Re: [PATCH] mm/slub: replace alloc_pages with folio_alloc

[Muchun Song]

On Sat, May 28, 2022 at 05:27:11PM +0100, Matthew Wilcox wrote:
> On Sun, May 29, 2022 at 12:11:58AM +0800, bh1scw@xxxxxxxxx wrote:
> > From: Fanjun Kong <bh1scw@xxxxxxxxx>
> > 
> > This patch will use folio allocation functions for allocating pages.
> 
> That's not actually a good idea.  folio_alloc() will do the
> prep_transhuge_page() step which isn't needed for slab.
>

You mean folio_alloc() is dedicated for THP allocation?  It is a little
surprise to me.  I thought folio_alloc() is just a variant of alloc_page(),
which returns a folio struct instead of a page.  Seems like I was wrong.
May I ask what made us decide to do this?

Thanks.