From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754541Ab0CDRky (ORCPT ); Thu, 4 Mar 2010 12:40:54 -0500 Received: from claw.goop.org ([74.207.240.146]:40445 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752966Ab0CDRkx (ORCPT ); Thu, 4 Mar 2010 12:40:53 -0500 Message-ID: <4B8FF0A3.9060305@goop.org> Date: Thu, 04 Mar 2010 09:40:51 -0800 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100301 Fedora/3.0.3-1.fc12 Lightning/1.0b2pre Thunderbird/3.0.3 MIME-Version: 1.0 To: Sheng Yang CC: Keir Fraser , Ingo Molnar , Ian Pratt , Ian Campbell , "linux-kernel@vger.kernel.org" , xen-devel Subject: Re: [PATCH 6/7] xen: Enable PV clocksource for HVM References: <1267695416-14988-1-git-send-email-sheng@linux.intel.com> <1267695416-14988-7-git-send-email-sheng@linux.intel.com> In-Reply-To: <1267695416-14988-7-git-send-email-sheng@linux.intel.com> 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 On 03/04/2010 01:36 AM, Sheng Yang wrote: > And enable it by default in PV extended HVM guest. > > Signed-off-by: Sheng Yang > --- > arch/x86/xen/hvmpv.c | 20 ++++++++++++++++++++ > arch/x86/xen/time.c | 4 +++- > 2 files changed, 23 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/xen/hvmpv.c b/arch/x86/xen/hvmpv.c > index 7a741ed..284e021 100644 > --- a/arch/x86/xen/hvmpv.c > +++ b/arch/x86/xen/hvmpv.c > @@ -43,6 +43,7 @@ static void __init xen_hvm_pv_banner(void) > pv_info.name); > printk(KERN_INFO "Xen version: %d.%d%s\n", > version>> 16, version& 0xffff, extra.extraversion); > + printk(KERN_INFO "PV feature: PV clocksource enabled\n"); > } > > static int __init xen_para_available(void) > @@ -117,6 +118,22 @@ static void __init init_shared_info(void) > per_cpu(xen_vcpu, 0) =&HYPERVISOR_shared_info->vcpu_info[0]; > } > > +extern struct clocksource xen_clocksource; > No externs in .c files. But aside from that, I'd prefer you export a function from xen/time.c to do the clocksource registration and call it from both places (even if its a one-liner). > + > +static void __init init_pv_clocksource(void) > +{ > + if (enable_hvm_pv(HVM_PV_CLOCK)) > + BUG(); > BUG is a bit severe. Will it really never, ever fail? And if it does, the consequence is hardly serious; we just fall back to emulated devices. > + > + pv_time_ops.sched_clock = xen_sched_clock; > + > + x86_platform.calibrate_tsc = xen_tsc_khz; > + x86_platform.get_wallclock = xen_get_wallclock; > + x86_platform.set_wallclock = xen_set_wallclock; > + > + clocksource_register(&xen_clocksource); > +} > + > void __init xen_guest_init(void) > { > int r; > @@ -130,4 +147,7 @@ void __init xen_guest_init(void) > return; > > init_shared_info(); > + > + /* PV clocksource would be enabled by default */ > + init_pv_clocksource(); > } > diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c > index 0d3f07c..c80eacb 100644 > --- a/arch/x86/xen/time.c > +++ b/arch/x86/xen/time.c > @@ -13,6 +13,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -243,7 +244,7 @@ int xen_set_wallclock(unsigned long now) > return -1; > } > > -static struct clocksource xen_clocksource __read_mostly = { > +struct clocksource xen_clocksource __read_mostly = { > .name = "xen", > .rating = 400, > .read = xen_clocksource_get_cycles, > @@ -252,6 +253,7 @@ static struct clocksource xen_clocksource __read_mostly = { > .shift = XEN_SHIFT, > .flags = CLOCK_SOURCE_IS_CONTINUOUS, > }; > +EXPORT_SYMBOL_GPL(xen_clocksource); > > /* > Xen clockevent implementation >