RE: A question on Zero Copy

["Y P Cheng" <ycheng@advansys.com>]

> > Does the iSCSI layer want:
> >
> > A) Plain Zero copy, where the upper layer (iSCSI) asks
> >    to read the next available "message" from the wire
> >    into a buffer passed to the transport by iSCSI?
> > <OR>
> > B) A directed Zero Copy, where the upper layer (iSCSI) asks
> >    to read a particular request to a specific buffer?
> >
> Randall,
>
> We would ideally have directed Zero Copy.
> <snip> <snip>

Costa:

I agree with everything you said, except that B) is required, a "MUST".

There are hundreds read requests to many targets can be outstanding at one
time.  The requests WILL come back in random order.  Therefore, reading the
next "available message" into a buffer does not make sense.

Y.P. Cheng