Messages in this thread | | | Date | Thu, 5 Jan 2023 09:16:43 +0100 | Subject | Re: [PATCH 0/3] mm/uffd: Fix missing markers on hugetlb | From | David Hildenbrand <> |
| |
On 04.01.23 23:52, Peter Xu wrote: > When James was developing the vma split fix for hugetlb pmd sharing, he > found that hugetlb uffd-wp is broken with the test case he developed [1]: > > https://lore.kernel.org/r/CADrL8HWSym93=yNpTUdWebOEzUOTR2ffbfUk04XdK6O+PNJNoA@mail.gmail.com > > Missing hugetlb pgtable pages caused uffd-wp to lose message when vma split > happens to be across a shared huge pmd range in the test. > > The issue is pgtable pre-allocation on hugetlb path was overlooked. That > was fixed in patch 1.
Nice timing, I stumbled over that while adjusting background snapshot code in QEMU and wondered why we are not allocating page tables in that case -- and wanted to ask you why :)
-- Thanks,
David / dhildenb
| |