[LSF/MM/BPF TOPIC] State Of The Page

[David Rientjes]

On Fri, 19 Jan 2024, Matthew Wilcox wrote:

> It's probably worth doing another roundup of where we are on our journey
> to separating folios, slabs, pages, etc.  Something suitable for people
> who aren't MM experts, and don't care about the details of how page
> allocation works.  I can talk for hours about whatever people want to
> hear about but some ideas from me:
> 
>  - Overview of how the conversion is going
>  - Convenience functions for filesystem writers
>  - What's next?
>  - What's the difference between &folio->page and page_folio(folio, 0)?
>  - What are we going to do about bio_vecs?
>  - How does all of this work with kmap()?
> 
> I'm sure people would like to suggest other questions they have that
> aren't adequately answered already and might be of interest to a wider
> audience.
> 

Thanks for proposing this again, Matthew, I'd definitely like to be 
involved in the discussion as I think a couple of my colleagues, cc'd, 
would has well.  Memory efficiency is a top priority for 2024 and, thus, 
getting on a pathway toward reducing the overhead of struct page is very 
important for our hosts that are not using large amounts of 1GB hugetlb.

I've seen your other thread regarding how the page allocator can be 
enlightened for memdesc, so I'm hoping that can either be covered in this 
topic or a separate topic.

Especially important for us would be the division of work so that we can 
parallelize development as much as possible for things like memdesc.  If 
there are any areas that just haven't been investigated yet but we *know* 
we'll need to address to get to the new world of memdesc, I think we'd 
love to discuss that.