Re: [RFC PATCH v2 11/17] cgroup: Implement new thread mode semantics

[Waiman Long <longman@redhat.com>]

On 06/01/2017 05:18 PM, Tejun Heo wrote:
> Hello,
>
> On Thu, Jun 01, 2017 at 05:12:42PM -0400, Waiman Long wrote:
>> Are you referring to keeping the no internal process restriction and
>> document how to work around that instead? I would like to hear what
>> workarounds are currently being used.
> What we've been talking about all along - just creating explicit leaf
> nodes.
>
>> Anyway, you currently allow internal process in thread mode, but not in
>> non-thread mode. I would prefer no such restriction in both thread and
>> non-thread mode.
> Heh, so, these aren't arbitrary.  The contraint is tied to
> implementing resource domains and thread subtree doesn't have resource
> domains in them, so they don't need the constraint.  I'm sorry about
> the short replies but I'm kinda really tied up right now.  I'm gonna
> do the thread mode so that it can be agnostic w.r.t. the internal
> process constraint and I think it could be helpful to decouple these
> discussions.  We've been having this discussion for a couple years now
> and it looks like we're gonna go through it all over, which is fine,
> but let's at least keep that separate.

I wouldn't argue further on that if you insist. However, I still want to
relax the constraint somewhat by abandoning the no internal process
constraint  when only threaded controllers (non-resource domains) are
enabled even when thread mode has not been explicitly enabled. It is a
modified version my second alternative. Now the question is which
controllers are considered to be resource domains. I think memory and
blkio are in the list. What else do you think should be considered
resource domains?

Cheers,
Longman



any of the resource domains (!threaded) controllers are enabled.