[SOVLED] CTD in cruise

[cwjohan]

Crashed to desktop midway in flight from EDDK to EDDF in TBM900 v1.0.5.  Autopilot was under GPS control at 6000 ft.  Vertical navigation on the autopilot had not yet been pushed but altitude constraints had been set up for the flight plan waypoints.  View was in cockpit, but had just returned from taking two exterior snapshots and one interior snapshot (Alt-R, Shft-Spacebar, Alt-R).  The interior snapshot is attached to assist debugging, since it shows there were no alerts and everything seemed to be going nicely.  While the aircraft was making a turn from OBOKA to COL, there was a sudden drop in FPS and a second or two later X-Plane crashed to desktop.  Windows 10 task manager was running but I neglected to monitor memory usage, so I don't know if this was an out of memory situation.  X-Plane version was 11.26r2.

Log_tbm_ctd01.txt

GizmoLog_tbm_ctd01.txt

Edited October 26, 2018 by skiselkov
Added Gizmolog.txt file

[cwjohan]

Happened again on same flight with TBM 900 v1.0.6.  This time, I had no altitude constraints entered.  Again, there were no alerts and engine parameters were in normal range.  Monitored memory and GPU usage with Task Manager -- didn't see any over usage of RAM, VRAM, or other resources.

Also had the brakes not working issue but changed the joystick trigger to "toggle brakes normal" until a fix is available.

After a CTD or an engine fire, I find it a lot of work to get the aircraft back into working order.  Maintenance bill now is about $2.5 million!  Is there a shortcut way to load the aircraft in a normal, undamaged state?

Log_tbm_ctd02.txt

GizmoLog_tbm_ctd02.txt

Edited October 26, 2018 by cwjohan

[cwjohan]

RESOLVED:  Deimos and coolhand reported that creating a 16 GB paging file solved the "CTD in cruise" problem for them.  So, in Windows 10. I used the Control Panel | System | Advanced System Options to create a paging file with a minimum size of 16 GB and a maximum size of 20 GB on my D-drive.  Previously, Windows 10 had been using a smallish system-managed paging file on my C-drive.   Since then, I have successfully made the flight from EDDK to EDDF with no issues other than the braking problem known to exist in  TBM 900 v1.0.6.  Note that I have been flying this route using level 16 ortho, which may use extra ram and vram.

The successful flight was completed without using altitude constraints or vertical navigation.  I'll try those tomorrow on the same route, but I don't expect any problem with them since they worked previously on a KSBP - KSBA flight.

[skiselkov]

Thank you for the information! Really helpful. We'll keep an eye out for users with 8GB of RAM and be sure to pass your recommendation along.

[cwjohan]

The bigger paging files solve the problem for the user, but, for developers, the bug remains.  If I were to guess what causes it, I would say getting a null pointer from a malloc.  Since there's no obvious memory leak, there must be something that grabs a huge chunk of memory all at once -- perhaps a memory block sub-allocator that increases the size of the block grabbed each time by a factor of 2.  Perhaps even the C++ vector object does that when you're appending items to it.

In my case, before I added the bigger paging files, the crash was occuring when the active waypoint in the flight plan was transitioning from an ordinary waypoint to one that was located in an airway -- something grabs a big chunk of memory at that point?

In any case, good luck hunting it down.  Cheers!

[cwjohan]

UPDATE:  I've done at least 3 successful flights since my last report of no problems.  No CTDs since enlarging the paging files.  My current version is 1.0.8.  Flight from CYVR to KSEA had no CTD problems.

[skiselkov]

12 hours ago, cwjohan said:

UPDATE:  I've done at least 3 successful flights since my last report of no problems.  No CTDs since enlarging the paging files.  My current version is 1.0.8.  Flight from CYVR to KSEA had no CTD problems.

Thanks for letting us know, appreciate the feedback!

[quijote]

If I have 32GB RAM, do I need to configure a paging file?

[skiselkov]

2 hours ago, quijote said:

If I have 32GB RAM, do I need to configure a paging file?

You shouldn't need to. Of course, depends a lot on the used scenery (especially when high-resolution Ortho scenery is used).