From aeebe84cc96cde4181807bc67c300c550d0ef123 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 16 Nov 2012 19:38:55 -0800 Subject: [PATCH] x86, mm: Use big page size for small memory range We could map small range in the middle of big range at first, so should use big page size at first to avoid using small page size to break down page table. Only can set big page bit when that range has ram area around it. -v2: fix 32bit boundary checking. We can not count ram above max_low_pfn for 32 bit. Signed-off-by: Yinghai Lu Link: http://lkml.kernel.org/r/1353123563-3103-19-git-send-email-yinghai@kernel.org Signed-off-by: H. Peter Anvin --- arch/x86/mm/init.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index bb44e9f2cc49..da591ebc8d12 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -88,6 +88,40 @@ static int __meminit save_mr(struct map_range *mr, int nr_range, return nr_range; } +/* + * adjust the page_size_mask for small range to go with + * big page size instead small one if nearby are ram too. + */ +static void __init_refok adjust_range_page_size_mask(struct map_range *mr, + int nr_range) +{ + int i; + + for (i = 0; i < nr_range; i++) { + if ((page_size_mask & (1<> PAGE_SHIFT) > max_low_pfn) + continue; +#endif + + if (memblock_is_region_memory(start, end - start)) + mr[i].page_size_mask |= 1<