[PATCH 7/7] rcutorture: Add number of GP information to reports

[Joel Fernandes (Google)]

Add 2 things to get visiblity around number of grace periods.
1. Add number of GPs to End-state print.
2. Just like End-state, add GP state to Start-state.

This helps determine how many GPs elapsed during a run of rcutorture and
what the initial state was.

Signed-off-by: Joel Fernandes (Google) <j...@joelfernandes.org>
---
 kernel/rcu/rcutorture.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 959a1f84d6904..c80725ddd9030 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -186,6 +186,7 @@ static long n_barrier_successes; /* did rcu_barrier test 
succeed? */
 static unsigned long n_read_exits;
 static struct list_head rcu_torture_removed;
 static unsigned long shutdown_jiffies;
+static unsigned long start_gp_seq;
 
 static int rcu_torture_writer_state;
 #define RTWS_FIXED_DELAY       0
@@ -2508,8 +2509,9 @@ rcu_torture_cleanup(void)
 
        rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq);
        srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq);
-       pr_alert("%s:  End-test grace-period state: g%lu f%#x\n",
-                cur_ops->name, gp_seq, flags);
+       pr_alert("%s:  End-test grace-period state: g%ld f%#x total-gps=%ld\n",
+                cur_ops->name, (long)gp_seq, flags,
+                rcutorture_seq_diff(gp_seq, start_gp_seq));
        torture_stop_kthread(rcu_torture_stats, stats_task);
        torture_stop_kthread(rcu_torture_fqs, fqs_task);
        if (rcu_torture_can_boost())
@@ -2633,6 +2635,8 @@ rcu_torture_init(void)
        long i;
        int cpu;
        int firsterr = 0;
+       int flags = 0;
+       unsigned long gp_seq = 0;
        static struct rcu_torture_ops *torture_ops[] = {
                &rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
                &busted_srcud_ops, &tasks_ops, &tasks_rude_ops,
@@ -2675,6 +2679,11 @@ rcu_torture_init(void)
                        nrealreaders = 1;
        }
        rcu_torture_print_module_parms(cur_ops, "Start of test");
+       rcutorture_get_gp_data(cur_ops->ttype, &flags, &gp_seq);
+       srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp, &flags, &gp_seq);
+       start_gp_seq = gp_seq;
+       pr_alert("%s:  Start-test grace-period state: g%ld f%#x\n",
+                cur_ops->name, (long)gp_seq, flags);
 
        /* Set up the freelist. */
 
-- 
2.27.0.111.gc72c7da667-goog