From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753478AbcADUlt (ORCPT ); Mon, 4 Jan 2016 15:41:49 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:26699 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753070AbcADUlj (ORCPT ); Mon, 4 Jan 2016 15:41:39 -0500 From: Joao Martins Subject: Re: [Xen-devel] [PATCH RFC 3/3] xen/Kconfig: add XEN_TIME_VSYSCALL option To: Boris Ostrovsky , David Vrabel References: <1451339557-24473-1-git-send-email-joao.m.martins@oracle.com> <1451339557-24473-4-git-send-email-joao.m.martins@oracle.com> <568A99DA.6000705@citrix.com> <568A9A88.8060702@oracle.com> Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xen.org, x86@kernel.org, Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner Message-ID: <568AD8F4.3090203@oracle.com> Date: Mon, 4 Jan 2016 20:41:24 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Icedove/38.4.0 MIME-Version: 1.0 In-Reply-To: <568A9A88.8060702@oracle.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Source-IP: aserv0021.oracle.com [141.146.126.233] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/04/2016 04:15 PM, Boris Ostrovsky wrote: > On 01/04/2016 11:12 AM, David Vrabel wrote: >> On 28/12/15 21:52, Joao Martins wrote: >>> This option enables support for pvclock vsyscall/vdso >>> support on Xen. Default is off, since Xen doesn't >>> expose yet the PVCLOCK_TSC_STABLE_BIT flag. >> Do we need a Kconfig option for this? I think this should always be >> enabled. >> >> The kernel support won't be merged until the hypervisor changes have >> been accepted. > I agree. xen_setup_vsyscall_time_info() will (harmlessly) fail if > PVCLOCK_TSC_STABLE_BIT is not set. > OK, I will remove this patch then. I only added it because even if PVCLOCK_TSC_STABLE_BIT is not supported it would leave the pvti registered with Xen during domain lifetime [it seems we can't unregister the pvti]. But perhaps this is not a concern. > -boris >