On Mon, Feb 03, 2020 at 03:32:28PM +0100, Michal Koutný wrote:

On Sun, Feb 02, 2020 at 10:37:02AM +0100, Christian Brauner [off-list ref] wrote:

quoted

cgroup_post_fork() is called past the point of no return for fork and
cgroup_css_set_put_fork() is explicitly documented as only being
callable before forks point of no return:

I missed this and somehow incorrectly assumed it's called at the end of
fork too. I find the css_set refcounting correct now.

BTW any reason why not to utilize cgroup_css_set_put_fork() for the
regular cleanup in cgroup_post_fork() too?

Hmyeah, should be doable if we do:
kargs->cset = NULL;
cgroup_css_set_put_fork(kargs);

Christian