From: Jon Maloy <jon.ma...@ericsson.com> Date: Wed, 30 Oct 2019 14:00:41 +0100
> We introduce a feature that works like a combination of TCP_NAGLE and > TCP_CORK, but without some of the weaknesses of those. In particular, > we will not observe long delivery delays because of delayed acks, since > the algorithm itself decides if and when acks are to be sent from the > receiving peer. > > - The nagle property as such is determined by manipulating a new > 'maxnagle' field in struct tipc_sock. If certain conditions are met, > 'maxnagle' will define max size of the messages which can be bundled. > If it is set to zero no messages are ever bundled, implying that the > nagle property is disabled. > - A socket with the nagle property enabled enters nagle mode when more > than 4 messages have been sent out without receiving any data message > from the peer. > - A socket leaves nagle mode whenever it receives a data message from > the peer. > > In nagle mode, messages smaller than 'maxnagle' are accumulated in the > socket write queue. The last buffer in the queue is marked with a new > 'ack_required' bit, which forces the receiving peer to send a CONN_ACK > message back to the sender upon reception. > > The accumulated contents of the write queue is transmitted when one of > the following events or conditions occur. > > - A CONN_ACK message is received from the peer. > - A data message is received from the peer. > - A SOCK_WAKEUP pseudo message is received from the link level. > - The write queue contains more than 64 1k blocks of data. > - The connection is being shut down. > - There is no CONN_ACK message to expect. I.e., there is currently > no outstanding message where the 'ack_required' bit was set. As a > consequence, the first message added after we enter nagle mode > is always sent directly with this bit set. > > This new feature gives a 50-100% improvement of throughput for small > (i.e., less than MTU size) messages, while it might add up to one RTT > to latency time when the socket is in nagle mode. > > Acked-by: Ying Xue <ying....@windreiver.com> > Signed-off-by: Jon Maloy <jon.ma...@ericsson.com> Applied, thanks Jon. _______________________________________________ tipc-discussion mailing list tipc-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tipc-discussion
