Comment 9 for bug 1951289

After some debugging, I realized the above is the same issue that this commit fixed upstream:

commit 71e5f6644fb2f3304fcb310145ded234a37e7cc1
Author: Dietmar Eggemann <dietmar.eggemann@XXX>
Date: Mon Feb 1 10:53:53 2021 +0100

    sched/topology: Fix sched_domain_topology_level alloc in sched_init_numa()

I've backported these fixes and submitted them to stable (5.10.y, 5.4.y & 4.19.y):

https://www.spinics.net/lists/stable/msg539011.html
https://www.spinics.net/lists/stable/msg539981.html

4.14.y's code is too different for these changes to easily apply.

I'll wait for them to bake there to shake out any regressions before submitting to Ubuntu. I expect that focal will pick up the fix from there naturally, but bionic will need an explicit submission since they won't make it into a 4.14.y release.