Re: [PATCH 09/12] mm/readahead: Align file mappings for non-DAX

[Matthew Wilcox]

On Mon, Jan 17, 2022 at 11:17:55AM +0800, Rongwei Wang wrote:
> It seems this patch will make all file mappings align with PMD_SIZE?

Only those which are big enough.  See __thp_get_unmapped_area():

        if (off_end <= off_align || (off_end - off_align) < size)
                return 0;

> And
> support realize all file THP, not only executable file THP?

Executables are not the only files which benefit from being mapped
to an aligned address.  If you can use a PMD to map a font file,
for example, that's valuable.