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authorWANG Cong <xiyou.wangcong@gmail.com>2012-03-06 03:05:13 +0400
committerIngo Molnar <mingo@elte.hu>2012-03-06 12:38:26 +0400
commit722bc6b16771ed80871e1fd81c86d3627dda2ac8 (patch)
treecfad3c8a90d44a548603c28fb9387bd2021f7a34 /arch/x86
parent550cf00dbc8ee402bef71628cb71246493dd4500 (diff)
downloadlinux-722bc6b16771ed80871e1fd81c86d3627dda2ac8.tar.xz
x86/mm: Fix the size calculation of mapping tables
For machines that enable PSE, the first 2/4M memory region still uses 4K pages, so needs more PTEs in this case, but find_early_table_space() doesn't count this. This patch fixes it. The bug was found via code review, no misbehavior of the kernel was observed. Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: <ianfang.cn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-kq6a00qe33h7c7ais2xsywnh@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/mm/init.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 6cabf6570d64..2e92fdcbea86 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -30,8 +30,14 @@ int direct_gbpages
#endif
;
-static void __init find_early_table_space(unsigned long end, int use_pse,
- int use_gbpages)
+struct map_range {
+ unsigned long start;
+ unsigned long end;
+ unsigned page_size_mask;
+};
+
+static void __init find_early_table_space(struct map_range *mr, unsigned long end,
+ int use_pse, int use_gbpages)
{
unsigned long puds, pmds, ptes, tables, start = 0, good_end = end;
phys_addr_t base;
@@ -56,6 +62,9 @@ static void __init find_early_table_space(unsigned long end, int use_pse,
#ifdef CONFIG_X86_32
extra += PMD_SIZE;
#endif
+ /* The first 2/4M doesn't use large pages. */
+ extra += mr->end - mr->start;
+
ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
} else
ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
@@ -85,12 +94,6 @@ void __init native_pagetable_reserve(u64 start, u64 end)
memblock_reserve(start, end - start);
}
-struct map_range {
- unsigned long start;
- unsigned long end;
- unsigned page_size_mask;
-};
-
#ifdef CONFIG_X86_32
#define NR_RANGE_MR 3
#else /* CONFIG_X86_64 */
@@ -262,7 +265,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
* nodes are discovered.
*/
if (!after_bootmem)
- find_early_table_space(end, use_pse, use_gbpages);
+ find_early_table_space(&mr[0], end, use_pse, use_gbpages);
for (i = 0; i < nr_range; i++)
ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,