Live data from Hacker News

Cores that don't count

muratbuffalo.blogspot.com

1–10 of 34 posts

Re: Cores that don't count

#2
Cores that don't count = floating-point coprocessor cores? :-)

But seriously, though,

> I think fail-silent CEEs is weaker than the adversary Byzantine failure model.

Of course they're weaker than byzantine failures. There's time locality, and the failure in themselves are not particularly hard to detect if some other core checks the results (although that obviously doesn't happen after every single computation).

Re: Cores that don't count

#3

Cores that don't count = floating-point coprocessor cores? :-) But seriously, though, > I think fail-silent CEEs is weaker than the adversary Byzantine failure model. Of course they're weaker than byzantine failures. There's time locality, and the failure in themselves are not particularly hard to detect if some other core checks the results (although that obviously doesn't happen after every single computation).

[deleted]

Re: Cores that don't count

#4
The conclusion is an utter joke: “Maybe this will lead to abondonment of complex deep-optimizing chipsets like Intel chipsets, and make simpler chipsets, like ARM chipsets, more popular for datacenter deployments.”

Re: Cores that don't count

#5

Cores that don't count = floating-point coprocessor cores? :-) But seriously, though, > I think fail-silent CEEs is weaker than the adversary Byzantine failure model. Of course they're weaker than byzantine failures. There's time locality, and the failure in themselves are not particularly hard to detect if some other core checks the results (although that obviously doesn't happen after every single computation).

wait... consensus algorithms exist? can they work for human brains?

experiment :

tell a bunch of people that if they form consensus about, say, a color, they all get $5 (or whatever). have them attempt to reach consensus only using the exact mechanisms of a consensus algorithm. (research what they are)

Re: Cores that don't count

#6

Cores that don't count = floating-point coprocessor cores? :-) But seriously, though, > I think fail-silent CEEs is weaker than the adversary Byzantine failure model. Of course they're weaker than byzantine failures. There's time locality, and the failure in themselves are not particularly hard to detect if some other core checks the results (although that obviously doesn't happen after every single computation).

wait... consensus algorithms exist? can they work for human brains? experiment : tell a bunch of people that if they form consensus about, say, a color, they all get $5 (or whatever). have them attempt to reach consensus only using the exact mechanisms of a consensus algorithm. (research what they are)

You need to specify further environment parameters: Is the communication channel lossy? Can all the participants be trusted? Is there a time limit?

Re: Cores that don't count

#7

Cores that don't count = floating-point coprocessor cores? :-) But seriously, though, > I think fail-silent CEEs is weaker than the adversary Byzantine failure model. Of course they're weaker than byzantine failures. There's time locality, and the failure in themselves are not particularly hard to detect if some other core checks the results (although that obviously doesn't happen after every single computation).

wait... consensus algorithms exist? can they work for human brains? experiment : tell a bunch of people that if they form consensus about, say, a color, they all get $5 (or whatever). have them attempt to reach consensus only using the exact mechanisms of a consensus algorithm. (research what they are)

behind the scenes, someone offers one of the participants $10 to prevent consensus.

Re: Cores that don't count

#8
What needs to happen is to bring ECC to all levels of a chips logic to solve this. ARM vs RISC-V vs x64 doesn't address the problem as nothing in them inherently solves the problem. Making adders that add with ECC will.

If all of the logic also operates on ECC with the data, chip yields will also be improved. Say an core of the chip only produces the correct result 99% of the time, currently you have to disable that core. With ECC logic, you can still use it, as it doesn't matter if it has an additional 1% chance of a bit flip, as all of your logic is now immune to single bitflips. For mission critical logic/applications, one can scale up the ECC so its immune to more bitflips before an error is introduced.

Re: Cores that don't count

#9
Maybe we should run the code twice on different cpu architecures and only accept the results if they are identical. I’ve heard of high reliability environments doing this, but maybe there are cases for doing it in web/IT as well.

This would help catch a large variety of possible errors, including but not limited to cpu bit flips, cpu bugs, memory errors.

Re: Cores that don't count

#10

Cores that don't count = floating-point coprocessor cores? :-) But seriously, though, > I think fail-silent CEEs is weaker than the adversary Byzantine failure model. Of course they're weaker than byzantine failures. There's time locality, and the failure in themselves are not particularly hard to detect if some other core checks the results (although that obviously doesn't happen after every single computation).

wait... consensus algorithms exist? can they work for human brains? experiment : tell a bunch of people that if they form consensus about, say, a color, they all get $5 (or whatever). have them attempt to reach consensus only using the exact mechanisms of a consensus algorithm. (research what they are)

You mean if people perform a successful vote on something they don't care about, you'll give each $5? You don't think anyone could do it in under a minute?
Post reply on HN