Re: [TUHS] ATC/OSDI'21 joint keynote: It's Time for Operating Systems to Rediscover Hardware (Timothy Roscoe)

[Bakul Shah <bakul@iitbombay.org>]

On Sep 17, 2021, at 10:51 AM, Jon Steinhart <jon@fourwinds.com> wrote:
> 
> Bakul Shah writes:
>> I have mixed feelings about this. Unix didn't "throw away"
>> the mainframe world of computing. It simply created a new
>> ecosystem, more suited for the microprocessor age. For IBM it
>> was perhaps the classic Innovator's Dilemma. Similarly now we
>> have (mostly) the Linux ecosystem, while the actual hardware
>> has diverged a lot from the C memory model. There are
>> security issues. There is firmware running on these system
>> about which the OS knows nothing. We have processors like
>> Esperanto Tech's 1088 64 bit Risc-V cores, each with its own
>> vector/tensor unit, 160MB onchip sram and 23.8B transistors
>> but can take only limited advantage of it. We have super
>> performant GPUs but programming them is vendor dependent and
>> a pain. If someone can see a clear path through all this,
>> and create a new software system, they will simply generate a
>> new ecosystem and not worry about 50 years worth of work.
> 
> You're kind of reminding me of the HEP (heterogeneous element
> processor) talk that I saw at I think Usenix in Santa Monica.
> My opinion is that it was a "kitchen sink" project - let's
> throw in a few of these and a few of those and so on.  Also
> analogous to what I saw in the housing market up here when
> people started cashing in their California huts for Oregon
> mansions - when we lived in California we could afford two
> columns out front but now we can afford 6 columns, 8 poticos,
> 6 dormers, 4 turrets, and so on.  Just because you can built
> it doesn't keep it from being an ugly mess.
> 
> So my question on many of these processors is, has anybody
> given any thought to system architecture?  Most likely all
> of us have had to suffer with some piece of spiffy hardware
> that was pretty much unprogrammable.  Do the performance
> numbers mean anything if they can't be achieved in an actual
> system configuration?

If you look at the chip architecture, it is pretty regular.
    https://www.esperanto.ai/technology/
and very low power (0.01W/core as opposed to 7W/core on X86-64)
     https://www.servethehome.com/esperanto-et-soc-1-1092-risc-v-ai-accelerator-solution-at-hot-chips-33/

The equivalent of turrets and porticos and columns and dormers
are IO ports like USB, ethernet, and various GPIOs etc. but they
use only a small portion of the available gates.

IMHO the real issue is that the software folks are *not* providing
and *can no*t provide any sort of guidance for general purpose
computing, as the memory underlying modern programming languages
is so far removed from reality. The situation is sorta like what
happens with people with newly acquired incredible wealth but no
background in how to spend or manage it wisely (and I don't mean
*investing* to get more wealth). At least in that case there are
people who can help you and a tremendous need. Here we can put
billions and billions of gates on a chip and even do wafer scale
integration but these gates are not fungible like money.