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| author | WANG Cong <xiyou.wangcong@gmail.com> | 2012-03-05 15:05:13 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2012-03-06 09:38:26 +0100 |
| commit | 722bc6b16771ed80871e1fd81c86d3627dda2ac8 (patch) | |
| tree | cfad3c8a90d44a548603c28fb9387bd2021f7a34 /arch/x86/mm/init.c | |
| parent | 550cf00dbc8ee402bef71628cb71246493dd4500 (diff) | |
| download | lwn-722bc6b16771ed80871e1fd81c86d3627dda2ac8.tar.gz lwn-722bc6b16771ed80871e1fd81c86d3627dda2ac8.zip | |
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/mm/init.c')
| -rw-r--r-- | arch/x86/mm/init.c | 21 |
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, |