Re: [tip:perfcounters/core] perf sched: Determine the number of CPUs automatically

Ingo Molnar
2009-09-17T19:45:46Z

* Arjan van de Ven <arjan@infradead.org> wrote:

> On Thu, 17 Sep 2009 18:07:09 GMT
> >
> > perf sched: Determine the number of CPUs automatically
> >
> > For 'perf sched map' output, determine max_cpu automatically,
> > instead of the static default of 15.
> >
> > static u32 curr_pid[MAX_CPUS] = { [0 ... MAX_CPUS-1] = -1 };
> >
> > @@ -1818,6 +1818,9 @@ static struct trace_sched_handler map_ops = {
> >
> > static void __cmd_map(void)
> > {
> > + max_cpu = system("exit `grep ^processor /proc/cpuinfo | wc
> > -l`");
>
> YUCK.
>
> what is wrong with
> max_cpu = sysconf(_SC_NPROCESSORS_CONF);
> ??

That's nicer - mind sending a patch?

Ingo