On 2024/10/22 18:06, Kirill A. Shutemov wrote:
On Tue, Oct 22, 2024 at 11:34:14AM +0800, Baolin Wang wrote:
IIUC, most file systems use method similar to iomap buffered IO (see
iomap_get_folio()) to allocate huge pages. What I mean is that, it would be
better to have a real use case to add a hint for allocating THP (other than
tmpfs).
I would be nice to hear from folks who works with production what the
actual needs are.
But I find asymmetry between MADV_ hints and FADV_ hints wrt huge pages
not justified. I think it would be easy to find use-cases for
FADV_HUGEPAGE/FADV_NOHUGEPAGE.
Furthermore I think it would be useful to have some kind of mechanism to
make these hints persistent: any open of a file would have these hints set
by default based on inode metadata on backing storage. Although, I am not
sure what the right way to archive that. xattrs?
May be can re-use mapping_set_folio_order_range()?
