On Fri, 2021-10-08 at 19:11 -0700, Sean Christopherson wrote:
> Don't update halt-polling stats if halt-polling wasn't attempted. This
> is a nop as @poll_ns is guaranteed to be '0' (poll_end == start), but it
> will allow a future patch to move the histogram stats into the helper to
> resolve a discrepancy in what is considered a "successful" halt-poll.
>
> No functional change intended.
>
> Reviewed-by: David Matlack <dmatlack@xxxxxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> virt/kvm/kvm_main.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 5d4a90032277..6156719bcbbc 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -3217,6 +3217,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
> {
> struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
> bool halt_poll_allowed = !kvm_arch_no_poll(vcpu);
> + bool do_halt_poll = halt_poll_allowed && vcpu->halt_poll_ns;
> ktime_t start, cur, poll_end;
> bool waited = false;
> u64 block_ns;
> @@ -3224,7 +3225,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
> kvm_arch_vcpu_blocking(vcpu);
>
> start = cur = poll_end = ktime_get();
> - if (vcpu->halt_poll_ns && halt_poll_allowed) {
> + if (do_halt_poll) {
> ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns);
>
> ++vcpu->stat.generic.halt_attempted_poll;
> @@ -3276,8 +3277,9 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
> kvm_arch_vcpu_unblocking(vcpu);
> block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
>
> - update_halt_poll_stats(
> - vcpu, ktime_to_ns(ktime_sub(poll_end, start)), waited);
> + if (do_halt_poll)
> + update_halt_poll_stats(
> + vcpu, ktime_to_ns(ktime_sub(poll_end, start)), waited);
>
> if (halt_poll_allowed) {
> if (!vcpu_valid_wakeup(vcpu)) {
Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Best regards,
Maxim Levitsky
