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    SubjectRe: [PATCH 1/3] KVM: Don't need to wakeup vCPU twice afer timer fire
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    On 31/07/19 13:27, Wanpeng Li wrote:
    > From: Wanpeng Li <wanpengli@tencent.com>
    >
    > kvm_set_pending_timer() will take care to wake up the sleeping vCPU which
    > has pending timer, don't need to check this in apic_timer_expired() again.

    No, it doesn't. kvm_make_request never kicks the vCPU.

    Paolo

    > Cc: Paolo Bonzini <pbonzini@redhat.com>
    > Cc: Radim Krčmář <rkrcmar@redhat.com>
    > Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
    > ---
    > arch/x86/kvm/lapic.c | 8 --------
    > 1 file changed, 8 deletions(-)
    >
    > diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
    > index 0aa1586..685d17c 100644
    > --- a/arch/x86/kvm/lapic.c
    > +++ b/arch/x86/kvm/lapic.c
    > @@ -1548,7 +1548,6 @@ static void kvm_apic_inject_pending_timer_irqs(struct kvm_lapic *apic)
    > static void apic_timer_expired(struct kvm_lapic *apic)
    > {
    > struct kvm_vcpu *vcpu = apic->vcpu;
    > - struct swait_queue_head *q = &vcpu->wq;
    > struct kvm_timer *ktimer = &apic->lapic_timer;
    >
    > if (atomic_read(&apic->lapic_timer.pending))
    > @@ -1566,13 +1565,6 @@ static void apic_timer_expired(struct kvm_lapic *apic)
    >
    > atomic_inc(&apic->lapic_timer.pending);
    > kvm_set_pending_timer(vcpu);
    > -
    > - /*
    > - * For x86, the atomic_inc() is serialized, thus
    > - * using swait_active() is safe.
    > - */
    > - if (swait_active(q))
    > - swake_up_one(q);
    > }
    >
    > static void start_sw_tscdeadline(struct kvm_lapic *apic)
    >

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