[Intel-gfx] Bug: wayland performance halfed when running es2gears_wayland at fedora17

[Alex Wu]

Hi all,
We are doing some performance profiling on wayland using es2gears and
found a issue that mesa-deoms/src/egl/opengles2/es2gears_wayland
(running drm backend) on platform-a (sandybridge, fedora 17 with kernel
version 3.5) has 30fps but es2gears_x11 60fps, but on platform-b
(sandybridge, Ubuntu 12.04 with kernel version 3.2) the fps is 60fps
both for es2gears_wayland and es2gears_x11.

Two platform has the same version status:

drm: 6fa2b29d226306870eebe93afb2106ca7d79569b
Mesa: 4e087de51ad0e7ba4a7199d3664e1d096f8dc510
demos: 7ba23583b237d4c07823006ef35dca434ebd5759
Wayland: 915cdeee29291332384c4cf9ee67758e19500131
weston: cd8cdccdd375058ae467974af5831a507ed016f5


I debugged on platform-a and found that drmModePageFlip in
weston/src/compositor-drm.c has calling rate of 30/s. If not set the
EGL_DEPTH_SIZE attribute on EGLContext in
mesa-deoms/src/egl/eglut/eglut.c, the fps of es2gears_wayland gets 60 fps.

we also installed ubuntu 12.04(with 3.2 kernel) on platform-a, and build
all the packages needed, the es2gears_wayland got 60fps.

So, my question is why wayland performance halfed when running
es2gears_wayland at fedora17 (kernel 3.5)?