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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 <paulmck@kernel.org>
This commit is contained in:
Paul E. McKenney 2022-08-03 16:40:48 -07:00
parent 37d6ade31c
commit f4754ad292
1 changed files with 10 additions and 0 deletions
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10
kernel/rcu/rcutorture.c
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@ -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