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

[Dou Liyang <douly.fnst@cn.fujitsu.com>]

Hi Baoquan,

At 02/08/2018 09:23 AM, Baoquan He wrote:
> On 02/08/18 at 09:14am, Dou Liyang wrote:
>> Hi Baoquan,
>>
>> At 02/07/2018 08:45 PM, Baoquan He wrote:
>>> On 02/07/18 at 08:34pm, Dou Liyang wrote:
>>>>
>>>>
>>>> At 02/07/2018 08:27 PM, Baoquan He wrote:
>>>>> On 02/07/18 at 08:17pm, Dou Liyang wrote:
>>>>>> 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.
>>>
>>> OK, I may get the reason. kaslr is enabled, right? You can try to
>>
>> I add 'nokaslr' to disable the KASLR feature.
>      ~~~added??

oops! yes, the kaslr had already disabled by this option when I tested.

>>
>> # cat /proc/cmdline
>> BOOT_IMAGE=/vmlinuz-4.15.0+ root=UUID=10f10326-c923-4098-86aa-afed5c54ee0b
>> ro crashkernel=512M rhgb console=tty0 console=ttyS0 nokaslr LANG=en_US.UTF-8
>>
>>> disable kaslr and try them again. Because phys_base and kaslr_offset are
>>> got from vmlinux, while these are generated at compiling time. Just a
>>> guess.
>>>
>>
>> Oh, I will recompile the kernel with KASLR disabled in .config.
> 
> Then it's not what I guessed. Need debug makedumpfile since using
> vmlinux is another code path, few people use it usually.
> 

Understood, I will try to look into it.

Thanks,
	dou

>>
>>
>> Thanks,
>> 	dou.
>>>>>>>>
>>>>>>>> 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':
>>>>>
>>>>> And what's the debugging printing when trigger crash by sysrq?
>>>>>
>>>>
>>>> kdump: dump target is /dev/vda2
>>>> kdump: saving to /sysroot//var/crash/127.0.0.1-2018-02-07-07:31:56/
>>>> [    2.751352] EXT4-fs (vda2): re-mounted. Opts: data=ordered
>>>> kdump: saving vmcore-dmesg.txt
>>>> kdump: saving vmcore-dmesg.txt complete
>>>> kdump: saving vmcore
>>>> 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
>>>>
>>>> num of NODEs : 1
>>>>
>>>>
>>>> Memory type  : SPARSEMEM_EX
>>>>
>>>> mem_map (0)
>>>>     mem_map    : ffffea0000000000
>>>>     pfn_start  : 0
>>>>     pfn_end    : 8000
>>>> mem_map (1)
>>>>     mem_map    : ffffea0000200000
>>>>     pfn_start  : 8000
>>>>     pfn_end    : 10000
>>>> mem_map (2)
>>>>     mem_map    : ffffea0000400000
>>>>     pfn_start  : 10000
>>>>     pfn_end    : 18000
>>>> mem_map (3)
>>>>     mem_map    : ffffea0000600000
>>>>     pfn_start  : 18000
>>>>     pfn_end    : 20000
>>>> mem_map (4)
>>>>     mem_map    : ffffea0000800000
>>>>     pfn_start  : 20000
>>>>     pfn_end    : 28000
>>>> mem_map (5)
>>>>     mem_map    : ffffea0000a00000
>>>>     pfn_start  : 28000
>>>>     pfn_end    : 30000
>>>> mem_map (6)
>>>>     mem_map    : ffffea0000c00000
>>>>     pfn_start  : 30000
>>>>     pfn_end    : 38000
>>>> mem_map (7)
>>>>     mem_map    : ffffea0000e00000
>>>>     pfn_start  : 38000
>>>>     pfn_end    : 40000
>>>> mem_map (8)
>>>>     mem_map    : ffffea0001000000
>>>>     pfn_start  : 40000
>>>>     pfn_end    : 48000
>>>> mem_map (9)
>>>>     mem_map    : ffffea0001200000
>>>>     pfn_start  : 48000
>>>>     pfn_end    : 50000
>>>> mem_map (10)
>>>>     mem_map    : ffffea0001400000
>>>>     pfn_start  : 50000
>>>>     pfn_end    : 58000
>>>> mem_map (11)
>>>>     mem_map    : ffffea0001600000
>>>>     pfn_start  : 58000
>>>>     pfn_end    : 60000
>>>> mem_map (12)
>>>>     mem_map    : ffffea0001800000
>>>>     pfn_start  : 60000
>>>>     pfn_end    : 68000
>>>> mem_map (13)
>>>>     mem_map    : ffffea0001a00000
>>>>     pfn_start  : 68000
>>>>     pfn_end    : 70000
>>>> mem_map (14)
>>>>     mem_map    : ffffea0001c00000
>>>>     pfn_start  : 70000
>>>>     pfn_end    : 78000
>>>> mem_map (15)
>>>>     mem_map    : ffffea0001e00000
>>>>     pfn_start  : 78000
>>>>     pfn_end    : 7ffd7
>>>> mmap() is available on the kernel.
>>>> Copying data                                      : [100.0 %] -  eta: 0s
>>>> Writing erase info...
>>>> offset_eraseinfo: 9567fb0, size_eraseinfo: 0
>>>> kdump: saving vmcore complete
>>>>
>>>> Thanks,
>>>> 	dou
>>>>
>>>>>>
>>>>>> [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
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>>
>>
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> 
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