ipc,msg: document volatile r_msg (4bb6657d) · Commits · 戴 / test

The need for volatile is not obvious, document it. Signed-off-by:

Manfred Spraul <manfred@colorfullife.com> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Signed-off-by:

ipc/msg.c

+7 −3

Original line number	Diff line number	Diff line
		@@ -42,9 +42,7 @@
		#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;
		@@ -53,6 +51,12 @@ struct msg_receiver {
		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;
		};