Sparsemem: Do not reserve section flags if VMEMMAP is in use Sparsemem with virtual memmap does not need the section flags in the page flags. Do not allocate the bits if they are not needed. This has the potential of freeing up a lot of page flags if SPARSE can be made to consistently use a virtual memmap. Signed-off-by: Christoph Lameter --- include/linux/mm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6/include/linux/mm.h =================================================================== --- linux-2.6.orig/include/linux/mm.h 2007-11-12 19:36:39.472347109 -0800 +++ linux-2.6/include/linux/mm.h 2007-11-12 19:37:05.197064250 -0800 @@ -378,7 +378,7 @@ static inline void set_compound_order(st * with space for node: | SECTION | NODE | ZONE | ... | FLAGS | * no space for node: | SECTION | ZONE | ... | FLAGS | */ -#ifdef CONFIG_SPARSEMEM +#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP) #define SECTIONS_WIDTH SECTIONS_SHIFT #else #define SECTIONS_WIDTH 0