# Re: \[PATCH v3 01/14\] memory-failure: fetch compound\_head after pgmap\_pfn\_valid()

- From: Joao Martins \<hidden\>
- Date: 2021-07-15 13:18:10 
- List: linux-doc
- Page: https://ratatoskr.run/linux-doc/2021/07/6509868
- Thread: https://ratatoskr.run/linux-mm/2021/07/6509813/t.md

```text


On 7/15/21 3:51 AM, Muchun Song wrote:
> On Thu, Jul 15, 2021 at 3:36 AM Joao Martins [ref] wrote:
>>
>> memory_failure_dev_pagemap() at the moment assumes base pages (e.g.
>> dax_lock_page()).  For pagemap with compound pages fetch the
>> compound_head in case a tail page memory failure is being handled.
>>
>> Currently this is a nop, but in the advent of compound pages in
>> dev_pagemap it allows memory_failure_dev_pagemap() to keep working.
>>
>> Reported-by: Jane Chu <redacted>
>> Signed-off-by: Joao Martins <redacted>
>> Reviewed-by: Naoya Horiguchi <redacted>
> 
> Reviewed-by: Muchun Song <redacted>
> 
Thanks!
```