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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2011-07-11 16:28:50 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-15 09:54:02 -0700
commitc64be78ffb415278d7d32d6f55de95c73dcc19a4 (patch)
tree0777bdbb0424a6ce948c817247757a4ba3b01a32
parent5dcd07b9f39ca3e9be5bcc387d193fc0674e1c81 (diff)
downloadop-kernel-dev-c64be78ffb415278d7d32d6f55de95c73dcc19a4.zip
op-kernel-dev-c64be78ffb415278d7d32d6f55de95c73dcc19a4.tar.gz
sched: Fix 32bit race
Commit 3fe1698b7fe0 ("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>
-rw-r--r--kernel/sched.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 9769c75..3dc716f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -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)
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