"KVM: s390: change default halt poll time to 50us Recent measurements indicate that using 50us results in a reduced CPU consumption, while still providing the benefit of halt polling. Let's use 50us instead." Acked-by: David Hildenbrand <david@xxxxxxxxxx> On 15.05.19 10:23, Christian Borntraeger wrote: > older performance measurements indicated that 50000 vs 80000 reduces cpu > consumption while still providing the benefit of halt polling. We had > this change in the IBM KVM product, but it got lost so it never went > upstream. Recent re-measurement indicate that 50k is still better than > 80k.> > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> > --- > arch/s390/include/asm/kvm_host.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h > index dbe254847e0d..cb63cc7bbf06 100644 > --- a/arch/s390/include/asm/kvm_host.h > +++ b/arch/s390/include/asm/kvm_host.h > @@ -36,7 +36,7 @@ > */ > #define KVM_NR_IRQCHIPS 1 > #define KVM_IRQCHIP_NUM_PINS 4096 > -#define KVM_HALT_POLL_NS_DEFAULT 80000 > +#define KVM_HALT_POLL_NS_DEFAULT 50000 > > /* s390-specific vcpu->requests bit members */ > #define KVM_REQ_ENABLE_IBS KVM_ARCH_REQ(0) > -- Thanks, David / dhildenb
