From 3947909814f38d524829bc41bd4c11068a15f0cd Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 9 Oct 2013 15:20:33 -0700 Subject: [PATCH] rcu: Let the world know when RCU adjusts its geometry Some RCU bugs have been specific to the layout of the rcu_node tree, but RCU will silently adjust the tree at boot time if appropriate. This obscures valuable debugging information, so print a message when this happens. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 518e08428b2e..30499508c72e 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3391,6 +3391,8 @@ static void __init rcu_init_geometry(void) if (rcu_fanout_leaf == CONFIG_RCU_FANOUT_LEAF && nr_cpu_ids == NR_CPUS) return; + pr_info("RCU: Adjusting geometry for rcu_fanout_leaf=%d, nr_cpu_ids=%d\n", + rcu_fanout_leaf, nr_cpu_ids); /* * Compute number of nodes that can be handled an rcu_node tree