Sculpt mode drawing leaks memory #76544

New Issue

Campbell Barton · 2020-05-08T13:12:59+02:00

Campbell Barton commented

2020-05-08 13:12:59 +02:00

Run Blender with -d debug flag.
Open this file sculpt_mode_drawing_memory_leak.blend, exit Blender
Error: Not freed memory blocks: 26, total unfreed memory 0.002777 MB
Loading the file multiple times increase the number of leaks on exit.

- Run Blender with `-d` debug flag. - Open this file [sculpt_mode_drawing_memory_leak.blend](https://archive.blender.org/developer/F8520492/sculpt_mode_drawing_memory_leak.blend), exit Blender - `Error: Not freed memory blocks: 26, total unfreed memory 0.002777 MB` - Loading the file multiple times increase the number of leaks on exit.

Campbell Barton commented

2020-05-08 13:12:59 +02:00

Added subscriber: @ideasman42

Campbell Barton changed title from ~~Sculpt mode leaks memory~~ to Sculpt mode drawing leaks memory

2020-05-08 13:15:28 +02:00

Sergey Sharybin commented

2020-05-08 15:20:16 +02:00

Added subscriber: @Sergey

Sergey Sharybin commented

2020-05-08 15:20:16 +02:00

Cant reproduce the leak, but do have some heap use after free: P1376
The leak might be different indication of the same root issue.

This is using blender 18f833be29 on Linux.

Cant reproduce the leak, but do have some heap use after free: [P1376](https://archive.blender.org/developer/P1376.txt) The leak might be different indication of the same root issue. This is using blender 18f833be29 on Linux.

Bohdan Lvov commented

2020-05-08 16:37:49 +02:00

Added subscriber: @ostapblender

Bohdan Lvov commented

2020-05-08 16:37:49 +02:00

I have similar behavior on Windows 10, but only when addons are enabled:

If addons folder are renamed to something different, no errors appear.

I have similar behavior on Windows 10, but only when addons are enabled: ![image.png](https://archive.blender.org/developer/F8520851/image.png) If addons folder are renamed to something different, no errors appear.

Ankit Meel commented

2020-05-08 17:40:39 +02:00

Added subscriber: @ankitm

Ankit Meel commented

2020-05-08 17:40:39 +02:00

File shouldn't be required.. In sculpting workspace, enable Dyntopo, make a stroke, close file.

Brecht Van Lommel commented

2020-05-09 10:58:57 +02:00

Added subscriber: @PabloDobarro

Brecht Van Lommel commented

2020-05-09 10:58:57 +02:00

Changed status from 'Needs Triage' to: 'Confirmed'

Jacques Lucke commented

2020-05-14 17:37:19 +02:00

Added subscriber: @JacquesLucke

Jacques Lucke commented

2020-05-14 17:37:19 +02:00

I tried to debug this for quite some time today, but I could not track down the root issue yet... I made some observations along the way though.
It's almost certainly a threading issue. I got many different outputs from asan. Furthermore, it's probably not only one issue, but multiple.

Reproduction steps:

Open file.
Start making brush strokes. Usually, it only takes one or two brush strokes to crash when ASAN is enabled.

#76544.blend

SCULPT_pbvh_calc_area_normal causes a warning: member call on address 0x613000adefc0 which does not point to an object of type 'task'. It does not seem to have a big impact, but it still feels like there is something wrong with the way parallel_reduce is used in BKE_pbvh_parallel_range.

Applying P1394 seems to fix all the issues for me. It disables threading in various locations. The patch also disables an unrelated assert, that should not be harmful. Enabling threading only on a single one of those, causes crashes. Depending on which one you enable, the crash looks is different. When more are enabled, it seems to be mostly a matter of luck which function fails first.

I tried to find some shared data that is not properly locked, but could not find any yet. I managed to get it working when I locked smaller code segments in the callbacks, but did not really win any significant insights from that.

I tried to debug this for quite some time today, but I could not track down the root issue yet... I made some observations along the way though. It's almost certainly a threading issue. I got many different outputs from asan. Furthermore, it's probably not only one issue, but multiple. Reproduction steps: 1. Open file. 2. Start making brush strokes. Usually, it only takes one or two brush strokes to crash when ASAN is enabled. [#76544.blend](https://archive.blender.org/developer/F8535433/T76544.blend) `SCULPT_pbvh_calc_area_normal` causes a warning: `member call on address 0x613000adefc0 which does not point to an object of type 'task'`. It does not seem to have a big impact, but it still feels like there is something wrong with the way `parallel_reduce` is used in `BKE_pbvh_parallel_range`. Applying [P1394](https://archive.blender.org/developer/P1394.txt) seems to fix all the issues for me. It disables threading in various locations. The patch also disables an unrelated assert, that should not be harmful. Enabling threading only on a single one of those, causes crashes. Depending on which one you enable, the crash looks is different. When more are enabled, it seems to be mostly a matter of luck which function fails first. I tried to find some shared data that is not properly locked, but could not find any yet. I managed to get it working when I locked smaller code segments in the callbacks, but did not really win any significant insights from that.

Brecht Van Lommel commented

2020-05-15 00:28:19 +02:00

Added subscriber: @brecht

Brecht Van Lommel commented

2020-05-15 00:28:19 +02:00

This sounds like multiple bugs in a single report? There's many different steps to redo and symptoms here.

The first issue is, does any of this happen in Blender in 2.83? If so, this should probably be a high priority bug. If not, it may be TBB related.

Further, git bisect might help pin down the cause?

This sounds like multiple bugs in a single report? There's many different steps to redo and symptoms here. The first issue is, does any of this happen in Blender in 2.83? If so, this should probably be a high priority bug. If not, it may be TBB related. Further, git bisect might help pin down the cause?

Brecht Van Lommel commented

2020-05-18 17:47:09 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Brecht Van Lommel closed this issue

2020-05-18 17:47:09 +02:00

Brecht Van Lommel self-assigned this 2020-05-18 17:47:09 +02:00

Brecht Van Lommel commented

2020-05-18 17:47:09 +02:00

Regarding the various issues reported here:

Dyntopo memory leak reported by @ankitm: fixed with 20b94257dc.
Original memory leak in description: unable to reproduce. Assuming this has already been fixed. If it still happens, @ideasman42 should run Blender with --debug-memory and specify the revision tested.
GPU draw buffers user after free. Given the asan logs, assuming the issue found by @Sergey and @JacquesLucke is the same, and to be handled in #76858 (Threading issue in sculpt mode).
Memory leak reported by @ostapblender: this would be a bug in an add-on using the bgl module. If that's an add-on shipped with Blender, a bug can be reported for that add-on.

Regarding the various issues reported here: * Dyntopo memory leak reported by @ankitm: fixed with 20b94257dc. * Original memory leak in description: unable to reproduce. Assuming this has already been fixed. If it still happens, @ideasman42 should run Blender with `--debug-memory` and specify the revision tested. * GPU draw buffers user after free. Given the asan logs, assuming the issue found by @Sergey and @JacquesLucke is the same, and to be handled in #76858 (Threading issue in sculpt mode). * Memory leak reported by @ostapblender: this would be a bug in an add-on using the `bgl` module. If that's an add-on shipped with Blender, a bug can be reported for that add-on.

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Sculpt mode drawing leaks memory #76544