Re: [PATCH/RFC] Have sane default values for cpusets

From: Lennart Poettering
Date: Thu May 13 2010 - 20:03:30 EST


On Thu, 13.05.10 23:19, Peter Zijlstra (peterz@xxxxxxxxxxxxx) wrote:

>
> On Thu, 2010-05-13 at 16:03 +0200, Lennart Poettering wrote:
> > > On Wed, 2010-05-12 at 21:07 +0200, Lennart Poettering wrote:
> > > > See Dhaval's patch on the background of systemd
> > > > (http://0pointer.de/blog/projects/systemd.html). When a service is
> > > > started in systemd, we create a cgroup for it, when it ends, we remove
> > > > it.
> > >
> > > I seriously hope that's optional, because I for one would really hate a
> > > system that does that. I still mostly build kernels with only cpuset in
> > > and really don't want anybody but me creating groups in there.
> >
> > By default systemd will create its groups in the "debug" hierarchy, (at
> > least for now, in the long run i'd like to see "noop" hierarchy or so,
> > that doesn't sound so temporary), since that controller is not useful
> > for anything but keeping track of processes. So it shouldn't bother you
> > at all.
>
> Will it still work with a CONFIG_CGROUP=n kernel? I see distributions
> deteriorate, you cannot even boot a raw bzImage kernel without initrd on
> most distros (sure, its not too hard to fix, but still).

No it won't work without cgroups.

> Also, I get all kinds of dumb-ass init-script failures for not having
> modules but stuff built-in. A prime example is NFS failing on start on
> both fedora and ubuntu with a built-in nfs server (for different but
> both retarded reasons).
>
> Requiring CONFIG_CGROUP=y to even get init running seems like a final
> straw to ensure nobody will ever get anything to boot these days.

Well, I wasn't aware that cgroups is now in the kernel for the purpose
that people should *not* use it.

Next time something is added to the kernel please mark it as "Hey,
please don't use it, this is only here so that you don't use
it. Thanks!" Maybe then dumb-ass folks like me will notice and refrain
from using it.

Requiring a single kernel options is not really too much to ask, is it?
Don't be that conservative. systemd certainly won't require an initrd
or anything else equally intrusive btw.

Lennart

--
Lennart Poettering Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/ GnuPG 0x1A015CC4
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