Commit ca1d51ed authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcutorture: Test SRCU cleanup code path 



The current rcutorture testing does not do any cleanup operations.
This works because the srcu_struct is statically allocated, but it
does represent a memory leak of the associated dynamically allocated
->per_cpu_ref per-CPU variables.  However, rcutorture currently uses
a statically allocated srcu_struct, which cannot legally be passed to
cleanup_srcu_struct().  Therefore, this commit adds a second form
of srcu (called srcud) that dynamically allocates and frees the
associated per-CPU variables.  This commit also adds a ->cleanup()
member to rcu_torture_ops that is invoked at the end of the test,
after ->cb_barriers().  This ->cleanup() pointer is NULL for all
existing tests, and thus only used for scrud.  Finally, the SRCU-P
torture-test configuration selects scrud instead of srcu, with SRCU-N
continuing to use srcu, thereby testing both static and dynamic
srcu_struct structures.

Reported-by: default avatar"Ahmed, Iftekhar" <ahmedi@onid.oregonstate.edu>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
parent 6c7ed42c

kernel/rcu/rcutorture.c

+58 −19
Original line number Diff line number Diff line
@@ -241,6 +241,7 @@ rcu_torture_free(struct rcu_torture *p) 
struct rcu_torture_ops {

	int ttype;

	void (*init)(void);

	void (*cleanup)(void);

	int (*readlock)(void);

	void (*read_delay)(struct torture_random_state *rrsp);

	void (*readunlock)(int idx);
@@ -477,10 +478,12 @@ static struct rcu_torture_ops rcu_busted_ops = { 
 */



DEFINE_STATIC_SRCU(srcu_ctl);

static struct srcu_struct srcu_ctld;

static struct srcu_struct *srcu_ctlp = &srcu_ctl;



static int srcu_torture_read_lock(void) __acquires(&srcu_ctl)

static int srcu_torture_read_lock(void) __acquires(srcu_ctlp)

{

	return srcu_read_lock(&srcu_ctl);

	return srcu_read_lock(srcu_ctlp);

}



static void srcu_read_delay(struct torture_random_state *rrsp)
@@ -499,49 +502,49 @@ static void srcu_read_delay(struct torture_random_state *rrsp) 
		rcu_read_delay(rrsp);

}



static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl)

static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp)

{

	srcu_read_unlock(&srcu_ctl, idx);

	srcu_read_unlock(srcu_ctlp, idx);

}



static unsigned long srcu_torture_completed(void)

{

	return srcu_batches_completed(&srcu_ctl);

	return srcu_batches_completed(srcu_ctlp);

}



static void srcu_torture_deferred_free(struct rcu_torture *rp)

{

	call_srcu(&srcu_ctl, &rp->rtort_rcu, rcu_torture_cb);

	call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb);

}



static void srcu_torture_synchronize(void)

{

	synchronize_srcu(&srcu_ctl);

	synchronize_srcu(srcu_ctlp);

}



static void srcu_torture_call(struct rcu_head *head,

			      void (*func)(struct rcu_head *head))

{

	call_srcu(&srcu_ctl, head, func);

	call_srcu(srcu_ctlp, head, func);

}



static void srcu_torture_barrier(void)

{

	srcu_barrier(&srcu_ctl);

	srcu_barrier(srcu_ctlp);

}



static void srcu_torture_stats(void)

{

	int cpu;

	int idx = srcu_ctl.completed & 0x1;

	int idx = srcu_ctlp->completed & 0x1;



	pr_alert("%s%s per-CPU(idx=%d):",

		 torture_type, TORTURE_FLAG, idx);

	for_each_possible_cpu(cpu) {

		long c0, c1;



		c0 = (long)per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx];

		c1 = (long)per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx];

		c0 = (long)per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu)->c[!idx];

		c1 = (long)per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu)->c[idx];

		pr_cont(" %d(%ld,%ld)", cpu, c0, c1);

	}

	pr_cont("\n");
@@ -549,7 +552,7 @@ static void srcu_torture_stats(void) 


static void srcu_torture_synchronize_expedited(void)

{

	synchronize_srcu_expedited(&srcu_ctl);

	synchronize_srcu_expedited(srcu_ctlp);

}



static struct rcu_torture_ops srcu_ops = {
@@ -569,6 +572,38 @@ static struct rcu_torture_ops srcu_ops = { 
	.name		= "srcu"

};



static void srcu_torture_init(void)

{

	rcu_sync_torture_init();

	WARN_ON(init_srcu_struct(&srcu_ctld));

	srcu_ctlp = &srcu_ctld;

}



static void srcu_torture_cleanup(void)

{

	cleanup_srcu_struct(&srcu_ctld);

	srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */

}



/* As above, but dynamically allocated. */

static struct rcu_torture_ops srcud_ops = {

	.ttype		= SRCU_FLAVOR,

	.init		= srcu_torture_init,

	.cleanup	= srcu_torture_cleanup,

	.readlock	= srcu_torture_read_lock,

	.read_delay	= srcu_read_delay,

	.readunlock	= srcu_torture_read_unlock,

	.started	= NULL,

	.completed	= srcu_torture_completed,

	.deferred_free	= srcu_torture_deferred_free,

	.sync		= srcu_torture_synchronize,

	.exp_sync	= srcu_torture_synchronize_expedited,

	.call		= srcu_torture_call,

	.cb_barrier	= srcu_torture_barrier,

	.stats		= srcu_torture_stats,

	.name		= "srcud"

};



/*

 * Definitions for sched torture testing.

 */
@@ -1053,7 +1088,7 @@ static void rcu_torture_timer(unsigned long unused) 
	p = rcu_dereference_check(rcu_torture_current,

				  rcu_read_lock_bh_held() ||

				  rcu_read_lock_sched_held() ||

				  srcu_read_lock_held(&srcu_ctl));

				  srcu_read_lock_held(srcu_ctlp));

	if (p == NULL) {

		/* Leave because rcu_torture_writer is not yet underway */

		cur_ops->readunlock(idx);
@@ -1127,7 +1162,7 @@ rcu_torture_reader(void *arg) 
		p = rcu_dereference_check(rcu_torture_current,

					  rcu_read_lock_bh_held() ||

					  rcu_read_lock_sched_held() ||

					  srcu_read_lock_held(&srcu_ctl));

					  srcu_read_lock_held(srcu_ctlp));

		if (p == NULL) {

			/* Wait for rcu_torture_writer to get underway */

			cur_ops->readunlock(idx);
@@ -1590,10 +1625,14 @@ rcu_torture_cleanup(void) 
			rcutorture_booster_cleanup(i);

	}



	/* Wait for all RCU callbacks to fire.  */



	/*

	 * Wait for all RCU callbacks to fire, then do flavor-specific

	 * cleanup operations.

	 */

	if (cur_ops->cb_barrier != NULL)

		cur_ops->cb_barrier();

	if (cur_ops->cleanup != NULL)

		cur_ops->cleanup();



	rcu_torture_stats_print();  /* -After- the stats thread is stopped! */
@@ -1670,8 +1709,8 @@ rcu_torture_init(void) 
	int cpu;

	int firsterr = 0;

	static struct rcu_torture_ops *torture_ops[] = {

		&rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &sched_ops,

		RCUTORTURE_TASKS_OPS

		&rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,

		&sched_ops, RCUTORTURE_TASKS_OPS

	};



	if (!torture_init_begin(torture_type, verbose, &torture_runnable))

tools/testing/selftests/rcutorture/configs/rcu/SRCU-P.boot

+1 −1
Original line number Diff line number Diff line 
rcutorture.torture_type=srcu
 
rcutorture.torture_type=srcud

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