Linux is not a RTOS and should not be running Tesla controls

[stopcrazypp]

TMore than likely it means the developer took a lock on a UI thread (waiting for e.g. something from the network). That shouldn't ever be done in theory, but it commonly is since it's simpler. Async programming is not for sissies.

Doing all the work on the UI thread is the default practice for Android developers so they don't have to deal with concurrency or creating a worker thread. Usually this is not a huge deal in terms of response time especially on something like the Tegra 3 in the Model S (except for the network case you mention, in which case it's recommended to have a different thread handle it).

But looking at the video, it seems the issue is not really UI responsiveness, but rather the AC cutting off with many button presses. That's probably a bug unrelated to what has been discussed so far.

 

[Cosmacelf]

What you've described (lag) is common on embedded (ARM) processors that are anemic CPUs (think phone/tablet CPUs) trying to run stuff in the background.

OK, but nav system lag shouldn't turn off something that should appear to be autonomous from the user's perspective.

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I've never seen a similar problem on my MS. It does appear you have a fairly slow 3G connection. If the maps update quickly (i.e. fast 3G connection), does the same problem still occur?

Don't know, I'll have to try it out in a better 3G area. I know one person on this thread said they had seen the same issue. It would be interesting if others on this thread tried to replicate it.

 

[stopcrazypp]

OK, but nav system lag shouldn't turn off something that should appear to be autonomous from the user's perspective.

That's a bug rather than anything that has to do with the system architecture. I think lots of people got confused by your talk about the RTOS since that implies your issue had to do with UI response times.

 

[Seattle]

The video should help Tesla figure it out. Try sending it to: [email protected]

I've never seen a similar problem on my MS. It does appear you have a fairly slow 3G connection. If the maps update quickly (i.e. fast 3G connection), does the same problem still occur?

I've had it on my model s a few times, just like this other person saw, the ac/fan went on and off a few times.

 

[TurboFroggy]

I have experienced this same issue too. I think it does it most often when I am loading, moving, zooming on the map with the satellite view. I think it takes a lot of bandwidth both 3g and cpu/gpu to do that. If I just don't use the satellite view on the map it doesn't repro. Our Leaf that uses Microsoft Windows Embedded never has this issue...

 

[yobigd20]

Our Leaf that uses Microsoft Windows Embedded never has this issue...

dear god ... well I guess that gives the meaning of "blue screen of death" a whole new context...

 

[brianman]

I am loading, moving, zooming on the map with the satellite view. I think it takes a lot of bandwidth both 3g and cpu/gpu to do that. If I just don't use the satellite view on the map it doesn't repro.

Thanks for sharing that info. I tend to avoid satellite view from the assumption that it would be slower due to a more complex image being downloaded. Interesting that your case seems to support that assumption.

 

[aviators99]

Thanks for sharing that info. I tend to avoid satellite view from the assumption that it would be slower due to a more complex image being downloaded. Interesting that your case seems to support that assumption.

Let's put it this way: it's much harder to repro, but it's possible.

 

[PRJIM]

Mine does this too but the radio turns off and on as well. Hopefully this bug is fixed very annoying, especially on hot/cold days.

 

[elreydetodo]

I'd like to point out that real time with regard to operations g systems doesn't mean what the OP seems to think it means. The main implication is that the task scheduler makes its decisions with deadlines in consideration and drop or delay certain tasks which are not going to meet the required deadline.

While an RT OS can be good for video watching and music playing, it is overkill for nearly everything else including your car. If your HVAC system turns off because the Nav CPU is busy, that's a design flaw in the HVAC logic, not a problem with Linux not being a real time scheduling os. The HVAC shouldn't have a watchdog timer set which turns it off in the event a sensor hasn't been polled in a certain amount of time. It should keep running at the existing setting until the next readings come in.

Also, Linux does have an rt patch series that has been getting slowly merged over the past 10 or so years, and there nothing we can point to to say that the version of Linux running here isn't patched with that series of changes. Even if it were, apps need to be specially tooled to deal with a deadline-aware scheduler. That's very tough coding.

 

[Cosmacelf]

FYI, I emailed ownership about the bug (with the video link) Monday night. No acknowledgement yet. FWIW, I heard from a Tesla employee that the SW team used to be 15 employees not too long ago - they have 85 in that team now. If QA was included in that number, 15 seemed way too small for such a project (think of all the embedded software systems), glad to hear they've hired more people.

 

[Cosmacelf]

And no sooner had I written the above that I get an email from Tesla saying this was a known bug and that they will have a fix in a future release. This board gets results :wink:

 

[dtich]

snip. too grouchy, and you did what i was suggesting anyway.....

 

[Cosmacelf]

So this really was a bug report, and it appears that this bug has been fixed in v4.5 (1.33.44). Thank you, Tesla!

 

[Alpha]

I've started having this issue daily on my car... Very annoying, especially when it's hot out.. I'm still on 4.4 -- I hope they push 4.5 to me soon!

 

[brianman]

I've started having this issue daily on my car... Very annoying, especially when it's hot out.. I'm still on 4.4 -- I hope they push 4.5 to me soon!

I have this issue right now, where "this" is me having no idea which issue you are referencing.

 

[Alpha]

Sorry, I thought it was clear from the beginning of the thread-- it's the issue where the AC starts cycling on and off when fiddling with the nav. system, and I eventually have to reboot it. I talked to Tesla about it and they said it's a known problem and the temporary solution is to not use Nav full screen. So I'm doing that and also sticking to non satellite mode for now.