rcutorture: Print time since GP end upon forward-progress failure
If rcutorture's forward-progress tests fail while a grace period is not
in progress, it is useful to print the time since the last grace period
ended as a way to detect failure to launch a new grace period. This
commit therefore makes this change.
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f916315..9180158 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2000,7 +2000,8 @@ static void rcu_gp_cleanup(void)
WRITE_ONCE(rcu_state.gp_activity, jiffies);
raw_spin_lock_irq_rcu_node(rnp);
- gp_duration = jiffies - rcu_state.gp_start;
+ rcu_state.gp_end = jiffies;
+ gp_duration = rcu_state.gp_end - rcu_state.gp_start;
if (gp_duration > rcu_state.gp_max)
rcu_state.gp_max = gp_duration;
@@ -2686,6 +2687,8 @@ void rcu_fwd_progress_check(unsigned long j)
__func__, jiffies - rcu_state.gp_start);
show_rcu_gp_kthreads();
} else {
+ pr_info("%s: Last GP end %lu jiffies ago\n",
+ __func__, jiffies - rcu_state.gp_end);
preempt_disable();
rdp = this_cpu_ptr(&rcu_data);
rcu_check_gp_start_stall(rdp->mynode, rdp, j);