If there is only one CPU, then invoking synchronize_sched_expedited() is by definition a grace period. This commit checks for this condition and does a short-circuit return in that case.
Signed-off-by: Paul E. McKenney <[email protected]> --- kernel/rcu/tree.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 81aa1cdc6bc9..bd2605c144cc 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3822,6 +3822,10 @@ void synchronize_sched_expedited(void) struct rcu_node *rnp; struct rcu_state *rsp = &rcu_sched_state; + /* If only one CPU, this is automatically a grace period. */ + if (rcu_blocking_is_gp()) + return; + /* Take a snapshot of the sequence number. */ s = rcu_exp_gp_seq_snap(rsp); -- 2.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
