From: David Laight <David.Laight@xxxxxxxxxx> Date: Wed, 9 Jul 2014 08:29:11 +0000 > If an application has disabled Nagle then it is almost impossible > to get more than one DATA chunk into an ethernet packet even if > the application has more than one data chunk ready to transmit. > > This could be fixed by adding an SCTP_CORK socket option - but > using that requires a lot of system calls. > An alternative is to honour MSG_MORE - using it to mean that > another chunk will be sent soon. > (There isn't much point using MSG_MORE to allow a chunk be extended, > sendv() can be used for fragmented data.) > > This is a partial implementation and takes a couple of shortcuts: > 1) We only worry about whether MSG_MORE was set on the last send. > Data sent (by the application) with MSG_MORE unset will only be > unsent for flow control reasons. > So if the last send had MSG_MORE set, and an ack opens the window > then the unsent data won't be sent immediately. > > 2) If the application doesn't do a send with MSG_MORE unset, then > buffered data shouldn't be buffered forever. > Rather than using a timer (as TCP does - which ought to be configurable > on a per-socket basis) we use the same rules as Nagle and ensure > that there is always some data outstanding. > This does mean that the first data chunk on an idle connection > is send in its own packet even if MSG_MORE is set. I need some SCTP experts to review this series, thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
