On Fri, Sep 27, 2024 at 05:44:52PM +0200, David Hildenbrand wrote:
> /**
> * folio_try_add_pins() - add pins to an already-pinned folio
> * @folio: the folio to add more pins to
> *
> * Try to add more pins to an already-pinned folio. The semantics
> * of the pin (e.g., FOLL_WRITE) follow any existing pin and cannot
> * be changed.
> *
> * This function is helpful when having obtained a pin on a large folio
> * using memfd_pin_folios(), but wanting to logically unpin parts
> * (e.g., individual pages) of the folio later, for example, using
> * unpin_user_page_range_dirty_lock().
> *
> * This is not the right interface to initially pin a folio.
> */
> int folio_try_add_pins(struct folio *folio, unsigned int pins)
> {
> VM_WARN_ON_ONCE(!folio_maybe_dma_pinned(folio));
>
> return try_grab_folio(folio, pins, FOLL_PIN);
> }
That looks pretty good to me too
Thanks,
Jason
