Commit ae18ad28 authored by Dietmar Eggemann's avatar Dietmar Eggemann Committed by Ingo Molnar
Browse files

sched: Remove MAX_USER_RT_PRIO 



Commit d46523ea ("[PATCH] fix MAX_USER_RT_PRIO and MAX_RT_PRIO")
was introduced due to a a small time period in which the realtime patch
set was using different values for MAX_USER_RT_PRIO and MAX_RT_PRIO.

This is no longer true, i.e. now MAX_RT_PRIO == MAX_USER_RT_PRIO.

Get rid of MAX_USER_RT_PRIO and make everything use MAX_RT_PRIO
instead.

Signed-off-by: default avatarDietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210128131040.296856-2-dietmar.eggemann@arm.com
parent 71e5f664

include/linux/sched/prio.h

+1 −8
Original line number Diff line number Diff line
@@ -11,16 +11,9 @@ 
 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH

 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority

 * values are inverted: lower p->prio value means higher priority.

 *

 * The MAX_USER_RT_PRIO value allows the actual maximum

 * RT priority to be separate from the value exported to

 * user-space.  This allows kernel threads to set their

 * priority to a value higher than any user task. Note:

 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.

 */



#define MAX_USER_RT_PRIO	100

#define MAX_RT_PRIO		MAX_USER_RT_PRIO

#define MAX_RT_PRIO		100



#define MAX_PRIO		(MAX_RT_PRIO + NICE_WIDTH)

#define DEFAULT_PRIO		(MAX_RT_PRIO + NICE_WIDTH / 2)

kernel/sched/core.c

+3 −4
Original line number Diff line number Diff line
@@ -5911,11 +5911,10 @@ static int __sched_setscheduler(struct task_struct *p, 


	/*

	 * Valid priorities for SCHED_FIFO and SCHED_RR are

	 * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,

	 * 1..MAX_RT_PRIO-1, valid priority for SCHED_NORMAL,

	 * SCHED_BATCH and SCHED_IDLE is 0.

	 */

	if ((p->mm && attr->sched_priority > MAX_USER_RT_PRIO-1) ||

	    (!p->mm && attr->sched_priority > MAX_RT_PRIO-1))

	if (attr->sched_priority > MAX_RT_PRIO-1)

		return -EINVAL;

	if ((dl_policy(policy) && !__checkparam_dl(attr)) ||

	    (rt_policy(policy) != (attr->sched_priority != 0)))
@@ -6983,7 +6982,7 @@ SYSCALL_DEFINE1(sched_get_priority_max, int, policy) 
	switch (policy) {

	case SCHED_FIFO:

	case SCHED_RR:

		ret = MAX_USER_RT_PRIO-1;

		ret = MAX_RT_PRIO-1;

		break;

	case SCHED_DEADLINE:

	case SCHED_NORMAL: