Vsync broken with i915 since [mesa/intel-dri/libgl]-7.10

Question

Hi,
I have a netbook with intel i945gme.
Since last update with mesa 7.10 running glxgears is not smooth and the fps are ~ 1/2 of the screen refresh rate.
chris@chriseee ~ % glxgears
Running synchronized to the vertical refresh. The framerate should be
approximately the same as the monitor refresh rate.
192 frames in 5.1 seconds = 37.623 FPS
146 frames in 5.0 seconds = 29.159 FPS
^C
130 chris@chriseee ~ %
But it does work without vsync. It is really smooth then (and proves that the fps are higher then 1/2 of the screen refresh rate when not limited):
chris@chriseee ~ % vblank_mode=0 glxgears
ATTENTION: default value of option vblank_mode overridden by environment.
ATTENTION: default value of option vblank_mode overridden by environment.
1633 frames in 5.0 seconds = 326.594 FPS
1639 frames in 5.0 seconds = 327.623 FPS
^C
130 chris@chriseee ~ %
I have no xorg.conf and no ~/.drirc.
Can anyone reproduce?

Answer 1

Gusar wrote:Can you then report issues in another app?
For me, personally? YouTube / Flash and even Neverball and Osmos. If I let the mouse idle, the performance begins to "jerk" a bit. It has gotten better with each new iteration of the intel driver, but it was noticeably worse with 2.10 through 2.12. Now it's not really too big of a deal (but it's still worse than 2.9.1 and earlier.)
I understand this "glxgears is not a benchmark" argument, but it does allow you to observe a change. For instance, running glxgears with intel driver 2.9.1 would not change framerate based on idle/active cursor. Then with 2.10+, it suddenly does, so it at least marks a noticeable difference that you can refer to if you have other issues. "I noticed such and such after I updated from version X to version Y. Maybe that's why this crashes after the recent updates."
Last edited by flan_suse (2011-02-15 04:20:50)