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x86/mm: Fix the size calculation of mapping tables

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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>
This commit is contained in:
WANG Cong 2012-03-05 15:05:13 -08:00 committed by Ingo Molnar
parent 550cf00dbc
commit 722bc6b167
1 changed files with 12 additions and 9 deletions
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21
arch/x86/mm/init.c
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@ -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,