fbcon uses workqueues and it has 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 few 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 schedule_work() routine with queue_work_on_any_cpu() sibling with system_wq as workqueue. This routine 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: Dave Airlie <airlied@xxxxxxxxxx> Cc: linux-fbdev@xxxxxxxxxxxxxxx Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> --- drivers/video/console/fbcon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c index 3cd6759..a900997 100644 --- a/drivers/video/console/fbcon.c +++ b/drivers/video/console/fbcon.c @@ -404,7 +404,7 @@ static void cursor_timer_handler(unsigned long dev_addr) struct fb_info *info = (struct fb_info *) dev_addr; struct fbcon_ops *ops = info->fbcon_par; - schedule_work(&info->queue); + queue_work_on_any_cpu(system_wq, &info->queue); mod_timer(&ops->cursor_timer, jiffies + HZ/5); } -- 1.7.12.rc2.18.g61b472e -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
