Commit ff3bf92d authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

torture: Allow inter-stutter interval to be specified 



Currently, the inter-stutter interval is the same as the stutter duration,
that is, whatever number of jiffies is passed into torture_stutter_init().
This has worked well for quite some time, but the addition of
forward-progress testing to rcutorture can delay processes for several
seconds, which can triple the time that they are stuttered.

This commit therefore adds a second argument to torture_stutter_init()
that specifies the inter-stutter interval.  While locktorture preserves
the current behavior, rcutorture uses the RCU CPU stall warning interval
to provide a wider inter-stutter interval.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
parent e8516c64

include/linux/torture.h

+1 −1
Original line number Diff line number Diff line
@@ -66,7 +66,7 @@ int torture_shutdown_init(int ssecs, void (*cleanup)(void)); 


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

bool stutter_wait(const char *title);

int torture_stutter_init(int s);

int torture_stutter_init(int s, int sgap);



/* Initialization and cleanup. */

bool torture_init_begin(char *ttype, int v);

kernel/locking/locktorture.c

+1 −1
Original line number Diff line number Diff line
@@ -975,7 +975,7 @@ static int __init lock_torture_init(void) 
			goto unwind;

	}

	if (stutter > 0) {

		firsterr = torture_stutter_init(stutter);

		firsterr = torture_stutter_init(stutter, stutter);

		if (firsterr)

			goto unwind;

	}

kernel/rcu/rcutorture.c

+4 −1
Original line number Diff line number Diff line
@@ -2373,7 +2373,10 @@ rcu_torture_init(void) 
	if (stutter < 0)

		stutter = 0;

	if (stutter) {

		firsterr = torture_stutter_init(stutter * HZ);

		int t;



		t = cur_ops->stall_dur ? cur_ops->stall_dur() : stutter * HZ;

		firsterr = torture_stutter_init(stutter * HZ, t);

		if (firsterr)

			goto unwind;

	}

kernel/torture.c

+4 −2
Original line number Diff line number Diff line
@@ -570,6 +570,7 @@ static void torture_shutdown_cleanup(void) 
static struct task_struct *stutter_task;

static int stutter_pause_test;

static int stutter;

static int stutter_gap;



/*

 * Block until the stutter interval ends.  This must be called periodically
@@ -621,7 +622,7 @@ static int torture_stutter(void *arg) 
		}

		WRITE_ONCE(stutter_pause_test, 0);

		if (!torture_must_stop())

			schedule_timeout_interruptible(stutter);

			schedule_timeout_interruptible(stutter_gap);

		torture_shutdown_absorb("torture_stutter");

	} while (!torture_must_stop());

	torture_kthread_stopping("torture_stutter");
@@ -631,9 +632,10 @@ static int torture_stutter(void *arg) 
/*

 * Initialize and kick off the torture_stutter kthread.

 */

int torture_stutter_init(const int s)

int torture_stutter_init(const int s, const int sgap)

{

	stutter = s;

	stutter_gap = sgap;

	return torture_create_kthread(torture_stutter, NULL, stutter_task);

}

EXPORT_SYMBOL_GPL(torture_stutter_init);

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