mm, memory hotplug: print debug message in the proper way for online_pages

online_pages() simply returns an error value if
memory_notify(MEM_GOING_ONLINE, &arg) return a value that is not what we
want for successfully onlining target pages.  This patch arms to print
more failure information like offline_pages() in online_pages.

This patch also converts printk(KERN_<LEVEL>) to pr_<level>(), and moves
__offline_pages() to not print failure information with KERN_INFO
according to David Rientjes's suggestion[1].

[1] https://lkml.org/lkml/2016/2/24/1094

Signed-off-by: Chen Yucong <slaoub@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 16 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index e62aa078f5c9..f5758b678608 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1059,10 +1059,9 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
 
         ret = memory_notify(MEM_GOING_ONLINE, &arg);
         ret = notifier_to_errno(ret);
-        if (ret) {
-                memory_notify(MEM_CANCEL_ONLINE, &arg);
-                return ret;
-        }
+        if (ret)
+                goto failed_addition;
+
         /*
          * If this zone is not populated, then it is not in zonelist.
          * This means the page allocator ignores this zone.
@@ -1080,12 +1079,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
                 if (need_zonelists_rebuild)
                         zone_pcp_reset(zone);
                 mutex_unlock(&zonelists_mutex);
-                printk(KERN_DEBUG "online_pages [mem %#010llx-%#010llx] failed\n",
-                       (unsigned long long) pfn << PAGE_SHIFT,
-                       (((unsigned long long) pfn + nr_pages)
-                            << PAGE_SHIFT) - 1);
-                memory_notify(MEM_CANCEL_ONLINE, &arg);
-                return ret;
+                goto failed_addition;
         }
 
         zone->present_pages += onlined_pages;
@@ -1118,6 +1112,13 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
         if (onlined_pages)
                 memory_notify(MEM_ONLINE, &arg);
         return 0;
+
+failed_addition:
+        pr_debug("online_pages [mem %#010llx-%#010llx] failed\n",
+                 (unsigned long long) pfn << PAGE_SHIFT,
+                 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1);
+        memory_notify(MEM_CANCEL_ONLINE, &arg);
+        return ret;
 }
 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
 
@@ -1529,8 +1530,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 
                 } else {
 #ifdef CONFIG_DEBUG_VM
-                        printk(KERN_ALERT "removing pfn %lx from LRU failed\n",
-                               pfn);
+                        pr_alert("removing pfn %lx from LRU failed\n", pfn);
                         dump_page(page, "failed to remove from LRU");
 #endif
                         put_page(page);
@@ -1858,7 +1858,7 @@ repeat:
                 ret = -EBUSY;
                 goto failed_removal;
         }
-        printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages);
+        pr_info("Offlined Pages %ld\n", offlined_pages);
         /* Ok, all of our target is isolated.
            We cannot do rollback at this point. */
         offline_isolated_pages(start_pfn, end_pfn);
@@ -1895,9 +1895,9 @@ repeat:
         return 0;
 
 failed_removal:
-        printk(KERN_INFO "memory offlining [mem %#010llx-%#010llx] failed\n",
-               (unsigned long long) start_pfn << PAGE_SHIFT,
-               ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
+        pr_debug("memory offlining [mem %#010llx-%#010llx] failed\n",
+                 (unsigned long long) start_pfn << PAGE_SHIFT,
+                 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1);
         memory_notify(MEM_CANCEL_OFFLINE, &arg);
         /* pushback to free area */
         undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE);