Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754523Ab3G2FVU (ORCPT ); Mon, 29 Jul 2013 01:21:20 -0400 Received: from mga14.intel.com ([143.182.124.37]:5567 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750877Ab3G2FVS (ORCPT ); Mon, 29 Jul 2013 01:21:18 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,766,1367996400"; d="scan'208";a="338270207" Date: Mon, 29 Jul 2013 13:05:14 -0400 From: Youquan Song To: Yinghai Lu Cc: Gleb Natapov , Youquan Song , Sheng Yang , Konrad Rzeszutek Wilk , Linux Kernel Mailing List , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , Youquan Song Subject: Re: [PATCH] x86, apic: Enable x2APIC physical when cpu < 256 native Message-ID: <20130729170514.GB30371@linux-youquan.bj.intel.com> References: <1373592159-459-1-git-send-email-youquan.song@intel.com> <20130724062254.GA16400@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1243 Lines: 34 > Yes. It would be great, if Youquan can point out where is the intel doc > about the change. > > Also if the patch can move on, hypervisor_x2apic_available() related > declaration and define > could be dropped. Hi Yinghai, Sorry I do not know the document change but I also do not find the words/description/explanation that x2APIC physical mode also need interrupt remapping support when CPU < 256. Of course, X2APIC cluster mode must has interrupt remapping support. I have tested many machines, both old and most recent machines and from desktop to server, x2APIC physical mode works without interrupt remapping when CPU < 256. In theory and real test, I do not find any issue about the patch. In order to make sure the patch without involving unexpected issues beyond I can understand, I will confirm with our expert about it. so please pend the patch going to mainline. If the patch can move on, I think I will also provide other patch changing, like direct EOI. Thanks -Youquan -- 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/