mm: add folio_get_nontail_page()

Patch series "Convert a couple migrate functions to use folios", v2.

This patchset introduces folio_movable_ops() and converts 3 functions in
mm/migrate.c to use folios.  It also introduces folio_get_nontail_page()
for folio conversions which may want to distinguish between head and tail
pages.


This patch (of 4):

folio_get_nontail_page() returns the folio associated with a head page. 
This is necessary for folio conversions where the behavior of that
function differs between head pages and tail pages.

Link: https://lkml.kernel.org/r/20230130214352.40538-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20230130214352.40538-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Vishal Moola (Oracle) 2023-01-30 13:43:49 -08:00 committed by Andrew Morton
parent 4a64981dfe
commit 3c1ea2c729

View File

@ -892,6 +892,13 @@ static inline bool get_page_unless_zero(struct page *page)
return page_ref_add_unless(page, 1, 0);
}
static inline struct folio *folio_get_nontail_page(struct page *page)
{
if (unlikely(!get_page_unless_zero(page)))
return NULL;
return (struct folio *)page;
}
extern int page_is_ram(unsigned long pfn);
enum {