Messages in this thread | | | Subject | Re: [PATCH tip/core/rcu 44/55] rcu: wire up RCU_BOOST_PRIO for rcutree | From | Mike Galbraith <> | Date | Tue, 13 Sep 2011 18:04:18 +0200 |
| |
On Tue, 2011-09-13 at 08:34 -0700, Paul E. McKenney wrote: > On Tue, Sep 13, 2011 at 02:02:14PM +0200, Mike Galbraith wrote:
> > @@ -1608,7 +1618,7 @@ static int rcu_node_kthread(void *arg) > > continue; > > } > > per_cpu(rcu_cpu_has_work, cpu) = 1; > > - sp.sched_priority = RCU_KTHREAD_PRIO; > > + sp.sched_priority = current->rt_priority; > > This is broken -- the per-node kthread runs at RT prio 99, but we usually > would not want to boost that high.
Ouch, right. My userland sets things on boot, so it works.
> Seems like we should have a global variable that tracks the current > priority. This global variable could then be set in a manner similar > to the softirq priorities -- or, perhaps better, simply set whenever > the softirq priority is changed. > > Thoughts?
RCU threads would have to constantly watch for user priority changes on their own, and update private data methinks.
-Mike
| |