lkml.org 
[lkml]   [2012]   [Mar]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:x86/mm] x86/mm: Fix the size calculation of mapping tables
Commit-ID:  722bc6b16771ed80871e1fd81c86d3627dda2ac8
Gitweb: http://git.kernel.org/tip/722bc6b16771ed80871e1fd81c86d3627dda2ac8
Author: WANG Cong <xiyou.wangcong@gmail.com>
AuthorDate: Mon, 5 Mar 2012 15:05:13 -0800
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 6 Mar 2012 09:38:26 +0100

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>
---
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 6cabf65..2e92fdc 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,

\
 
 \ /
  Last update: 2012-03-06 17:19    [W:0.040 / U:0.068 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site