Messages in this thread | | | Date | Thu, 19 May 2016 19:48:45 +0800 | Subject | Re: [PATCH] KVM: halt-polling: poll if emulated lapic timer will fire soon | From | Wanpeng Li <> |
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2016-05-19 19:42 GMT+08:00 Christian Borntraeger <borntraeger@de.ibm.com>: > On 05/19/2016 01:35 PM, Wanpeng Li wrote: >> 2016-05-19 19:23 GMT+08:00 Christian Borntraeger <borntraeger@de.ibm.com>: >>> 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
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