Another Mesa regression and a bug in Mesa 10.5

[Luke]

Early in November the Oibaf PPA in Ubuntu Utopic switched over to the new mesa 10.5 builds. I am running Ubuntu Vivid but the PPA has yet to add Vivid and generally in this stage of an alpha the PPA's from the recently released version work fine. Anyway, I fired up the game scorched3d for the first time in a while and found ugly problems. First, the game locked up on loading skins for the tanks. Last time I saw this it was a hyper-Z bug, so I tried disabling hyper-Z, it did not help. Perhaps this is an issue with a single OpenGL extension?
I could enable everything in the game except the tank skins and it would work, but framerates plummeted from the 50-60fps range down to 18-22fps. Perhaps the splash screen is the most repeatable, it dropped from 24fps down to 8-11 fps.

Next I fired up Criticalmass (executable is called critter). This 2d game in opengl gives very fast framerates that drop with the number of sprites on the board. The least loaded framerate dropped about 15%, but the max loaded framerate roughly cut in half.

Where should I file the bug report for this against the Oibaf PPA version of Mesa 10.5? In the meantime I've rolled back to mesa 10.4 and gotten back all the performance, verifying that the problem has to be in one of those packages.

[asdfblah]

From https://launchpad.net/~oibaf/+archiv...aphics-drivers :

=== Debugging and reporting problems ===
If you have some problem with the drivers try running the application from the command line and see if there are graphics related warnings. Also type dmesg to see if there are other related informations here.

If you get crashes install the relevant -dbg pacakges (libgl1-mesa-dri-dbg or libgl1-mesa-dri-experimental-dbg for 3D drivers and xserver-xorg-video-intel-dbg , xserver-xorg-video-nouveau-dbg or xserver-xorg-video-radeon-dbg for X drivers) and reproduce the crash with gdb. Example:
$ gdb glxgears
[...make your application crash and then get a backtrace with:]
(gdb) bt

If X.org crashes look at /var/log/Xorg.0.log (or /var/log/Xorg.0.log.old when a new X session is started after the crash).

With the gathered informations try searching at https://bugs.freedesktop.org/query.cgi (also try with google) if someone already reported a similar bug. If not you may want to report a new bug:
for 3D drivers bugs: https://bugs.freedesktop.org/enter_bug.cgi?product=Mesa
for X / 2D driver bugs: https://bugs.freedesktop.org/enter_bug.cgi?product=xorg

[Luke]

The freeze in Scorched3d is silent

From https://launchpad.net/~oibaf/+archiv...aphics-drivers :

I ran Scorched3d from the command line, setting resolution for 1080x1920 but not fullscreen so my whole xserver would not be locked up and I could get back to the terminal. No output whatsoever. Bypassing the freeze by xkilling the window from which the game is launched generated only the "resource unavailable" line normally associated with killing an X window in this way. Nothing showed up in dmesg either.

I would not know the slightest thing about running the game in gdb, which I have installed but have never used.

[asdfblah]

Do you see any error messages in dmesg/syslog? Are you sure this is not a Ubuntu specific bug? What's your hardware (iGPU/dGPU, CPU, memory, ...)/software(distros in which this happens, kernel/Xorg/mesa/... versions)? How are you running the game (command line, game settings, Xorg settings, etc.)? Did you try debugging remotely through SSH?

I ran Scorched3d from the command line, setting resolution for 1080x1920 but not fullscreen so my whole xserver would not be locked up and I could get back to the terminal. No output whatsoever. Bypassing the freeze by xkilling the window from which the game is launched generated only the "resource unavailable" line normally associated with killing an X window in this way. Nothing showed up in dmesg either.

I would not know the slightest thing about running the game in gdb, which I have installed but have never used.

Oh yeah, sorry, I meant to show you the links to the bug tracker... that's where you report your bugs. Remember to search for similar problems before posting, and/or post comments in related bug reports if you think they haven't been fixed. Also, you can ask in the IRC channel, #radeon in freenode (webchat: https://webchat.freenode.net/?channels=radeon , may require registration). Or just wait for a radeon dev to reply

[Luke]

hardware listing

Do you see any error messages in dmesg/syslog? Are you sure this is not a Ubuntu specific bug? What's your hardware (iGPU/dGPU, CPU, memory, ...)/software(distros in which this happens, kernel/Xorg/mesa/... versions)? How are you running the game (command line, game settings, Xorg settings, etc.)? Did you try debugging remotely through SSH?


Oh yeah, sorry, I meant to show you the links to the bug tracker... that's where you report your bugs. Remember to search for similar problems before posting, and/or post comments in related bug reports if you think they haven't been fixed. Also, you can ask in the IRC channel, #radeon in freenode (webchat: https://webchat.freenode.net/?channels=radeon , may require registration). Or just wait for a radeon dev to reply

CPU is AMD FX 8120, GPU is Radeon HD6750, same results on AMD Phenom II x4 with Radeon HD5570. I've never tried to do a remote debugging, getting to the console was a simple matter of not fullscreening the game. I'm not on IRC, know little about it. Can you post the bug tracker link? For now I've just rolled back mesa and can leave it that way until this gets fixed.

[Luke]

No errors in dmesg

Do you see any error messages in dmesg/syslog? Are you sure this is not a Ubuntu specific bug? What's your hardware (iGPU/dGPU, CPU, memory, ...)/software(distros in which this happens, kernel/Xorg/mesa/... versions)? How are you running the game (command line, game settings, Xorg settings, etc.)? Did you try debugging remotely through SSH?


Oh yeah, sorry, I meant to show you the links to the bug tracker... that's where you report your bugs. Remember to search for similar problems before posting, and/or post comments in related bug reports if you think they haven't been fixed. Also, you can ask in the IRC channel, #radeon in freenode (webchat: https://webchat.freenode.net/?channels=radeon , may require registration). Or just wait for a radeon dev to reply

There were no errors in dmesg,running the game not in fullscreen let me get to the terminal from which it was launched, no text at all there,

[Luke]

Fixed as of January

This bug was fixed, I think it was later in December simply because I don't remember any test/rollback session this month. Wasn't an issue very long and thankfully was quickly found and fixed.