Upgrade experience 5.1p10->5.2 Beta

[Justin Smith]

>Are you running with GENERIC from 5.2-BETA?  If so, you may wish to
>recompile your kernel with WITNESS and INVARIANTS turned off and see if
>that helps.  These debugging features are critical during the development
>process, but also seriously impact performance and might make the
>difference you're seeing.
>  
>
This worked like a charm! Everything, including opengl-intensive 
applications seem to work perfectly. It's amazing only problem was in 
the debugging code! Thank you.