> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:general- > [EMAIL PROTECTED] On Behalf Of Talpey, Thomas > Sent: Tuesday, May 27, 2008 9:39 AM > To: Tom Tucker > Cc: Roland Dreier; [email protected] > Subject: Re: [ofa-general] [PATCH RFC v3 1/2] > RDMA/Core:MEM_MGT_EXTENSIONS support > > At 11:33 AM 5/27/2008, Tom Tucker wrote: > >So I think from an NFSRDMA coding perspective it's a wash... > > Just to be clear, you're talking about the NFS/RDMA server. However, > it's > pretty much a wash on the client, for different reasons. > > >When posting the WR, We check the fastreg capabilities bit + transport > >type bit: > >If fastreg is true --> > > Post FastReg > > If iWARP (or with a cap bit read-with-inv-flag) > > post rdma read w/ invalidate > > >... For iWARP's case, this means rdma-read-w-inv, > >plus rdma-send-w-inv, etc... > > > Maybe I'm confused, but I don't understand this. iWARP RDMA Read > requests > don't support remote invalidate. At least, the table in RFC5040 (p.22) > doesn't: > > > > -------+-----------+-------+------+-------+-----------+------------- > - > RDMA | Message | Tagged| STag | Queue | Invalidate| Message > Message| Type | Flag | and | Number| STag | Length > OpCode | | | TO | | | Communicated > | | | | | | between DDP > | | | | | | and RDMAP > -------+-----------+-------+------+-------+-----------+------------- > - > 0000b | RDMA Write| 1 | Valid| N/A | N/A | Yes > | | | | | | > -------+-----------+-------+------+-------+-----------+------------- > - > 0001b | RDMA Read | 0 | N/A | 1 | N/A | Yes > | Request | | | | | > -------+-----------+-------+------+-------+-----------+------------- > - > 0010b | RDMA Read | 1 | Valid| N/A | N/A | Yes > | Response | | | | | > -------+-----------+-------+------+-------+-----------+------------- > - > 0011b | Send | 0 | N/A | 0 | N/A | Yes > | | | | | | > -------+-----------+-------+------+-------+-----------+------------- > - > 0100b | Send with | 0 | N/A | 0 | Valid | Yes > | Invalidate| | | | | > -------+-----------+-------+------+-------+-----------+------------- > - > 0101b | Send with | 0 | N/A | 0 | N/A | Yes > | SE | | | | | > -------+-----------+-------+------+-------+-----------+------------- > - > 0110b | Send with | 0 | N/A | 0 | Valid | Yes > | SE and | | | | | > | Invalidate| | | | | > -------+-----------+-------+------+-------+-----------+------------- > - > 0111b | Terminate | 0 | N/A | 2 | N/A | Yes > | | | | | | > -------+-----------+-------+------+-------+-----------+------------- > - > 1000b | | > to | Reserved | Not Specified > 1111b | | > -------+-----------+------------------------------------------------ > - RDMA Read with Local Invalidate does not affect the wire. The 'must invalidate' state is kept in the RNIC that issues the RDMA Read Request... > > > > I want to take this opportunity to also mention that the RPC/RDMA > client-server > exchange does not support remote-invalidate currently. Because of the > multiple > stags supported by the rpcrdma chunking header, and because the client > needs > to verify that the stags were in fact invalidated, there is significant > overhead, > and the jury is out on that benefit. In fact, I suspect it's a lose at > the client. > > Tom (Talpey). > > _______________________________________________ > general mailing list > [email protected] > http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general > > To unsubscribe, please visit http://openib.org/mailman/listinfo/openib- > general _______________________________________________ general mailing list [email protected] http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general
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