[PATCH 0/3] KVM: lapic: optimize injection of already-expired timer

From: Paolo Bonzini
Date: Thu Jun 29 2017 - 12:59:01 EST


This is my take on Wanpeng's optimization, whose effect I've now measured
with vmexit.flat. Indeed, without patch 3 the new tscdeadline_immed
benchmark is 50% slower with preemption_timer=1 than with preemption_timer=0.

Patch 1 refactors start_hv_timer to prepare for the next one and to
simplify Wanpeng's patch (a lot). Patch 2 avoids a bug that I didn't
catch in my earlier review: kvm_x86_ops->set_timer must not be called
directly when the TSC goes backwards.

Paolo

Paolo Bonzini (2):
KVM: lapic: reorganize start_hv_timer
KVM: lapic: reorganize restart_apic_timer

Wanpeng Li (1):
KVM: LAPIC: Fix lapic timer injection delay

arch/x86/kvm/lapic.c | 116 ++++++++++++++++++++++++++++-----------------------
arch/x86/kvm/lapic.h | 2 +-
arch/x86/kvm/vmx.c | 3 +-
arch/x86/kvm/x86.c | 8 ++--
4 files changed, 71 insertions(+), 58 deletions(-)

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1.8.3.1