Re: [PATCH 0/5] Reduce cross CPU IPI interference

[Gilad Ben-Yossef]

On Mon, Sep 26, 2011 at 10:20 AM, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote:
> On Sun, 2011-09-25 at 11:54 +0300, Gilad Ben-Yossef wrote:
>> This first version creates an on_each_cpu_mask infrastructure API
>
> But we already have the existing smp_call_function_many() doing that.

I might be wrong but my understanding is that smp_call_function_many()
does not invoke the IPI handler on the current processor. The original
code I replaced uses on_each_cpu() which does, so I figured a wrapper
was in order and then I discovered the same wrapper in arch specific
code.

> The on_each_cpu() thing is mostly a hysterical relic and could be
> completely depricated

Wont this require each caller to call smp_call_function_* and then
check to see if it needs to also invoke the IPI handler locally ? I
thought that was the reason for on_each_cpu existence... What have I
missed?

Thanks,
Gilad





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Gilad Ben-Yossef
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