On Thu, Jun 13, 2019 at 07:39:24PM +0200, Håkon Bugge wrote: > > > > On 13 Jun 2019, at 19:23, Jason Gunthorpe <jgg@xxxxxxxx> wrote: > > > > On Thu, Jun 13, 2019 at 06:58:30PM +0200, Håkon Bugge wrote: > > > >> If you refer to the backlog parameter in rdma_listen(), I cannot see > >> it being used at all for IB. > >> > >> For CX-3, which is paravirtualized wrt. MAD packets, it is the proxy > >> UD receive queue length for the PF driver that can be construed as a > >> backlog. > > > > No, in IB you can drop UD packets if your RQ is full - so the proxy RQ > > is really part of the overall RQ on QP1. > > > > The backlog starts once packets are taken off the RQ and begin the > > connection accept processing. > > Do think we say the same thing. If, incoming REQ processing is > severly delayed, the backlog is #entries in the QP1 receive queue in > the PF. I can call rdma_listen() with a backlog of a zillion, but it > will not help. backlog and queue depth are different things, we shouldn't confuse them together.. Jason
