On Mon, 18 Nov 2019 13:58:04 +0100 Thomas Hellström (VMware) <thomas_os@xxxxxxxxxxxx> wrote: > >> Is a -stable backport warranted? > > I believe it is. > > Note that this was caught during a code audit rather than a real > experienced problem. It looks to me like the only implementation that > currently creates huge pud pagetable entries is dev_dax_huge_fault() > which doesn't appear to care much about private (COW) mappings or > write-tracking which is, I believe, a prerequisite for create_huge_pud() > falling back on thread 1, but not in thread 2. > > This means (assuming that's intentional) that a stable backport > shouldn't be needed. > > For the WIP huge page support for graphics memory we'll be allowing both > COW mappings and write-tracking, though, but that's still some time away. > > In any case, I think this patch needs -rc testing to catch potential > pud_devmap issues before submitted to stable. OK, thanks, I'll queue it for 5.5-rc1 with a -stable tag. Hopefully that way it will get a bit of exposure before the stable trees pick it up. Maybe this is optimistic..
