Re: [PATCH 0/2] Convert some gmap functions to use folios

[Heiko Carstens <hca@linux.ibm.com>]

On Fri, Mar 22, 2024 at 04:11:45PM +0000, Matthew Wilcox (Oracle) wrote:
> struct page is going to lose its refcount (someday) and as part of
> that page_ref_freeze() will go away.  s390's ultravisor is one of
> the few remaining places that uses it, so convert it over to folios.
> From previous interactions, I understand that ultravisor doesn't support
> large folios, so this simply declines to make large folios secure.
> I think you'd be better off splitting the folio if it is large, but
> that's something I'd rather leave to someone who can test it.
> 
> These patches do have the effect of making this more efficient; we lose
> at least five hidden calls to compound_head().
> 
> Matthew Wilcox (Oracle) (2):
>   s390: Convert make_page_secure to use a folio
>   s390: Convert gmap_make_secure to use a folio
> 
>  arch/s390/kernel/uv.c | 50 +++++++++++++++++++++++--------------------
>  1 file changed, 27 insertions(+), 23 deletions(-)

Christian, Janosch, or Claudio, could you have a look at this please;
and provide an ACK if this is ok with you?