Commit f4754ad2 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcutorture: Verify long-running reader prevents full polling from completing 



This commit adds full-state polling checks to accompany the old-style
polling checks in the rcu_torture_one_read() function.  If a polling
cycle within an RCU reader completes, a WARN_ONCE() is triggered.

Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 37d6ade3

kernel/rcu/rcutorture.c

+10 −0
Original line number Diff line number Diff line
@@ -1770,6 +1770,7 @@ rcutorture_loop_extend(int *readstate, struct torture_random_state *trsp, 
static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid)

{

	unsigned long cookie;

	struct rcu_gp_oldstate cookie_full;

	int i;

	unsigned long started;

	unsigned long completed;
@@ -1787,6 +1788,8 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid) 
	rcutorture_one_extend(&readstate, newstate, trsp, rtrsp++);

	if (cur_ops->get_gp_state && cur_ops->poll_gp_state)

		cookie = cur_ops->get_gp_state();

	if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full)

		cur_ops->get_gp_state_full(&cookie_full);

	started = cur_ops->get_gp_seq();

	ts = rcu_trace_clock_local();

	p = rcu_dereference_check(rcu_torture_current,
@@ -1827,6 +1830,13 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid) 
			  rcu_torture_writer_state_getname(),

			  rcu_torture_writer_state,

			  cookie, cur_ops->get_gp_state());

	if (cur_ops->get_gp_state_full && cur_ops->poll_gp_state_full)

		WARN_ONCE(cur_ops->poll_gp_state_full(&cookie_full),

			  "%s: Cookie check 6 failed %s(%d) online %*pbl\n",

			  __func__,

			  rcu_torture_writer_state_getname(),

			  rcu_torture_writer_state,

			  cpumask_pr_args(cpu_online_mask));

	rcutorture_one_extend(&readstate, 0, trsp, rtrsp);

	WARN_ON_ONCE(readstate);

	// This next splat is expected behavior if leakpointer, especially