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:
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.