From 44551b2f693d1ddcab4ca9895074f8f61c3a72af Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Sun, 29 Sep 2019 09:06:56 +0800 Subject: 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 Cc: Marcelo Tosatti Signed-off-by: Wanpeng Li Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) (limited to 'virt') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index fd68fbe0a75d..67ef3f2e19e8 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2360,20 +2360,23 @@ out: 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); -- cgit v1.2.3