From: Oscar Salvador <osalvador@xxxxxxx> __pagininit macro is being used to mark functions for: a) Functions that we do not need to keep once the system is fully initialized with regard to memory. b) Functions that will be needed for the memory-hotplug code, and because of that we need to keep them after initialization. Right now, the condition to choose between one or the other is based on CONFIG_SPARSEMEM, but I think that this should be changed to be based on CONFIG_MEMORY_HOTPLUG. The reason behind this is that it can very well be that we have CONFIG_SPARSEMEM enabled, but not CONFIG_MEMORY_HOTPLUG, and thus, we will not need the functions marked as __paginginit to stay around, since no memory-hotplug code will call them. Although the amount of freed bytes is not that big, I think it will become more clear what __paginginit is used for. Signed-off-by: Oscar Salvador <osalvador@xxxxxxx> --- mm/internal.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/mm/internal.h b/mm/internal.h index 33c22754d282..c9170b4f7699 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -392,10 +392,11 @@ static inline struct page *mem_map_next(struct page *iter, /* * FLATMEM and DISCONTIGMEM configurations use alloc_bootmem_node, * so all functions starting at paging_init should be marked __init - * in those cases. SPARSEMEM, however, allows for memory hotplug, - * and alloc_bootmem_node is not used. + * in those cases. + * In case that MEMORY_HOTPLUG is enabled, we need to keep those + * functions around since they can be called when hot-adding memory. */ -#ifdef CONFIG_SPARSEMEM +#ifdef CONFIG_MEMORY_HOTPLUG #define __paginginit __meminit #else #define __paginginit __init -- 2.13.6
