mm/migrate: Use a folio in migrate_misplaced_transhuge_page()

Unify alloc_misplaced_dst_page() and alloc_misplaced_dst_page_thp().
Removes an assumption that compound pages are HPAGE_PMD_ORDER.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>

diff --git a/mm/migrate.c b/mm/migrate.c
index 9894e90..6c31ee1 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1997,32 +1997,20 @@ static struct page *alloc_misplaced_dst_page(struct page *page,
                                           unsigned long data)
 {
        int nid = (int) data;
-       struct page *newpage;
-
-       newpage = __alloc_pages_node(nid,
-                                        (GFP_HIGHUSER_MOVABLE |
-                                         __GFP_THISNODE | __GFP_NOMEMALLOC |
-                                         __GFP_NORETRY | __GFP_NOWARN) &
-                                        ~__GFP_RECLAIM, 0);
-
-       return newpage;
-}
-
-static struct page *alloc_misplaced_dst_page_thp(struct page *page,
-                                                unsigned long data)
-{
-       int nid = (int) data;
-       struct page *newpage;
-
-       newpage = alloc_pages_node(nid, (GFP_TRANSHUGE_LIGHT | __GFP_THISNODE),
-                                  HPAGE_PMD_ORDER);
-       if (!newpage)
-               goto out;
-
-       prep_transhuge_page(newpage);
+       int order = compound_order(page);
+       gfp_t gfp = __GFP_THISNODE;
+       struct folio *new;
+
+       if (order > 0)
+               gfp |= GFP_TRANSHUGE_LIGHT;
+       else {
+               gfp |= GFP_HIGHUSER_MOVABLE | __GFP_NOMEMALLOC | __GFP_NORETRY |
+                       __GFP_NOWARN;
+               gfp &= ~__GFP_RECLAIM;
+       }
+       new = __folio_alloc_node(gfp, order, nid);
 
-out:
-       return newpage;
+       return &new->page;
 }
 
 static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
@@ -2080,22 +2068,8 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
        int nr_remaining;
        unsigned int nr_succeeded;
        LIST_HEAD(migratepages);
-       new_page_t *new;
-       bool compound;
        int nr_pages = thp_nr_pages(page);
 
-       /*
-        * PTE mapped THP or HugeTLB page can't reach here so the page could
-        * be either base page or THP.  And it must be head page if it is
-        * THP.
-        */
-       compound = PageTransHuge(page);
-
-       if (compound)
-               new = alloc_misplaced_dst_page_thp;
-       else
-               new = alloc_misplaced_dst_page;
-
        /*
         * Don't migrate file pages that are mapped in multiple processes
         * with execute permissions as they are probably shared libraries.
@@ -2116,9 +2090,9 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
                goto out;
 
        list_add(&page->lru, &migratepages);
-       nr_remaining = migrate_pages(&migratepages, *new, NULL, node,
-                                    MIGRATE_ASYNC, MR_NUMA_MISPLACED,
-                                    &nr_succeeded);
+       nr_remaining = migrate_pages(&migratepages, alloc_misplaced_dst_page,
+                                    NULL, node, MIGRATE_ASYNC,
+                                    MR_NUMA_MISPLACED, &nr_succeeded);
        if (nr_remaining) {
                if (!list_empty(&migratepages)) {
                        list_del(&page->lru);