1 files changed, 20 insertions, 3 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index ca58bfcdadac..2f6d30db4c94 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6725,8 +6725,12 @@ int alloc_contig_range(unsigned long start, unsigned long end,
         if (ret)
                 return ret;
 
+        /*
+         * In case of -EBUSY, we'd like to know which page causes problem.
+         * So, just fall through. We will check it in test_pages_isolated().
+         */
         ret = __alloc_contig_migrate_range(&cc, start, end);
-        if (ret)
+        if (ret && ret != -EBUSY)
                 goto done;
 
         /*
@@ -6753,12 +6757,25 @@ int alloc_contig_range(unsigned long start, unsigned long end,
         outer_start = start;
         while (!PageBuddy(pfn_to_page(outer_start))) {
                 if (++order >= MAX_ORDER) {
-                        ret = -EBUSY;
-                        goto done;
+                        outer_start = start;
+                        break;
                 }
                 outer_start &= ~0UL << order;
         }
 
+        if (outer_start != start) {
+                order = page_order(pfn_to_page(outer_start));
+
+                /*
+                 * outer_start page could be small order buddy page and
+                 * it doesn't include start page. Adjust outer_start
+                 * in this case to report failed page properly
+                 * on tracepoint in test_pages_isolated()
+                 */
+                if (outer_start + (1UL << order) <= start)
+                        outer_start = start;
+        }
+
         /* Make sure the range is really isolated. */
         if (test_pages_isolated(outer_start, end, false)) {
                 pr_info("%s: [%lx, %lx) PFNs busy\n",