locking/ww_mutex: Begin kselftests for ww_mutex

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter 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/20161201114711.28697-4-chris@chris-wilson.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Chris Wilson 2016-12-01 11:47:06 +00:00 committed by Ingo Molnar
parent 0186a6cbdc
commit f2a5fec173
3 changed files with 153 additions and 0 deletions

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@ -28,3 +28,4 @@ obj-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
obj-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem-xadd.o
obj-$(CONFIG_QUEUED_RWLOCKS) += qrwlock.o
obj-$(CONFIG_LOCK_TORTURE_TEST) += locktorture.o
obj-$(CONFIG_WW_MUTEX_SELFTEST) += test-ww_mutex.o

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@ -0,0 +1,140 @@
/*
* Module-based API test facility for ww_mutexes
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*/
#include <linux/kernel.h>
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/ww_mutex.h>
static DEFINE_WW_CLASS(ww_class);
struct test_mutex {
struct work_struct work;
struct ww_mutex mutex;
struct completion ready, go, done;
unsigned int flags;
};
#define TEST_MTX_SPIN BIT(0)
#define TEST_MTX_TRY BIT(1)
#define TEST_MTX_CTX BIT(2)
#define __TEST_MTX_LAST BIT(3)
static void test_mutex_work(struct work_struct *work)
{
struct test_mutex *mtx = container_of(work, typeof(*mtx), work);
complete(&mtx->ready);
wait_for_completion(&mtx->go);
if (mtx->flags & TEST_MTX_TRY) {
while (!ww_mutex_trylock(&mtx->mutex))
cpu_relax();
} else {
ww_mutex_lock(&mtx->mutex, NULL);
}
complete(&mtx->done);
ww_mutex_unlock(&mtx->mutex);
}
static int __test_mutex(unsigned int flags)
{
#define TIMEOUT (HZ / 16)
struct test_mutex mtx;
struct ww_acquire_ctx ctx;
int ret;
ww_mutex_init(&mtx.mutex, &ww_class);
ww_acquire_init(&ctx, &ww_class);
INIT_WORK_ONSTACK(&mtx.work, test_mutex_work);
init_completion(&mtx.ready);
init_completion(&mtx.go);
init_completion(&mtx.done);
mtx.flags = flags;
schedule_work(&mtx.work);
wait_for_completion(&mtx.ready);
ww_mutex_lock(&mtx.mutex, (flags & TEST_MTX_CTX) ? &ctx : NULL);
complete(&mtx.go);
if (flags & TEST_MTX_SPIN) {
unsigned long timeout = jiffies + TIMEOUT;
ret = 0;
do {
if (completion_done(&mtx.done)) {
ret = -EINVAL;
break;
}
cpu_relax();
} while (time_before(jiffies, timeout));
} else {
ret = wait_for_completion_timeout(&mtx.done, TIMEOUT);
}
ww_mutex_unlock(&mtx.mutex);
ww_acquire_fini(&ctx);
if (ret) {
pr_err("%s(flags=%x): mutual exclusion failure\n",
__func__, flags);
ret = -EINVAL;
}
flush_work(&mtx.work);
destroy_work_on_stack(&mtx.work);
return ret;
#undef TIMEOUT
}
static int test_mutex(void)
{
int ret;
int i;
for (i = 0; i < __TEST_MTX_LAST; i++) {
ret = __test_mutex(i);
if (ret)
return ret;
}
return 0;
}
static int __init test_ww_mutex_init(void)
{
int ret;
ret = test_mutex();
if (ret)
return ret;
return 0;
}
static void __exit test_ww_mutex_exit(void)
{
}
module_init(test_ww_mutex_init);
module_exit(test_ww_mutex_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Intel Corporation");

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@ -1180,6 +1180,18 @@ config LOCK_TORTURE_TEST
Say M if you want these torture tests to build as a module.
Say N if you are unsure.
config WW_MUTEX_SELFTEST
tristate "Wait/wound mutex selftests"
help
This option provides a kernel module that runs tests on the
on the struct ww_mutex locking API.
It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
with this test harness.
Say M if you want these self tests to build as a module.
Say N if you are unsure.
endmenu # lock debugging
config TRACE_IRQFLAGS