Messages in this thread | | | Subject | Re: Very high CPU load when idle with 3.0-rc1 | From | Peter Zijlstra <> | Date | Mon, 30 May 2011 23:33:39 +0200 |
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On Mon, 2011-05-30 at 14:28 -0700, Paul E. McKenney wrote: > On Mon, May 30, 2011 at 07:19:49PM +0200, Peter Zijlstra wrote: > > On Mon, 2011-05-30 at 09:23 -0700, Paul E. McKenney wrote: > > > sp.sched_priority = RCU_KTHREAD_PRIO; > > > sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); > > > > Why are those things RT tasks anyway? The old ksoftirq runs as a regular > > task. And once you start boosting things you can boost this into FIFO as > > well... > > > > just wondering.. > > Because priority boosting doesn't help unless the callbacks also run > RT priority. > > I could make it so that they ran as normal tasks if !RCU_BOOST, but > they would still need to run as RT tasks for RCU_BOOST. I figured > running them the same way in both cases would be simpler.
Ah, I thought you'd boost the threads along with the waiters, to the same prio so that they wouldn't disturb higher priority tasks for no reason.
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