| Message ID | bd28ebcf-4d42-7184-8189-ffed6fe7d4dc@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [next] mm/migrate: fix remove_migration_pte() of hugetlb entry | expand |
On Sat, Feb 26, 2022 at 06:25:15PM -0800, Hugh Dickins wrote: > - if (!folio_test_ksm(folio)) > + /* Skip call in common case, plus .pgoff is invalid for KSM */ > + if (pvmw.nr_pages != 1 && !folio_test_hugetlb(folio)) > idx = linear_page_index(vma, pvmw.address) - pvmw.pgoff; How do you feel about this instead? - if (!folio_test_ksm(folio)) + /* pgoff is invalid for ksm pages, but they are never large */ + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) idx = linear_page_index(vma, pvmw.address) - pvmw.pgoff;
On Mon, 28 Feb 2022, Matthew Wilcox wrote: > On Sat, Feb 26, 2022 at 06:25:15PM -0800, Hugh Dickins wrote: > > - if (!folio_test_ksm(folio)) > > + /* Skip call in common case, plus .pgoff is invalid for KSM */ > > + if (pvmw.nr_pages != 1 && !folio_test_hugetlb(folio)) > > idx = linear_page_index(vma, pvmw.address) - pvmw.pgoff; > > How do you feel about this instead? > > - if (!folio_test_ksm(folio)) > + /* pgoff is invalid for ksm pages, but they are never large */ > + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) > idx = linear_page_index(vma, pvmw.address) - pvmw.pgoff; > That looks nicer to me too. I'll assume that's what you will add or squash in your tree, and no need for me to resend - thanks. Hugh
--- mmotm/mm/migrate.c +++ linux/mm/migrate.c @@ -182,7 +182,8 @@ static bool remove_migration_pte(struct struct page *new; unsigned long idx = 0; - if (!folio_test_ksm(folio)) + /* Skip call in common case, plus .pgoff is invalid for KSM */ + if (pvmw.nr_pages != 1 && !folio_test_hugetlb(folio)) idx = linear_page_index(vma, pvmw.address) - pvmw.pgoff; new = folio_page(folio, idx);
The foliation of remove_migration_pte() is currently wrong on hugetlb anon entries, causing LTP move_pages12 to crash on BUG_ON(!PageLocked) in hugepage_add_anon_rmap(). Fixes: b4010e88f071 ("mm/migrate: Convert remove_migration_ptes() to folios") Signed-off-by: Hugh Dickins <hughd@google.com> --- Please just fold in if you agree. mm/migrate.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)