diff options
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index db3b270254f1..8e0fa209d533 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -596,7 +596,7 @@ static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) unsigned long pfn; /* - * Online the pages in MAX_ORDER - 1 aligned chunks. The callback might + * Online the pages in MAX_ORDER aligned chunks. The callback might * decide to not expose all pages to the buddy (e.g., expose them * later). We account all pages as being online and belonging to this * zone ("present"). @@ -605,7 +605,18 @@ static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) * this and the first chunk to online will be pageblock_nr_pages. */ for (pfn = start_pfn; pfn < end_pfn;) { - int order = min(MAX_ORDER - 1UL, __ffs(pfn)); + int order; + + /* + * Free to online pages in the largest chunks alignment allows. + * + * __ffs() behaviour is undefined for 0. start == 0 is + * MAX_ORDER-aligned, Set order to MAX_ORDER for the case. + */ + if (pfn) + order = min_t(int, MAX_ORDER, __ffs(pfn)); + else + order = MAX_ORDER; (*online_page_callback)(pfn_to_page(pfn), order); pfn += (1UL << order); |