The Movable Feast Machine
movablefeastmachine.org
The Movable Feast Machine
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Re: The Movable Feast Machine
#2Maybe I've been living under a rock, but this is the first time I've seen robust-first computing and this is pretty fascinating. I'm imagining that the application of this to a physical scenario would involve, say, a grid of very low-power CPUs that could each be "taken over" by an atom.
Re: The Movable Feast Machine
#3I wonder how the Demon Horde Sort would work if the bounds were not in a nice grid like that? Is it possible to put inputs on the right and outputs on the left? What happens if the grid changes size?
Re: The Movable Feast Machine
#4I wonder how the Demon Horde Sort would work if the bounds were not in a nice grid like that? Is it possible to put inputs on the right and outputs on the left? What happens if the grid changes size?
I think the idea is that the bounds are finite but not fixed. The architect of the system could hot-plug in a bunch of nodes to any direction and the playing field would instantly expand. However, at any given time, there are a knowable, fixed number of nodes.
Re: The Movable Feast Machine
#5My bedtime reading recently has been Propagator Networks[1][2][3] ... and I keep daydreaming of a resource management system just like Dave describes in this video... I do believe "mostly correct" computing is going to play a big role in the future.
[1] http://web.mit.edu/~axch/www/phd-thesis.pdf [2] http://web.mit.edu/~axch/www/art.pdf [3] http://groups.csail.mit.edu/mac/users/gjs/propagators/
Re: The Movable Feast Machine
#6It'd love to see the same example with a regulator generating incorrectly programmed sorters. How does the system handle a programmer bug that inverted the sort direction?
Re: The Movable Feast Machine
#7How well does this scale up? The example in the video seems toy-scale. I can see a few dimensions of potential scaling:
* larger numbers -- for example large numbers of tiny processor / memory cells on a single chip (thousands to millions?)
* more dimensions, either symmetric (lattice) or asymmetric (hyper-pyramid that gets more sparse as you go up)
* more complex cells -- more memory, processor power, bandwidth
* specialization -- heterogeneous cellsRe: The Movable Feast Machine
#8It'd love to see the same example with a regulator generating incorrectly programmed sorters. How does the system handle a programmer bug that inverted the sort direction?
then you'd debug it, or program debuggers to flit around looking for programmer error then address it
the system is clear about its capabilities regarding 'correctness'
which seems to imply the programmer's job is to optimise with those built in inaccuracies
but what those inaccuracies afford is what ackley is calling robustness and indefinite scalability
ackley addresses your question directly with a sorting comparison(o) from a later video
the graph fails to exhibit where maxwell's demon(i) horde sort would express itself on the graph, but sorting corruption is addressed in the paper(ii)
The demon horde sort’s performance may be just adequate,
by that measure, but its robustness seems quite impressive.
Figure 23 shows results of one experiment in which we
randomly corrupted site memory with simulated bit errors at
a range of probabilities. Each error occurrence selects a random
site and then flips from one to eight of its 64 atomic bits.
We can see that while channel length helps performance, it
does not help robustness against this system perturbation—
but the system is strikingly robust anyway, tolerating upward
of 10 multibit corruptions per million events with essentially
no visible performance degradation, regardless of channel
length.
Above about 50 errors/Mevent the system reliably falls
apart—and the pathology appears to run a reliable course..
but going further as to deal with unintended performance of hardware
if you have a multi core system running an incorrectly programmed sort and one core fails the whole thing shuts down, but an incorrectly programmed sorter in the demon horde will keep functioning even with failed cores, affording the opportunity to adjust while performing
(o) https://youtu.be/7hwO8Q_TyCA?t=688
(i) https://en.wikipedia.org/wiki/Maxwell%27s_demon
(ii) http://comjnl.oxfordjournals.org/content/56/12/1450.full.pdf...
Re: The Movable Feast Machine
#9I wonder how the Demon Horde Sort would work if the bounds were not in a nice grid like that? Is it possible to put inputs on the right and outputs on the left? What happens if the grid changes size?
the 'grid' changing bounds is the intended mode of existence
in regard to demon horde the paper(o) states 'channel size increases performance'
but this should be uncontroversial
more resources give better results
it will be an optimisation problem to determine necessary resource alocation for desired results
the shape of the simulation was stated(i) to be a simplified representation of the functionality
the paper discusses 'a movable membrane whose contents cannot diffuse out', the figure is an almost organic shape, much more adaptable than the rectangular simulation demonstration
(o) comjnl.oxfordjournals.org/content/56/12/1450.full.pdf+htmlb
Re: The Movable Feast Machine
#10I wonder how the Demon Horde Sort would work if the bounds were not in a nice grid like that? Is it possible to put inputs on the right and outputs on the left? What happens if the grid changes size?
the 'grid' changing bounds is the intended mode of existence in regard to demon horde the paper(o) states 'channel size increases performance' but this should be uncontroversial more resources give better results it will be an optimisation problem to determine necessary resource alocation for desired results the shape of the simulation was stated(i) to be a simplified representation of the functionality the paper dis…
There's also a more recent 'router' demo(1) that -- though still rigid and rectangular -- does build its own boundary rather than relying on the grid boundary.