From: Viresh Kumar viresh.kumar@linaro.org Date: Mon, 18 Mar 2013 20:53:26 +0530
Phylib uses workqueues for multiple purposes. There is no real dependency of scheduling these on the cpu which scheduled them.
On a idle system, it is observed that and idle cpu wakes up many times just to service this work. It would be better if we can schedule it on a cpu which isn't idle to save on power.
By idle cpu (from scheduler's perspective) we mean:
- Current task is idle task
- nr_running == 0
- wake_list is empty
This patch replaces the schedule_work() and schedule_delayed_work() routines with their queue_[delayed_]work_on_any_cpu() siblings with system_wq as parameter.
These routines would look for the closest (via scheduling domains) non-idle cpu (non-idle from schedulers perspective). If the current cpu is not idle or all cpus are idle, work will be scheduled on local cpu.
Cc: "David S. Miller" davem@davemloft.net Cc: netdev@vger.kernel.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org
This will need to be applied to whatever tree adds these new interfaces, and for that:
Acked-by: David S. Miller davem@davemloft.net