Messages in this thread | | | Date | Fri, 1 Nov 2019 19:03:32 -0200 | From | Marcelo Tosatti <> | Subject | Re: [PATCH 1/5] KVM: simplify branch check in host poll code |
| |
On Sat, Oct 26, 2019 at 11:23:55AM +0800, Zhenzhong Duan wrote: > Remove redundant check. > > Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> > --- > virt/kvm/kvm_main.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 67ef3f2..2ca2979 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -2366,13 +2366,12 @@ void kvm_vcpu_block(struct kvm_vcpu *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) > - 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 &&
This is not a redundant check: it avoids from calling into grow_halt_poll_ns, which will do:
1) Multiplication 2) Cap that back to halt_poll_ns 3) Invoke the trace_kvm_halt_poll_ns_grow tracepoint (when in fact vcpu->halt_poll_ns did not grow).
| |