More PI issues with -rt

More PI issues with -rt

[Dinakar Guniguntala]

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Hi,

I found that PI boosted SCHED_OTHER tasks behave like they have
SCHED_FIFO policy, while PI boosted SCHED_RR tasks continue to
behave like they have SCHED_RR policy. This didn't seem right

Does something like the following patch make sense?

	-Dinakar



[-- Attachment #2: pi-fix.patch --]
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Index: linux-2.6.14/kernel/sched.c
===================================================================
--- linux-2.6.14.orig/kernel/sched.c	2005-11-25 01:24:06.000000000 +0530
+++ linux-2.6.14/kernel/sched.c	2005-11-25 01:24:26.000000000 +0530
@@ -2986,8 +2986,9 @@
 		 * On PREEMPT_RT, boosted tasks will also get into this
 		 * branch and wont get their timeslice decreased until
 		 * they have done their work.
+		 * Boosted SCHED_OTHER tasks round-robin as well
 		 */
-		if ((p->policy == SCHED_RR) && !--p->time_slice) {
+		if ((p->policy != SCHED_FIFO) && !--p->time_slice) {
 			p->time_slice = task_timeslice(p);
 			p->first_time_slice = 0;
 			set_tsk_need_resched(p);

Re: More PI issues with -rt

[Dinakar Guniguntala]

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Ingo/David,

Resending this as I did not get any reply.
This time I am attaching the testcases where I am noticing this
Any feedback is appreciated

	-Dinakar


On Fri, Nov 25, 2005 at 01:26:01AM +0530, Dinakar Guniguntala wrote:
> Hi,
> 
> I found that PI boosted SCHED_OTHER tasks behave like they have
> SCHED_FIFO policy, while PI boosted SCHED_RR tasks continue to
> behave like they have SCHED_RR policy. This didn't seem right
> 
> Does something like the following patch make sense?
> 
> 	-Dinakar
> 
> 

> Index: linux-2.6.14/kernel/sched.c
> ===================================================================
> --- linux-2.6.14.orig/kernel/sched.c	2005-11-25 01:24:06.000000000 +0530
> +++ linux-2.6.14/kernel/sched.c	2005-11-25 01:24:26.000000000 +0530
> @@ -2986,8 +2986,9 @@
>  		 * On PREEMPT_RT, boosted tasks will also get into this
>  		 * branch and wont get their timeslice decreased until
>  		 * they have done their work.
> +		 * Boosted SCHED_OTHER tasks round-robin as well
>  		 */
> -		if ((p->policy == SCHED_RR) && !--p->time_slice) {
> +		if ((p->policy != SCHED_FIFO) && !--p->time_slice) {
>  			p->time_slice = task_timeslice(p);
>  			p->first_time_slice = 0;
>  			set_tsk_need_resched(p);


[-- Attachment #2: pitests.tar.gz --]
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