Created attachment 25107 [details]
Sysprofile with mesa-master and mesa-7.4 glxgears performance.

To begin with I am using Debian (sid) and my X stack is

libdrm2                  2.4.9-1
xserver-xorg-video-intel 2:2.7.0-1
xserver-xorg-core        2:1.6.1-1
libgl1-mesa-dri          7.4-2
libgl1-mesa-glx          7.4-2
libglu1-mesa             7.4-2
libosmesa6               7.4-2

In all cases CPU is set to performance governor
# cpufreq-set -g performance

My hardware is
00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c)
and I use AccelMethod "UXA"

I used to get 40-50fps with RegnumOnline game at some point when I was using mesa from master before 7.4 release.

After 7.4 release a bug was introduced that textures are not rendered correctly so I was forced to use master again. 
Performance dropped to 20fps and then again after some commits to 8-15fps which is not playable.

There are two regressions that overlaps so git-bisect with lots of luck might find last one, not the one that happened after 7.4 release.

I am attaching sysprof results profiling both versions of mesa along with
comparison of medians from 10 fps samples.

With master glxgears for 10 samples
x <- c(800.376, 848.689, 810.539, 797.115, 811.153, 810.357, 810.774, 809.774, 811.079, 809.032)
> median(x)
[1] 810.448

With 7.4 glxgears for 10 samples
x <- c(1008.398, 1006.403, 1006.601, 1006.267, 1006.721, 1006.811, 1005.906, 1008.047, 1008.378, 1006.707)
> median(x)
[1] 1006.714