On Fri, 2017-01-13 at 18:01 +0300, Alexey Kodanev wrote: > Hi, > > Got the issue when running LTP/netstress test on localhost with mss > greater than the send window advertised by client (right after 3WHS). > Here is the testscenario that can reproduce this:
Hi Alexey So this is a combination of Fastopen + small window + large MSS ? I would rather not force burning tons of coal or other fossil fuel, by making each tcp_sendmsg() done by billions of linux devices more expensive, only to accommodate for some LTP test doing something not sensible ;) Fact that you removed one condition in the BUG_ON() might hide another issue later in the path. I would suggest to clamp MSS to half the initial window, but I guess this is impractical since window in SYN/SYNACK are not scaled. Care to send a packetdrill test so that we have a clear picture of what is going on ? Thanks.
