sched: Fix 32bit race

Commit 3fe1698b7f ("sched: Deal with non-atomic min_vruntime reads
on 32bit") forgot to initialize min_vruntime_copy which could lead to
an infinite while loop in task_waking_fair() under some circumstances
(early boot, lucky timing).

[ This bug was also reported by others that blamed it on the RCU
  initialization problems ]

Reported-and-tested-by: Bruno Wolff III <bruno@wolff.to>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Peter Zijlstra 2011-07-11 16:28:50 +02:00 committed by Linus Torvalds
parent 5dcd07b9f3
commit c64be78ffb

View file

@ -7757,6 +7757,9 @@ static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq)
#endif
#endif
cfs_rq->min_vruntime = (u64)(-(1LL << 20));
#ifndef CONFIG_64BIT
cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
#endif
}
static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq)