mm: migrate: move_pages() supports thp migration

This patch enables thp migration for move_pages(2).

Link: http://lkml.kernel.org/r/20170717193955.20207-10-zi.yan@sent.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Nellans <dnellans@nvidia.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/migrate.c b/mm/migrate.c
index bf5366a..1088cef 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -185,8 +185,8 @@ void putback_movable_pages(struct list_head *l)
                        unlock_page(page);
                        put_page(page);
                } else {
-                       dec_node_page_state(page, NR_ISOLATED_ANON +
-                                       page_is_file_cache(page));
+                       mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
+                                       page_is_file_cache(page), -hpage_nr_pages(page));
                        putback_lru_page(page);
                }
        }
@@ -1146,8 +1146,8 @@ out:
                 * as __PageMovable
                 */
                if (likely(!__PageMovable(page)))
-                       dec_node_page_state(page, NR_ISOLATED_ANON +
-                                       page_is_file_cache(page));
+                       mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
+                                       page_is_file_cache(page), -hpage_nr_pages(page));
        }
 
        /*
@@ -1421,7 +1421,17 @@ static struct page *new_page_node(struct page *p, unsigned long private,
        if (PageHuge(p))
                return alloc_huge_page_node(page_hstate(compound_head(p)),
                                        pm->node);
-       else
+       else if (thp_migration_supported() && PageTransHuge(p)) {
+               struct page *thp;
+
+               thp = alloc_pages_node(pm->node,
+                       (GFP_TRANSHUGE | __GFP_THISNODE) & ~__GFP_RECLAIM,
+                       HPAGE_PMD_ORDER);
+               if (!thp)
+                       return NULL;
+               prep_transhuge_page(thp);
+               return thp;
+       } else
                return __alloc_pages_node(pm->node,
                                GFP_HIGHUSER_MOVABLE | __GFP_THISNODE, 0);
 }
@@ -1448,6 +1458,8 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
        for (pp = pm; pp->node != MAX_NUMNODES; pp++) {
                struct vm_area_struct *vma;
                struct page *page;
+               struct page *head;
+               unsigned int follflags;
 
                err = -EFAULT;
                vma = find_vma(mm, pp->addr);
@@ -1455,8 +1467,10 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
                        goto set_status;
 
                /* FOLL_DUMP to ignore special (like zero) pages */
-               page = follow_page(vma, pp->addr,
-                               FOLL_GET | FOLL_SPLIT | FOLL_DUMP);
+               follflags = FOLL_GET | FOLL_DUMP;
+               if (!thp_migration_supported())
+                       follflags |= FOLL_SPLIT;
+               page = follow_page(vma, pp->addr, follflags);
 
                err = PTR_ERR(page);
                if (IS_ERR(page))
@@ -1466,7 +1480,6 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
                if (!page)
                        goto set_status;
 
-               pp->page = page;
                err = page_to_nid(page);
 
                if (err == pp->node)
@@ -1481,16 +1494,22 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
                        goto put_and_set;
 
                if (PageHuge(page)) {
-                       if (PageHead(page))
+                       if (PageHead(page)) {
                                isolate_huge_page(page, &pagelist);
+                               err = 0;
+                               pp->page = page;
+                       }
                        goto put_and_set;
                }
 
-               err = isolate_lru_page(page);
+               pp->page = compound_head(page);
+               head = compound_head(page);
+               err = isolate_lru_page(head);
                if (!err) {
-                       list_add_tail(&page->lru, &pagelist);
-                       inc_node_page_state(page, NR_ISOLATED_ANON +
-                                           page_is_file_cache(page));
+                       list_add_tail(&head->lru, &pagelist);
+                       mod_node_page_state(page_pgdat(head),
+                               NR_ISOLATED_ANON + page_is_file_cache(head),
+                               hpage_nr_pages(head));
                }
 put_and_set:
                /*