On Wed, Jul 28, 2010 at 12:02:16PM -0500, Christoph Lameter wrote: > On Thu, 29 Jul 2010, Minchan Kim wrote: > > invalid memmap pages will be freed by free_memmap and will be used > > on any place. How do we make sure it has PG_reserved? > > Not present memmap pages make pfn_valid fail already since there is no > entry for the page table (vmemmap) or blocks are missing in the sparsemem > tables. > > > Maybe I don't understand your point. > > I thought we are worrying about holes in the memmap blocks containing page > structs. Some page structs point to valid pages and some are not. The > invalid page structs need to be marked consistently to allow the check. The thing is that memmap pages which contains struct page array on hole will be freed by free_memmap in ARM. Please loot at arch/arm/mm/init.c. And it will be used by page allocator as free pages. -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>