Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261302AbVELCWc (ORCPT ); Wed, 11 May 2005 22:22:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261313AbVELCWc (ORCPT ); Wed, 11 May 2005 22:22:32 -0400 Received: from usbb-lacimss2.unisys.com ([192.63.108.52]:23312 "EHLO usbb-lacimss2.unisys.com") by vger.kernel.org with ESMTP id S261302AbVELCW3 convert rfc822-to-8bit (ORCPT ); Wed, 11 May 2005 22:22:29 -0400 X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Subject: RE: [patch 1/1] Do not enforce unique IO_APIC_ID for Xeon processors in EM64T mode (x86_64) Date: Wed, 11 May 2005 21:22:13 -0500 Message-ID: <19D0D50E9B1D0A40A9F0323DBFA04ACCE04B6A@USRV-EXCH4.na.uis.unisys.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [patch 1/1] Do not enforce unique IO_APIC_ID for Xeon processors in EM64T mode (x86_64) Thread-Index: AcVWXtEiqwhh9gTfTHOWiZ1p9nTEdgAOSKQQ From: "Protasevich, Natalie" To: "Andi Kleen" Cc: , , , , , X-OriginalArrivalTime: 12 May 2005 02:22:13.0463 (UTC) FILETIME=[6896DE70:01C55699] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1910 Lines: 53 > On Wed, May 11, 2005 at 11:21:15AM -0500, Protasevich, Natalie wrote: > > > > Looks like the need in the unique id can only be keyed of the > > > > local APIC id, and probably it is a good idea to keep the > > > > NO_IOAPIC_CHECK for subarchs that can override the heuristics? > > > > > > I prefer not to do that. How about a simple > > > > > > if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && > > > boot_cpu_data.x86 < 15) > > > /* do uniqueness check */ > > > else > > > /* don't do it */ > > > > > > ? > > > > > > Rationale is that P4s and newer and systems not from Intel don't > > > have serial APIC busses and don't need this uniqueness check. > > > > > > > Yes, indeed this looks like the only undisputed (and sufficient) > > criteria. I tried the below with Xeon box and it worked fine: > > > > --- mpparse.c.orig 2005-05-11 02:10:35.000000000 -0400 > > +++ mpparse.c 2005-05-11 02:12:31.000000000 -0400 > > @@ -912,7 +913,15 @@ void __init mp_register_ioapic ( > > mp_ioapics[idx].mpc_apicaddr = address; > > > > set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address); > > - mp_ioapics[idx].mpc_apicid = io_apic_get_unique_id(idx, id); > > + if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && > > (boot_cpu_data.x86 >= 15)) > > + mp_ioapics[idx].mpc_apicid = id; > > + else > > That's still wrong because it does not trigger on AMD > systems. So no AMD systems need that check? OK, I'll change it as below. > Please make it > > if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && > boot_cpu_data.x86 < 15) > mp_ioapics[idx].mpc_apicid = > io_apic_get_unique_id(idx,id); > else > mp_ioapics[idx].mpc_apicid = id; > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/