- Don't allow nice to have such a large effect on priority. This was

   causing poor interactive performance while unnice processes were running.
   The new scheme still allows nice to have an effect on priority but it is
   not as dramatic as the effect of the interactivity score.

1 files changed, 7 insertions, 8 deletions

diff --git a/sys/kern/sched_ule.c b/sys/kern/sched_ule.c
index 3932c6c..9e01ef8 100644
--- a/sys/kern/sched_ule.c
+++ b/sys/kern/sched_ule.c
@@ -124,23 +124,22 @@ struct p_sched *proc0_sched = NULL;
 struct td_sched *thread0_sched = &td_sched;
 
 /*
- * This priority range has 20 priorities on either end that are reachable
- * only through nice values.
+ * The priority is primarily determined by the interactivity score.  Thus, we
+ * give lower(better) priorities to kse groups that use less CPU.  The nice
+ * value is then directly added to this to allow nice to have some effect
+ * on latency.
  *
  * PRI_RANGE:	Total priority range for timeshare threads.
- * PRI_NRESV:	Reserved priorities for nice.
+ * PRI_NRESV:	Number of nice values.
  * PRI_BASE:	The start of the dynamic range.
- * DYN_RANGE:	Number of priorities that are available int the dynamic
- *		priority range.
  */
 #define	SCHED_PRI_RANGE		(PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE + 1)
 #define	SCHED_PRI_NRESV		PRIO_TOTAL
 #define	SCHED_PRI_NHALF		(PRIO_TOTAL / 2)
 #define	SCHED_PRI_NTHRESH	(SCHED_PRI_NHALF - 1)
-#define	SCHED_PRI_BASE		((SCHED_PRI_NRESV / 2) + PRI_MIN_TIMESHARE)
-#define	SCHED_DYN_RANGE		(SCHED_PRI_RANGE - SCHED_PRI_NRESV)
+#define	SCHED_PRI_BASE		(PRI_MIN_TIMESHARE)
 #define	SCHED_PRI_INTERACT(score)					\
-    ((score) * SCHED_DYN_RANGE / SCHED_INTERACT_MAX)
+    ((score) * SCHED_PRI_RANGE / SCHED_INTERACT_MAX)
 
 /*
  * These determine the interactivity of a process.