2005-10-27 01:53:29

by Chen, Kenneth W

Subject: [patch] optimize activate_task()

recalc_task_prio() is called from activate_task() to calculate
dynamic priority and interactive credit for the activating task.
For real-time scheduling process, all that dynamic calculation
is thrown away at the end because rt priority is fixed. Patch
to optimize recalc_task_prio() away for rt processes.


Signed-off-by: Ken Chen <[email protected]>


--- ./kernel/sched.c.orig 2005-10-26 10:39:40.594015398 -0700
+++ ./kernel/sched.c 2005-10-26 18:43:12.187410006 -0700
@@ -833,7 +833,8 @@ static void activate_task(task_t *p, run
}
#endif

- p->prio = recalc_task_prio(p, now);
+ if (!rt_task(p))
+ p->prio = recalc_task_prio(p, now);

/*
* This checks to make sure it's not an uninterruptible task

2005-10-28 08:38:31

by Ingo Molnar

Subject: Re: [patch] optimize activate_task()

* Chen, Kenneth W <[email protected]> wrote:

> recalc_task_prio() is called from activate_task() to calculate dynamic
> priority and interactive credit for the activating task. For real-time
> scheduling process, all that dynamic calculation is thrown away at the
> end because rt priority is fixed. Patch to optimize
> recalc_task_prio() away for rt processes.
>
>
> Signed-off-by: Ken Chen <[email protected]>

Acked-by: Ingo Molnar <[email protected]>

Ingo