Use of grease pencil consistanly crashes display server #54210

New Issue

Mai Lavelle · 2018-03-03T10:52:31+01:00

Mai Lavelle commented

2018-03-03 10:52:31 +01:00

Blender (both master and 2.8) somehow is able to crash the display server while doing grease pencil drawing using a Wacom tablet. I'm able to reproduce this consistently, but so far this is the only error I've been able to find in any log:

after 95493 requests (95493 known processed) with 2 events remaining.```


Theres no backtrace, Blender (and every other process in the session) exits with code 1.

Perhaps this is some bug in the display server, but this only ever happens when drawing in Blender, other apps work just fine without causing this problem, so maybe there is something in how Blender is interacting with input / display that should be fixed.

Not really sure how to debug this...

Arch Linux
Xorg 1.19.6

Blender (both master and 2.8) somehow is able to crash the display server while doing grease pencil drawing using a Wacom tablet. I'm able to reproduce this consistently, but so far this is the only error I've been able to find in any log: ```XIO: fatal IO error 11 (Resource temporarily unavailable) on X server ":1" ``` after 95493 requests (95493 known processed) with 2 events remaining.``` ``` Theres no backtrace, Blender (and every other process in the session) exits with code 1. Perhaps this is some bug in the display server, but this only ever happens when drawing in Blender, other apps work just fine without causing this problem, so maybe there is something in how Blender is interacting with input / display that should be fixed. Not really sure how to debug this... Arch Linux Xorg 1.19.6

Mai Lavelle commented

2018-03-03 10:52:32 +01:00

Added subscriber: @MaiLavelle

Antonio Vazquez commented

2018-03-03 11:21:14 +01:00

Added subscriber: @antoniov

Antonio Vazquez commented

2018-03-03 11:21:14 +01:00

I use Windows and I cannot reproduce the error in my system. In the production of Hero open movie some artist are using Linux with tablet/Cintiq and they have not reported any issue.

Coud you try to review Wacom drivers?

I use Windows and I cannot reproduce the error in my system. In the production of Hero open movie some artist are using Linux with tablet/Cintiq and they have not reported any issue. Coud you try to review Wacom drivers?

Brecht Van Lommel commented

2018-03-03 14:23:17 +01:00

Added subscriber: @brecht

Brecht Van Lommel commented

2018-03-03 14:23:17 +01:00

Suggestions for debugging:

Check Xorg.0.log or other system logs for related error message.
Try disabling various tablet related code in GHOST X11, like refreshXInputDevices, proximity checks, tilt, .. and see if any of that is the cause of the problem.
Add various printfs to see what the code is doing and check if anything is out of the ordinary, something specific happens right before the crash, etc.

Suggestions for debugging: * Check Xorg.0.log or other system logs for related error message. * Try disabling various tablet related code in GHOST X11, like refreshXInputDevices, proximity checks, tilt, .. and see if any of that is the cause of the problem. * Add various printfs to see what the code is doing and check if anything is out of the ordinary, something specific happens right before the crash, etc.

Mai Lavelle commented

2018-03-06 10:13:56 +01:00

Bit of an update...

Still haven't found anything useful in system logs. I've managed to cause the crash without a tablet, tho doing so requires quite some erratic mouse movements.

I also tried disabling all tablet related code, and also disabling all grease pencil drawing code. The display server still crashes without that code.

Tried using the tablet and erratic movements in other areas of blender and other apps, the crash only happens when using grease pencil.

Unsure at the moment what to try next..

Bit of an update... Still haven't found anything useful in system logs. I've managed to cause the crash without a tablet, tho doing so requires quite some erratic mouse movements. I also tried disabling all tablet related code, and also disabling all grease pencil drawing code. The display server still crashes without that code. Tried using the tablet and erratic movements in other areas of blender and other apps, the crash only happens when using grease pencil. Unsure at the moment what to try next..

Antonio Vazquez commented

2018-03-06 19:28:19 +01:00

@MaiLavelle When you talk about disable grease pencil drawing code, what code did you disable?

The actual drawing code is in gpencil_engine.c in bf_draw. Maybe you could disable all callback and enable one by one to try to find where is the problem.

@MaiLavelle When you talk about disable grease pencil drawing code, what code did you disable? The actual drawing code is in gpencil_engine.c in bf_draw. Maybe you could disable all callback and enable one by one to try to find where is the problem.

Mai Lavelle commented

2018-03-07 09:55:22 +01:00

To disable drawing I had made the ED_gpencil_draw_* functions in drawgpencil.c in master branch noops.

After some after several sessions crashes and gdb via tmux, I was able to get a backtrace, and altho that itself wasn't reliable or provided much info, I've been able to narrow things down to GHOST_WindowX11::setWindowCustomCursorShape.

So what I gather at this point is that it isn't exactly related to grease pencil, but rather what ever is happening is possibility some sort of timing issue, which is triggered by a high rate of events and calls to setWindowCustomCursorShape (which is what you get with a tablet and the code from 2b9d80643). After discovering this I tried provoking the crash from other areas where a custom cursor shape is used and was able to reproduce in the text editor by moving the mouse pointer quickly in and out of the area.

To disable drawing I had made the `ED_gpencil_draw_*` functions in drawgpencil.c in master branch noops. After some after several sessions crashes and gdb via tmux, I was able to get a backtrace, and altho that itself wasn't reliable or provided much info, I've been able to narrow things down to `GHOST_WindowX11::setWindowCustomCursorShape`. So what I gather at this point is that it isn't exactly related to grease pencil, but rather what ever is happening is possibility some sort of timing issue, which is triggered by a high rate of events and calls to `setWindowCustomCursorShape` (which is what you get with a tablet and the code from 2b9d80643). After discovering this I tried provoking the crash from other areas where a custom cursor shape is used and was able to reproduce in the text editor by moving the mouse pointer quickly in and out of the area.

Antonio Vazquez commented

2018-03-07 10:11:56 +01:00

In new greasepencil-object branch (base on 2.8 branch) the drawpencil.c are not used in viewport. Now all drawing code is using the draw manager and is included in bf_draw project.

Mai Lavelle commented

2018-03-10 10:01:54 +01:00

Changed status from 'Open' to: 'Archived'

Mai Lavelle closed this issue

2018-03-10 10:01:54 +01:00

Mai Lavelle self-assigned this 2018-03-10 10:01:54 +01:00

Mai Lavelle commented

2018-03-10 10:01:54 +01:00

Narrowed this down further to some bug in the proprietary Nvidia drivers, at some point after version 381.22. Still nothing in the logs.

Since this appears to be a driver issue I'll close this task, and try to report to Nvidia. Thanks for the help with this.

In summary: High rate of setting a custom X11 cursor shape crashes proprietary Nvidia drivers (bug introduced between versions 381.22 and 387.34).

Narrowed this down further to some bug in the proprietary Nvidia drivers, at some point after version 381.22. Still nothing in the logs. Since this appears to be a driver issue I'll close this task, and try to report to Nvidia. Thanks for the help with this. In summary: High rate of setting a custom X11 cursor shape crashes proprietary Nvidia drivers (bug introduced between versions 381.22 and 387.34).

Antonio Vazquez commented

2018-03-10 10:34:57 +01:00

Thanks @MaiLavelle for the info. I will inform the Hero team to be careful with driver version.

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Use of grease pencil consistanly crashes display server #54210