On Thu Aug 20, 2026 at 3:40 PM EDT, Yeoreum Yun wrote: > Since glibc commit 321e1fc73f (“malloc: Enable 2MB THP by default on > AArch64”), > glibc may call madvise(MADV_HUGEPAGE) for sufficiently large allocations > made by memalign(). > > The underlying VMA may start at a different address from the aligned > address returned by memalign(). Furthermore, a subsequent > madvise(MADV_HUGEPAGE) call does not split the VMA because the flag is > already set. > > This causes split_huge_page_test to fail because the check_huge_xxx() > helpers incorrectly require the address returned by memalign() to > match the VMA start address reported in /proc/self/smaps. > > Fix this by using /proc/self/pagemap and /proc/kpageflags instead of > /proc/self/smaps to detect huge pages and change the meaning of > check_huge_xxx()'s nr_hpages argument:
Have you checked Baolin's patches[1] in mm-new? They resue gather_after_split_folio_orders() to reimplement check_huge_xxx(), also based on pagemap and kpageflags. Does it fix the issue? [1] https://lore.kernel.org/all/[email protected]/ > > - nr_hpages > 0: check all of pages in the range are huge page. > - nr_hpages < 0: check all of pages in the range are not huge page. > - nr_hpages == 0: invalid. > > Reported-by: David Hildenbrand (Arm) <[email protected]> > Signed-off-by: Yeoreum Yun <[email protected]> > --- > tools/testing/selftests/mm/khugepaged.c | 26 ++--- > tools/testing/selftests/mm/split_huge_page_test.c | 6 +- > tools/testing/selftests/mm/vm_util.c | 135 > ++++++++++++++++++---- > tools/testing/selftests/mm/vm_util.h | 1 + > 4 files changed, 131 insertions(+), 37 deletions(-) > -- Best Regards, Yan, Zi
