sched: let +nice tasks have smaller impact

Michel Dänzr has bisected an interactivity problem with plus-reniced tasks back to this commit: 810e95c is first bad commit commit 810e95c Author: Peter Zijlstra <[email protected]> Date: Mon Oct 15 17:00:14 2007 +0200 sched: another wakeup_granularity fix unit mis-match: wakeup_gran was used against a vruntime fix this by assymetrically scaling the vtime of positive reniced tasks. Bisected-by: Michel Dänzer <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Signed-off-by: Ingo Molnar <[email protected]>
kishon · Jan 31, 2008 · ef9884e · ef9884e
1 parent 296825c
commit ef9884e
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
@@ -1106,7 +1106,11 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
 	}
 
 	gran = sysctl_sched_wakeup_granularity;
-	if (unlikely(se->load.weight != NICE_0_LOAD))
+	/*
+	 * More easily preempt - nice tasks, while not making
+	 * it harder for + nice tasks.
+	 */
+	if (unlikely(se->load.weight > NICE_0_LOAD))
 		gran = calc_delta_fair(gran, &se->load);
 
 	if (pse->vruntime + gran < se->vruntime)