On 2019-12-30 02:29, Jack Wang wrote: > diff --git a/drivers/infiniband/ulp/rtrs/README b/drivers/infiniband/ulp/rtrs/README Other kernel driver documentation exists under the Documentation/ directory. Should this README file perhaps be moved to a subdirectory of the Documentation/ directory? > +**************************** > +InfiniBand Transport (RTRS) > +**************************** The abbreviation does not match the full title. Do you agree that this is confusing? > +RTRS is used by the RNBD (Infiniband Network Block Device) modules. Is RNBD an RDMA or an InfiniBand network block device? > + > +================== > +Transport protocol > +================== > + > +Overview > +-------- > +An established connection between a client and a server is called rtrs > +session. A session is associated with a set of memory chunks reserved on the > +server side for a given client for rdma transfer. A session > +consists of multiple paths, each representing a separate physical link > +between client and server. Those are used for load balancing and failover. > +Each path consists of as many connections (QPs) as there are cpus on > +the client. > + > +When processing an incoming rdma write or read request rtrs client uses memory A quote from https://linuxplumbersconf.org/event/4/contributions/367/attachments/331/555/LPC_2019_RMDA_MC_IBNBD_IBTRS_Upstreaming.pdf: "Only RDMA writes with immediate". Has the wire protocol perhaps been changed such that both RDMA reads and writes are used? I haven't found any references to RDMA reads in the "IO path" section in this file. Did I perhaps overlook something? Thanks, Bart.
