Re: [RFC PATCH v7 1/7] Restartable sequences system call

[Mathieu Desnoyers]

----- On Aug 10, 2016, at 9:33 AM, Peter Zijlstra peterz@xxxxxxxxxxxxx wrote:

> On Wed, Aug 10, 2016 at 01:26:04PM +0000, Mathieu Desnoyers wrote:
> 
>> static bool rseq_update_cpu_id_event_counter(struct task_struct *t)
>> {
>>         union rseq_cpu_event u;
>> 
>>         u.e.cpu_id = raw_smp_processor_id();
>>         u.e.event_counter = ++t->rseq_event_counter;
>>         if (__put_user(u.v, &t->rseq->u.v))
>>                 return false;
>>         trace_rseq_inc(t->rseq_event_counter);
> 
> I had not previously noticed the trace_* muck, but I would suggest
> passing in t and leaving it up to the tracepoint implementation to pick
> out the value.

OK, fixed.

> 
> Also, since this not only increments (it also updates the cpu number)
> the naming is 'wrong'.

I'll rename the event to "rseq_update" then, and have two fields:
cpu_id and event_counter.

Thanks,

Mathieu

> 
>>         return true;
> > }

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com