On 1/11/23 06:28, Matthew Wilcox (Oracle) wrote:
We can use folio->_pincount directly, since all users are guarded by
tests of compound/large.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
Documentation/core-api/pin_user_pages.rst | 29 +++++++++++------------
include/linux/mm.h | 14 ++---------
include/linux/mm_types.h | 5 ----
mm/debug.c | 4 ++--
mm/gup.c | 8 +++----
mm/huge_memory.c | 4 ++--
mm/hugetlb.c | 4 ++--
mm/page_alloc.c | 9 ++++---
8 files changed, 32 insertions(+), 45 deletions(-)
Looks very nice, just a couple of questions about casts, below.
...
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4d9afa1048ea..d1e5ec875fd0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -775,11 +775,13 @@ void free_compound_page(struct page *page)
static void prep_compound_head(struct page *page, unsigned int order)
{
+ struct folio *folio = (struct folio *)page;
Casting, eh? I wonder if prep_compound_head() should just take a folio?
There are only a few callers of that.
+
set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
set_compound_order(page, order);
atomic_set(compound_mapcount_ptr(page), -1);
atomic_set(subpages_mapcount_ptr(page), 0);
- atomic_set(compound_pincount_ptr(page), 0);
+ atomic_set(&folio->_pincount, 0);
}
static void prep_compound_tail(struct page *head, int tail_idx)
@@ -1291,6 +1293,7 @@ static inline bool free_page_is_bad(struct page *page)
static int free_tail_pages_check(struct page *head_page, struct page *page)
{
+ struct folio *folio = (struct folio *)head_page;
Similar to above: should the function just accept a folio instead of a
page?
Anyway, the patch as-is is good, and those points could be follow-up
changes if they are done, so either way, please feel free to add:
Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
thanks,
--
John Hubbard
NVIDIA
