Messages in this thread | | | Date | Thu, 14 Jun 2012 18:20:39 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [RFC patch 2/5] smpboot: Provide infrastructure for percpu hotplug threads |
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On Thu, 14 Jun 2012, Paul E. McKenney wrote:
> On Thu, Jun 14, 2012 at 04:56:29PM +0200, Peter Zijlstra wrote: > > On Thu, 2012-06-14 at 07:47 -0700, Paul E. McKenney wrote: > > > RCU callback processing consumes the entire CPU in RCU_BOOST case where > > > processing runs at real-time priority. This is analogous to RT throttling > > > in the scheduler. > > > > But previously we can in non-preemptible softirq context, why would if > > behave differently when done from a RT task? > > In -rt, yes, but in mainline, ksoftirqd does not run at RT prio, right? > > > Also, no its not quite like the throttling, that really idles the cpu > > even if there's no SCHED_OTHER tasks to run. > > Agreed, not -exactly- like throttling, but it has a broadly similar > goal, namely to prevent a given type of processing from starving > everything else in the system. > > That said, why does throttling idle the CPU even if there is no other > SCHED_OTHER tasks to run?
For simplicity reasons :)
Thanks,
tglx
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