rcu: Forgive slow expedited grace periods at boot time

Boot-time processing often loops in the kernel longer than one might
prefer, which can prevent expedited grace periods from completing in
a timely manner.  This in turn triggers a splat In nohz_full CPUs  One
could argue that long-looping code should be fixed, but on the other hand,
boot time is a bit special.

This commit therefore removes the splat.  Later commits will add the
splat back in, but in a way that removes false positives.

Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 6935a9e..dcbd757 100644 (file)
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -508,7 +508,6 @@ static void synchronize_rcu_expedited_wait(void)
                                tick_dep_set_cpu(cpu, TICK_DEP_BIT_RCU_EXP);
                        }
                }
-               WARN_ON_ONCE(1);
        }
 
        for (;;) {