Re: CPU scheduler question/problem

[Ingo Molnar]

* Pawel Dziekonski <dzieko@xxxxxxxxx> wrote:

> 2009/1/23 Peter Zijlstra <peterz@xxxxxxxxxxxxx>:
> 
> > The pipe workload you mentioned has would behave that way because pipes
> > 'assume' a produces/consumer behaviour, and thus are more likely to
> > place both tasks on the same cpu -- but will eventually pull them apart
> > if they want to run concurrently.
> >
> > You might enable SCHED_DEBUG=y and try
> >  echo NO_SYNC_WAKEUPS > /debug/sched_features
> 
> Hello,
> 
> that did the trick. Openssl now gets a whole core exclusively and gives 
> full performance.
> 
> Regarding quantum chemistry application -- it is also using pipes for 
> communication between worker processes. Now this app works OK.

Could you please try the fuller fix below too please, does it still do the 
trick and does the scheduler still maximize openssl and your quantum 
chemistry app's throughput?

There should be no need for you to tune anything - the scheduler must get 
such workloads right out of the box.

	Ingo

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