Re: Futexes & Folios

[Thomas Gleixner]

On Sat, May 13 2023 at 17:16, Matthew Wilcox wrote:

> Here's a patch which converts the futex code from using pages to using
> folios.  I do have some questions.
>
>  - I assume we really do want to base the key on the page offset of the
>    futex in the file.  That is, it's not good enough to base the key
>    on the folio's index because the folio can be split after setting up
>    the key, and if it is we'd then fail to find the futex later.

Correct.

>  - In hugetlbfs, it doesn't matter whether the pgoff is based on base
>    pages or huge page size -- as long as it's consistent between
>    invocations, everything will work

Yes.

The patch looks sane, but I need to have a look with brain more awake

Thanks,

        tglx