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authorPaul E. McKenney <paulmck@linux.ibm.com>2018-10-22 08:04:03 -0700
committerPaul E. McKenney <paulmck@linux.ibm.com>2018-11-08 21:41:57 -0800
commit08543bda42ef06c5ee4cd74501c894aa7cc13ea8 (patch)
tree41249a4a05ffa2faf9200e57a607601a84c188ec /kernel/rcu
parent042d4c70a203998697b34eaad1a99f6f09d09e4d (diff)
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rcu: Eliminate BUG_ON() for kernel/rcu/tree.c
The tree.c file has a number of calls to BUG_ON(), which panics the kernel, which is not a good strategy for devices (like embedded) that don't have a way to capture console output. This commit therefore converts these BUG_ON() calls to WARN_ON_ONCE() and WARN_ONCE(). Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 121f833acd04..bdb6659a8dbc 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2826,7 +2826,7 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func, int cpu, bool lazy)
* Very early boot, before rcu_init(). Initialize if needed
* and then drop through to queue the callback.
*/
- BUG_ON(cpu != -1);
+ WARN_ON_ONCE(cpu != -1);
WARN_ON_ONCE(!rcu_is_watching());
if (rcu_segcblist_empty(&rdp->cblist))
rcu_segcblist_init(&rdp->cblist);
@@ -3485,7 +3485,8 @@ static int __init rcu_spawn_gp_kthread(void)
rcu_scheduler_fully_active = 1;
t = kthread_create(rcu_gp_kthread, NULL, "%s", rcu_state.name);
- BUG_ON(IS_ERR(t));
+ if (WARN_ONCE(IS_ERR(t), "%s: Could not start grace-period kthread, OOM is now expected behavior\n", __func__))
+ return 0;
rnp = rcu_get_root();
raw_spin_lock_irqsave_rcu_node(rnp, flags);
rcu_state.gp_kthread = t;