Re: linux scheduler and "cache-mate" processors

From: Chuck Ebbert
Date: Wed Jan 31 2007 - 15:22:29 EST


Arjan van de Ven wrote:
>> 1) does the scheduler know enough to try to spread tasks
>> equally over both the pairs to make best use of the 16MB total
>> cache? (i.e. given cpu bound processes "1" and "2", if they
>> are both on CPU "A", then the "C-D" cache remains unused, but
>> keeping "1" on "a" and "2" on "C" would tend to minimize
>> their caches being consumed by each other.
>>
>
> yes this works just fine
>
>
>
>> 2) Since either A&B both have access to the 8MB cache, then
>> if a process was running on "A", it seems it would have a
>> low migration cost to be scheduled on "B" -- i.e. shouldn't
>> the process, if it were migrated to "A"'s "cache-mate", "B",
>> be able to benefit by any previous caching done on "A"?
>> If that's true, does the scheduler give preference, when
>> migrating a process, to a CPU's "cache-mate"?
>>
>
> afaik yes as well
>
>
You do have to enable "Multi-core scheduler support" in the kernel
.config, though.

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