From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932804AbcFOMrL (ORCPT ); Wed, 15 Jun 2016 08:47:11 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:35407 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932370AbcFOMrA (ORCPT ); Wed, 15 Jun 2016 08:47:00 -0400 From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: x86@kernel.org, Andy Lutomirski , Ingo Molnar , Minfei Huang Subject: [PATCH v2 2/2] x86: vdso: use __pvclock_read_cycles Date: Wed, 15 Jun 2016 14:46:51 +0200 Message-Id: <1465994811-55091-3-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1465994811-55091-1-git-send-email-pbonzini@redhat.com> References: <1465994811-55091-1-git-send-email-pbonzini@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The new simplified __pvclock_read_cycles does the same computation as vread_pvclock, except that (because it takes the pvclock_vcpu_time_info pointer) it has to be moved inside the loop. Since the loop is expected to never roll, this makes no difference. Cc: Andy Lutomirski Cc: Ingo Molnar Cc: Minfei Huang Signed-off-by: Paolo Bonzini --- If acked I'd like to take this through the KVM tree. arch/x86/entry/vdso/vclock_gettime.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c index db1e3b4c3693..94d54d0defa7 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -96,9 +96,8 @@ static notrace cycle_t vread_pvclock(int *mode) { const struct pvclock_vcpu_time_info *pvti = &get_pvti0()->pvti; cycle_t ret; - u64 tsc, pvti_tsc; - u64 last, delta, pvti_system_time; - u32 version, pvti_tsc_to_system_mul, pvti_tsc_shift; + u64 last; + u32 version; /* * Note: The kernel and hypervisor must guarantee that cpu ID @@ -130,18 +129,9 @@ static notrace cycle_t vread_pvclock(int *mode) return 0; } - tsc = rdtsc_ordered(); - pvti_tsc_to_system_mul = pvti->tsc_to_system_mul; - pvti_tsc_shift = pvti->tsc_shift; - pvti_system_time = pvti->system_time; - pvti_tsc = pvti->tsc_timestamp; + ret = __pvclock_read_cycles(pvti); } while (pvclock_read_retry(pvti, version)); - delta = tsc - pvti_tsc; - ret = pvti_system_time + - pvclock_scale_delta(delta, pvti_tsc_to_system_mul, - pvti_tsc_shift); - /* refer to vread_tsc() comment for rationale */ last = gtod->cycle_last; -- 1.8.3.1