Re: [ckrm-tech] [PATCH 1/7] containers (V7): Generic container system abstracted from cpusets code

Paul Menage
2007-03-08T10:40:38Z

On 3/8/07, Srivatsa Vaddagiri <vatsa@in.ibm.com> wrote:
> On Wed, Mar 07, 2007 at 12:50:03PM -0800, Paul Menage wrote:
> > The callback mutex (which is what container_lock() actually locks) is
> > also used to synchronize fork/exit against subsystem additions, in the
> > event that some subsystem has registered fork or exit callbacks. We
> > could probably have a separate subsystem_mutex for that instead.
>
> Why can't manage_mutex itself be used there (to serialize fork/exit callbacks
> against modification to hierarchy)?

Because manage_mutex can be held for very long periods of time. I
think that a combination of a new lock that's only taken by fork/exit
and register_subsys, plus task_lock (which prevents the current task
from being moved) would be more lightweight.

Paul