Containers: css_put() dilemma

[Paul (宝瑠) Menage]

On 7/17/07, Balbir Singh <balbir at linux.vnet.ibm.com> wrote:
> without too much knowledge of each other. BTW, what are the semantics
> of css_put() is it expected to free the container/run the release agent
> when the reference count of the container_subsys_state drops to zero?
>

If you css_put() the last reference on a subsystem state object and
the associated container is marked as notify_on_release, then
check_for_release() is called which does a more full check of whether
the container is releasable. If it is, a workqueue task is scheduled
to run the userspace release agent, which can then do anything it
wants, including potentially deleting the empty container.

Paul