diff options
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index c606752f6d2a..51b55f2d2db5 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1139,6 +1139,9 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page, int rc = MIGRATEPAGE_SUCCESS; struct page *newpage; + if (!thp_migration_supported() && PageTransHuge(page)) + return -ENOMEM; + newpage = get_new_page(page, private); if (!newpage) return -ENOMEM; @@ -1160,14 +1163,6 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page, goto out; } - if (unlikely(PageTransHuge(page) && !PageTransHuge(newpage))) { - lock_page(page); - rc = split_huge_page(page); - unlock_page(page); - if (rc) - goto out; - } - rc = __unmap_and_move(page, newpage, force, mode); if (rc == MIGRATEPAGE_SUCCESS) set_page_owner_migrate_reason(newpage, reason); @@ -1381,6 +1376,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, retry = 0; list_for_each_entry_safe(page, page2, from, lru) { +retry: cond_resched(); if (PageHuge(page)) @@ -1394,6 +1390,26 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, switch(rc) { case -ENOMEM: + /* + * THP migration might be unsupported or the + * allocation could've failed so we should + * retry on the same page with the THP split + * to base pages. + * + * Head page is retried immediately and tail + * pages are added to the tail of the list so + * we encounter them after the rest of the list + * is processed. + */ + if (PageTransHuge(page)) { + lock_page(page); + rc = split_huge_page_to_list(page, from); + unlock_page(page); + if (!rc) { + list_safe_reset_next(page, page2, lru); + goto retry; + } + } nr_failed++; goto out; case -EAGAIN: @@ -1480,8 +1496,6 @@ static int add_page_for_migration(struct mm_struct *mm, unsigned long addr, /* FOLL_DUMP to ignore special (like zero) pages */ follflags = FOLL_GET | FOLL_DUMP; - if (!thp_migration_supported()) - follflags |= FOLL_SPLIT; page = follow_page(vma, addr, follflags); err = PTR_ERR(page); |