camel@sbsiddha-desk.sc.intel.com> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-12-12 at 15:21 -0800, Berck E. Nash wrote: > On 12/11/2011 08:40 PM, Yinghai Lu wrote: > > x2apic pre-enabled skip the mapping for lapic address. so need map it > > after fall back. > > > > please check attached -v5.. > > It appears to work correctly as far as I can tell. Ok. In this case, it looks like bios didn't enable interrupt-remapping (part of vt-d) and just enabled x2apic with out touching or exporting vt-d HW. Yinghai, In other scenarios where OS can't recover, mostly likely we will fail in check_timer() when we fall back to xapic. Can we add a printk in this case to convey the potential reason (that I mentioned in the previous e-mail), so that the user can get more accurate information for the check timer failure. thanks, suresh