From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754483AbaDUUfP (ORCPT ); Mon, 21 Apr 2014 16:35:15 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:60365 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753542AbaDUUfM (ORCPT ); Mon, 21 Apr 2014 16:35:12 -0400 From: "Rafael J. Wysocki" To: Baoquan He Cc: linux-kernel@vger.kernel.org, lenb@kernel.org, linux-acpi@vger.kernel.org, jiang.liu@linux.intel.com, vgoyal@redhat.com Subject: Re: [PATCH] acpi: try to trust cpu_index from x86_cpu_to_apicid Date: Mon, 21 Apr 2014 22:51:31 +0200 Message-ID: <11963454.DotWb00OAa@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.14.0-rc7+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1397519754-10205-1-git-send-email-bhe@redhat.com> References: <1397519754-10205-1-git-send-email-bhe@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, April 15, 2014 07:55:54 AM Baoquan He wrote: > In smp with multi cpus, when enter into kdump kernel with only 1 cpu, > a warning message is printed out: > > acpi LNXCPU:0a: BIOS reported wrong ACPI id 0 for the processor > > In this case kdump kernel use the same ACPI tables as 1st kernel, > means lapic information is got from MADT. The acpi_id related to > this cpu index and lapic_id may not be 0, so the code to assign > value to cpu_index is not correct in this case per cpu0_initialized. > cpu index stored in x86_cpu_to_apicid need be respected. > > Now fix it in this patch per boot_cpu_physical_apicid. When cpu index > related to boot_cpu_physical_apicid is not stored in x86_cpu_to_apicid, > then we can say this is UP system running SMP kernel with no LAPIC in MADT Why don't you fix the warning message instead to cover this case too? > Signed-off-by: Baoquan He > --- > drivers/acpi/acpi_processor.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c > index c29c2c3..1ae460c 100644 > --- a/drivers/acpi/acpi_processor.c > +++ b/drivers/acpi/acpi_processor.c > @@ -267,7 +267,7 @@ static int acpi_processor_get_info(struct acpi_device *device) > pr->apic_id = apic_id; > > cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id); > - if (!cpu0_initialized) { > + if (!cpu0_initialized && (boot_cpu_physical_apicid == pr->apic_id)) { > cpu0_initialized = 1; > /* Handle UP system running SMP kernel, with no LAPIC in MADT */ > if ((cpu_index == -1) && (num_online_cpus() == 1)) > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.