That is 2^29 milliseconds. I dread to imagine the reasons leading to 28-bit millisecond time in an airplane.
Maybe it’s counting in microseconds?
Some models of Airbus A350 airliners need to be hard-rebooted after 149 hours
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Re: Some models of Airbus A350 airliners need to be hard-rebooted after 149 hours
#62That is 2^29 milliseconds. I dread to imagine the reasons leading to 28-bit millisecond time in an airplane.
Presumably someone is using the high four bits for some other purpose. It wouldn't surprise me if parts of an A350's avionics software is old enough that those sorts of space optimizations made sense.
It could also be a tagged value. These are quite common in code created by "high reliability" languages (Ada, OCaml). The high bits are used to carry some metadata.
E.g. you might want to set a certain bit if the value went outside the defined input range of a function (think for example far from the accepted numerical window of a Taylor series expansion). Instead of dealing error conditions at each and every step (thereby making the timing properties of the code unpredictable) you just collect all error conditions and at the end decide if you discard the value, or just use it partially (e.g. it might still be "good enough" to be used as a parametizing input of an adaptive filter, where it averages out with the rest).
Re: Some models of Airbus A350 airliners need to be hard-rebooted after 149 hours
#63I think the comments here say more about us as an audience than they do about the Airbus. We're totally accustomed to hardware & software problems whose solution is, "just restart it," and we don't even find it all that disturbing - mostly just humorous. Our standards as developers & testers have gotten pretty low. I think the only way you'd see outrage here at HN is if the restart involved a real physical crash (as…
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Re: Some models of Airbus A350 airliners need to be hard-rebooted after 149 hours
#64Time- ~Late 1990s.
Place- Small financial institution in the NE.
Having just finished two weeks on the job, one Friday evening before heading out I decided to reboot my Sun Sparcstation. I of course did not have root but there was L1-A which put you into the BIOS. Then: sync;sync;reboot
Workstation starts rebooting.
30 seconds later the sysadmin is standing over my shoulder.
SA - "What did you do?"
me - "I rebooted it"
SA - Incredulous. Like I just set my hair on fire. "Why?"
me - "Its been two week, you know defrag memory, free up the page tables"
(some vague psuedo cs bs)
SA - "This is a Solaris X.Y/SunOS Q.Y machine.
It had an uptime of 180+days.
I have machines here with an uptime of 2+ years."
me - "Really?"
SA - "These machines do not need a reboot. Ever. Please do not do this again."
How far we have (pro|re)gressed in 20 years! ;) (edits - typo)
Re: Some models of Airbus A350 airliners need to be hard-rebooted after 149 hours
#65Earlier quoted context omitted.
> I think the only way you'd see outrage here at HN is if the restart involved a real physical crash Or if it were an American company. There wasn’t any outrage when Germanwings’s lack of attention to their suicidal pilot’s mental health even though there were significant warning signs before he crashed a plane into the Alps. Little outrage over Malaysian Air despite their pilot practicing his suicidal crash in the s…
Both of the examples you gave were of mental health issues, which we're shitty at handling as a society. I've seen multiple posts on reddit about people "glamorizing" mental health problems, when really they're just more comfortable openly talking about it. People still just don't want to hear it. We don't see these problems as real issues to be dealt with as a society. There's still widespread belief that these are…
I even dispute the notion that there is anything wrong with being anti-American. It's not a personal insult unless one chooses to take it as such. I am American by birth, have lived abroad, and find the way things are done in the US to be abhorrent on many fronts. It seems to me anything done well elsewhere is rejected out of some weird sense of independence. America's profit driven healthcare business ruined my life and is still making it miserable. The only decent care I have ever received was in a European country. There is a default idea on the internet that America is the world. There is a default idea in much of America that conservatism is "true America". There is a default idea that success as a human is "being rich" and "winning". My family has this belief system and anytime those beliefs or the country are criticized, even if its one amongst 100 comments, its focused on as how everyone is biased against them and they are "victimized" by this. I find the incredibly common idea in the USA, that one should be less critical of the nation because "this is the best place for us to get rich" is the opposite to what I consider important values, and is in fact antithetical to the hacker ethos. The hackers I admire don't do so to enrich themselves...they do it to fix problems and improve the world, even if only for one other person.
Re: Some models of Airbus A350 airliners need to be hard-rebooted after 149 hours
#66I think the comments here say more about us as an audience than they do about the Airbus. We're totally accustomed to hardware & software problems whose solution is, "just restart it," and we don't even find it all that disturbing - mostly just humorous. Our standards as developers & testers have gotten pretty low. I think the only way you'd see outrage here at HN is if the restart involved a real physical crash (as…
> I think the only way you'd see outrage here at HN is if the restart involved a real physical crash Or if it were an American company. There wasn’t any outrage when Germanwings’s lack of attention to their suicidal pilot’s mental health even though there were significant warning signs before he crashed a plane into the Alps. Little outrage over Malaysian Air despite their pilot practicing his suicidal crash in the s…
—-WARNING: META-DISCUSSION——
Fact check: Harsh but mostly true. This used to be the forum for the rationalist and capitalist community in tech, or at least people that tolerated them or were willing to engage without downvotes. Now it attracts those with such distaste for rationalist viewpoints to the point pg himself is altering his essays[1]. His original point was much clearer and more memorable than his revision. Are there any alternatives to this site that look more like the news.ycombinator of 5+ years ago? Maybe a discord or subreddit or telegram group?
[1] http://www.paulgraham.com/ineq.html
EDIT: the replies to your post only reinforce your point, you are being called a kook (“completely insane”) for your post, which is antithetical to civil discussion.
Re: Some models of Airbus A350 airliners need to be hard-rebooted after 149 hours
#67Earlier quoted context omitted.
Airbus is already using formal method for creation and validation of the code which are the ultimate version of testing.
Whatever method prevents buffer overflows. AFAIK that is what happens here. "The CPIOM is effectively a mini computer; in the A350 CPIOMs run discrete avionics "applications", in the sense of apps. CRDCs themselves do not host or run applications, suggesting that the failure condition detailed in the EASA AD may mean loss of a particular app on a CPIOM after a buffer overflow."
s/AFAIK/I'm guessing/
Or do you have any objective basis for suspecting that this is a buffer overflow?
Re: Some models of Airbus A350 airliners need to be hard-rebooted after 149 hours
#68I think the comments here say more about us as an audience than they do about the Airbus. We're totally accustomed to hardware & software problems whose solution is, "just restart it," and we don't even find it all that disturbing - mostly just humorous. Our standards as developers & testers have gotten pretty low. I think the only way you'd see outrage here at HN is if the restart involved a real physical crash (as…
Or maybe it is a testament to how high our standards are that the expectation is that we should essentially never have to restart things. I can't say that my car has ever gone 149 hours without a "reboot" of some kind or another.
Mine sure has, and just about every car these days does. The ECU doesn't lose power when you turn off the car; the only way to "reboot" your car is to disconnect the battery.
Re: Some models of Airbus A350 airliners need to be hard-rebooted after 149 hours
#69Earlier quoted context omitted.
> So this has almost nothing to do with Airbus at this point, the directive and the "sighs" uttered by the EU aviation agency are directed at the airlines that won't install the update. Why won’t EASA ground the un-updated airplanes?
As mentioned else-thread, the plane requires a certain level of inspection after the software update, which merely takes a few weeks and lots of human effort.
I find this interesting to compare to the 737 Max. Here the reaction is "just reboot because the inspection after installing the fix takes too long". But with the 737 Max, the reaction is "Create MCAS to avoid the cost of having to retrain pilots? How could you be so stupid?"
I know, the A350 bug hasn't killed anyone (yet). But I see the parallels in the issue, and yet the reactions here are completely opposite.
Re: Some models of Airbus A350 airliners need to be hard-rebooted after 149 hours
#70Earlier quoted context omitted.
As mentioned else-thread, the plane requires a certain level of inspection after the software update, which merely takes a few weeks and lots of human effort.
I find this interesting to compare to the 737 Max. Here the reaction is "just reboot because the inspection after installing the fix takes too long". But with the 737 Max, the reaction is "Create MCAS to avoid the cost of having to retrain pilots? How could you be so stupid?" I know, the A350 bug hasn't killed anyone (yet). But I see the parallels in the issue, and yet the reactions here are completely opposite.
Part of it, I'm sure, is that the A350 bug is comprehensively root-caused and that root cause is understood to be completely bounded by rebooting the system, whereas MCAS reduces the number of points of failure to, in certain builds of the 737 MAX, a single sensor.