* [patch] sched-rebalance-fix-2.5.69-A1
@ 2003-05-19 8:43 Ingo Molnar
0 siblings, 0 replies; only message in thread
From: Ingo Molnar @ 2003-05-19 8:43 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-kernel, Mike Galbraith
the attached patch fixes a race noticed by Mike Galbraith: the scheduler
can lose a rebalance tick if some task happens to not be rescheduled in
time. This is not a fatal condition, but an inconsistency nevertheless.
Ingo
--- linux/kernel/sched.c.orig
+++ linux/kernel/sched.c
@@ -1180,7 +1180,7 @@ void scheduler_tick(int user_ticks, int
/* Task might have expired already, but not scheduled off yet */
if (p->array != rq->active) {
set_tsk_need_resched(p);
- return;
+ goto out;
}
spin_lock(&rq->lock);
/*
@@ -1207,7 +1207,7 @@ void scheduler_tick(int user_ticks, int
dequeue_task(p, rq->active);
enqueue_task(p, rq->active);
}
- goto out;
+ goto out_unlock;
}
if (!--p->time_slice) {
dequeue_task(p, rq->active);
@@ -1223,8 +1223,9 @@ void scheduler_tick(int user_ticks, int
} else
enqueue_task(p, rq->active);
}
-out:
+out_unlock:
spin_unlock(&rq->lock);
+out:
rebalance_tick(rq, 0);
}
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2003-05-19 8:43 [patch] sched-rebalance-fix-2.5.69-A1 Ingo Molnar
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