Re: TCP RDMA option to accelerate NFS, CIFS, SCSI, etc.

[Brian E Carpenter <brian@hursley.ibm.com>]

As I recall, Van's solution required an unconventional I/O system where DMA went
straight into user memory right off the LAN chip. Not too many people make
computers like that.

  Brian

Alan Cox wrote:
> 
> > Gb/s it requires some innovation and lots of silicon. The RDMA option makes
> > it possible at a far lower price. And the zero copy it enables might go
> > deep into the application space as it is only an annotation on packets.
> 
> I am not convinced the amount of silicon changes between the two. The
> RDMA id make be faked by an attacker so must still be verified.
> 
> Va Jacobson proposed and to an extent implemented a system where the user
> context does all the TCP work. In that sort of situation and with a more
> sensible API than the BSD socket one you dont appear to need a lot of silicon,
> in fact the worst case is the wildcard.
> 
> Alan