Bug 408668

Summary:	Hardware acceleration does not work in kwin_wayland
Product:	[Plasma] kwin	Reporter:	eugene
Component:	wayland-generic	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DOWNSTREAM
Severity:	normal
Priority:	NOR
Version First Reported In:	5.14.5
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description eugene 2019-06-13 22:22:04 UTC

SUMMARY
Hardware acceleration does not work in kwin_wayland.

STEPS TO REPRODUCE
Launch kwin_wayland, directly or via dbus-run-session startplasmacompositor, run some apps.

OBSERVED RESULT
High CPU usage, low FPS, capable apps reporting llvmpipe driver being used.

EXPECTED RESULT
High performance similar to kwin_x11 or weston, with no noticeable CPU usage in non-demanding apps, GPU-specific GL driver being used by apps.

SOFTWARE/OS VERSIONS
Operating System: NixOS 19.03.172866.4649b6ef4b5
KDE Plasma Version: 5.14.5
Qt Version: 5.12.0
KDE Frameworks Version: 5.54.0
Kernel Version: 4.19.49
OS Type: 64-bit
Processors: 4 × Intel® Xeon® CPU E3-1225 V2 @ 3.20GHz
Memory: 15.4 GiB of RAM

ADDITIONAL INFORMATION
This problem may be specific to NixOS with its non-canonical filesystem hierarchy, however I think there should be at least some code to log useful info about whatever steps required to use hardware acceleration and make it available to clients have failed. I've tried various args and env vars, didn't get anything.
I've also tried running apps under kwin_wayland with env captured in weston, no luck.
I noticed that unlike weston and kwin_x11, kwin_wayland has its /proc/<pid>/ contents owned by root. Probably capabilities related, not sure if it matters. /dev/dri/card0 is opened, as expected.
I've got 2nd GPU in my system, but it's blacklisted and passed to VM.

Comment 1 eugene 2019-06-13 23:28:26 UTC

Tried EGL_LOG_LEVEL=debug, in kwin_wayland:

libEGL debug: DRI2: dlopen(/run/opengl-driver/lib/dri/swrast_dri.so)

in weston and x11:

libEGL debug: pci id for fd 4: 8086:016a, driver i965

libEGL debug: DRI2: dlopen(/run/opengl-driver/lib/dri/i965_dri.so)

Comment 2 eugene 2019-06-14 10:18:44 UTC

How graphics card device node fd is passed to client, actually? Maybe it's really /proc/<compositor_pid>/fd permissions issue, will check this soon.

Comment 3 Martin Flöser 2019-06-14 11:19:52 UTC

Please test with another distribution.

Comment 4 eugene 2019-06-15 11:09:59 UTC

Ubuntu 18.10, kwin_wayland 5.13.5 works well. NixOS kwin_wayland 5.14.5 and 5.15.3 don't, running client with root perms doesn't help either. I see that compositors with working acceleration all have wl_drm in their wl_registry, which client uses to choose the GPU, while kwin_wayland in NixOS doesn't have it.

Comment 5 Bug Janitor Service 2019-06-30 04:33:08 UTC

Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!

Comment 6 Martin Flöser 2019-06-30 06:12:42 UTC

Please report your findings to nixos.