The following commit has been merged into the core/rcu branch of tip: Commit-ID: 3480d6774f07341e3e1cf3114f58bef98ea58ae0 Gitweb: https://git.kernel.org/tip/3480d6774f07341e3e1cf3114f58bef98ea58ae0 Author: Paul E. McKenney <paulmck@xxxxxxxxxx> AuthorDate: Sun, 30 Aug 2020 21:48:23 -07:00 Committer: Paul E. McKenney <paulmck@xxxxxxxxxx> CommitterDate: Fri, 06 Nov 2020 17:13:29 -08:00 locktorture: Track time of last ->writeunlock() 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. Acked-by: Davidlohr Bueso <dbueso@xxxxxxx> 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");