Re: [PATCH v3 00/20] mm/zsmalloc: add zpdesc memory descriptor for zswap.zpool

[David Hildenbrand]

On 15.07.24 03:33, Alex Shi wrote:
> On 7/8/24 2:33 PM, alexs@xxxxxxxxxx wrote:
> > From: Alex Shi (Tencent) <alexs@xxxxxxxxxx>
> >
> > According to Metthew's plan, the page descriptor will be replace by a 8
> > bytes mem_desc on destination purpose.
> > https://lore.kernel.org/lkml/YvV1KTyzZ+Jrtj9x@xxxxxxxxxxxxxxxxxxxx/
> >
> > Here is a implement on zsmalloc to replace page descriptor by 'zpdesc',
> > which is still overlay on struct page now. but it's a step move forward
> > above destination.
> >
> > To name the struct zpdesc instead of zsdesc, since there are still 3
> > zpools under zswap: zbud, z3fold, zsmalloc for now(z3fold maybe removed
> > soon), and we could easyly extend it to other zswap.zpool in needs.
> >
> > For all zswap.zpools, they are all using single page since often used
> > under memory pressure. So the conversion via folio series helper is
> > better than page's for compound_head check saving.
> >
> > For now, all zpools are using some page struct members, like page.flags
> > for PG_private/PG_locked. and list_head lru, page.mapping for page migration.
> >
> > This patachset does not increase the descriptor size nor introduce any
> > functional changes, and could save about 122Kbytes zsmalloc.o size.
> >
> > Thanks
> > Alex
>
> Any comments for this patchset?

Planning on taking a peek soon (busy traveling), but I'm hoping that 
people more familiar with the code can provide feedback.

--
Cheers,

David / dhildenb