On Wed, Jan 08, 2020 at 07:10:49PM +0100, Christian Brauner wrote: > On Wed, Jan 08, 2020 at 05:01:02PM +0100, Michal Koutný wrote: > > On Mon, Dec 23, 2019 at 07:15:03AM +0100, Christian Brauner <christian.brauner@xxxxxxxxxx> wrote: > > > This adds support for creating a process in a different cgroup than its > > > parent. > > Binding fork and migration together looks useful. > > > > > --- a/kernel/cgroup/cgroup.c > > > +++ b/kernel/cgroup/cgroup.c > > > @@ -5882,21 +5882,176 @@ void cgroup_fork(struct task_struct *child) > > > INIT_LIST_HEAD(&child->cg_list); > > Just a nitpick, I noticed the comment for cgroup_fork should be updated > > too (generic migration happens in cgroup_post_fork). > > Thanks. > > > > > > --- a/kernel/fork.c > > > +++ b/kernel/fork.c > > > [...] > > > @@ -2279,8 +2278,7 @@ static __latent_entropy struct task_struct *copy_process( > > > write_unlock_irq(&tasklist_lock); > > > > > > proc_fork_connector(p); > > > - cgroup_post_fork(p); > > > - cgroup_threadgroup_change_end(current); > > > + cgroup_post_fork(current, p, args); > > I can see that when CLONE_INTO_CGROUP | CLONE_NEWCGROUP is passed, then > > the child's cgroup NS will be rooted at parent's css set > > (copy_namespaces precedes cgroup_post_fork). > > > > Wouldn't it make better sense if this flags combination resulted in > > child's NS rooted in its css set? > > I need to take a closer look but it sounds like we should move the > copying of the cgroup namespace to a later point; but again I need to > look into this. Ok, this is way simpler I think, we just set the root_cset of the new cgroup namespace to the child's cset in cgroup_post_fork() if CLONE_NEWCGROUP is requested. Christian
