[$] Fixing a race in hugetlbfs

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