real, REAL bad performance with dri2 and ati kms

[pedepy]

ive just been trying ati kms for the 1st time using kernel 2.6.31 and the git driver and libraries dated october 12th. (the available drivers and libs don't seem to work the the kernel provided by my distro).

anyway, kms does seem to work and all, no errors can be seen, but the performance is just *awful*. scrolling in ff is real bad; compiz and kwin compositing often halt the whole computer when trying to move or resize windows ... glxgears reports about a third of my usual frames per second and playing video is choppy if i try to do anything else at the same time.

i know these things probably need some optimization work but this is just ridiculous. that is, unless there's something im not doing or configuring right. or maybe i just caught a bad revision of the git driver. who knows...


anyone?

[nhaehnle]

More information would be nice, because it seems other people obviously don't have this problem. For example: did you get the latest Mesa in addition to the DDX driver? If Compiz is very slow, maybe Compiz is using software rendering? Also, on what hardware is this? And so on... just arbitrary ranting is unlikely to get the problem resolved.

[Vash63]

Other than the Firefox being slow I have none of those issues, you probably don't have all the required pieces. AFAIK, scrolling in FF is still slow though with the latest drm, libdrm, radeon and mesa. Chromium seems smooth though.

[nhaehnle]

If I recall correctly, somebody mentioned Firefox was slow because it abuses the XGetImage interface, which has not been optimized in the KMS case.

[madman2k]

More information would be nice, because it seems other people obviously don't have this problem.

well, actually I had the same problem: http://www.phoronix.com/forums/showthread.php?t=18939

[rob2687]

Does the xorg-edgers ppa give you DRI2? cause I found that to be pretty slow on Karmic.

[tettamanti]

Current git (Linus' tree) seems better, previously I've seen Xorg monopolizing one core.
Oprofile shows that Xorg is hitting find_vma pretty hard:

samples  %        image name               symbol name
7861     59.9481  vmlinux                  find_vma
1629     12.4228  radeon                   /radeon
369       2.8140  drm                      /drm
337       2.5700  Xorg                     /usr/bin/Xorg
243       1.8531  libpixman-1.so.0.16.2    /usr/lib/libpixman-1.so.0.16.2
227       1.7311  radeon_drv.so            set_default_state

[madman2k]

Current git (Linus' tree) seems better, previously I've seen Xorg monopolizing one core.

yeah, thats exactly the phenomenon I see with DRI2 in Karmic with xorg-edgers.

[pedepy]

More information would be nice, because it seems other people obviously don't have this problem. For example: did you get the latest Mesa in addition to the DDX driver? If Compiz is very slow, maybe Compiz is using software rendering? Also, on what hardware is this? And so on... just arbitrary ranting is unlikely to get the problem resolved.

all i know i that i updated every 'relevant' packages to what was then the latest available git snapshot (20091012 methinks)..

it's not just compiz thats slow it's everything direct rendering related. i know for a fact that it's enabled, only thing is that the performance of direct rendering is all of a sudden much worse than it was before.

ill try to play around with various configurations and driver snapshots to see if anything comes up. i just wondered if there wasnt some possibly obvious xorg 'flag' or module option to be set that would 'unblock' everything .. somehow ...

[legume]

.....

What is your card/chip?