From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754661Ab1LZLhZ (ORCPT ); Mon, 26 Dec 2011 06:37:25 -0500 Received: from e23smtp04.au.ibm.com ([202.81.31.146]:44107 "EHLO e23smtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754540Ab1LZLhU (ORCPT ); Mon, 26 Dec 2011 06:37:20 -0500 From: Nikunj A Dadhania To: Avi Kivity Cc: Ingo Molnar , peterz@infradead.org, linux-kernel@vger.kernel.org, vatsa@linux.vnet.ibm.com, bharata@linux.vnet.ibm.com Subject: Re: [RFC PATCH 0/4] Gang scheduling in CFS In-Reply-To: <4EF838BD.60406@redhat.com> References: <20111219083141.32311.9429.stgit@abhimanyu.in.ibm.com> <20111219112326.GA15090@elte.hu> <87sjke1a53.fsf@abhimanyu.in.ibm.com> <4EF1B85F.7060105@redhat.com> <877h1o9dp7.fsf@linux.vnet.ibm.com> <20111223103620.GD4749@elte.hu> <4EF701C7.9080907@redhat.com> <87vcp4t45p.fsf@linux.vnet.ibm.com> <4EF838BD.60406@redhat.com> User-Agent: Notmuch/0.10.2+70~gf0e0053 (http://notmuchmail.org) Emacs/23.3.1 (x86_64-redhat-linux-gnu) Date: Mon, 26 Dec 2011 17:03:07 +0530 Message-ID: <87d3bbtvnw.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii x-cbid: 11122601-9264-0000-0000-000000819653 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 26 Dec 2011 11:05:01 +0200, Avi Kivity wrote: > On 12/26/2011 05:14 AM, Nikunj A Dadhania wrote: > > > > > > btw you can get an additional speedup by enabling x2apic, for > > > default_send_IPI_mask_logical(). > > > > > In the host? > > > > In the host, > The machine(IBM x3650 M2, Nehalem) does not seem to support x2apic. I have enabled the following in my config; [root@krm1 linux-tip]# grep X2APIC .config CONFIG_X86_X2APIC=y [root@krm1 linux-tip]# And booted the kernel with "apic=verbose" command. [root@krm1 linux-tip]# dmesg | grep -i x2apic [root@krm1 linux-tip]# Does not give anything. I safely assumed that x2apic is not supported. Is there something to do in the bios to enable this? > for the guest: > > qemu -cpu ...,+x2apic > I need to try this, i have libvirt setup. Let me dig how to enable this through xml file. Regards Nikunj