Re: [PATCH 4.14 023/159] mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y

Dou Liyang
2018-02-07T12:17:47Z

Hi Baoquan,

At 02/07/2018 08:08 PM, Baoquan He wrote:
> On 02/07/18 at 08:00pm, Dou Liyang wrote:
>> Hi Kirill,Mike
>>
>> At 02/07/2018 06:45 PM, Mike Galbraith wrote:
>>> On Wed, 2018-02-07 at 13:41 +0300, Kirill A. Shutemov wrote:
>>>> On Wed, Feb 07, 2018 at 05:25:05PM +0800, Dou Liyang wrote:
>>>>> Hi All,
>>>>>
>>>>> I met the makedumpfile failed in the upstream kernel which contained
>>>>> this patch. Did I missed something else?
>>>>
>>>> None I'm aware of.
>>>>
>>>> Is there a reason to suspect that the issue is related to the bug this patch
>>>> fixed?
>>>
>>
>> I did a contrastive test by my colleagues Indoh's suggestion.
>>
>> Revert your two commits:
>>
>> commit 83e3c48729d9ebb7af5a31a504f3fd6aff0348c4
>> Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
>> Date: Fri Sep 29 17:08:16 2017 +0300
>>
>> commit 629a359bdb0e0652a8227b4ff3125431995fec6e
>> Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
>> Date: Tue Nov 7 11:33:37 2017 +0300
>>
>> ...and keep others unchanged, the makedumpfile works well.
>>
>>> Still works fine for me with .today. Box is only 16GB desktop box though.
>>>
>> Btw, In the upstream kernel which contained this patch, I did two tests:
>>
>> 1) use the makedumpfile as core_collector in /etc/kdump.conf, then
>> trigger the process of kdump by echo 1 >/proc/sysrq-trigger, the
>> makedumpfile works well and I can get the vmcore file.
>>
>> ......It is OK
>>
>> 2) use cp as core_collector, do the same operation to get the vmcore file.
>> then use makedumpfile to do like above:
>>
>> [douly@localhost code]$ ./makedumpfile -d 31 --message-level 31 -x
>> vmlinux_4.15+ vmcore_4.15+_from_cp_command vmcore_4.15+
>
> Oh, then please ignore my previous comment. Adding '-D' can give more
> debugging message.

I added '-D', Just like before, no more debugging message:

BTW, I use crash to analyze the vmcore file created by 'cp' command.

./crash ../makedumpfile/code/vmcore_4.15+_from_cp_command
../makedumpfile/code/vmlinux_4.15+

the crash works well, It's so interesting.

Thanks,
dou.

The debugging message with '-D':

[douly@localhost code]$ ./makedumpfile -D -d 31 --message-level 31 -x
vmlinux_4.15+ vmcore_4.15+_from_cp_command vmcore_4.15+
sadump: does not have partition header
sadump: read dump device as unknown format
sadump: unknown format
LOAD (0)
phys_start : 1000000
phys_end : 2a86000
virt_start : ffffffff81000000
virt_end : ffffffff82a86000
LOAD (1)
phys_start : 1000
phys_end : 9fc00
virt_start : ffff880000001000
virt_end : ffff88000009fc00
LOAD (2)
phys_start : 100000
phys_end : 13000000
virt_start : ffff880000100000
virt_end : ffff880013000000
LOAD (3)
phys_start : 33000000
phys_end : 7ffd7000
virt_start : ffff880033000000
virt_end : ffff88007ffd7000
Linux kdump
page_size : 4096

max_mapnr : 7ffd7

Buffer size for the cyclic mode: 131061
The kernel version is not supported.
The makedumpfile operation may be incomplete.

num of NODEs : 1

Memory type : SPARSEMEM_EX

mem_map (0)
mem_map : ffff88007ff26000
pfn_start : 0
pfn_end : 8000
mem_map (1)
mem_map : 0
pfn_start : 8000
pfn_end : 10000
mem_map (2)
mem_map : 0
pfn_start : 10000
pfn_end : 18000
mem_map (3)
mem_map : 0
pfn_start : 18000
pfn_end : 20000
mem_map (4)
mem_map : 0
pfn_start : 20000
pfn_end : 28000
mem_map (5)
mem_map : 0
pfn_start : 28000
pfn_end : 30000
mem_map (6)
mem_map : 0
pfn_start : 30000
pfn_end : 38000
mem_map (7)
mem_map : 0
pfn_start : 38000
pfn_end : 40000
mem_map (8)
mem_map : 0
pfn_start : 40000
pfn_end : 48000
mem_map (9)
mem_map : 0
pfn_start : 48000
pfn_end : 50000
mem_map (10)
mem_map : 0
pfn_start : 50000
pfn_end : 58000
mem_map (11)
mem_map : 0
pfn_start : 58000
pfn_end : 60000
mem_map (12)
mem_map : 0
pfn_start : 60000
pfn_end : 68000
mem_map (13)
mem_map : 0
pfn_start : 68000
pfn_end : 70000
mem_map (14)
mem_map : 0
pfn_start : 70000
pfn_end : 78000
mem_map (15)
mem_map : 0
pfn_start : 78000
pfn_end : 7ffd7
mmap() is available on the kernel.
Checking for memory holes : [100.0 %] |
STEP [Checking for memory holes ] : 0.000014 seconds
__vtop4_x86_64: Can't get a valid pte.
readmem: Can't convert a virtual address(ffff88007ffd7000) to physical
address.
readmem: type_addr: 0, addr:ffff88007ffd7000, size:32768
__exclude_unnecessary_pages: Can't read the buffer of struct page.
create_2nd_bitmap: Can't exclude unnecessary pages.
Checking for memory holes : [100.0 %] \
STEP [Checking for memory holes ] : 0.000006 seconds
Checking for memory holes : [100.0 %] -
STEP [Checking for memory holes ] : 0.000004 seconds
__vtop4_x86_64: Can't get a valid pte.
readmem: Can't convert a virtual address(ffff88007ffd7000) to physical
address.
readmem: type_addr: 0, addr:ffff88007ffd7000, size:32768
__exclude_unnecessary_pages: Can't read the buffer of struct page.
create_2nd_bitmap: Can't exclude unnecessary pages.

makedumpfile Failed.

>
>>
>> ......It causes makedumpfile failed.
>>
>>
>> Thanks,
>> dou.
>>
>>> -Mike
>>>
>>>
>>>
>>
>>