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For a brief period, the Windows kernel tried to deal with gamma rays

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Re: For a brief period, the Windows kernel tried to deal with gamma rays

#71

Post by trhway »

sevensor wrote: post #51
spullara wrote: post #19

If you don't believe in bit flips, try this! http://dinaburg.org/bitsquatting.html I did that for a bit on cloudfront.net and got dozens of them in a short amount of time.

I used to work in DRAM manufacturing. I believe 100% in bitflips -- we saw them in testing all the time. I also believe the rate at which bitflips are caused by gamma rays is absolutely dwarfed by the rate at which bitflips are caused by manufacturing defects. It's really easy to manufacture a weak cell when you're making billions of tiny capacitors at the same time. SRAM might also see lots of bitflips, but that see…

>the rate at which bitflips are caused by gamma rays is absolutely dwarfed by the rate at which bitflips are caused by manufacturing defects.

back in USSR/Russia gamma rays and aliens were not-an-issue compare to the extremely low reliability of USSR/Russia hardware. The military hardware back then (and some telco hardware built in Russia in 199x (some even for export into Western countries!)) was built as triplicate systems - i.e. primitive quorum/consensus computing.

Similarly, as far as i heard back then, due to low reliability of Itanium especially in the beginning, the Itanium based Tandems were also available as "Tridems".

Re: For a brief period, the Windows kernel tried to deal with gamma rays

#72

Post by myrandomcomment »

srcmap wrote: post #68
myrandomcomment wrote: post #58

A bunch of years ago Cisco had an issue with some RAM in a new switch model, I think it was in the 65xx. They where crashing randomly but only in certain places in the world. Cisco spent tons of money on this. No idea. They brought in a physics professor. The devices with the most issues were located in countries up near the artic circle. Cosmic Rays caused a bit flip in this particular set of RAM due to something in…

I used to work for two switch chip companies also. I know both of them has SW/logic in the switch chips guard against random errors in SRAM - "Alpha particles". I have seen detail test report that ran the system in nuclear lab and graph out the level of radiation level vs impact on the system error/recoverable error rate. I knew big customers (such as Cisco) can ask for such test reports and they do get it. It would…

We would take the switches to the labs and have the "shoot" various types of particles other radiation sources at it to check resistance in both HW and SW. Depending on what you did sometime it takes months get get the device back as it has to "cool down".

It was pretty neat.

Re: For a brief period, the Windows kernel tried to deal with gamma rays

#73

Post by seandougall »

eli wrote: post #42
amichal wrote: post #35

Earlier quoted context omitted.

While i like the sibling comment's network errors answer better then mine I didn't see any reasoning other then a unfounded statement[1] in the article or on a quick skim for "typo" in the referenced whitepaper: [1] "These requests were not typos or other manually entered URLs"

"All of these requests used only four domains in the HTTP Host header, as shown in Table 4. Three out of four domains contain more than one bit error, ruling out a simple mistype of fbbdn.net for fbcdn.net. "

Not to mention, the number of people typing "fbcdn.net" into a browser has to be vanishingly small to begin with.

Re: For a brief period, the Windows kernel tried to deal with gamma rays

#74

Post by bumby »

datenwolf wrote: post #49

Invalidating the caches is kind of a cringe inducing approach on this (actual) problem. Especially in HPC radiation related single event upsets have become a real problem. If you do the math, all the silicon area devoted to memory (DRAM, caches, registers) adds up, and what you've got is essentially particle detector. Compared to the effective volume of a purpose designed one (ATLAS, CMS, Super Kaminokade, etc.) rath…

NASA calls out preparing for this specifically in their software engineering requirements. My understanding is that this was added specifically to address bit flips from radiation effects.

See section 3.7.2.f https://nodis3.gsfc.nasa.gov/npg_img/N_PR_7150_002B_/N_PR_71...

Re: For a brief period, the Windows kernel tried to deal with gamma rays

#75

Post by privong »

evanb wrote: post #63
Nokinside wrote: post #53

Earlier quoted context omitted.

Could physicists and astronomers use all this distributed particle detection for research? Like a app in a phone or desktop that sends reports back with location and time information.

You may be interested to learn of arXiv:1510.07655, "Detecting particles with cell phones: the Distributed Electronic Cosmic-ray Observatory" by Vandenbroucke et al. I don't know if any novel results have come out of this kind of thing. https://arxiv.org/abs/1510.07665

There was also this one, a bit earlier, "Observing Ultra-High Energy Cosmic Rays with Smartphones".

https://arxiv.org/abs/1410.2895

I (thought I) signed up to be informed of beta releases, but never heard anything. I just checked their website[0] and it mentions a beta app, but that seems to just go to a signup page.

[0] https://crayfis.io

Re: For a brief period, the Windows kernel tried to deal with gamma rays

#76

Post by Pica_soO »

datenwolf wrote: post #49

Invalidating the caches is kind of a cringe inducing approach on this (actual) problem. Especially in HPC radiation related single event upsets have become a real problem. If you do the math, all the silicon area devoted to memory (DRAM, caches, registers) adds up, and what you've got is essentially particle detector. Compared to the effective volume of a purpose designed one (ATLAS, CMS, Super Kaminokade, etc.) rath…

The reason this is researched is also, that it would allow for cheaper manufacturing, as nearly 100 % non radioactive waver raw material is hard to come by. So, the incentive is not just space and science resistant hardware, but computers, who survive there own flawed material with the occasional decay.

Re: For a brief period, the Windows kernel tried to deal with gamma rays

#77

Post by elahieh »

worldlinx wrote: post #18
xpaulbettsx wrote: post #17

I found this code as an intern at Microsoft, while the manufacturer is hidden in the post, I'll give you a clue - the company starts with "I" and ends with "ntel"

Unless you know what you are doing, you might want to delete that. Probably goes against the NDA you've signed, no?

The comment with Intel was already mentioned in 2008 at https://deadracoon.livejournal.com/87049.html

Re: For a brief period, the Windows kernel tried to deal with gamma rays

#78

Post by weberc2 »

When I was fresh out of college, I worked as a contractor for a prominent agricultural equipment manufacturer. I was responsible for building out the touch-screen interface for the radio (a Qt app). I was told by an engineer who worked for the equipment manufacturer that my application wasn't good enough because needed to be able to operate correctly in the face of arbitrary bit flips "from lightning strikes"--I kindly asked her to show me the requirements which was sufficient to get her to relent, but that was still the wackiest request I've ever received.

Re: For a brief period, the Windows kernel tried to deal with gamma rays

#79

Post by russdill »

weberc2 wrote: post #78

When I was fresh out of college, I worked as a contractor for a prominent agricultural equipment manufacturer. I was responsible for building out the touch-screen interface for the radio (a Qt app). I was told by an engineer who worked for the equipment manufacturer that my application wasn't good enough because needed to be able to operate correctly in the face of arbitrary bit flips "from lightning strikes"--I kind…

The requirement request is a great way to push back on feature creep. There's a lot of cargo culting that goes on in the "protection against bit-flips". You sometimes have to go a step further and ask what error rate are you required to be below. Once you have that number, you can start asking what your current error rate is without mitigations, and how much a given mitigation will reduce your error rate.

Re: For a brief period, the Windows kernel tried to deal with gamma rays

#80

Post by theclaw »

spullara wrote: post #19

If you don't believe in bit flips, try this! http://dinaburg.org/bitsquatting.html I did that for a bit on cloudfront.net and got dozens of them in a short amount of time.

The youtube video[1] of his defcon talk is super interesting -although some of his concerns about serving malicious scripts from bitsquatted domains are thankfully mitigated by widespread adoption of TLS.

[1] http://www.youtube.com/watch?v=lZ8s1JwtNas

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