From mboxrd@z Thu Jan 1 00:00:00 1970 From: Siju George Subject: LAPCI disabled for second Processor in 2.6.8-11-amd64-k8-smp kernel - need help reading source code Date: Wed, 28 Dec 2005 20:41:19 +0530 Message-ID: References: Mime-Version: 1.0 Content-Transfer-Encoding: 7BIT Return-path: In-Reply-To: Content-Disposition: inline Sender: linux-smp-owner@vger.kernel.org List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-smp@vger.kernel.org Hi, I need some help to sort out this :-) The following lines appear in the dmesg of my Dual Opteron Server running on 2.6.8-11-amd64-k8-smp kernel -------------- Processor #0 15:5 APIC version 16 ACPI: LAPIC (acpi_id[0x02] lapic_id[0x01] enabled) Processor #1 15:5 APIC version 16 ACPI: LAPIC (acpi_id[0x03] lapic_id[0x82] disabled) ACPI: LAPIC (acpi_id[0x04] lapic_id[0x83] disabled) --------------------------------- What is LAPIC? Why is it disabled for the second processor? Is it normal beavior? I have posted to several mailinglist and got no reply on this :-( I have traced to the kernel code at http://fxr.watson.org/fxr/source/drivers/acpi/tables.c?v=linux-2.6.11.8#L121 >From lines 121-127 I find this. ----------------------------- case ACPI_MADT_LAPIC: { struct acpi_table_lapic *p = (struct acpi_table_lapic*) header; printk(KERN_INFO PREFIX "LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n", p->acpi_id, p->id, p->flags.enabled?"enabled":"disabled"); } ---------------------------------- Could some one who works on the kernel or who knows C please interpret this for me? The code version is differrent but I hope it does not affect. Please let me know if you need the full dmesg Thankyou so much :-) Kind Regards Siju