commit 2bba22c50b06abe9fd0d23933b1e64d35b419262
author Mike Galbraith <efault@gmx.de> Wed Sep 09 15:41:37 2009 +0200
committer Ingo Molnar <mingo@elte.hu> Wed Sep 09 17:30:05 2009 +0200
tree 5ac0373fa1d18f043cb27183f9f185ceda598915
parent b5d9d734a53e0204aab0089079cbde2a1285a38f

sched: Turn off child_runs_first

Set child_runs_first default to off.

It hurts 'optimal' make -j<NR_CPUS> workloads as make jobs
get preempted by child tasks, reducing parallelism.

Note, this patch might make existing races in user
applications more prominent than before - so breakages
might be bisected to this commit.

Child-runs-first is broken on SMP to begin with, and we
already had it off briefly in v2.6.23 so most of the
offenders ought to be fixed. Would be nice not to revert
this commit but fix those apps finally ...

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1252486344.28645.18.camel@marge.simson.net>
[ made the sysctl independent of CONFIG_SCHED_DEBUG, in case
  people want to work around broken apps. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>