rcu: Record ->gp_state for both phases of grace-period initialization

Grace-period initialization first processes any recent CPU-hotplug
operations, and then initializes state for the new grace period.  These
two phases of initialization are currently not distinguished in debug
prints, but the distinction is valuable in a number of debug situations.
This commit therefore introduces two new values for ->gp_state,
RCU_GP_ONOFF and RCU_GP_INIT, in order to make this distinction.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index a2503ef1bbe2..ee218d743226 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1891,6 +1891,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
          * for subsequent online CPUs, and that quiescent-state forcing
          * will handle subsequent offline CPUs.
          */
+        rsp->gp_state = RCU_GP_ONOFF;
         rcu_for_each_leaf_node(rsp, rnp) {
                 spin_lock(&rsp->ofl_lock);
                 raw_spin_lock_irq_rcu_node(rnp);
@@ -1950,6 +1951,7 @@ static bool rcu_gp_init(struct rcu_state *rsp)
          * The grace period cannot complete until the initialization
          * process finishes, because this kthread handles both.
          */
+        rsp->gp_state = RCU_GP_INIT;
         rcu_for_each_node_breadth_first(rsp, rnp) {
                 rcu_gp_slow(rsp, gp_init_delay);
                 raw_spin_lock_irqsave_rcu_node(rnp, flags);