Sorry for my lack of knowledge, but i thought that on this forum someone could help our problem.

With XBMC running on Linux, the community discovered that playing 1080p HD h264 content with it the performance on Ubuntu Intrepid's new 2.6.27 kernels are way worse than on the older 2.6.24 Ubuntu Hardy kernel.

After a whole lot of debugging and discussions we relized that the problem should be the new CFS scheduler intruduced in newer kernels. We see some really strange things while playing back the video. For example checking TOP threads shown it can be seen that XBMC uses 2 main threads decoding the video with almost even cpu time given to them, but when we check the core utilizations the cores are loaded 90%-15% very uneven while on Hardy it is some 50% - 50%.

With Intrepid's new kernel we have a lot of dropped frames (sometimes more than a hundred in 1 min clip) while the same plays without a drop on Hardy.

Can someone help how we could tune the new scheduler to run at least with the same performance like the old one ?

If it is not possible can it be reverted to the old scheduler with the new kernels ?

Thanks for any suggestions or expreiences.

Oh and XBMC using ffmpeg multithreaded version.