Dale Ghent wrote:
> On Jun 10, 2009, at 1:52 AM, Garrett D'Amore wrote:
>
>> Nicolas Williams wrote:
>>> On Tue, Jun 09, 2009 at 10:24:53PM -0700, Garrett D'Amore wrote:
>>>
>>>> Bzzt. You're conflating things here. VLAN and Jumbo frames affect
>>>> *on the wire* transmission and *need* to be tunable.
>>>>
>>>> TSO and LSO are *optimizations* that don't affect on the wire
>>>> presentation, and needing to tune them at all is a *bug*.
>>>>
>>>
>>> Unless you're trying to demonstrate them and the perf benefit you get
>>> from having them, or just to see for yourself. Sure, a feature whose
>>> only value is, in a way, marketing. But marketing matters.
>>>
>>
>> For marketing purposes, a specially hacked driver, or a private
>> tunable, are adequate. We don't need to pollute our framework for
>> this, nor should we confuse administrators by presenting something to
>> them that they shouldn't be tuning.
>>
>> Solaris suffers from ETOOMANYTUNABLES. Canonizing more of them is
>> not the right way forward.
>
> Sure, I can buy that sentiment. How about a read-only representation
> of whether some offload feature is even present? I think we allow for
> read-only properties, right?
>
> Take a driver such as bge or e1000g for example. These two drivers
> support a ton of silicon parts that have quite varied feature sets
> among. Some do jumbo, some don't. Some have various levels of
> off-loading and checksumming, some none at all. It would be useful, I
> would think, for an admin to know if a particular (offload) feature is
> present on a particular chipset without trying to dig up the chipset's
> docs, make sense of source code, or guess. Right now this area is sort
> of like mystery meat.
>
> Extrapolating this into the future, who knows what other features lay
> in wait when it comes to ethernet chipset one-upmanship... iscsi crap,
> RDMA, and so on. All I'm saying is that info is good, even in
> read-only form. It can take the sleuthing out of wondering what you've
> got when you put in a new Intel PRO card or are wondering what exactly
> your Nvidia chip is capable of.
I'd be OK with a kstat or somesuch.
-- Garrett
>
> /dale
>
