Commit-ID: c51d7b5e6c94aa6b554c27bd2b0eb64ebef02334
Gitweb: https://git.kernel.org/tip/c51d7b5e6c94aa6b554c27bd2b0eb64ebef02334
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
AuthorDate: Wed, 3 Oct 2018 17:25:33 -0700
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
CommitDate: Sat, 1 Dec 2018 12:45:40 -0800
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@xxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 5 ++++-
kernel/rcu/tree.h | 2 ++
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index f91631541965..9180158756d2 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);
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index a8f82b7dc5e2..d90b02b53c0e 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -328,6 +328,8 @@ struct rcu_state {
/* force_quiescent_state(). */
unsigned long gp_start; /* Time at which GP started, */
/* but in jiffies. */
+ unsigned long gp_end; /* Time last GP ended, again */
+ /* in jiffies. */
unsigned long gp_activity; /* Time of last GP kthread */
/* activity in jiffies. */
unsigned long gp_req_activity; /* Time of last GP request */
|