On 2024/6/13 22:51, Matthew Wilcox wrote:
On Thu, Jun 13, 2024 at 06:53:43PM +0800, Kefeng Wang wrote:
+++ b/include/linux/mm.h
@@ -4071,9 +4071,7 @@ enum mf_action_page_type {
};
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
-extern void clear_huge_page(struct page *page,
- unsigned long addr_hint,
- unsigned int pages_per_huge_page);
+void clear_large_folio(struct folio *folio, unsigned long addr_hint);
I think this is properly called
void folio_zero_user(struct folio *folio, unsigned long user_addr);
OK,
-void clear_huge_page(struct page *page,
- unsigned long addr_hint, unsigned int pages_per_huge_page)
+void clear_large_folio(struct folio *folio, unsigned long addr_hint)
{
+ unsigned int pages_per_huge_page = folio_nr_pages(folio);
I think it's worth renaming to nr_pages here. >
unsigned long addr = addr_hint &
~(((unsigned long)pages_per_huge_page << PAGE_SHIFT) - 1);
This can just be:
unsigned long addr = user_addr & ~(folio_size(folio) - 1);
Umm. Except this assumes that the folio is always mapped to userspace
at its natural alignment. And that's true for hugetlb, but not true
for THP. So I think this needs to be moved into the callers for which
it is true, and we need documentation that user_addr is expected to be
the base address that the folio is mapped at.
It's better to move it into the callers, but one more question, the
user_addr is that the app will access, or the base addres if we can't
know it, so even in hugetlb, we should use vmf->real_address in
hugetlb_no_page(), also Cced Huang Ying, correct me if I'm wrong.
Thanks.
