Re: [Xen-devel] [PATCH v4 3/6] smp: add function to execute a function synchronously on a cpu

[Juergen Gross <jgross@xxxxxxxx>]

On 05/04/16 10:11, Peter Zijlstra wrote:
> On Tue, Apr 05, 2016 at 07:10:04AM +0200, Juergen Gross wrote:
>> +int smp_call_on_cpu(unsigned int cpu, bool pin, int (*func)(void *), void 
>> *par)
> 
> Why .pin and not .phys? .pin does not (to me) reflect the
> hypervisor/physical-cpu thing.

I don't mind either way. As you don't like .pin, lets name it .phys.

> Also, as per smp_call_function_single() would it not be more consistent
> to make this the last argument?

Okay, I'll change it.

> 
>> +{
>> +    struct smp_call_on_cpu_struct sscs = {
>> +            .work = __WORK_INITIALIZER(sscs.work, smp_call_on_cpu_callback),
>> +            .done = COMPLETION_INITIALIZER_ONSTACK(sscs.done),
>> +            .func = func,
>> +            .data = par,
>> +            .cpu  = pin ? cpu : -1,
>> +    };
>> +
>> +    if (cpu >= nr_cpu_ids)
> 
> You might want to also include cpu_online().
> 
>       if (cpu >= nr_cpu_ids || !cpu_online(cpu))

Indeed, good idea.

>> +            return -ENXIO;
> 
> Seeing how its fairly hard to schedule work on a cpu that's not actually
> there.

Really? ;-)


Juergen

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel