On Tue, Jun 26, 2018 at 11:38:20AM +0200, Peter Zijlstra wrote:
> On Mon, Jun 25, 2018 at 03:43:32PM -0700, Paul E. McKenney wrote:
> > + preempt_disable();
> > + for_each_leaf_node_possible_cpu(rnp, cpu) {
> > + if (cpu_is_offline(cpu)) /* Preemption disabled. */
> > + continue;
>
> Create for_each_node_online_cpu() instead? Seems a bit pointless to
> iterate possible mask only to then check it against the online mask.
> Just iterate the online mask directly.
>
> Or better yet, write this as:
>
> preempt_disable();
> cpu = cpumask_next(rnp->grplo - 1, cpu_online_mask);
> if (cpu > rnp->grphi)
> cpu = WORK_CPU_UNBOUND;
> queue_work_on(cpu, rcu_par_gp_wq, &rnp->rew.rew_work);
> preempt_enable();
>
> Which is what it appears to be doing.
>
Make sense! Thanks ;-)
Applied this and running a TREE03 rcutorture. If all go well, I will
send the updated patch.
Regards,
Boqun
> > + queue_work_on(cpu, rcu_par_gp_wq, &rnp->rew.rew_work);
> > + rnp->exp_need_flush = true;
> > + break;
> > + }
> > + preempt_enable();
> > + if (!rnp->exp_need_flush) { /* All offline, report QSes. */
> > + queue_work(rcu_par_gp_wq, &rnp->rew.rew_work);
> > + rnp->exp_need_flush = true;
> > + }
> > }
> >
> > /* Wait for workqueue jobs (if any) to complete. */
> > --
> > 2.17.1
> >
signature.asc
Description: PGP signature
