Re: lots of brief rcu stalls.

Paul E. McKenney
2013-12-05T02:44:07Z

On Wed, Dec 04, 2013 at 06:18:30PM -0800, Eric Dumazet wrote:
> On Wed, 2013-12-04 at 16:16 -0800, Paul E. McKenney wrote:
> > + if (rdp->rsp == rcu_state &&
> > + ULONG_CMP_GE(ACCESS_ONCE(jiffies), rdp->rsp->jiffies_resched)) {
> > + rdp->rsp->jiffies_resched += 5;
> > + resched_cpu(rdp->cpu);
> > + }
> > +
> > return 0;
> > }
>
> jiffies should not need ACCESS_ONCE(), right ?
>
> It is one of the few variables marked with volatile keyword.

Good point! I have queued a patch fixing this and four other occurrences
with your Submitted-by.

Thanx, Paul