From ed7d2f1abee48a90fae5fdf5c60d71803a5a1d10 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 1 Aug 2022 16:57:17 -0700 Subject: rcutorture: Allow per-RCU-flavor polled double-GP check Only vanilla RCU needs a double grace period for its compressed polled grace-period old-state cookie. This commit therefore adds an rcu_torture_ops per-flavor function ->poll_need_2gp to allow this check to be adapted to the RCU flavor under test. A NULL pointer for this function says that doubled grace periods are never needed. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'kernel/rcu/rcutorture.c') diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index c3c94e343eb2..f2564c7633a8 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -341,6 +341,7 @@ struct rcu_torture_ops { unsigned long (*start_gp_poll)(void); bool (*poll_gp_state)(unsigned long oldstate); bool (*poll_gp_state_full)(struct rcu_gp_oldstate *rgosp); + bool (*poll_need_2gp)(bool poll, bool poll_full); void (*cond_sync)(unsigned long oldstate); call_rcu_func_t call; void (*cb_barrier)(void); @@ -492,6 +493,11 @@ static void rcu_sync_torture_init(void) INIT_LIST_HEAD(&rcu_torture_removed); } +static bool rcu_poll_need_2gp(bool poll, bool poll_full) +{ + return poll || (!IS_ENABLED(CONFIG_TINY_RCU) && poll_full && num_online_cpus() <= 1); +} + static struct rcu_torture_ops rcu_ops = { .ttype = RCU_FLAVOR, .init = rcu_sync_torture_init, @@ -511,6 +517,7 @@ static struct rcu_torture_ops rcu_ops = { .start_gp_poll = start_poll_synchronize_rcu, .poll_gp_state = poll_state_synchronize_rcu, .poll_gp_state_full = poll_state_synchronize_rcu_full, + .poll_need_2gp = rcu_poll_need_2gp, .cond_sync = cond_synchronize_rcu, .get_gp_state_exp = get_state_synchronize_rcu, .start_gp_poll_exp = start_poll_synchronize_rcu_expedited, @@ -1228,7 +1235,7 @@ static void do_rtws_sync(struct torture_random_state *trsp, void (*sync)(void)) cookie = cur_ops->get_gp_state(); if (dopoll_full) cur_ops->get_gp_state_full(&cookie_full); - if (dopoll || (!IS_ENABLED(CONFIG_TINY_RCU) && dopoll_full && num_online_cpus() <= 1)) + if (cur_ops->poll_need_2gp && cur_ops->poll_need_2gp(dopoll, dopoll_full)) sync(); sync(); WARN_ONCE(dopoll && !cur_ops->poll_gp_state(cookie), -- cgit