tree 62fcfc395e98ff7a4ff6bee3364d0bb86024b171
parent a7be37ac8e1565e00880531f4e2aff421a21c803
author Peter Zijlstra <a.p.zijlstra@chello.nl> 1214566872 +0200
committer Ingo Molnar <mingo@elte.hu> 1214569888 +0200

sched: fix calc_delta_asym()

calc_delta_asym() is supposed to do the same as calc_delta_fair() except
linearly shrink the result for negative nice processes - this causes them
to have a smaller preemption threshold so that they are more easily preempted.

The problem is that for task groups se->load.weight is the per cpu share of
the actual task group weight; take that into account.

Also provide a debug switch to disable the asymmetry (which I still don't
like - but it does greatly benefit some workloads)

This would explain the interactivity issues reported against group scheduling.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>