[PATCH] makedumpfile: Support ARM64

sgoel at codeaurora.org sgoel at codeaurora.org
Fri Aug 21 13:37:57 PDT 2015


> Can you compare "Virtual kernel memory layout:" print of Linux kernel boot
> with
> makedumpfile print for page_offset, vmalloc_start, vmemmap_start etc, and
> see if
> they match?
>
> They should match.


Yes this was a problem. The assumed Kernel struct page size in the tool is
64. For our platform this evaluates to 56. After changing this value all
the memory mapping values match.

I wanted to ask if the page table translation function would be any
different if the page size is 4k instead of 64k?

Thanks,
Sameer


> Hi Sameer,
>
> On 20/08/2015:04:11:24 PM, sgoel at codeaurora.org wrote:
>> Hi Pratush,
>> I have made the change now.
>>
>> The reason for changing the KVBASE was to get non zero value for mem_map
>> as seen from the crash tool. If KVBASE stays at page offset we do not
>> get
>> into the function that looks for the free pages.
>
> OK.. I made the change for KVBASE and pushed it to my github repo.
>
>>
>> After looking at the page usage using the crash tool it seems that ~80%
>> of
>> the pages are free.
>>
>> Maybe there is something else that I am missing here. The page look up
>> fails when writing the crashdump file.
>
> Not sure if you can share the output with --message-level 31, but do you
> see any
> thing susceptible there?
>
> # makedumpfile -l --message-level 31 rawvmcore makedumpfilevmcore
>
> Can you compare "Virtual kernel memory layout:" print of Linux kernel boot
> with
> makedumpfile print for page_offset, vmalloc_start, vmemmap_start etc, and
> see if
> they match?
>
> They should match.
>
> ~Pratyush
>





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