cpuidle: Add decaying history logic to menu idle predictor
authorPallipadi, Venkatesh <venkatesh.pallipadi@intel.com>
Tue, 30 Dec 2008 22:46:02 +0000 (14:46 -0800)
committerLen Brown <len.brown@intel.com>
Tue, 30 Dec 2008 23:48:01 +0000 (18:48 -0500)
commit816bb611e41be29b476dc16f6297eb551bf4d747
treefe48f23db073e47a83de5e9e08796c252c7a307d
parent4a6908a3a050aacc9c3a2f36b276b46c0629ad91
cpuidle: Add decaying history logic to menu idle predictor

Add decaying history of predicted idle time, instead of using the last early
wakeup. This logic helps menu governor do better job of predicting idle time.

With this change, we also measured noticable (~8%) power savings on
a DP server system with CPUs supporting deep C states, when system
was lightly loaded. There was no change to power or perf on other load
conditions.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
drivers/cpuidle/governors/menu.c