[RFC] Consider CPU idle state while choosing a new CPU

From: Sebastian Andrzej Siewior
Date: Wed Jan 30 2013 - 16:19:45 EST


The scheduler does not consider the power states CPUs while selecting
an idle one. So it might happen, that it puts load on a cpu which is
in a deeper power state than another idle one, which has higher
latency and power costs than pushing the load to the core which is not
in a deep power saving state.

This patch series implements infrastructure which allows to consider
the power state in the selection process of an idle cpu. The decision
function is default off and can be enabled via a sysctl.

This is just the basic infrastructure. Further modifications are
necessary to hand in proper state information from the various idle
implementation. Its has been tested with a static testcase plugged
into the cpuidle core.

Sebastian
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/