Re: [RFC PATCH 0/4] timers: framework for migration between CPU

[Ingo Molnar]

* Vaidyanathan Srinivasan <svaidy@xxxxxxxxxxxxxxxxxx> wrote:

> My understanding is that we will certainly have a sysfs 
> tunable to 'enable' timer migration or consolidation, similar 
> to the sched_mc=2 policy, but the actual set of CPUs to 
> evacuate and the correct set of target CPUs to consolidate 
> should come from the scheduler and not necessarily from the 
> user space.

Yes.

> The scheduler should be able to figure out the following 
> parameters:
> 
> * Identify set of idle CPUs (CPU package) from which timers 
>   can be removed
> * Identify a semi-idle or idle CPU package to which the timers
>   can be moved
> * Decide when to start moving timers as the system has large
>   number of idle CPUs
> * Decide when to stop migrating as system becomes less idle
>   and utilisation increases
> 
> Guiding all of the above decisions from user space may not be 
> fast enough.

Exactly.

	Ingo
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