[Crash-utility] [PATCH] display information about "struct page" on SPARSEMEM.
Hi Dave,
This patch fixes the problem that the crash utility cannot display
"struct page" information about SPARSEMEM (not SPARSEMEM_EXTREME) properly.
The symbol mem_section is defined as the pointer array in SPARSEMEM_EXTREME.
On the other hand, SPARSEMEM's one is defined as the array of structure
mem_section like the following:
linux-2.6.23/mm/sparse.c:18L
#ifdef CONFIG_SPARSEMEM_EXTREME
struct mem_section *mem_section[NR_SECTION_ROOTS]
____cacheline_internodealigned_in_smp;
#else
struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
____cacheline_internodealigned_in_smp;
#endif
EXPORT_SYMBOL(mem_section);
The crash utility considers SPARSEMEM's one to be the pointer array,
but it is wrong. This patch fixes it.
The following results are this patch effects.
* Before applying this patch
crash> kmem -p
PAGE PHYSICAL MAPPING INDEX CNT FLAGS
100 0 ------- ----- 0 0
120 1000 ------- ----- 0 0
140 2000 ------- ----- 0 0
160 3000 ------- ----- 0 0
180 4000 ------- ----- 0 0
1a0 5000 ------- ----- 0 0
1c0 6000 ------- ----- 0 0
1e0 7000 ------- ----- 0 0
200 8000 ------- ----- 0 0
[snip]
crash>
* After applying this patch
crash> kmem -p
PAGE PHYSICAL MAPPING INDEX CNT FLAGS
c5000000 0 ------- ----- 1 400
c5000020 1000 ------- ----- 1 400
c5000040 2000 ------- ----- 1 400
c5000060 3000 ------- ----- 1 400
c5000080 4000 ------- ----- 1 400
c50000a0 5000 ------- ----- 1 400
c50000c0 6000 ------- ----- 1 400
c50000e0 7000 ------- ----- 1 400
c5000100 8000 ------- ----- 0 80000
[snip]
crash>
Thanks
Ken'ichi Ohmichi
---
Signed-off-by: Ken'ichi Ohmichi <oomichi(a)mxs.nes.nec.co.jp>
---
diff -rpuN crash-4.0-4.8.org/memory.c crash-4.0-4.8/memory.c
--- crash-4.0-4.8.org/memory.c 2007-10-31 11:49:16.000000000 +0900
+++ crash-4.0-4.8/memory.c 2007-11-01 10:28:15.000000000 +0900
@@ -12229,7 +12229,9 @@ nr_to_section(ulong nr)
addr = mem_sec[SECTION_NR_TO_ROOT(nr)] +
(nr & SECTION_ROOT_MASK()) * SIZE(mem_section);
else
- addr = mem_sec[0] + (nr & SECTION_ROOT_MASK()) * SIZE(mem_section);
+ addr = symbol_value("mem_section") +
+ (SECTIONS_PER_ROOT() * SECTION_NR_TO_ROOT(nr) +
+ (nr & SECTION_ROOT_MASK())) * SIZE(mem_section);
if (!IS_KVADDR(addr))
return 0;
_