Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756707Ab0FOIln (ORCPT ); Tue, 15 Jun 2010 04:41:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48898 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756630Ab0FOIlm (ORCPT ); Tue, 15 Jun 2010 04:41:42 -0400 Message-ID: <4C173CC3.8000506@redhat.com> Date: Tue, 15 Jun 2010 11:41:39 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100430 Fedora/3.0.4-3.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: Zachary Amsden CC: mtosatti@redhat.com, glommer@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 12/17] Add helper function get_kernel_ns References: <1276587259-32319-1-git-send-email-zamsden@redhat.com> <1276587259-32319-13-git-send-email-zamsden@redhat.com> In-Reply-To: <1276587259-32319-13-git-send-email-zamsden@redhat.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 Content-Length: 1585 Lines: 46 On 06/15/2010 10:34 AM, Zachary Amsden wrote: > Add a helper function for the multiple places this is used. Note that it > must not be called in preemptible context, as that would mean the kernel > could enter software suspend state, which would cause non-atomic operation > of the monotonic_to_bootbased computation. > > Open question: should the KVM_SET_CLOCK / KVM_GET_CLOCK ioctls use this > as well? Currently, they are not bootbased (but perhaps should be). > > Signed-off-by: Zachary Amsden > --- > arch/x86/kvm/x86.c | 26 +++++++++++++------------- > 1 files changed, 13 insertions(+), 13 deletions(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 703ea43..15c7317 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -915,6 +915,16 @@ static void kvm_get_time_scale(uint32_t scaled_khz, uint32_t base_khz, > __func__, base_khz, scaled_khz, shift, *pmultiplier); > } > > +static inline u64 get_kernel_ns(void) > +{ > + struct timespec ts; > + > + WARN_ON(preemptible()); > + ktime_get_ts(&ts); > + monotonic_to_bootbased(&ts); > + return timespec_to_ns(&ts); > +} > + > static DEFINE_PER_CPU(unsigned long, cpu_tsc_khz); > > Isn't something like this a candidate for the time infrastructure? -- error compiling committee.c: too many arguments to function -- 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/