Messages in this thread | | | Date | Sun, 20 Oct 2013 08:42:03 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH 2/6] x86: allow to call text_poke_bp during boot |
| |
On Sat, Oct 19, 2013 at 06:02:39PM -0400, Steven Rostedt wrote: > On Sat, 19 Oct 2013 14:33:50 -0700 > "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> 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.
Makes sense to me! Whoever adds the ability to run on zero, negative, or complex numbers of CPUs can adjust on_each_cpu() accordingly.
Thanx, Paul
| |