Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754224AbYGMBcy (ORCPT ); Sat, 12 Jul 2008 21:32:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752653AbYGMBcq (ORCPT ); Sat, 12 Jul 2008 21:32:46 -0400 Received: from mga02.intel.com ([134.134.136.20]:54437 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752638AbYGMBcq (ORCPT ); Sat, 12 Jul 2008 21:32:46 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.30,352,1212390000"; d="scan'208";a="414427198" Date: Sat, 12 Jul 2008 18:32:44 -0700 From: Suresh Siddha To: "Eric W. Biederman" Cc: Yinghai Lu , "Siddha, Suresh B" , Ingo Molnar , "hpa@zytor.com" , "tglx@linutronix.de" , "akpm@linux-foundation.org" , "arjan@linux.intel.com" , "andi@firstfloor.org" , "jbarnes@virtuousgeek.org" , "steiner@sgi.com" , "linux-kernel@vger.kernel.org" , "jeremy@goop.org" Subject: Re: [patch 00/26] x64, x2apic/intr-remap: Interrupt-remapping and x2apic support Message-ID: <20080713013244.GF1678@linux-os.sc.intel.com> References: <20080711200957.GA8173@elte.hu> <20080711203151.GU1678@linux-os.sc.intel.com> <86802c440807111342j5fbf21e1ibd5129718cde4e43@mail.gmail.com> <20080711204521.GA15689@elte.hu> <20080711212418.GV1678@linux-os.sc.intel.com> <86802c440807111502n9835b5fybd99ed388bb71b7d@mail.gmail.com> <86802c440807112016k38c8161aq143463ee57b24c35@mail.gmail.com> <86802c440807112317h23118e29j51113a052720d8db@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1068 Lines: 23 On Sat, Jul 12, 2008 at 12:02:54AM -0700, Eric W. Biederman wrote: > "Yinghai Lu" writes: > > also read the x2APIC spec pdf, it doesn't say anything about interrupt > > remapping...need to be used with x2apic... > > Clustered logical mode won't work as it requires > 16 bits of apicid. > So only flat physical mode will work. Eric, As I mentioned just now in another thread, even flat physical mode might not work, if cpu or chipset thinks that they are in different modes. For example if CPU is in extended mode, chipset may block non-remapped intr-messages and not fwd these to the cpu. So while in theory, physical mode for < 255 apic id's may work, Intel is not validating and not recommending to enable x2apic mode in the CPU with out enabling intr-remapping in the chipset. thanks, suresh -- 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/