locktorture: Support rwsems
We can easily do so with our new reader lock support. Just an arbitrary
design default: readers have higher (5x) critical region latencies than
writers: 50 ms and 10 ms, respectively.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/Documentation/locking/locktorture.txt b/Documentation/locking/locktorture.txt
index 7a72621..be71501 100644
--- a/Documentation/locking/locktorture.txt
+++ b/Documentation/locking/locktorture.txt
@@ -47,6 +47,8 @@
o "mutex_lock": mutex_lock() and mutex_unlock() pairs.
+ o "rwsem_lock": read/write down() and up() semaphore pairs.
+
torture_runnable Start locktorture at boot time in the case where the
module is built into the kernel, otherwise wait for
torture_runnable to be set via sysfs before starting.
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index c1073d7..8480118 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -265,6 +265,71 @@
.name = "mutex_lock"
};
+static DECLARE_RWSEM(torture_rwsem);
+static int torture_rwsem_down_write(void) __acquires(torture_rwsem)
+{
+ down_write(&torture_rwsem);
+ return 0;
+}
+
+static void torture_rwsem_write_delay(struct torture_random_state *trsp)
+{
+ const unsigned long longdelay_ms = 100;
+
+ /* We want a long delay occasionally to force massive contention. */
+ if (!(torture_random(trsp) %
+ (nrealwriters_stress * 2000 * longdelay_ms)))
+ mdelay(longdelay_ms * 10);
+ else
+ mdelay(longdelay_ms / 10);
+#ifdef CONFIG_PREEMPT
+ if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
+ preempt_schedule(); /* Allow test to be preempted. */
+#endif
+}
+
+static void torture_rwsem_up_write(void) __releases(torture_rwsem)
+{
+ up_write(&torture_rwsem);
+}
+
+static int torture_rwsem_down_read(void) __acquires(torture_rwsem)
+{
+ down_read(&torture_rwsem);
+ return 0;
+}
+
+static void torture_rwsem_read_delay(struct torture_random_state *trsp)
+{
+ const unsigned long longdelay_ms = 100;
+
+ /* We want a long delay occasionally to force massive contention. */
+ if (!(torture_random(trsp) %
+ (nrealwriters_stress * 2000 * longdelay_ms)))
+ mdelay(longdelay_ms * 2);
+ else
+ mdelay(longdelay_ms / 2);
+#ifdef CONFIG_PREEMPT
+ if (!(torture_random(trsp) % (nrealreaders_stress * 20000)))
+ preempt_schedule(); /* Allow test to be preempted. */
+#endif
+}
+
+static void torture_rwsem_up_read(void) __releases(torture_rwsem)
+{
+ up_read(&torture_rwsem);
+}
+
+static struct lock_torture_ops rwsem_lock_ops = {
+ .writelock = torture_rwsem_down_write,
+ .write_delay = torture_rwsem_write_delay,
+ .writeunlock = torture_rwsem_up_write,
+ .readlock = torture_rwsem_down_read,
+ .read_delay = torture_rwsem_read_delay,
+ .readunlock = torture_rwsem_up_read,
+ .name = "rwsem_lock"
+};
+
/*
* Lock torture writer kthread. Repeatedly acquires and releases
* the lock, checking for duplicate acquisitions.
@@ -467,7 +532,8 @@
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,
+ &lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops,
+ &mutex_lock_ops, &rwsem_lock_ops,
};
if (!torture_init_begin(torture_type, verbose, &torture_runnable))