From f0ad56e876cdd67730065274625edbcfe0cca278 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 22 Oct 2018 08:33:06 -0700 Subject: [PATCH] rcu: Eliminate BUG_ON() for kernel/rcu/update.c The update.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 Signed-off-by: Paul E. McKenney --- kernel/rcu/update.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index f203b94f6b5b..cb26de25658a 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -822,7 +822,8 @@ static int __init rcu_spawn_tasks_kthread(void) struct task_struct *t; t = kthread_run(rcu_tasks_kthread, NULL, "rcu_tasks_kthread"); - BUG_ON(IS_ERR(t)); + if (WARN_ONCE(IS_ERR(t), "%s: Could not start Tasks-RCU grace-period kthread, OOM is now expected behavior\n", __func__)) + return 0; smp_mb(); /* Ensure others see full kthread. */ WRITE_ONCE(rcu_tasks_kthread_ptr, t); return 0;