Commit 474e59b4 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcutorture: Check GP completion at stutter end 



The rcu_torture_writer() function invokes stutter_wait() at the end of
each writer pass, which occasionally blocks for an extended time period
in order to ensure that RCU can handle intermittent loads.  But part of
handling a busy period is invoking all the callbacks before the end of
the idle period induced by stutter_wait().

This commit therefore adds a return value to stutter_wait() indicating
whether stutter_wait() actually waited.  In addition, this commit causes
rcu_torture_writer() to test this value and if set, checks that all the
elements of the rcu_tortures[] array have been freed up.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent f4de46ed

include/linux/torture.h

+1 −1
Original line number Diff line number Diff line
@@ -77,7 +77,7 @@ void torture_shutdown_absorb(const char *title); 
int torture_shutdown_init(int ssecs, void (*cleanup)(void));



/* Task stuttering, which forces load/no-load transitions. */

void stutter_wait(const char *title);

bool stutter_wait(const char *title);

int torture_stutter_init(int s);



/* Initialization and cleanup. */

kernel/rcu/rcutorture.c

+4 −1
Original line number Diff line number Diff line
@@ -1144,7 +1144,10 @@ rcu_torture_writer(void *arg) 
				       !rcu_gp_is_normal();

		}

		rcu_torture_writer_state = RTWS_STUTTER;

		stutter_wait("rcu_torture_writer");

		if (stutter_wait("rcu_torture_writer"))

			for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++)

				if (list_empty(&rcu_tortures[i].rtort_free))

					WARN_ON_ONCE(1);

	} while (!torture_must_stop());

	/* Reset expediting back to unexpedited. */

	if (expediting > 0)

kernel/torture.c

+2 −1
Original line number Diff line number Diff line
@@ -573,7 +573,7 @@ static int stutter; 
 * Block until the stutter interval ends.  This must be called periodically

 * by all running kthreads that need to be subject to stuttering.

 */

void stutter_wait(const char *title)

bool stutter_wait(const char *title)

{

	int spt;
@@ -590,6 +590,7 @@ void stutter_wait(const char *title) 
		}

		torture_shutdown_absorb(title);

	}

	return !!spt;

}

EXPORT_SYMBOL_GPL(stutter_wait);

CRA Git | Maintained and supported by SUSTech CRA and CCSE