Re: [PATCH] cpumask: convert cpumask_of_cpu() with cpumask_of()

From: KOSAKI Motohiro
Date: Sun May 29 2011 - 21:40:22 EST


>> The trick is,
>> - Typical linux userland applications don't use mempolicy and/or cpusets
>> API at all.
>> - Then, 99.99% thread's tsk->cpus_alloed have cpu_all_mask.
>> - cpu_all_mask case, every thread can share the same bitmap. It may help to
>> reduce L1 cache miss in scheduler.
>>
>> What do you think?
>
> Nice!
>
> If you finish the first patch (sort the TODOs) I'll take it.

Yeah, now I'm submitting a lot of cpumask cleanup patches to various arch and
subsystems. So, I expect I can finish this work in June.

> I'm unsure about the PF_THREAD_UNBOUND thing though, then again, the
> alternative is adding another struct cpumask * and have that point to
> the shared mask or the private mask.

Ahhh, I'm sorry. My explanation was bad. PF_THREAD_UNBOUND is not my point.
It's only concept proof patch, not for submitting. yes, I did cheat for getting
number easily. I think the good way is probably to add another cpumask* and
implement COW shared mask. but I'm ok other way too.


> But yeah, looks quite feasible.

Thank you to pay attention my patch!

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