The cpu_load decays on time according past cpu load of rq. The sched_avg also decays tasks' load on time. Now we has 2 kind decay for cpu_load. That is a kind of redundancy. And increase the system load by decay calculation. This patch try to remove the cpu_load decay.
There are 5 load_idx used for cpu_load in sched_domain. busy_idx and idle_idx are not zero usually, but newidle_idx, wake_idx and forkexec_idx are all zero on every arch. A shortcut to remove cpu_Load decay in the first patch. just one line patch for this change. Then I try to clean up code followed by this change.
V4, 1, rebase on latest tip/master 2, replace target_load by biased_load as Morten's suggestion
V3, 1, correct the wake_affine bias. Thanks for Morten's reminder! 2, replace source_load by weighted_cpuload for better function name meaning.
V2, 1, This version do some tuning on load bias of target load. 2, Got further to remove the cpu_load in rq. 3, Revert the patch 'Limit sd->*_idx range on sysctl' since no needs
Any testing/comments are appreciated.
This patch rebase on latest tip/master. The git tree for this patchset at: git@github.com:alexshi/power-scheduling.git noload
Thanks Alex
[PATCH 01/11] sched: shortcut to remove load_idx [PATCH 02/11] sched: remove rq->cpu_load[load_idx] array [PATCH 03/11] sched: clean up cpu_load update [PATCH 04/11] sched: unify imbalance bias for target group [PATCH 05/11] sched: rewrite update_cpu_load_nohz [PATCH 06/11] sched: clean up source_load/target_load [PATCH 07/11] sched: replace source_load by weighted_cpuload [PATCH 08/11] sched: replace target_load by biased_load [PATCH 09/11] sched: remove rq->cpu_load and rq->nr_load_updates [PATCH 10/11] sched: rename update_*_cpu_load [PATCH 11/11] sched: clean up task_hot function