From 6f7d760e86fa84862d749e36ebd29abf31f4f883 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Mon, 13 Feb 2023 20:34:44 +0800 Subject: migrate_pages: move THP/hugetlb migration support check to simplify code This is a code cleanup patch, no functionality change is expected. After the change, the line number reduces especially in the long migrate_pages_batch(). Link: https://lkml.kernel.org/r/20230213123444.155149-10-ying.huang@intel.com Signed-off-by: "Huang, Ying" Suggested-by: Alistair Popple Reviewed-by: Zi Yan Cc: Yang Shi Cc: Baolin Wang Cc: Oscar Salvador Cc: Matthew Wilcox Cc: Bharata B Rao Cc: Xin Hao Cc: Minchan Kim Cc: Mike Kravetz Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Andrew Morton --- mm/migrate.c | 83 ++++++++++++++++++++++++++---------------------------------- 1 file changed, 36 insertions(+), 47 deletions(-) (limited to 'mm') diff --git a/mm/migrate.c b/mm/migrate.c index 2fa420e4f68c..ef68a1aff35c 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1117,9 +1117,6 @@ static int migrate_folio_unmap(new_page_t get_new_page, free_page_t put_new_page bool locked = false; bool dst_locked = false; - if (!thp_migration_supported() && folio_test_transhuge(src)) - return -ENOSYS; - if (folio_ref_count(src) == 1) { /* Folio was freed from under us. So we are done. */ folio_clear_active(src); @@ -1380,16 +1377,6 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, struct anon_vma *anon_vma = NULL; struct address_space *mapping = NULL; - /* - * Migratability of hugepages depends on architectures and their size. - * This check is necessary because some callers of hugepage migration - * like soft offline and memory hotremove don't walk through page - * tables or check whether the hugepage is pmd-based or not before - * kicking migration. - */ - if (!hugepage_migration_supported(page_hstate(hpage))) - return -ENOSYS; - if (folio_ref_count(src) == 1) { /* page was freed from under us. So we are done. */ folio_putback_active_hugetlb(src); @@ -1556,6 +1543,20 @@ static int migrate_hugetlbs(struct list_head *from, new_page_t get_new_page, cond_resched(); + /* + * Migratability of hugepages depends on architectures and + * their size. This check is necessary because some callers + * of hugepage migration like soft offline and memory + * hotremove don't walk through page tables or check whether + * the hugepage is pmd-based or not before kicking migration. + */ + if (!hugepage_migration_supported(folio_hstate(folio))) { + nr_failed++; + stats->nr_failed_pages += nr_pages; + list_move_tail(&folio->lru, ret_folios); + continue; + } + rc = unmap_and_move_huge_page(get_new_page, put_new_page, private, &folio->page, pass > 2, mode, @@ -1565,16 +1566,9 @@ static int migrate_hugetlbs(struct list_head *from, new_page_t get_new_page, * Success: hugetlb folio will be put back * -EAGAIN: stay on the from list * -ENOMEM: stay on the from list - * -ENOSYS: stay on the from list * Other errno: put on ret_folios list */ switch(rc) { - case -ENOSYS: - /* Hugetlb migration is unsupported */ - nr_failed++; - stats->nr_failed_pages += nr_pages; - list_move_tail(&folio->lru, ret_folios); - break; case -ENOMEM: /* * When memory is low, don't bother to try to migrate @@ -1664,6 +1658,28 @@ retry: cond_resched(); + /* + * Large folio migration might be unsupported or + * the allocation might be failed so we should retry + * on the same folio with the large folio split + * to normal folios. + * + * Split folios are put in split_folios, and + * we will migrate them after the rest of the + * list is processed. + */ + if (!thp_migration_supported() && is_thp) { + nr_large_failed++; + stats->nr_thp_failed++; + if (!try_split_folio(folio, &split_folios)) { + stats->nr_thp_split++; + continue; + } + stats->nr_failed_pages += nr_pages; + list_move_tail(&folio->lru, ret_folios); + continue; + } + rc = migrate_folio_unmap(get_new_page, put_new_page, private, folio, &dst, pass > 2, avoid_force_lock, mode, reason, ret_folios); @@ -1675,36 +1691,9 @@ retry: * -EAGAIN: stay on the from list * -EDEADLOCK: stay on the from list * -ENOMEM: stay on the from list - * -ENOSYS: stay on the from list * Other errno: put on ret_folios list */ switch(rc) { - /* - * Large folio migration might be unsupported or - * the allocation could've failed so we should retry - * on the same folio with the large folio split - * to normal folios. - * - * Split folios are put in split_folios, and - * we will migrate them after the rest of the - * list is processed. - */ - case -ENOSYS: - /* Large folio migration is unsupported */ - if (is_large) { - nr_large_failed++; - stats->nr_thp_failed += is_thp; - if (!try_split_folio(folio, &split_folios)) { - stats->nr_thp_split += is_thp; - break; - } - } else if (!no_split_folio_counting) { - nr_failed++; - } - - stats->nr_failed_pages += nr_pages; - list_move_tail(&folio->lru, ret_folios); - break; case -ENOMEM: /* * When memory is low, don't bother to try to migrate -- cgit v1.2.3-58-ga151