From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756269AbZBSWoC (ORCPT ); Thu, 19 Feb 2009 17:44:02 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754223AbZBSWnx (ORCPT ); Thu, 19 Feb 2009 17:43:53 -0500 Received: from hera.kernel.org ([140.211.167.34]:41782 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754048AbZBSWnw (ORCPT ); Thu, 19 Feb 2009 17:43:52 -0500 Message-ID: <499DE05A.40804@kernel.org> Date: Thu, 19 Feb 2009 14:42:34 -0800 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Suresh Siddha CC: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Andrew Morton , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] x86: enable x2apic early at the first point References: <499DD40F.40102@kernel.org> <1235081612.14523.23.camel@vayu> In-Reply-To: <1235081612.14523.23.camel@vayu> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Suresh Siddha wrote: > On Thu, 2009-02-19 at 13:50 -0800, Yinghai Lu wrote: >> Impact: fix bug. >> >> otherwise will get panic from early_acpi_boot_init() >> also make disable_x2apic global, so could use it it x2_apic_xxx.c >> and can get warning if preenabled system using nox2apic. >> >> Signed-off-by: Yinghai Lu >> >> --- >> arch/x86/kernel/apic/apic.c | 3 +-- >> arch/x86/kernel/apic/x2apic_cluster.c | 5 ++++- >> arch/x86/kernel/apic/x2apic_phys.c | 5 ++++- >> arch/x86/kernel/apic/x2apic_uv_x.c | 4 +++- >> drivers/pci/dmar.c | 3 ++- >> 5 files changed, 14 insertions(+), 6 deletions(-) >> >> Index: linux-2.6/arch/x86/kernel/apic/x2apic_cluster.c >> =================================================================== >> --- linux-2.6.orig/arch/x86/kernel/apic/x2apic_cluster.c >> +++ linux-2.6/arch/x86/kernel/apic/x2apic_cluster.c >> @@ -14,8 +14,11 @@ DEFINE_PER_CPU(u32, x86_cpu_to_logical_a >> >> static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id) >> { >> - if (cpu_has_x2apic) >> + if (cpu_has_x2apic && !disable_x2apic) { >> + x2apic = 1; >> + enable_x2apic(); > > Yinghai, I also ran into couple of x2apic issues on the latest tip and > this issue is one of them. I don't like this patch mainly because we are > enabling x2apic mode in the cpu, with out checking the intr-remapping > support. We should fall back to xapic mode (in a clean fashion) if there > is any issue with intr-remapping. So I am planning to post another patch > to fix this early hang issue that we both encountered. Ingo want to decouple that x2apic and intr_remapping. it seems it does work with x2apic without intr_remapping in one of setup. YH