tipc: change socket buffer overflow control to respect sk_rcvbuf
As per feedback from the netdev community, we change the buffer
overflow protection algorithm in receiving sockets so that it
always respects the nominal upper limit set in sk_rcvbuf.
Instead of scaling up from a small sk_rcvbuf value, which leads to
violation of the configured sk_rcvbuf limit, we now calculate the
weighted per-message limit by scaling down from a much bigger value,
still in the same field, according to the importance priority of the
received message.
To allow for administrative tunability of the socket receive buffer
size, we create a tipc_rmem sysctl variable to allow the user to
configure an even bigger value via sysctl command. It is a size of
three (min/default/max) to be consistent with things like tcp_rmem.
By default, the value initialized in tipc_rmem[1] is equal to the
receive socket size needed by a TIPC_CRITICAL_IMPORTANCE message.
This value is also set as the default value of sk_rcvbuf.
Originally-by: Jon Maloy <jon.maloy@ericsson.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
[Ying: added sysctl variation to Jon's original patch]
Signed-off-by: Ying Xue <ying.xue@windriver.com>
[PG: don't compile sysctl.c if not config'd; add Documentation]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 515ce38..aba4255 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -43,8 +43,6 @@
#define SS_LISTENING -1 /* socket is listening */
#define SS_READY -2 /* socket is connectionless */
-#define CONN_OVERLOAD_LIMIT ((TIPC_FLOW_CONTROL_WIN * 2 + 1) * \
- SKB_TRUESIZE(TIPC_MAX_USER_MSG_SIZE))
#define CONN_TIMEOUT_DEFAULT 8000 /* default connect timeout = 8s */
struct tipc_sock {
@@ -203,6 +201,7 @@
sock_init_data(sock, sk);
sk->sk_backlog_rcv = backlog_rcv;
+ sk->sk_rcvbuf = sysctl_tipc_rmem[1];
sk->sk_data_ready = tipc_data_ready;
sk->sk_write_space = tipc_write_space;
tipc_sk(sk)->p = tp_ptr;
@@ -1233,10 +1232,10 @@
* For all connectionless messages, by default new queue limits are
* as belows:
*
- * TIPC_LOW_IMPORTANCE (5MB)
- * TIPC_MEDIUM_IMPORTANCE (10MB)
- * TIPC_HIGH_IMPORTANCE (20MB)
- * TIPC_CRITICAL_IMPORTANCE (40MB)
+ * TIPC_LOW_IMPORTANCE (4 MB)
+ * TIPC_MEDIUM_IMPORTANCE (8 MB)
+ * TIPC_HIGH_IMPORTANCE (16 MB)
+ * TIPC_CRITICAL_IMPORTANCE (32 MB)
*
* Returns overload limit according to corresponding message importance
*/
@@ -1246,9 +1245,10 @@
unsigned int limit;
if (msg_connected(msg))
- limit = CONN_OVERLOAD_LIMIT;
+ limit = sysctl_tipc_rmem[2];
else
- limit = sk->sk_rcvbuf << (msg_importance(msg) + 5);
+ limit = sk->sk_rcvbuf >> TIPC_CRITICAL_IMPORTANCE <<
+ msg_importance(msg);
return limit;
}
@@ -1847,7 +1847,8 @@
static struct proto tipc_proto = {
.name = "TIPC",
.owner = THIS_MODULE,
- .obj_size = sizeof(struct tipc_sock)
+ .obj_size = sizeof(struct tipc_sock),
+ .sysctl_rmem = sysctl_tipc_rmem
};
/**