2003-05-21 20:28:04

by Joe Korty

[permalink] [raw]
Subject: [PATCH] setscheduler resched bug

setscheduler is not forcing a reschedule when needed like set_user_nice
does. It should.

Joe


--- 2.5.69/kernel/sched.c.orig 2003-05-21 14:50:53.000000000 -0400
+++ 2.5.69/kernel/sched.c 2003-05-21 15:01:13.000000000 -0400
@@ -1716,6 +1716,7 @@
unsigned long flags;
runqueue_t *rq;
task_t *p;
+ int oldprio;

if (!param || pid < 0)
goto out_nounlock;
@@ -1778,12 +1779,20 @@
retval = 0;
p->policy = policy;
p->rt_priority = lp.sched_priority;
+ oldprio = p->prio;
if (policy != SCHED_NORMAL)
p->prio = MAX_USER_RT_PRIO-1 - p->rt_priority;
else
p->prio = p->static_prio;
- if (array)
+ if (array) {
__activate_task(p, task_rq(p));
+ /*
+ * Reschedule if on a CPU and the priority dropped, or not on
+ * a CPU and the priority rose above the currently running task.
+ */
+ if ((rq->curr == p) ? (p->prio > oldprio) : (p->prio < rq->curr->prio))
+ resched_task(rq->curr);
+ }

out_unlock:
task_rq_unlock(rq, &flags);