Messages in this thread Patch in this message | | | From | Huang Ying <> | Subject | [PATCH -v4 9/9] migrate_pages: move THP/hugetlb migration support check to simplify code | Date | Mon, 6 Feb 2023 14:33:13 +0800 |
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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().
Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Suggested-by: Alistair Popple <apopple@nvidia.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Bharata B Rao <bharata@amd.com> Cc: haoxin <xhao@linux.alibaba.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> --- mm/migrate.c | 83 +++++++++++++++++++++++----------------------------- 1 file changed, 36 insertions(+), 47 deletions(-)
diff --git a/mm/migrate.c b/mm/migrate.c index ca6e2ff02a09..83d7ec8dfa66 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1099,9 +1099,6 @@ 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); @@ -1359,16 +1356,6 @@ 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. */ putback_active_hugepage(hpage); @@ -1535,6 +1522,20 @@ 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, @@ -1544,16 +1545,9 @@ 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 @@ -1639,6 +1633,28 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page, 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, force_lock, mode, reason, ret_folios); @@ -1650,36 +1666,9 @@ static int migrate_pages_batch(struct list_head *from, new_page_t get_new_page, * -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 -- 2.35.1
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