[PATCH] sched: Fix and clean up rate-limit newidle code

[Mike Galbraith]

commit eae0c9dfb534cb3449888b9601228efa6480fdb5 upstream.

Commit 1b9508f, "Rate-limit newidle" has been confirmed to fix
the netperf UDP loopback regression reported by Alex Shi.

This is a cleanup and a fix:

 - moved to a more out of the way spot

 - fix to ensure that balancing doesn't try to balance
   runqueues which haven't gone online yet, which can
   mess up CPU enumeration during boot.

Reported-by: Alex Shi <alex.shi@xxxxxxxxx>
Reported-by: Zhang, Yanmin <yanmin_zhang@xxxxxxxxxxxxxxx>
Signed-off-by: Mike Galbraith <efault@xxxxxx>
Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <1257821402.5648.17.camel@xxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

aka:
http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.32.y.git;a=commit;h=35c1ee3e78766d5666f418af638def9c67e63ecb

Reverting this from a clean 32.2 tree results in a kernel with newidle
fix, but still working halt/reboot. The only difference between this and
the bisected one is the additional change in cpumask handling.

That was more fun than expected :)

Holger
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