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: Paul E. McKenney <[email protected]> --- include/linux/torture.h | 2 +- kernel/rcu/rcutorture.c | 5 ++++- kernel/torture.c | 3 ++- 3 files changed, 7 insertions(+), 3 deletions(-) diff --git a/include/linux/torture.h b/include/linux/torture.h index 61dfd93b6ee4..48fad21109fc 100644 --- a/include/linux/torture.h +++ b/include/linux/torture.h @@ -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. */ diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 7df8142a6a22..ae10ad531993 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -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) diff --git a/kernel/torture.c b/kernel/torture.c index 1ac24a826589..17d91f5fba2a 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -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); -- 2.17.1
