Hi Johannes,

A few quick comments on first reading; I'll do a second and more
thorough reading on Monday.

On Fri, Jul 13, 2018 at 12:17:56PM -0400, Johannes Weiner wrote:

First off, what I want to do can indeed be done without a strong link
of a sleeping task to a CPU. We don't rely on it, and it's something I
only figured out in v2. The important thing is not, as I previously
thought, that CPUs are tracked independently from each other, but that
we use potential execution threads as the baseline for potential that
could be wasted by resource delays. Tracking CPUs independently just
happens to do that implicitly, but it's not a requirement.

I don't follow, but I don't think I agree.

Consider the case of 2 CPUs and 2 blocked tasks. If they both blocked on
the same CPU, then only that CPU has lost potential. Whereas the only
thing that matters is the number of blocked tasks and the number of idle
CPUs.

Those two tasks can fill the two idle CPUs. Tracking per CPU just
utterly confuses the matter.