locktorture: Support rwlocks
Add a "rw_lock" torture test to stress kernel rwlocks and their irq
variant. Reader critical regions are 5x longer than writers. As such
a similar ratio of lock acquisitions is seen in the statistics. In the
case of massive contention, both hold the lock for 1/10 of a second.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 540d5df..0762b25 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -27,6 +27,7 @@
#include <linux/kthread.h>
#include <linux/err.h>
#include <linux/spinlock.h>
+#include <linux/rwlock.h>
#include <linux/mutex.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
@@ -229,6 +230,110 @@
.name = "spin_lock_irq"
};
+static DEFINE_RWLOCK(torture_rwlock);
+
+static int torture_rwlock_write_lock(void) __acquires(torture_rwlock)
+{
+ write_lock(&torture_rwlock);
+ return 0;
+}
+
+static void torture_rwlock_write_delay(struct torture_random_state *trsp)
+{
+ const unsigned long shortdelay_us = 2;
+ const unsigned long longdelay_ms = 100;
+
+ /* We want a short delay mostly to emulate likely code, and
+ * we want a long delay occasionally to force massive contention.
+ */
+ if (!(torture_random(trsp) %
+ (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
+ mdelay(longdelay_ms);
+ else
+ udelay(shortdelay_us);
+}
+
+static void torture_rwlock_write_unlock(void) __releases(torture_rwlock)
+{
+ write_unlock(&torture_rwlock);
+}
+
+static int torture_rwlock_read_lock(void) __acquires(torture_rwlock)
+{
+ read_lock(&torture_rwlock);
+ return 0;
+}
+
+static void torture_rwlock_read_delay(struct torture_random_state *trsp)
+{
+ const unsigned long shortdelay_us = 10;
+ const unsigned long longdelay_ms = 100;
+
+ /* We want a short delay mostly to emulate likely code, and
+ * we want a long delay occasionally to force massive contention.
+ */
+ if (!(torture_random(trsp) %
+ (cxt.nrealreaders_stress * 2000 * longdelay_ms)))
+ mdelay(longdelay_ms);
+ else
+ udelay(shortdelay_us);
+}
+
+static void torture_rwlock_read_unlock(void) __releases(torture_rwlock)
+{
+ read_unlock(&torture_rwlock);
+}
+
+static struct lock_torture_ops rw_lock_ops = {
+ .writelock = torture_rwlock_write_lock,
+ .write_delay = torture_rwlock_write_delay,
+ .writeunlock = torture_rwlock_write_unlock,
+ .readlock = torture_rwlock_read_lock,
+ .read_delay = torture_rwlock_read_delay,
+ .readunlock = torture_rwlock_read_unlock,
+ .name = "rw_lock"
+};
+
+static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock)
+{
+ unsigned long flags;
+
+ write_lock_irqsave(&torture_rwlock, flags);
+ cxt.cur_ops->flags = flags;
+ return 0;
+}
+
+static void torture_rwlock_write_unlock_irq(void)
+__releases(torture_rwlock)
+{
+ write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
+}
+
+static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock)
+{
+ unsigned long flags;
+
+ read_lock_irqsave(&torture_rwlock, flags);
+ cxt.cur_ops->flags = flags;
+ return 0;
+}
+
+static void torture_rwlock_read_unlock_irq(void)
+__releases(torture_rwlock)
+{
+ write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
+}
+
+static struct lock_torture_ops rw_lock_irq_ops = {
+ .writelock = torture_rwlock_write_lock_irq,
+ .write_delay = torture_rwlock_write_delay,
+ .writeunlock = torture_rwlock_write_unlock_irq,
+ .readlock = torture_rwlock_read_lock_irq,
+ .read_delay = torture_rwlock_read_delay,
+ .readunlock = torture_rwlock_read_unlock_irq,
+ .name = "rw_lock_irq"
+};
+
static DEFINE_MUTEX(torture_mutex);
static int torture_mutex_lock(void) __acquires(torture_mutex)
@@ -535,8 +640,11 @@
int i, j;
int firsterr = 0;
static struct lock_torture_ops *torture_ops[] = {
- &lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops,
- &mutex_lock_ops, &rwsem_lock_ops,
+ &lock_busted_ops,
+ &spin_lock_ops, &spin_lock_irq_ops,
+ &rw_lock_ops, &rw_lock_irq_ops,
+ &mutex_lock_ops,
+ &rwsem_lock_ops,
};
if (!torture_init_begin(torture_type, verbose, &torture_runnable))
@@ -571,7 +679,8 @@
cxt.debug_lock = true;
#endif
#ifdef CONFIG_DEBUG_SPINLOCK
- if (strncmp(torture_type, "spin", 4) == 0)
+ if ((strncmp(torture_type, "spin", 4) == 0) ||
+ (strncmp(torture_type, "rw_lock", 7) == 0))
cxt.debug_lock = true;
#endif