Re: Tiny Core v17.0 upgrade issues

[Stefann]

So.. still running at 15:00; that means 30hrs runtime without crash

So, to summarize....
TC15:
- including kext: usb-serial-6.6.8-tinycore.tcz
- recompile full application
- run application with "every second 812byte read from /dev/ttyUSB0; baudrate 11520"
- no crash over multiple month

TC17:
- including kext: usb-serial-6.18.2-tinycore.tcz
- recompile full application
- run application with "every second 812byte read from /dev/ttyUSB0; baudrate 11520"
- 4..6x tested, always crashes, mostly after about 15hrs; always within 24hrs

TC17:
- including kext: usb-serial-6.18.2-tinycore.tcz
- SAME application, NO recompile
- run application with disabled read from /dev/ttyUSB0 by configuration constant
- 1x tested, no crash after 30hrs

Now...
This does NOT proof that the read-action is the rootcasue because earlier experiments did show that "more general load" makes the crashing earlier.

What I now have done:
- modify application code
- same "every second 812byte read from /dev/ttyUSB0; baudrate 11520"
- but close device and re-open after every 15minutes
- started at 16:00 European time

If this keeps running than I think its demonstrated that usb-serial-6.18.2-tinycore.tcz has an issue with "reading long time without intermediate closing"

fingers crossed

[patrikg]

Have you consider the BIOS with USB energy saving.

[Stefann]

I doubt my 2008 board has that.
But..... isn't that only applicable while idle? the computer is never idle but in 24/7 use.

[Stefann]

Sad.... an other crash this night at 1:30 am; after 33.5 hours

So.....
On TC17 crash after 33.5 hours if constantly reading reading from serial-over-usb port AND close/open filedescriptor every 15mins.

But....
2 days ago I concluded that running without reading serial-over-usb was crash-free as I manually stopped after 30hr of crash-free run.
>> that conclusion may be premature

Still..
WITH constant reading of serial-over-usb crash is normally in about 15hrs, and always within 24 hours.
So... although there is variation... it still looks like "altering settings of serial-over-usb" influences the behavior.

I got a tip from my brother that "SELECT" is a quite complicated kernel call.
I'm using SELECT to check that the pipe is ready for read but I can just as well call read from it in nonblocking mode without checking.
So... I now changed that...
- removed the SELECT
- read in non-blocking mode
I also made using read, select, 15min_close/open configurable by a runtime settable variable such that I can test different configurations without recompile (to exclude impact of compilation on results)

Started at 8:22 am:

TC17:
- including kext: usb-serial-6.18.2-tinycore.tcz
- new compiled executable with runtime configurable serial read modes
- run application with non-blocking read without SELECT
- "every second 812byte read from /dev/ttyUSB0; baudrate 11520" from /dev/ttyUSB0


Recap of results so far:

TC15:
- including kext: usb-serial-6.6.8-tinycore.tcz
- recompile full application
- run application with "every second 812byte read from /dev/ttyUSB0; baudrate 11520"
- no crash over multiple month

TC17:
- including kext: usb-serial-6.18.2-tinycore.tcz
- recompile full application
- run application with "every second 812byte read from /dev/ttyUSB0; baudrate 11520"
- 4..6x tested, always crashes, mostly after about 15hrs; always within 24hrs

TC17:
- including kext: usb-serial-6.18.2-tinycore.tcz
- SAME application, NO recompile
- run application with disabled read from /dev/ttyUSB0 by configuration constant
- 1x tested, NO CRASH after 30hrs >> I thought this was good but as next config crashed after 33.5hrs I may not have been running long enough

TC17:
- including kext: usb-serial-6.18.2-tinycore.tcz
- include every 15 minute close/open file descriptor for /dev/ttyUSB0
- recompile full application
- run application with "every second 812byte read from /dev/ttyUSB0; baudrate 11520"
- 1x tested, crash after 33.5hrs