Re: 2.6.32 cgroup regression

[Mike Galbraith <efault@gmx.de>]

On Tue, 2010-08-31 at 16:25 +0900, Minoru Usui wrote:
> Hi, Mike
> 
> On Wed, 25 Aug 2010 07:56:01 +0200
> Mike Galbraith <efault@gmx.de> wrote:
> 
> > On Tue, 2010-08-24 at 13:10 -0700, Josh Hunt wrote:
> > > This commit makes the ltp cpuctl latency test #2 hang indefinitely:
> > > 
> > > commit b5d9d734a53e0204aab0089079cbde2a1285a38f
> > > Author: Mike Galbraith <efault@gmx.de>
> > > Date:   Tue Sep 8 11:12:28 2009 +0200
> > > 
> > >     sched: Ensure that a child can't gain time over it's parent after fork()
> > 
> > Ouch.  Yeah, that commit is buggy, and never got fixed up in stable.
> > Reverting it will restore a slightly less buggy, but not very good
> > situation.  Getting the fork problems all fixed up took a while.
> > (quick fix vs revert didn't help your testcase)
> 
> I'm interested in this problem, because I hit the same problem in RHEL6 beta2.
> (It based on 2.6.32)
> 
> Are you writing a patch to solving this problem?

No, the necessary patches were already written.  I just needed to
backport.  Illness and squabbles with git sendemail (i lost) held me up.

> If you are doing, I can test it in RHEL6 beta2 (or latest).

I just sent a 50 patch series, ever so lovingly git am applied. git
format-patch exported, then imported into evolution one darn patch at a
time, to stable to either apply or bin as maintainers see fit.  To test,
all you should need to do is test mainline.  If you'd like a quilt
tarball against 32.21 anyway, just holler.

The series has all the fork/exec/wakeup/hotplug yada yada fixes I think
are mana from heaven for our long-term stable kernel.  I may well get
"are you outta yer ever lovin' mind?" back, but _I_ think it's needed,
so...

	-Mike