From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christian Borntraeger <borntraeger@de.ibm.com>
Subject: Re: [PATCH] KVM: halt-polling: poll if emulated lapic timer will fire
 soon
Date: Thu, 19 May 2016 13:42:32 +0200
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Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	kvm <kvm@vger.kernel.org>, Wanpeng Li <wanpeng.li@hotmail.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
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To: Wanpeng Li <kernellwp@gmail.com>
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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?