Hello, The intention behind sending this series is to get some initial feedback on the idea of specially handling CPUs which only have SCHED_IDLE activity enqueued on them, before investing too much effort on it. The current implementation handles very few code-paths and there is a lot more that we would need to do to make it work well for us.
This allows enqueuing more tasks to a CPUs which only have tasks with SCHED_IDLE policy currently, as the new tasks should run on them without any significant delays. And this avoids waking up an otherwise idle CPU, hence save power without impacting performance. We don't have lots of SCHED_IDLE tasks in Android currently, but it should be possible to convert a few of the background tasks and take advantage of this feature. Only basic testing is done with the help of rt-app [1] currently to make sure the task is getting placed correctly. -- viresh Viresh Kumar (2): sched: Start tracking SCHED_IDLE tasks count in cfs_rq sched: Enqueue tasks on a cpu with only SCHED_IDLE tasks kernel/sched/core.c | 23 ++++++++++++++++ kernel/sched/fair.c | 64 +++++++++++++++++++++++++++++++++----------- kernel/sched/sched.h | 5 ++++ 3 files changed, 76 insertions(+), 16 deletions(-) -- 2.19.1.568.g152ad8e3369a [1] json: https://pastebin.ubuntu.com/p/Y4fr9xddV8/
