From: Paul E. McKenney Date: Wed, 3 Aug 2022 23:40:48 +0000 (-0700) Subject: rcutorture: Verify long-running reader prevents full polling from completing X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f4754ad2922e5a2b08c8aecf33d1ec03d7219fb4;p=linux.git 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: Paul E. McKenney --- diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 236bd6b57277f..3d85420108477 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -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