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 <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This commit is contained in:
Pranith Kumar 2014-07-17 20:11:01 -04:00 committed by Paul E. McKenney
parent 35ce7f29a4
commit 22c2f66961

View file

@ -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;
}