Re: [GIT PULL] Memory folios for v5.15

From: Matthew Wilcox
Date: Thu Aug 26 2021 - 13:20:31 EST


On Tue, Aug 24, 2021 at 12:48:13PM -0700, Linus Torvalds wrote:
> On Tue, Aug 24, 2021 at 12:38 PM Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > "pageset" is such a great name that we already use it, so I guess that
> > doesn't work.
>
> Actually, maybe I can backtrack on that a bit.
>
> Maybe 'pageset' would work as a name. It's not used as a type right
> now, but the usage where we do have those comments around 'struct
> per_cpu_pages' are actually not that different from the folio kind of
> thing. It has a list of "pages" that have a fixed order.
>
> So that existing 'pageset' user might actually fit in conceptually.
> The 'pageset' is only really used in comments and as part of a field
> name, and the use does seem to be kind of consistent with the Willy's
> use of a "aligned allocation-group of pages".

The 'pageset' in use in mm/page_alloc.c really seems to be more of a
pagelist than a pageset. The one concern I have about renaming it is
that we actually print the word 'pagesets' in /proc/zoneinfo.

There's also some infiniband driver that uses the word "pageset"
which really seems to mean "DMA range".

So if I rename the existing mm pageset to pagelist, and then modify all
these patches to call a folio a pageset, you'd take this patchset?