Re: [PATCH] Force rcutorture tasks to spread over CPUs

[Ingo Molnar]

* Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Tue, 12 Jun 2007 21:28:04 -0700
> "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote:
> 
> > +	while (!startwriters)
> > +		barrier();	/* Force scheduler to spread over CPUs. */
> 
> one wonders whether a cpu_relax() would be a bit nicer here.  That 
> implicitly does a barrier().
> 
> This patch doesn't make much sense for non-SMP builds?

i think this patch should be unnecessary because we found the real SMP 
balancing bug in the upstream scheduler causing this rcu problem, see:

 commit 92c4ca5c3a5e180e9762438db235f41d192cb955
 Author: Christoph Lameter <clameter@xxxxxxx>
 Date:   Sat Jun 23 17:16:33 2007 -0700

     sched: fix next_interval determination in idle_balance()

	Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/