James Carlson wrote:
> Garrett D'Amore writes:
>
>> In any case, this is *debug*, not normal usage, and should never be
>> needed if the hardware and drivers are working properly. (I.e. if they
>> aren't suffering from bugs.) An mdb or /etc/system tunable is fine
>> here... it may require the customer to unplumb/replumb the interface,
>> but, again, we do not expect this to be used unless our
>> software/hardware is somehow buggy. Its far better that we make sure
>> the checksum support is bug free than that we give customers some knob
>> to control it, IMO.
>>
>
> It sounds like we're in sync on that.
>
>
>> "Advanced usage" != debug usage. Those values are perfectly reasonable
>> things for the customer to tune, at least as long as we don't have a
>> facility in place to auto-tune them. (One could argue that the
>> bcopy/dma stuff should not be customer tunable, but right now we don't
>> have any facility to auto-tune them. The ipg properties are definitely
>> a customer tunable, and do represent unusual/advanced usage, but they
>> aren't something that we can auto-tune for the customer.)
>>
>
> Yep; agreed. The ipg bits are strange, but they're on-the-wire
> properties rather than being things merely inside of Solaris.
>
> I really do think that the bcopy issue needs more work. Putting a
> fundamental internal design issue like that into the hands of
> customers to resolve strikes me as a very poor compromise.
>
I agree wholeheartedly.
But we need to provide _something_ here, until we have a better
solution. Maybe you have heard me pitch my ideas for a Nemo II
project. This is the sort of thing that should be handled as part of
Nemo II. Maybe someday I'll be able to get a funded project to further
enhance Nemo to do this sort of thing. (Heck, maybe someday I'll be
able to get funding to get a regular full time position! :-)
-- Garrett
