On 05/21/2020 07:19 PM, Hugh Dickins wrote:
> Fix 5.7-rc6-mm1 page migration crash in unmap_and_move(): when the
> page to be migrated has been freed from under us, that is considered
> a MIGRATEPAGE_SUCCESS, but no newpage has been allocated (and I don't
> think it would ever need to be counted as a successful THP migration).
>
> Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
> ---
> Fix to mm-vmstat-add-events-for-pmd-based-thp-migration-without-split.patch
>
> mm/migrate.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- 5.7-rc6-mm1/mm/migrate.c 2020-05-20 12:21:56.117693827 -0700
> +++ linux/mm/migrate.c 2020-05-20 15:08:12.319476978 -0700
> @@ -1248,7 +1248,7 @@ out:
> * we want to retry.
> */
> if (rc == MIGRATEPAGE_SUCCESS) {
> - if (PageTransHuge(newpage))
> + if (newpage && PageTransHuge(newpage))
> thp_migration_success(true);
> put_page(page);
> if (reason == MR_MEMORY_FAILURE) {
>
Thanks Hugh. I am preparing to respin the vmstat patch accommodating some
earlier comments. Wondering if I should also fold these changes here after
adding your signed-off-by ?
- Anshuman
