Re: [PATCH] mm/hugetlb: Convert &folio->page to folio_page(folio, 0)

[Fan Ni <nifan.cxl@gmail.com>]

On Wed, Apr 09, 2025 at 04:15:30AM +0100, Matthew Wilcox wrote:
> On Tue, Apr 08, 2025 at 05:49:10PM -0700, nifan.cxl@gmail.com wrote:
> > From: Fan Ni <fan.ni@samsung.com>
> > 
> > Convert the use of &folio->page to folio_page(folio, 0) where struct
> > filio fits in. This is part of the efforts to move some fields out of
> > struct page to reduce its size.
> 
> Thanks for sending the patch.  You've mixed together quite a few things;
> I'd suggest focusing on one API at a time.
> 
... 
> >  out:
> > -	trace_mm_khugepaged_scan_pmd(mm, &folio->page, writable, referenced,
> > -				     none_or_zero, result, unmapped);
> > +	trace_mm_khugepaged_scan_pmd(mm, folio_page(folio, 0), writable,
> > +				     referenced, none_or_zero, result,
> > +				     unmapped);
> >  	return result;
> 
> ditto,
> 
> >  	result = install_pmd
> > -			? set_huge_pmd(vma, haddr, pmd, &folio->page)
> > +			? set_huge_pmd(vma, haddr, pmd, folio_page(folio, 0))
> >  			: SCAN_SUCCEED;
> 
> I feel that set_huge_pmd() should take a folio.
There is a patch on the mailing list for it,
https://lore.kernel.org/linux-mm/20240817095122.2460977-5-wangkefeng.wang@huawei.com/

If the above patch is needed, do_set_pmd() should be converted to use folio.

Fan