RE: [Xen-devel] [PATCH] trivial fix for vcpu_set_affinity

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

Yes, you're right. Though I test this patch working, it may be instead 
migrated at later schedule point instead of immediately by this hypercall.

Thanks,
Kevin

>-----Original Message-----
>From: Keir Fraser [mailto:keir@xxxxxxxxxxxxx]
>Sent: 2007年1月11日 17:44
>To: Tian, Kevin; xen-devel@xxxxxxxxxxxxxxxxxxx
>Subject: Re: [Xen-devel] [PATCH] trivial fix for vcpu_set_affinity
>
>It's true that the vcpu_migrate() is a no-op if v==current, but the
>vcpu_sleep_nosync() does have to be executed, otherwise current will
>not be
>migrated before returning to guest context (because the schedule softirq
>will not be asserted). This would mean that a dom0 vcpu could no longer
>synchronously migrate itself. In any case this patch has no upside -- the
>existing code works just fine.
>
> -- Keir
>
>On 11/1/07 08:42, "Tian, Kevin" <kevin.tian@xxxxxxxxx> wrote:
>
>> No need to try migration in current context since self migrate
>> will be handled by next vcpu after context switch.
>>
>> Signed-off-by Kevin Tian <kevin.tian@xxxxxxxxx>
>>
>> diff -r e66f047bc97e xen/common/schedule.c
>> --- a/xen/common/schedule.c Tue Jan 09 18:56:44 2007 -0800
>> +++ b/xen/common/schedule.c Thu Jan 11 16:31:37 2007 +0800
>> @@ -243,7 +243,7 @@ int vcpu_set_affinity(struct vcpu *v, cp
>>
>>      vcpu_schedule_unlock_irqrestore(v, flags);
>>
>> -    if ( test_bit(_VCPUF_migrating, &v->vcpu_flags) )
>> +    if ( (v != current) && test_bit(_VCPUF_migrating,
>&v->vcpu_flags) )
>>      {
>>          vcpu_sleep_nosync(v);
>>          vcpu_migrate(v);
>>
>> Thanks,
>> Kevin
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>> http://lists.xensource.com/xen-devel

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