Re: CPU scheduler question/problem

From: Pawel Dziekonski
Date: Mon Jan 26 2009 - 08:56:20 EST


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.

Where I can read more on tuning sched_features for different workloads?

Also, is there a way get a list of available schedulers and how to switch
between them?

thanks, Pawel
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