Multithreading - The Future of PA and Titans

Hi @Sorian,

I'm one of the developers working on the Linux AMD OpenGL drivers. There has been a long reported rendering issue that is apparently due to a missing mutex in the UI rendering code [1]. Any chance you can confirm this is a bug in the game as claimed in comment 12 and whether it will be fixed?

Thanks for your time,
Tim

[1] https://bugs.freedesktop.org/show_bug.cgi?id=65968#c12

Sim speed dropping down to unplayable levels is not not rare the way my group plays the game. These sim speed crashes are almost guaranteed.

Dear Linux AMD OpenGL driver developer. I am not able to say if i am running into same rendering issues as stated in your thread. But I could make a screenshot if you want.

BUT.

I doubt that it's PA fault to not clear the memeory.

Because -

On my PC, the dirty UI area contains some other user's graphic stuff. UI, video and images blocks, all distorted.

I use several X server instances. Every time i boot my standard Ubuntu, I log into graphic UI several times. With different usernames. One username for working, one for surfing and gaming and one for finance. Then I switch between these instances with CTRL+ALT+F7 ... F9

These should be different security contexts for the driver and i dont understand, why PA memory can acces to finance graphics.

But I wonder why PA isn't filling this dirty area...

Anyway, the bug is not really annoying for me, as the dirty areas refresh as soon as the commander drops into the game and the game starts. F5 also solves this when not using windowed mode.

Its awesome seeing you back on track working with mikeyh and the rest of the crew, really refuels my love for PA!

The one thing that caught my eye (tnx @nimzodragonlord ) is the bit about an economy update. @Sorian @panews is that referring to a performance issue in some way, or a mechanics change!? Or maybe *gasp* balance??

Cant wait to see what comes next !

sorry for spamming in this thread, but i wanted to share my screenshot to timothyja:


(in this case, only content from same x server instance "leaks",...)

I'm aware of the problem but if comment 12 in the bug report is correct then
there is a bigger problem then just not clearing the buffers.

You can force radeonsi to clear the buffers with radeonsi_zerovram=true or
R600_DEBUG=zerovram environment variables but this does not fully fix the
problem.

According the bug report a missing mutex causes a use after free on a
previously allocated buffer in this case we cannot work around the problem
in the driver.

I was hoping @Sorian could confirm if there is indeed a missing mutex that
could cause this problem

@emarkus, what about your Vram usage at that point? say you're playing sandbox and no more units are being produced (pause the game), does Vram usage continue to climb? what about RAM?

If neither climb (all that much, I should hope then when paused game history doesn't continue to push things to ram) then I think your bug is unrelated and might have more to do with your high screen resolution (2160p, so 4K) which PA was known to have problems with in the past, especially with AMD/ATI graphic cards.

is your DPI set at 100 ? I doubt it as it would make your ubuntu pretty tough to read as a general rule.

The goal is not to keep it this way but to determine if yes or no this is a DPI issue : try setting your DPI to 100 reboot and run your PA bug repro again, does the bug still occur?

Also attach PAlogs if you please

That discussion is not catching the point. In case memory is leaked from another x server instance, then it isn't PA related (or not only). I just attached the screenshot, to show how roughly the memory corruption or what ever looks like.

btw, i use 4k with 96 DPI. cant tell about vram usage. but shouldn't matter