On Thu 07-11-19 22:41:13, Roman Gushchin wrote:
On Thu, Nov 07, 2019 at 06:02:00PM +0100, Michal Hocko wrote:
On Thu 07-11-19 16:42:41, Roman Gushchin wrote:
[...]
It's an exiting task with the PF_EXITING flag set and it's in their late stages of life.
This is a signal delivery path AFAIU (get_signal) and the coredumping happens before do_exit. My understanding is that that unlinking happens from cgroup_exit. So either I am misreading the backtrace or there is some other way to leave cgroups or there is something more going on.
Yeah, you're right. I have no better explanation for this and the similar, mentioned in the commit bsd accounting issue,
Tejun mentioned bsd accounting issue as well, but I do not see any explicit reference to it in neither of the two patches.
than some very rare race condition that allows cgroups to be offlined with a task inside.
I'll think more about it.
Thanks a lot. As I've said, I am not opposing this change once we have a proper changelog but I find the explanation really weak. If there is a race then it should be fixed as well.
Thanks!