Re: [PATCH RFC 0/2] kvm: Improving undercommit,overcommit scenariosin PLE handler

[Peter Zijlstra]

On Mon, 2012-09-24 at 18:59 +0530, Raghavendra K T wrote:
> However Rik had a genuine concern in the cases where runqueue is not
> equally distributed and lockholder might actually be on a different run 
> queue but not running.

Load should eventually get distributed equally -- that's what the
load-balancer is for -- so this is a temporary situation.

We already try and favour the non running vcpu in this case, that's what
yield_to_task_fair() is about. If its still not eligible to run, tough
luck.

> Do you think instead of using rq->nr_running, we could get a global 
> sense of load using avenrun (something like avenrun/num_onlinecpus) 

To what purpose? Also, global stuff is expensive, so you should try and
stay away from it as hard as you possibly can.
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