From: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
This commit adds a maximally broken locking primitive in which
lock acquisition and release are both no-ops.
Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com>
---
kernel/locking/locktorture.c | 33 ++++++++++++++++++++++++++++++++-
1 file changed, 32 insertions(+), 1 deletion(-)
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index a18c5a44ea39..b0993d7dcdb0 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -112,6 +112,37 @@ static struct lock_torture_ops *cur_ops;
* Definitions for lock torture testing.
*/
+static int torture_lock_busted_write_lock(void)
+{
+ return 0; /* BUGGY, do not use in real life!!! */
+}
+
+static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
+{
+ const unsigned long longdelay_us = 100;
+
+ /* We want a long delay occasionally to force massive contention. */
+ if (!(torture_random(trsp) %
+ (nrealwriters_stress * 2000 * longdelay_us)))
+ mdelay(longdelay_us);
+#ifdef CONFIG_PREEMPT
+ if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
+ preempt_schedule(); /* Allow test to be preempted. */
+#endif
+}
+
+static void torture_lock_busted_write_unlock(void)
+{
+ /* BUGGY, do not use in real life!!! */
+}
+
+static struct lock_torture_ops lock_busted_ops = {
+ .writelock = torture_lock_busted_write_lock,
+ .write_delay = torture_lock_busted_write_delay,
+ .writeunlock = torture_lock_busted_write_unlock,
+ .name = "lock_busted"
+};
+
static DEFINE_SPINLOCK(torture_spinlock);
static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock)
@@ -320,7 +351,7 @@ static int __init lock_torture_init(void)
int i;
int firsterr = 0;
static struct lock_torture_ops *torture_ops[] = {
- &spin_lock_ops, &spin_lock_irq_ops,
+ &lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops,
};
torture_init_begin(torture_type, verbose, &locktorture_runnable);
--
1.8.1.5
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