From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9401C04AA7 for ; Mon, 13 May 2019 19:39:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 882B220873 for ; Mon, 13 May 2019 19:39:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726548AbfEMTjl (ORCPT ); Mon, 13 May 2019 15:39:41 -0400 Received: from mga06.intel.com ([134.134.136.31]:21263 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726554AbfEMTjl (ORCPT ); Mon, 13 May 2019 15:39:41 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 May 2019 12:39:40 -0700 X-ExtLoop1: 1 Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.36]) by orsmga003.jf.intel.com with ESMTP; 13 May 2019 12:39:40 -0700 Date: Mon, 13 May 2019 12:39:40 -0700 From: Sean Christopherson To: Wanpeng Li Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Paolo Bonzini , Radim =?utf-8?B?S3LEjW3DocWZ?= , Liran Alon Subject: Re: [PATCH 1/3] KVM: LAPIC: Extract adaptive tune timer advancement logic Message-ID: <20190513193940.GL28561@linux.intel.com> References: <1557401361-3828-1-git-send-email-wanpengli@tencent.com> <1557401361-3828-2-git-send-email-wanpengli@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1557401361-3828-2-git-send-email-wanpengli@tencent.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, May 09, 2019 at 07:29:19PM +0800, Wanpeng Li wrote: > From: Wanpeng Li > > Extract adaptive tune timer advancement logic to a single function. Why? > > Cc: Paolo Bonzini > Cc: Radim Krčmář > Cc: Sean Christopherson > Cc: Liran Alon > Signed-off-by: Wanpeng Li > --- > arch/x86/kvm/lapic.c | 57 ++++++++++++++++++++++++++++++---------------------- > 1 file changed, 33 insertions(+), 24 deletions(-) > > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c > index bd13fdd..e7a0660 100644 > --- a/arch/x86/kvm/lapic.c > +++ b/arch/x86/kvm/lapic.c > @@ -1501,11 +1501,41 @@ static inline void __wait_lapic_expire(struct kvm_vcpu *vcpu, u64 guest_cycles) > } > } > > -void wait_lapic_expire(struct kvm_vcpu *vcpu) > +static inline void adaptive_tune_timer_advancement(struct kvm_vcpu *vcpu, > + u64 guest_tsc, u64 tsc_deadline) > { > struct kvm_lapic *apic = vcpu->arch.apic; > u32 timer_advance_ns = apic->lapic_timer.timer_advance_ns; > - u64 guest_tsc, tsc_deadline, ns; > + u64 ns; > + > + if (!apic->lapic_timer.timer_advance_adjust_done) { > + /* too early */ > + if (guest_tsc < tsc_deadline) { > + ns = (tsc_deadline - guest_tsc) * 1000000ULL; > + do_div(ns, vcpu->arch.virtual_tsc_khz); > + timer_advance_ns -= min((u32)ns, > + timer_advance_ns / LAPIC_TIMER_ADVANCE_ADJUST_STEP); > + } else { > + /* too late */ > + ns = (guest_tsc - tsc_deadline) * 1000000ULL; > + do_div(ns, vcpu->arch.virtual_tsc_khz); > + timer_advance_ns += min((u32)ns, > + timer_advance_ns / LAPIC_TIMER_ADVANCE_ADJUST_STEP); > + } > + if (abs(guest_tsc - tsc_deadline) < LAPIC_TIMER_ADVANCE_ADJUST_DONE) > + apic->lapic_timer.timer_advance_adjust_done = true; > + if (unlikely(timer_advance_ns > 5000)) { > + timer_advance_ns = 0; > + apic->lapic_timer.timer_advance_adjust_done = true; > + } > + apic->lapic_timer.timer_advance_ns = timer_advance_ns; > + } This whole block is indented too far. > +} > + > +void wait_lapic_expire(struct kvm_vcpu *vcpu) > +{ > + struct kvm_lapic *apic = vcpu->arch.apic; > + u64 guest_tsc, tsc_deadline; > > if (apic->lapic_timer.expired_tscdeadline == 0) > return; > @@ -1521,28 +1551,7 @@ void wait_lapic_expire(struct kvm_vcpu *vcpu) > if (guest_tsc < tsc_deadline) > __wait_lapic_expire(vcpu, tsc_deadline - guest_tsc); > > - if (!apic->lapic_timer.timer_advance_adjust_done) { > - /* too early */ > - if (guest_tsc < tsc_deadline) { > - ns = (tsc_deadline - guest_tsc) * 1000000ULL; > - do_div(ns, vcpu->arch.virtual_tsc_khz); > - timer_advance_ns -= min((u32)ns, > - timer_advance_ns / LAPIC_TIMER_ADVANCE_ADJUST_STEP); > - } else { > - /* too late */ > - ns = (guest_tsc - tsc_deadline) * 1000000ULL; > - do_div(ns, vcpu->arch.virtual_tsc_khz); > - timer_advance_ns += min((u32)ns, > - timer_advance_ns / LAPIC_TIMER_ADVANCE_ADJUST_STEP); > - } > - if (abs(guest_tsc - tsc_deadline) < LAPIC_TIMER_ADVANCE_ADJUST_DONE) > - apic->lapic_timer.timer_advance_adjust_done = true; > - if (unlikely(timer_advance_ns > 5000)) { > - timer_advance_ns = 0; > - apic->lapic_timer.timer_advance_adjust_done = true; > - } > - apic->lapic_timer.timer_advance_ns = timer_advance_ns; > - } > + adaptive_tune_timer_advancement(vcpu, guest_tsc, tsc_deadline); > } > > static void start_sw_tscdeadline(struct kvm_lapic *apic) > -- > 2.7.4 >