Re: CFS Bandwidth Control - Test results of cgroups tasks pinned vsunpinnede

[Srivatsa Vaddagiri]

* Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> [2011-09-16 10:28:40]:

> > I think more compelling here is that it looks like nohz load-balance 
> > needs more love.
> 
> Quite probable,

Staring at nohz load-balancer for sometime, I see a potential issue:

'first_pick_cpu' and 'second_pick_cpu' can be idle without stopping
ticks for quite a while. When that happens, they stop bothering to
kick ilb cpu because of this snippet in nohz_kick_needed():

   static inline int nohz_kick_needed(struct rq *rq, int cpu)
   {

	..

        if (rq->idle_at_tick)
                return 0;

	..

   }


?

- vatsa
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