Re: [PATCH 2/6] x86: allow to call text_poke_bp during boot

From: Steven Rostedt
Date: Sat Oct 19 2013 - 18:02:44 EST


On Sat, 19 Oct 2013 14:33:50 -0700
"Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote:


> > > It's used to convert the calls to mcount to nops. But maybe a better
> > > thing to do is to check if we only have a single CPU:
> > >
> > > static void run_sync(void)
> > > {
> > > if (num_online_cpus() != 1)
> >
> > Hmm, to be more robust to handle our future "ideal" machines, perhaps
> > this should be:
> >
> > /* Ideally we would like to run on zero CPUS! */
> > if (num_online_cpus() < 2)
>

Bah! And for such a simple computation, I got it wrong.


/* Ideally we would like to run on zero CPUS! */
if (num_online_cpus > 1)

But I guess the question comes. If we are running on zero CPUS, should
we perform the "on_each_cpu(do_sync_core, NULL, 1);" or not? Same goes
with 5i-3 CPUS, or negative number CPUs. If we need to do on_each_cpu(),
then I guess the != 1 will suffice.

-- Steve
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