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authorJon Paul Maloy <jon.maloy@ericsson.com>2015-03-13 16:08:11 -0400
committerDavid S. Miller <davem@davemloft.net>2015-03-14 14:38:32 -0400
commite3eea1eb47ac616ee09cf0ae5d1e7790ef8461ea (patch)
tree8d940842c102ed18354bc51ef64598374deb893c /net/tipc/msg.h
parent05dcc5aa4dcced4f59f925625cea669e82b75519 (diff)
tipc: clean up handling of message priorities
Messages transferred by TIPC are assigned an "importance priority", -an integer value indicating how to treat the message when there is link or destination socket congestion. There is no separate header field for this value. Instead, the message user values have been chosen in ascending order according to perceived importance, so that the message user field can be used for this. This is not a good solution. First, we have many more users than the needed priority levels, so we end up with treating more priority levels than necessary. Second, the user field cannot always accurately reflect the priority of the message. E.g., a message fragment packet should really have the priority of the enveloped user data message, and not the priority of the MSG_FRAGMENTER user. Until now, we have been working around this problem in different ways, but it is now time to implement a consistent way of handling such priorities, although still within the constraint that we cannot allocate any more bits in the regular data message header for this. In this commit, we define a new priority level, TIPC_SYSTEM_IMPORTANCE, that will be the only one used apart from the four (lower) user data levels. All non-data messages map down to this priority. Furthermore, we take some free bits from the MSG_FRAGMENTER header and allocate them to store the priority of the enveloped message. We then adjust the functions msg_importance()/msg_set_importance() so that they read/set the correct header fields depending on user type. This small protocol change is fully compatible, because the code at the receiving end of a link currently reads the importance level only from user data messages, where there is no change. Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc/msg.h')
-rw-r--r--net/tipc/msg.h65
1 files changed, 34 insertions, 31 deletions
diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index e5fc5fdb2ea7..bd3969a80dd4 100644
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -54,6 +54,8 @@ struct plist;
* - TIPC_HIGH_IMPORTANCE
* - TIPC_CRITICAL_IMPORTANCE
*/
+#define TIPC_SYSTEM_IMPORTANCE 4
+
/*
* Payload message types
@@ -64,6 +66,19 @@ struct plist;
#define TIPC_DIRECT_MSG 3
/*
+ * Internal message users
+ */
+#define BCAST_PROTOCOL 5
+#define MSG_BUNDLER 6
+#define LINK_PROTOCOL 7
+#define CONN_MANAGER 8
+#define CHANGEOVER_PROTOCOL 10
+#define NAME_DISTRIBUTOR 11
+#define MSG_FRAGMENTER 12
+#define LINK_CONFIG 13
+#define SOCK_WAKEUP 14 /* pseudo user */
+
+/*
* Message header sizes
*/
#define SHORT_H_SIZE 24 /* In-cluster basic payload message */
@@ -170,16 +185,6 @@ static inline void msg_set_user(struct tipc_msg *m, u32 n)
msg_set_bits(m, 0, 25, 0xf, n);
}
-static inline u32 msg_importance(struct tipc_msg *m)
-{
- return msg_bits(m, 0, 25, 0xf);
-}
-
-static inline void msg_set_importance(struct tipc_msg *m, u32 i)
-{
- msg_set_user(m, i);
-}
-
static inline u32 msg_hdr_sz(struct tipc_msg *m)
{
return msg_bits(m, 0, 21, 0xf) << 2;
@@ -336,6 +341,25 @@ static inline void msg_set_seqno(struct tipc_msg *m, u32 n)
/*
* Words 3-10
*/
+static inline u32 msg_importance(struct tipc_msg *m)
+{
+ if (unlikely(msg_user(m) == MSG_FRAGMENTER))
+ return msg_bits(m, 5, 13, 0x7);
+ if (likely(msg_isdata(m) && !msg_errcode(m)))
+ return msg_user(m);
+ return TIPC_SYSTEM_IMPORTANCE;
+}
+
+static inline void msg_set_importance(struct tipc_msg *m, u32 i)
+{
+ if (unlikely(msg_user(m) == MSG_FRAGMENTER))
+ msg_set_bits(m, 5, 13, 0x7, i);
+ else if (likely(i < TIPC_SYSTEM_IMPORTANCE))
+ msg_set_user(m, i);
+ else
+ pr_warn("Trying to set illegal importance in message\n");
+}
+
static inline u32 msg_prevnode(struct tipc_msg *m)
{
return msg_word(m, 3);
@@ -458,20 +482,6 @@ static inline struct tipc_msg *msg_get_wrapped(struct tipc_msg *m)
*/
/*
- * Internal message users
- */
-#define BCAST_PROTOCOL 5
-#define MSG_BUNDLER 6
-#define LINK_PROTOCOL 7
-#define CONN_MANAGER 8
-#define ROUTE_DISTRIBUTOR 9 /* obsoleted */
-#define CHANGEOVER_PROTOCOL 10
-#define NAME_DISTRIBUTOR 11
-#define MSG_FRAGMENTER 12
-#define LINK_CONFIG 13
-#define SOCK_WAKEUP 14 /* pseudo user */
-
-/*
* Connection management protocol message types
*/
#define CONN_PROBE 0
@@ -743,13 +753,6 @@ static inline void msg_set_link_tolerance(struct tipc_msg *m, u32 n)
msg_set_bits(m, 9, 0, 0xffff, n);
}
-static inline u32 tipc_msg_tot_importance(struct tipc_msg *m)
-{
- if ((msg_user(m) == MSG_FRAGMENTER) && (msg_type(m) == FIRST_FRAGMENT))
- return msg_importance(msg_get_wrapped(m));
- return msg_importance(m);
-}
-
static inline u32 msg_tot_origport(struct tipc_msg *m)
{
if ((msg_user(m) == MSG_FRAGMENTER) && (msg_type(m) == FIRST_FRAGMENT))