revert ("sched: fair-group: SMP-nice for group scheduling")

revert ("sched: fair-group: SMP-nice for group scheduling")

Yanmin Zhang reported:

Comparing with 2.6.25, volanoMark has big regression with kernel 2.6.26-rc1.
It's about 50% on my 8-core stoakley, 16-core tigerton, and Itanium Montecito.

With bisect, I located the following patch:

| 18d95a2832c1392a2d63227a7a6d433cb9f2037e is first bad commit
| commit 18d95a2832c1392a2d63227a7a6d433cb9f2037e
| Author: Peter Zijlstra <[email protected]>
| Date:   Sat Apr 19 19:45:00 2008 +0200
|
|     sched: fair-group: SMP-nice for group scheduling

Revert it so that we get v2.6.25 behavior.

Bisected-by: Yanmin Zhang <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>