diff options
| author | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-10-22 08:26:00 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-11-12 08:15:16 -0800 |
| commit | 9213784b48f8ba666b4695ca3f5d34f583daab83 (patch) | |
| tree | 85e18021d0a25c3f524cd2903124e9387bea98ba /kernel/rcu | |
| parent | 08543bda42ef06c5ee4cd74501c894aa7cc13ea8 (diff) | |
rcu: Eliminate BUG_ON() for kernel/rcu/tree_plugin.h
The tree_plugin.h 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>
[ paulmck: Fix typo: s/rcuo/rcub/. ]
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 05915e536336..adda608874a8 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1464,7 +1464,8 @@ static void __init rcu_spawn_boost_kthreads(void) for_each_possible_cpu(cpu) per_cpu(rcu_cpu_has_work, cpu) = 0; - BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec)); + if (WARN_ONCE(smpboot_register_percpu_thread(&rcu_cpu_thread_spec), "%s: Could not start rcub kthread, OOM is now expected behavior\n", __func__)) + return; rcu_for_each_leaf_node(rnp) (void)rcu_spawn_one_boost_kthread(rnp); } @@ -2322,7 +2323,8 @@ static int rcu_nocb_kthread(void *arg) tail = rdp->nocb_follower_tail; rdp->nocb_follower_tail = &rdp->nocb_follower_head; raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags); - BUG_ON(!list); + if (WARN_ON_ONCE(!list)) + continue; trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WokeNonEmpty")); /* Each pass through the following loop invokes a callback. */ @@ -2495,7 +2497,8 @@ static void rcu_spawn_one_nocb_kthread(int cpu) /* Spawn the kthread for this CPU. */ t = kthread_run(rcu_nocb_kthread, rdp_spawn, "rcuo%c/%d", rcu_state.abbr, cpu); - BUG_ON(IS_ERR(t)); + if (WARN_ONCE(IS_ERR(t), "%s: Could not start rcuo kthread, OOM is now expected behavior\n", __func__)) + return; WRITE_ONCE(rdp_spawn->nocb_kthread, t); } |