On Thu, Aug 01, 2019 at 01:13:50PM +0200, Peter Zijlstra wrote:
> A rather embarrasing mistake had us call sched_setscheduler() before
> initializing the parameters passed to it.
>
> Cc: Juri Lelli <juri.le...@redhat.com>
> Cc: "Paul E. McKenney" <paul...@linux.ibm.com>
Thank you for having CCed me this time. ;-)
Reviewed-by: Paul E. McKenney <paul...@linux.ibm.com>
> Fixes: 1a763fd7c633 ("rcu/tree: Call setschedule() gp ktread to SCHED_FIFO
> outside of atomic region")
> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
> ---
> kernel/rcu/tree.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -3234,13 +3234,13 @@ static int __init rcu_spawn_gp_kthread(v
> t = kthread_create(rcu_gp_kthread, NULL, "%s", rcu_state.name);
> if (WARN_ONCE(IS_ERR(t), "%s: Could not start grace-period kthread, OOM
> is now expected behavior\n", __func__))
> return 0;
> - if (kthread_prio)
> + if (kthread_prio) {
> + sp.sched_priority = kthread_prio;
> sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
> + }
> rnp = rcu_get_root();
> raw_spin_lock_irqsave_rcu_node(rnp, flags);
> rcu_state.gp_kthread = t;
> - if (kthread_prio)
> - sp.sched_priority = kthread_prio;
> raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
> wake_up_process(t);
> rcu_spawn_nocb_kthreads();
>
>
