On Mon, Nov 26, 2012 at 12:35:52PM -0500, Steven Rostedt wrote:

On Mon, 2012-11-26 at 09:03 -0800, Paul E. McKenney wrote:

quoted

If I understand correctly (though also suffering turkey OD), the idea is
to offload work to more energy-efficient CPUs.

This is determined by a CPU that isn't running the idle task? Is it
because a CPU that just woke up may be running at a lower freq, and thus
not as efficient? But pushing off to another CPU may cause cache misses
as well. Wouldn't that also be a factor in efficiencies, if a CPU is
stalled waiting for memory to be loaded?

Two different microarchitectures -- same instruction set (at user level,
anyway), but different power/performance characteristics.  One set is
optimized for performance, the other for energy efficiency.  For example,
ARM's big.LITTLE architecture.

I should also ask the obvious. Has these patches shown real world
efficiencies or is this just a theory? Do these patches actually improve
battery life when applied?

I must defer to Viresh on this one.

							Thanx, Paul

Just asking.

-- Steve