sched_getparam was just plain broke for time-share

processes. It did not return an error but instead
just let garbage be passed back. This I fix so
it actually properly translates the priority the
process is at to a posix's high means more priority.
I also fix it so that if the ULE scheduler has bumped
it up to a realtime process you get back a sane value
i.e. the highest priority (63 for time-share).

sched_setscheduler() had the setting of the
timeshare class priority disabled. With some notes
about rejecting the posix high numbers is greater
priority and use nice instead. This fix also
adjusts that to work, with the cavet that a t-s
process may well get bumped up or down i.e. the
setscheduler() will NOT change the nice value only
the current priority. I think this is reasonable
considering if the user wants to play with nice then
he can. At least all the posix'ish interfaces now
respond sanely.

MFC after:	3 weeks

1 files changed, 19 insertions, 8 deletions

diff --git a/sys/kern/ksched.c b/sys/kern/ksched.c
index 192034f..2d11363 100644
--- a/sys/kern/ksched.c
+++ b/sys/kern/ksched.c
@@ -81,9 +81,8 @@ ksched_detach(struct ksched *ks)
  *	higher priority.  It also permits sched_setparam to be
  *	implementation defined for SCHED_OTHER.  I don't like
  *	the notion of inverted priorites for normal processes when
- *  you can use "setpriority" for that.
+ *      you can use "setpriority" for that.
  *
- *	I'm rejecting sched_setparam for SCHED_OTHER with EINVAL.
  */
 
 /* Macros to convert between the unix (lower numerically is higher priority)
@@ -93,6 +92,9 @@ ksched_detach(struct ksched *ks)
 #define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P))
 #define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P))
 
+#define p4prio_to_tsprio(P) ((PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE) - (P))
+#define tsprio_to_p4prio(P) ((PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE) - (P))
+
 /* These improve readability a bit for me:
  */
 #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX)
@@ -134,9 +136,6 @@ ksched_setparam(struct ksched *ksched,
 
 	if (e == 0)
 	{
-		if (policy == SCHED_OTHER)
-			e = EINVAL;
-		else
 			e = ksched_setscheduler(ksched, td, policy, param);
 	}
 
@@ -152,7 +151,16 @@ ksched_getparam(struct ksched *ksched,
 	pri_to_rtp(td, &rtp);
 	if (RTP_PRIO_IS_REALTIME(rtp.type))
 		param->sched_priority = rtpprio_to_p4prio(rtp.prio);
-
+	else {
+		if (PRI_MIN_TIMESHARE < rtp.prio) 
+			/*
+		 	 * The interactive score has it to min realtime
+			 * so we must show max (64 most likely
+			 */ 
+			param->sched_priority = (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE);
+		else
+			param->sched_priority = tsprio_to_p4prio(rtp.prio);
+	}
 	return 0;
 }
 
@@ -191,11 +199,14 @@ ksched_setscheduler(struct ksched *ksched,
 		break;
 
 		case SCHED_OTHER:
-		{
+		if (param->sched_priority >= 0 &&
+			param->sched_priority <= (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE)) {
 			rtp.type = RTP_PRIO_NORMAL;
 			rtp.prio = p4prio_to_rtpprio(param->sched_priority);
 			rtp_to_pri(&rtp, td);
-		}
+		} else
+			e = EINVAL;
+
 		break;
 		
 		default: