mutex: Add w/w mutex slowpath debugging

[mirror_ubuntu-zesty-kernel.git] / include / linux / mutex.h

diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index a56b0ccc8a6c9737d5a36a980367d2c5e7e5cd07..3793ed7feeeb1de4f0eec721da5bf008b92f786d 100644 (file)
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -98,6 +98,10 @@ struct ww_acquire_ctx {
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
        struct lockdep_map dep_map;
 #endif
+#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
+       unsigned deadlock_inject_interval;
+       unsigned deadlock_inject_countdown;
+#endif
 };
 
 struct ww_mutex {
@@ -283,6 +287,10 @@ static inline void ww_acquire_init(struct ww_acquire_ctx *ctx,
                         &ww_class->acquire_key, 0);
        mutex_acquire(&ctx->dep_map, 0, 0, _RET_IP_);
 #endif
+#ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH
+       ctx->deadlock_inject_interval = 1;
+       ctx->deadlock_inject_countdown = ctx->stamp & 0xf;
+#endif
 }
 
 /**