On 05/19/2016 01:48 PM, Wanpeng Li wrote: > 2016-05-19 19:42 GMT+08:00 Christian Borntraeger <[email protected]>: >> On 05/19/2016 01:35 PM, Wanpeng Li wrote: >>> 2016-05-19 19:23 GMT+08:00 Christian Borntraeger <[email protected]>: >>>> 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)) {
Maybe just use -1UL to have a "will never expire" and change the return value into u64 while changing that.
