#include <linux/uaccess.h>
#include "util.h"
-/*
- * one msg_receiver structure for each sleeping receiver:
- */
+/* one msg_receiver structure for each sleeping receiver */
struct msg_receiver {
struct list_head r_list;
struct task_struct *r_tsk;
long r_msgtype;
long r_maxsize;
+ /*
+ * Mark r_msg volatile so that the compiler
+ * does not try to get smart and optimize
+ * it. We rely on this for the lockless
+ * receive algorithm.
+ */
struct msg_msg *volatile r_msg;
};