[$] Fixing a race in hugetlbfs

As the memory-management track at the 2022 Linux Storage,
Filesystem, Memory-management and BPF Summit (LSFMM) neared its
conclusion, Mike Kravetz ran a session remotely to talk about page
sharing with hugetlbfs, which is a special filesystem that provides access
to huge pages. (See this article series
for lots of information about hugetlbfs). Hugetlbfs can help to reduce
page-table overhead when pages are shared between large numbers of
processes, but there is a problem that he is trying to find a solution for.