Hey, Giuseppe reported that the the affinity mask isn't updated when a process is spawned directly into the target cgroup via CLONE_INTO_CGROUP. However, migrating a process will cause the affinity mask to be updated (see the repro at [1]. I took a quick look and the issue seems to be that we don't call the various attach handlers during CLONE_INTO_CGROUP whereas we do for migration. So the solution seems to roughly be that we need to call the various attach handlers during CLONE_INTO_CGROUP as well when the parent's cgroups is different from the child cgroup. I think we need to call all of them, can, cancel and attach. The plumbing here might be a bit intricate since the arguments that the fork handlers take are different from the attach handlers. Christian [1]: https://paste.centos.org/view/f434fa1a
