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SCHED_SMT for corei ?
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Massimo B.
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PostPosted: Tue Dec 13, 2016 10:22 am    Post subject: SCHED_SMT for corei ? Reply with quote

Hi, this CPU is a i7-2620M.
Which of these kernel options is recommended? CONFIG_SCHED_MC or CONFIG_SCHED_SMT or both? Physically this CPU has 2 cores but each with hyperthreading, resulting in 4 logical cores. So this is both a multicore but also hyperthreaded CPU which is common today, though I would prefer 4 real cores.

The docs of SCHED_SMT only describe the P4 or Core2, not the core-i:
Quote:
SMT scheduler support improves the CPU scheduler's decision making when dealing with Intel P4/Core 2 chips with HyperThreading at a cost of slightly increased overhead in some places.

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eccerr0r
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PostPosted: Tue Dec 13, 2016 5:00 pm    Post subject: Reply with quote

Both
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Massimo B.
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PostPosted: Wed Dec 14, 2016 10:27 am    Post subject: Reply with quote

Thanks.
btw, what do you think about WQ_POWER_EFFICIENT_DEFAULT on the Mobile core-i in a Laptop, is that worth the power saving or is the loss of cpu performance too much? I also think about less heating and cooling, but performance has highest priority.
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eccerr0r
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PostPosted: Wed Dec 14, 2016 10:42 am    Post subject: Reply with quote

Up to you.
Depends on your application on how much penalty scheduling threads on different queues will be.
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