Unusably slow OpenGL performance on nouveau (GeForce 9600 GT) with rotated output under DRI 3
Submitted by Adam Williamson
Assigned to Nouveau Project
Description
Running Fedora 23, I just rebooted my system after it had been up for a long time and found GNOME Shell was unusably slow - far slower than a debug kernel, far slower than software rendering.
Running glxgears from an Xfce session had the same problem reported a speed of less than 2fps.
After trying various downgrades I finally hit the jackpot:
Packages Altered:
Downgrade xorg-x11-drv-dummy-0.3.6-23.fc23.x86_64 @@commandline
Downgraded 0.3.6-24.fc23.x86_64 @updates-testing
Downgrade xorg-x11-drv-libinput-0.14.0-1.fc23.x86_64 @@commandline
Downgraded 0.14.0-2.fc23.x86_64 @updates-testing
Downgrade xorg-x11-drv-nouveau-1:1.0.11-4.fc23.x86_64 @@commandline
Downgraded 1:1.0.12-0.2.fc23.x86_64 @updates-testing
Downgrade xorg-x11-server-Xephyr-1.17.2-2.fc23.x86_64 @@commandline
Downgraded 1.18.0-0.4.20150907.fc23.x86_64 @updates-testing
Downgrade xorg-x11-server-Xorg-1.17.2-2.fc23.x86_64 @@commandline
Downgraded 1.18.0-0.4.20150907.fc23.x86_64 @updates-testing
Downgrade xorg-x11-server-Xwayland-1.17.2-2.fc23.x86_64 @@commandline
Downgraded 1.18.0-0.4.20150907.fc23.x86_64 @updates-testing
Downgrade xorg-x11-server-common-1.17.2-2.fc23.x86_64 @@commandline
Downgraded 1.18.0-0.4.20150907.fc23.x86_64 @updates-testing
i.e. I went from the 1.18.0 X server snapshot down to 1.17.2 (and downgraded driver packages, since 1.18 has an ABI bump), and my performance is back to normal, Shell is usable again.
Note I did try an earlier build of the 1.18.0 snapshot - 1.18.0-0.2.20150907 - and it didn't help, so I'm pretty sure the bug is between 1.17.2 and the 1.18 snapshot, unless it's between -1 and -2 which seems unlikely.
Hardware is an NVIDIA GeForce 9600 GT:
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation G94 [GeForce 9600 GT] [10de:0622] (rev a1)
there were no obvious related messages in the system log, even with drm.debug=14. Please let me know what else I can do to help track this down. I'll try and see if I can build a current git snapshot and see if that works.