Hi David, I am not sure this is needed, because we already have a stricter checker: check_hotplug_memory_range() You could call it from online_pages(), if you think there is a reason to do it, but other than that it is done from add_memory_resource() and from remove_memory(). Thank you, Pavel On 8/16/18 6:06 AM, David Hildenbrand wrote: > onlining/offlining code works on whole sections, so let's enforce that. > Existing code only allows to add memory in memory block size. And only > whole memory blocks can be onlined/offlined. Memory blocks are always > aligned to sections, so this should not break anything. > > online_pages/offline_pages will implicitly mark whole sections > online/offline, so the code really can only handle such granularities. > > (especially offlining code cannot deal with pageblock_nr_pages but > theoretically only MAX_ORDER-1) > > Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> > --- > mm/memory_hotplug.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 090cf474de87..30d2fa42b0bb 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -897,6 +897,11 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ > struct memory_notify arg; > struct memory_block *mem; > > + if (!IS_ALIGNED(pfn, PAGES_PER_SECTION)) > + return -EINVAL; > + if (!IS_ALIGNED(nr_pages, PAGES_PER_SECTION)) > + return -EINVAL; > + > /* > * We can't use pfn_to_nid() because nid might be stored in struct page > * which is not yet initialized. Instead, we find nid from memory block. > @@ -1600,10 +1605,9 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) > struct zone *zone; > struct memory_notify arg; > > - /* at least, alignment against pageblock is necessary */ > - if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) > + if (!IS_ALIGNED(start_pfn, PAGES_PER_SECTION)) > return -EINVAL; > - if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) > + if (!IS_ALIGNED(nr_pages, PAGES_PER_SECTION)) > return -EINVAL; > /* This makes hotplug much easier...and readable. > we assume this for now. .*/ >
