[Crash-utility] [PATCH v4] arm64/x86_64: show zero pfn information when using vtop

[HAGIO KAZUHITO(萩尾 一仁)]

On 2023/05/29 22:13, lijiang wrote:
> On Mon, May 29, 2023 at 7:56 PM Rongwei Wang <rongwei.wang at linux.alibaba.com>
> wrote:
> 
>> Now vtop can not show us the page is zero pfn
>> when PTE or PMD has attached ZERO PAGE. This
>> patch supports show this information directly
>> when using vtop, likes:
>>
>> crash> vtop -c 13674 ffff8917e000
>> VIRTUAL     PHYSICAL
>> ffff8917e000  836e71000
>>
>> PAGE DIRECTORY: ffff000802f8d000
>>     PGD: ffff000802f8dff8 => 884e29003
>>     PUD: ffff000844e29ff0 => 884e93003
>>     PMD: ffff000844e93240 => 840413003
>>     PTE: ffff000800413bf0 => 160000836e71fc3
>>    PAGE: 836e71000  (ZERO PAGE)
>> ...
>>
>> If huge page found:
>>
>> crash> vtop -c 14538 ffff95800000
>> VIRTUAL     PHYSICAL
>> ffff95800000  910c00000
>>
>> PAGE DIRECTORY: ffff000801fa0000
>>     PGD: ffff000801fa0ff8 => 884f53003
>>     PUD: ffff000844f53ff0 => 8426cb003
>>     PMD: ffff0008026cb560 => 60000910c00fc1
>>    PAGE: 910c00000  (2MB, ZERO PAGE)
>> ...
>>
>> That seems be sensible with this patch. And there
>> are two points have to be noted for 'ZERO PAGE'
>> label:
>> 1. only supports displaying zero page for THP(except for 1G THP)
>> 2. do not support for the hugetlb cases
>>
>> Thank you for the update, Rongwei.
> 
> I have no other issues. So, for the v4: Ack.

Thank you.  After all, changed the commit log and applied:
https://github.com/crash-utility/crash/commit/a0eceb041dfa248d66f9f9a455106184b7823bec

Thanks,
Kazu