From 22c2f669611590b428647ac9a73bc63ef3989d4b Mon Sep 17 00:00:00 2001 From: Pranith Kumar Date: Thu, 17 Jul 2014 20:11:01 -0400 Subject: [PATCH] rcu: Check for have_rcu_nocb_mask instead of rcu_nocb_mask If we configure a kernel with CONFIG_NOCB_CPU=y, CONFIG_RCU_NOCB_CPU_NONE=y and CONFIG_CPUMASK_OFFSTACK=n and do not pass in a rcu_nocb= boot parameter, the cpumask rcu_nocb_mask can be garbage instead of NULL. Hence this commit replaces checks for rcu_nocb_mask == NULL with a check for have_rcu_nocb_mask. Signed-off-by: Pranith Kumar Signed-off-by: Paul E. McKenney Tested-by: Paul Gortmaker --- kernel/rcu/tree_plugin.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 31c7afb611fd..39e68bcf6d83 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2578,7 +2578,7 @@ static void __init rcu_organize_nocb_kthreads(struct rcu_state *rsp) struct rcu_data *rdp_leader = NULL; /* Suppress misguided gcc warn. */ struct rcu_data *rdp_prev = NULL; - if (rcu_nocb_mask == NULL) + if (!have_rcu_nocb_mask) return; if (ls == -1) { ls = int_sqrt(nr_cpu_ids); @@ -2608,9 +2608,9 @@ static void __init rcu_organize_nocb_kthreads(struct rcu_state *rsp) /* Prevent __call_rcu() from enqueuing callbacks on no-CBs CPUs */ static bool init_nocb_callback_list(struct rcu_data *rdp) { - if (rcu_nocb_mask == NULL || - !cpumask_test_cpu(rdp->cpu, rcu_nocb_mask)) + if (!rcu_is_nocb_cpu(rdp->cpu)) return false; + rdp->nxttail[RCU_NEXT_TAIL] = NULL; return true; }