2016-05-19 19:42 GMT+08:00 Christian Borntraeger <borntraeger@xxxxxxxxxx>: > On 05/19/2016 01:35 PM, Wanpeng Li wrote: >> 2016-05-19 19:23 GMT+08:00 Christian Borntraeger <borntraeger@xxxxxxxxxx>: >>> On 05/19/2016 11:26 AM, Wanpeng Li wrote: >>> >>> I think in general a good idea to poll if a timer will expire soon. >>> >>> Some patch comments: >>> >>> Same for all non-x86 archs: >>>> +static inline unsigned int kvm_arch_timer_remaining(struct kvm_vcpu *vcpu) {} >>> >>> A function returning int, without a return statement? >>> That gives at least a compiler warning. >> >> How about return 0 for all non-x86 archs? > > We will provide an s390 implementation soon, but until then a proper > default would be good. > > [....] >>>> + if (vcpu->halt_poll_ns || (remaining < halt_poll_ns_base)) { > > but then remaining is 0 and the 2nd condition will always be true, no? Nice catch! How about something like below: + if (vcpu->halt_poll_ns || + (remaining != 0 && remaining < halt_poll_ns_base)) { Regards, Wanpeng Li -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html