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>

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index e62aa07..f5758b6 100644 (file)
--- 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);