The rcutorture test suite sometimess triggers a random scheduler
preemption call while simulating a read delay. Unfortunately, its
direct call to preempt_schedule() bypasses the static call/key filter
used by CONFIG_PREEMPT_DYNAMIC. This breaks the no-preempt assumption
when the dynamic preemption mode is "none".
For example, rcu_blocking_is_gp() is fooled and abbreviates grace periods
when the CPU runs in no-preempt UP mode.
Fix this by making torture_preempt_schedule() call __preempt_schedule(),
which uses the static call/key.
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
_torture_stop_kthread("Stopping " #n " task", &(tp))
#ifdef CONFIG_PREEMPTION
-#define torture_preempt_schedule() preempt_schedule()
+#define torture_preempt_schedule() __preempt_schedule()
#else
#define torture_preempt_schedule() do { } while (0)
#endif