From: Vlad Yasevich > On 07/22/2014 09:45 AM, David Laight wrote: > > From: Vlad Yasevich > >> On 07/22/2014 04:59 AM, David Laight wrote: > >>> If MSG_MORE is set then the data chunk will be buffered until either > >>> a full packet would be generated, or something causes a chunk to be > >>> sent (eg data without MSG_MORE or a heartbeat). > >> > >> heartbeat will not cause a data flush. Only SACKs do that as they control > >> congestion and flow. > > > > Experimentally heartbeats cause data to be sent. > > I'd only got one IP address at each end - so don't know what happens to > > any 'probe' HBs. > > I frigged my code to set MSG_MORE if the data chunk was over 200 bytes. > > A single long fragment would be collected by a short one, or by a heartbeat. > > I did wonder if that was a bug - but it would happen for data delayed by Nagle. > > That sounds kind like a bug. The end of packet usually causes a flush of the outqueue, > but any delayed data shouldn't be sent as HB should not cause a data flush. I think the data is already in the relevant queue, it would have been sent earlier if there had been a packet with anything in it. So maybe the HB does get bundled with pending data. Try applying my patch and doing some simple tests... David -- 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
