Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754347AbZJRIYW (ORCPT ); Sun, 18 Oct 2009 04:24:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753504AbZJRIYV (ORCPT ); Sun, 18 Oct 2009 04:24:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55866 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752913AbZJRIYS (ORCPT ); Sun, 18 Oct 2009 04:24:18 -0400 Message-ID: <4ADAD070.5080002@redhat.com> Date: Sun, 18 Oct 2009 17:23:12 +0900 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Thunderbird/3.0b3 MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: Jeremy Fitzhardinge , Linux Kernel Mailing List , Xen-devel , kurt.hackel@oracle.com, Glauber de Oliveira Costa , the arch/x86 maintainers , Chris Mason Subject: Re: [GIT PULL RFC] pvclock cleanups and pvclock vsyscall support References: <1255548516-15260-1-git-send-email-jeremy.fitzhardinge@citrix.com> <4AD6C679.3000001@redhat.com> <4AD77C21.2050506@goop.org> <4ADAB8F4.6090502@redhat.com> <4ADACF48.9020907@goop.org> In-Reply-To: <4ADACF48.9020907@goop.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1342 Lines: 39 On 10/18/2009 05:18 PM, Jeremy Fitzhardinge wrote: > On 10/18/09 15:43, Avi Kivity wrote: > >> On 10/16/2009 04:46 AM, Jeremy Fitzhardinge wrote: >> >>> Care to cook up a patch to implement the kvm bits to make sure it all >>> works OK for you? >>> >>> >> I've started to do that, but it occurs to me that we're missing out on >> NUMA placement by forcing all clocks to be on the same page. OTOH, if >> the clocks are heavily used, they'll stay in cache, and if not, who >> cares. >> > Yes, I'd say so. I'd expect the data to be very close to read-only, so > the lines should be shared pretty efficiently. > > There wouldn't be any sharing since each clock is on its own cache line. But the point is valid regardless. > On the other hand, there's nothing to stop us from moving to multiple > pages in future (either to support NUMA placement, or just more than 64 > cpus). > I'm already allocating multiple pages, so we'd just need to adjust the fixmap. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. -- 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/