Am 20.02.2018 um 13:35 schrieb Peter Zijlstra:
This really should've been Cc'ed to me.
On Thu, Feb 15, 2018 at 03:19:42PM +0100, Christian König wrote:
diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h
index 39fda195bf78..dd580db289e8 100644
--- a/include/linux/ww_mutex.h
+++ b/include/linux/ww_mutex.h
@@ -358,4 +358,21 @@ static inline bool ww_mutex_is_locked(struct ww_mutex
*lock)
return mutex_is_locked(&lock->base);
}
+/**
+ * ww_mutex_is_owned_by - is the w/w mutex locked by this task in that context
+ * @lock: the mutex to be queried
+ * @task: the task structure to check
+ * @ctx: the w/w acquire context to test
+ *
+ * Returns true if the mutex is locked in the context by the given task, false
+ * otherwise.
+ */
+static inline bool ww_mutex_is_owned_by(struct ww_mutex *lock,
+ struct task_struct *task,
+ struct ww_acquire_ctx *ctx)
+{
+ return likely(__mutex_owner(&lock->base) == task) &&
+ READ_ONCE(lock->ctx) == ctx;
+}
Nak on that interface, that's racy and broken by design.
Why?
Regards,
Christian.
