KVM: Don't shrink/grow vCPU halt_poll_ns if host side polling is disabled

Don't waste cycles to shrink/grow vCPU halt_poll_ns if host
side polling is disabled.

Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Wanpeng Li 2019-09-29 09:06:56 +08:00 committed by Paolo Bonzini
parent 9de25d182b
commit 44551b2f69
1 changed files with 16 additions and 13 deletions

View File

@ -2360,20 +2360,23 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
kvm_arch_vcpu_unblocking(vcpu);
block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
if (!vcpu_valid_wakeup(vcpu))
shrink_halt_poll_ns(vcpu);
else if (halt_poll_ns) {
if (block_ns <= vcpu->halt_poll_ns)
;
/* we had a long block, shrink polling */
else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
if (!kvm_arch_no_poll(vcpu)) {
if (!vcpu_valid_wakeup(vcpu)) {
shrink_halt_poll_ns(vcpu);
/* we had a short halt and our poll time is too small */
else if (vcpu->halt_poll_ns < halt_poll_ns &&
block_ns < halt_poll_ns)
grow_halt_poll_ns(vcpu);
} else
vcpu->halt_poll_ns = 0;
} else if (halt_poll_ns) {
if (block_ns <= vcpu->halt_poll_ns)
;
/* we had a long block, shrink polling */
else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns)
shrink_halt_poll_ns(vcpu);
/* we had a short halt and our poll time is too small */
else if (vcpu->halt_poll_ns < halt_poll_ns &&
block_ns < halt_poll_ns)
grow_halt_poll_ns(vcpu);
} else {
vcpu->halt_poll_ns = 0;
}
}
trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu));
kvm_arch_vcpu_block_finish(vcpu);