> Have you verified that the scenario you're describing can actually > happen? AFAICS, cgroup_migrate_add_src() already does the pinning. Hmmm. Looking at it, group_migrate_add_src() does grab a ref on the css_set which contains the css, and the comments mention that grabbing a ref on the css_set will stop the css from being dropped. I must've misunderstood one of your previous emails (where you said that such code was not safe in the ->can_fork(), ->cancel_fork() and ->fork()) path. You also mentioned that depending on the css_set's ref being bumped to protect the contained csses is "sort of implementation detail. It can be implemented in different ways." Which made me think that depending on that is not a good idea. But if it's safe to depend on the cgroup_migrate_add_src() pinning the ref on the css_set, I'll drop this patch and fix up the other one accordingly. -- Aleksa Sarai (cyphar) www.cyphar.com -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
