[PATCH] x86_64: do not assume head_64.S used 4KB pages when !use_pse

From: stefano.stabellini
Date: Thu Jun 23 2011 - 07:10:32 EST

From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>

head_64.S, which sets up the initial page table on x86_64, is not aware
of PSE being enabled or disabled and it always allocates the initial
mapping using 2MB pages.

Therefore on x86_64 find_early_table_space shouldn't update the amount
of pages needed for pte pages depending on the size of the initial
mapping, because we know for sure that no pte pages have been allocated

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Reported-by: Ingo Molnar <mingo@xxxxxxx>
arch/x86/mm/init.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 36bacfe..1e3098b 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -42,12 +42,19 @@ static void __init find_early_table_space(unsigned long start,
pmd_mapped *= (PMD_SIZE * PTRS_PER_PMD);

+ /*
+ * On x86_64 do not limit the size we need to cover with 4KB pages
+ * depending on the initial allocation because head_64.S always uses
+ * 2MB pages.
+ */
+#ifdef CONFIG_X86_32
if (start < PFN_PHYS(max_pfn_mapped)) {
if (PFN_PHYS(max_pfn_mapped) < end)
size -= PFN_PHYS(max_pfn_mapped) - start;
size = 0;

if (end > pud_mapped) {

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/