On 05.08.22 20:14, Peter Xu wrote: > On Fri, Aug 05, 2022 at 01:03:28PM +0200, David Hildenbrand wrote: >> diff --git a/mm/mmap.c b/mm/mmap.c >> index 61e6135c54ef..462a6b0344ac 100644 >> --- a/mm/mmap.c >> +++ b/mm/mmap.c >> @@ -1683,6 +1683,13 @@ int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot) >> if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED))) >> return 0; >> >> + /* >> + * Hugetlb does not require/support writenotify; especially, it does not >> + * support softdirty tracking. >> + */ >> + if (is_vm_hugetlb_page(vma)) >> + return 0; > > I'm kind of confused here.. you seems to be fixing up soft-dirty for > hugetlb but here it's explicitly forbidden. > > Could you explain a bit more on why this patch is needed if (assume > there'll be a working) patch 2 being provided? I want something simple to backport. And even with patch #2 in place, as long as we don't support softdirty tracking, it doesn't make sense to enable it here as of now. -- Thanks, David / dhildenb
