2009/235 dladm Possible Values List

[Michael Shapiro]

This case currently does not address the issue of how an administrator
or layered software determines the optimal large MTU, as opposed to
the maximum MTU.  The two are not always the same.  For example, on
Neptune (nxge), the maximum is 9000, but the optimal large MTU is 8150,
because of the size of the DMA transfers the card does in hardware.
This case needs to address this issue explicitly, by either:

(a) Defining an additional interface by which the optimal value
    can be returned from the driver as another attribute, OR

(b) Making extremely clear to driver writers that if a large MTU
    size less than the maximum is more optimal than the maximum,
    that the optimal size should be returned by this interface.

My preference is for option (a), but others should weigh in.

-Mike

-- 
Mike Shapiro, Sun Microsystems Open Storage / Fishworks. blogs.sun.com/mws/