2022-10-25 07:55:18

by J. R. Okajima

Subject: v6.1-rc1, remap_file_pages() and vma linked list?

Hello,

Linux-v4.10 has a commit
48f7df329474 2016-02-18 mm: fix regression in remap_file_pages() emulation
and it contains a small test program where remap_file_pages() will split
a region into two VMAs.

Linux-v6.1-rc1 remap_file_pages() doesn't pass that old test.
I tried investigation, but I am not good in this tech field. I could
only find there may be related to the commit
763ecb035029 2022-09-26 mm: remove the vma linked list
but I am not sure.
How can we make the old test pass?
"Don't use remap_file_pages()" or "Ignore such old test" is not an
option.


J. R. Okajima

2022-10-25 16:09:54

by Liam R. Howlett

Subject: Re: v6.1-rc1, remap_file_pages() and vma linked list?

* J. R. Okajima <[email protected]> [221025 03:09]:
> Hello,
>
> Linux-v4.10 has a commit
> 48f7df329474 2016-02-18 mm: fix regression in remap_file_pages() emulation
> and it contains a small test program where remap_file_pages() will split
> a region into two VMAs.
>
> Linux-v6.1-rc1 remap_file_pages() doesn't pass that old test.

I broke this in the commit you reference below.

> I tried investigation, but I am not good in this tech field. I could
> only find there may be related to the commit
> 763ecb035029 2022-09-26 mm: remove the vma linked list
> but I am not sure.
> How can we make the old test pass?
> "Don't use remap_file_pages()" or "Ignore such old test" is not an
> option.

Thanks for reporting this issue. I have a fix that will be sent out
shortly.

Regards,
Liam