Re: [PATCH v3 2/3] mm: move folio LRU code out of swap

[Baoquan He <baoquan.he@linux.dev>]

On 06/02/26 at 04:57pm, Matthew Wilcox wrote:
> On Tue, Jun 02, 2026 at 09:01:16AM +0800, Jianyue Wu wrote:
> > Rename mm/swap.c to mm/folio_lru.c so the filename better matches
> > the code's main responsibility.
> > 
> > This keeps the implementation split from swap-specific code without
> > changing the published LRU helper interfaces.
> 
> At the same time, we have Tal trying to split folio_wait.c out
> of filemap.c.  https://lore.kernel.org/linux-mm/20260520-filemap-split-v1-0-c36ddc2b6cf2@columbia.edu/
> 
> I wonder if instead of folio_lru.c and folio_wait.c, we shouldn't simply
> have folio.c.  Tal has 700 lines in his diffstat, you'll have about 1100
> lines, so that's about 1800 llines which seems like a good size.
> There's some functions from mm/util.c that would fit nicely too --
> folio_mapping(), folio_anon_vma(), folio_copy(), flush_dcache_folio()

I think folio_lru.c and folio_wait.c are better than a single folio.c.

A single folio.c with all of them would have no clear boundary for what
belongs there and what doesn't. For comparison, page_alloc.c isn't called
page.c (we have files called mm/page*.c).

> 
> Other people have thoughts?
>