On 12/9/22 13:10, John Hubbard wrote:
On 12/9/22 06:27, Muchun Song wrote:
From you advise, I think we can remove VM_BUG_ON and handle non-zero
order page, something like:
Yes, and thanks for summarizing all the individual feedback into a
proposed solution.
If we go this route, then I'd suggest a little note above the function,
such as:
/*
* For non-large folios, this will have no effect, other than possibly
* generating a warning, if the caller attempts to set a non-zero folio order
* for a non-large folio.
*/
static inline void folio_set_order(struct folio *folio,
unsigned int order)
{
if (!folio_test_large(folio)) {
WARN_ON(order);
Although, on second thought...I'm still a little confused about why
keeping the same name is so important?
A very direct approach that has more accurate naming (and therefore no
need for a strange comment explaining the behavior) would be:
static inline void large_folio_set_order(struct folio *folio,
unsigned int order)
{
if (WARN_ON_ONCE(!folio_test_large(folio)))
return;
folio->_folio_order = order;
#ifdef CONFIG_64BIT
folio->_folio_nr_pages = order ? 1U << order : 0;
#endif
}
thanks,
--
John Hubbard
NVIDIA
