On Thu, 05 Nov 2020, paulmck@xxxxxxxxxx wrote:
From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
This commit adds a last_lock_release variable that tracks the time of
the last ->writeunlock() call, which allows easier diagnosing of lock
hangs when using a kernel debugger.
This makes sense to have.
Acked-by: Davidlohr Bueso <dbueso@xxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/locking/locktorture.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 62d215b..316531d 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -60,6 +60,7 @@ static struct task_struct **reader_tasks;
static bool lock_is_write_held;
static bool lock_is_read_held;
+static unsigned long last_lock_release;
struct lock_stress_stats {
long n_lock_fail;
@@ -632,6 +633,7 @@ static int lock_torture_writer(void *arg)
lwsp->n_lock_acquired++;
cxt.cur_ops->write_delay(&rand);
lock_is_write_held = false;
+ WRITE_ONCE(last_lock_release, jiffies);
cxt.cur_ops->writeunlock();
stutter_wait("lock_torture_writer");
--
2.9.5
