rcu: Remove obsolete force-quiescent-state statistics for debugfs

The debugfs interface displayed statistics on RCU-pending checks but
this interface has since been removed.  This commit therefore removes the
no-longer-used rcu_state structure's ->n_force_qs_lh and ->n_force_qs_ngp
fields along with their updates.  (Though the ->n_force_qs_ngp field
was actually not used at all, embarrassingly enough.)

If this information proves necessary in the future, the corresponding
event traces will be added.

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

1 files changed, 1 insertions, 4 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 99d59be761d1..86fc087c7777 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2844,10 +2844,8 @@ static void force_quiescent_state(struct rcu_state *rsp)
                       !raw_spin_trylock(&rnp->fqslock);
                 if (rnp_old != NULL)
                         raw_spin_unlock(&rnp_old->fqslock);
-                if (ret) {
-                        rsp->n_force_qs_lh++;
+                if (ret)
                         return;
-                }
                 rnp_old = rnp;
         }
         /* rnp_old == rcu_get_root(rsp), rnp == NULL. */
@@ -2856,7 +2854,6 @@ static void force_quiescent_state(struct rcu_state *rsp)
         raw_spin_lock_irqsave_rcu_node(rnp_old, flags);
         raw_spin_unlock(&rnp_old->fqslock);
         if (READ_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
-                rsp->n_force_qs_lh++;
                 raw_spin_unlock_irqrestore_rcu_node(rnp_old, flags);
                 return;  /* Someone beat us to it. */
         }