linux-kernel - [RFC PATCH v3 0/6] KVM: x86: avoid redundant REQ

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Date:   Mon, 19 Dec 2016 10:47:12 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     rkrcmar@...hat.com, rkagan@...tuozzo.com, dplotnikov@...tuozzo.com
Subject: [RFC PATCH v3 0/6] KVM: x86: avoid redundant REQ_EVENT

This is the result of cleaning up the places that set REQ_EVENT unnecessarily.
The savings on self-IPI kvm-unit-tests are:

    self_ipi_sti_nop                ~300 clock cycles
    self_ipi_sti_hlt                ~300 clock cycles
    self_ipi_tpr                    ~400 clock cycles
    self_ipi_tpr_sti_nop            ~700 clock cycles
    self_ipi_tpr_sti_hlt            ~700 clock cycles
 
which is in the 5-10% range.  Please help me comparing this series with
"[PATCH v2] KVM: x86: avoid redundant REQ_EVENT" on the real workload!

Thanks,

Paolo

Paolo Bonzini (6):
  KVM: x86: add VCPU stat for KVM_REQ_EVENT processing
  KVM: lapic: do not set KVM_REQ_EVENT unnecessarily on EOI
  KVM: vmx: speed up TPR below threshold vmexits
  KVM: lapic: remove unnecessary KVM_REQ_EVENT on PPR update
  KVM: lapic: do not set KVM_REQ_EVENT unnecessarily on PPR update
  KVM: lapic: do not scan IRR when delivering an interrupt

 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/lapic.c            | 58 +++++++++++++++++++++++++----------------
 arch/x86/kvm/lapic.h            |  1 +
 arch/x86/kvm/vmx.c              |  2 +-
 arch/x86/kvm/x86.c              |  2 ++
 5 files changed, 41 insertions(+), 23 deletions(-)

-- 
1.8.3.1