Commit 0186a6cb authored by Chris Wilson's avatar Chris Wilson Committed by Ingo Molnar
Browse files

locking/ww_mutex: Add ww_mutex to locktorture test 



Although ww_mutexes degenerate into mutexes, it would be useful to
torture the deadlock handling between multiple ww_mutexes in addition to
torturing the regular mutexes.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maarten Lankhorst <dev@mblankhorst.nl>
Cc: Nicolai Hähnle <nhaehnle@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161201114711.28697-3-chris@chris-wilson.co.uk


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent af2e859e

kernel/locking/locktorture.c

+73 −0
Original line number Diff line number Diff line
@@ -372,6 +372,78 @@ static struct lock_torture_ops mutex_lock_ops = { 
	.name		= "mutex_lock"

};



#include <linux/ww_mutex.h>

static DEFINE_WW_CLASS(torture_ww_class);

static DEFINE_WW_MUTEX(torture_ww_mutex_0, &torture_ww_class);

static DEFINE_WW_MUTEX(torture_ww_mutex_1, &torture_ww_class);

static DEFINE_WW_MUTEX(torture_ww_mutex_2, &torture_ww_class);



static int torture_ww_mutex_lock(void)

__acquires(torture_ww_mutex_0)

__acquires(torture_ww_mutex_1)

__acquires(torture_ww_mutex_2)

{

	LIST_HEAD(list);

	struct reorder_lock {

		struct list_head link;

		struct ww_mutex *lock;

	} locks[3], *ll, *ln;

	struct ww_acquire_ctx ctx;



	locks[0].lock = &torture_ww_mutex_0;

	list_add(&locks[0].link, &list);



	locks[1].lock = &torture_ww_mutex_1;

	list_add(&locks[1].link, &list);



	locks[2].lock = &torture_ww_mutex_2;

	list_add(&locks[2].link, &list);



	ww_acquire_init(&ctx, &torture_ww_class);



	list_for_each_entry(ll, &list, link) {

		int err;



		err = ww_mutex_lock(ll->lock, &ctx);

		if (!err)

			continue;



		ln = ll;

		list_for_each_entry_continue_reverse(ln, &list, link)

			ww_mutex_unlock(ln->lock);



		if (err != -EDEADLK)

			return err;



		ww_mutex_lock_slow(ll->lock, &ctx);

		list_move(&ll->link, &list);

	}



	ww_acquire_fini(&ctx);

	return 0;

}



static void torture_ww_mutex_unlock(void)

__releases(torture_ww_mutex_0)

__releases(torture_ww_mutex_1)

__releases(torture_ww_mutex_2)

{

	ww_mutex_unlock(&torture_ww_mutex_0);

	ww_mutex_unlock(&torture_ww_mutex_1);

	ww_mutex_unlock(&torture_ww_mutex_2);

}



static struct lock_torture_ops ww_mutex_lock_ops = {

	.writelock	= torture_ww_mutex_lock,

	.write_delay	= torture_mutex_delay,

	.task_boost     = torture_boost_dummy,

	.writeunlock	= torture_ww_mutex_unlock,

	.readlock       = NULL,

	.read_delay     = NULL,

	.readunlock     = NULL,

	.name		= "ww_mutex_lock"

};



#ifdef CONFIG_RT_MUTEXES

static DEFINE_RT_MUTEX(torture_rtmutex);
@@ -793,6 +865,7 @@ static int __init lock_torture_init(void) 
		&spin_lock_ops, &spin_lock_irq_ops,

		&rw_lock_ops, &rw_lock_irq_ops,

		&mutex_lock_ops,

		&ww_mutex_lock_ops,

#ifdef CONFIG_RT_MUTEXES

		&rtmutex_lock_ops,

#endif

tools/testing/selftests/rcutorture/configs/lock/CFLIST

+1 −0
Original line number Diff line number Diff line
@@ -4,3 +4,4 @@ LOCK03 
LOCK04

LOCK05

LOCK06

LOCK07

tools/testing/selftests/rcutorture/configs/lock/LOCK07

0 → 100644
+6 −0
Original line number Diff line number Diff line 
CONFIG_SMP=y

CONFIG_NR_CPUS=4

CONFIG_HOTPLUG_CPU=y

CONFIG_PREEMPT_NONE=n

CONFIG_PREEMPT_VOLUNTARY=n

CONFIG_PREEMPT=y

tools/testing/selftests/rcutorture/configs/lock/LOCK07.boot

0 → 100644
+1 −0
Original line number Diff line number Diff line 
locktorture.torture_type=ww_mutex_lock

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