Re: Missing recalculation of scheduler tunables in case of cpu hot add/remove

[Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>]

Peter Zijlstra wrote:
> On Thu, 2009-11-26 at 17:25 +0100, Christian Ehrhardt wrote:
>   
>>> Aside from that, we probably should put an upper limit in place, as I
>>> guess large cpu count machines get silly large values
>>>       
>> I agree to that, but in the code is already an upper limit of 
>> 200.000.000 - well we might discuss if that is too low/high.
>>     
>
> Yeah, I think we should cap it around the 8-16 CPUs.
>
>   
ok for me, driven by that finding I think I have to measure different 
kind of scalings anyway, but as usually that takes some time :-/
At least too time much for the discussion & solution of that bug I guess.

The question for now is what we do on cpu hot add/remove?
Would hooking somewhere in kernel/cpu.c be the right approach - I'm not 
quite sure about my own suggestion yet :-).

-- 

Grüsse / regards, Christian Ehrhardt
IBM Linux Technology Center, Open Virtualization