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

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

On Wed, Aug 10, 2016 at 01:26:04PM +0000, Mathieu Desnoyers wrote:

quoted

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

quoted

        return true;
}

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