On Fri 05-04-13 18:23:07, KOSAKI Motohiro wrote: > >> - if (!new_hpage) > >> + /* > >> + * Getting a new hugepage with alloc_huge_page() (which can happen > >> + * when migration is caused by mbind()) can return ERR_PTR value, > >> + * so we need take care of the case here. > >> + */ > >> + if (!new_hpage || IS_ERR_VALUE(new_hpage)) > >> return -ENOMEM; > > > > Please no. get_new_page returns NULL or a page. You are hooking a wrong > > callback here. The error value doesn't make any sense here. IMO you > > should just wrap alloc_huge_page by something that returns NULL or page. > > I suggest just opposite way. new_vma_page() always return ENOMEM, ENOSPC etc instad > of NULL. and caller propegate it to userland. > I guess userland want to distingush why mbind was failed. Sure, and I wasn't suggesting to change alloc_huge_page. I was just pointing out that new_page_t used to return page or NULL and hugetlb unmap_and_move shouldn't be any different in that direction so using alloc_huge_page is not a good fit here. > Anyway, If new_vma_page() have a change to return both NULL and > -ENOMEM. That's a bug. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>