mm: show page state on migration failure

It is very useful to find the reason of the migration failure if we
know what the page is not migrated and the state of the page.

Change-Id: If6def51cbe8ac5b48a49c860a925633a36b498a2
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>

diff --git a/mm/migrate.c b/mm/migrate.c
index 4662c5cba9339eac18c5eae5ddfaf42fa670cf26..798acd1aa97dbc8fa3d0e7e971beea1243b6997f 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1430,6 +1430,16 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
                                                private, page, pass > 2, mode,
                                                reason);
 
+                       if ((rc != -EAGAIN) && (rc != MIGRATEPAGE_SUCCESS)) {
+                               phys_addr_t pa = page_to_phys(page);
+
+                               pr_err("%s failed(%d): PA%pa,mapcnt%d,cnt%d\n",
+                                       __func__, rc, &pa,
+                                       page_mapcount(page), page_count(page));
+
+                               dump_page_owner(page);
+                       }
+
                        switch(rc) {
                        case -ENOMEM:
                                nr_failed++;