diff mbox series

[v2,26/28] gup: Convert compound_range_next() to gup_folio_range_next()

Message ID 20220110042406.499429-27-willy@infradead.org (mailing list archive)
State New
Headers show
Series Convert GUP to folios | expand

Commit Message

Matthew Wilcox Jan. 10, 2022, 4:24 a.m. UTC 
Convert the only caller to work on folios instead of pages.
This removes the last caller of put_compound_head(), so delete it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/mm.h |  4 ++--
 mm/gup.c           | 38 ++++++++++++++++++--------------------
 2 files changed, 20 insertions(+), 22 deletions(-)

Comments

Christoph Hellwig Jan. 10, 2022, 8:41 a.m. UTC | #1 
On Mon, Jan 10, 2022 at 04:24:04AM +0000, Matthew Wilcox (Oracle) wrote:
> +static inline struct folio *gup_folio_range_next(unsigned long i,
>  		unsigned long npages, struct page *start, unsigned int *ntails)
>  {
> -	struct page *next, *page;
> +	struct page *next;
> +	struct folio *folio;
>  	unsigned int nr = 1;
>  
>  	next = nth_page(start, i);
> +	folio = page_folio(next);

Superficial nit:  initialization next and folio at declaration time
would reada little better.

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Matthew Wilcox Jan. 10, 2022, 1:41 p.m. UTC | #2 
On Mon, Jan 10, 2022 at 12:41:22AM -0800, Christoph Hellwig wrote:
> On Mon, Jan 10, 2022 at 04:24:04AM +0000, Matthew Wilcox (Oracle) wrote:
> > +static inline struct folio *gup_folio_range_next(unsigned long i,
> >  		unsigned long npages, struct page *start, unsigned int *ntails)
> >  {
> > -	struct page *next, *page;
> > +	struct page *next;
> > +	struct folio *folio;
> >  	unsigned int nr = 1;
> >  
> >  	next = nth_page(start, i);
> > +	folio = page_folio(next);
> 
> Superficial nit:  initialization next and folio at declaration time
> would reada little better.

Done.  Also the previous patch:

-static inline struct page *compound_next(struct page **list,
+static inline struct folio *gup_folio_next(struct page **list,
                unsigned long npages, unsigned long i, unsigned int *ntails)
 {
-       struct page *page;
+       struct folio *folio = page_folio(list[i]);
        unsigned int nr;

-       page = compound_head(list[i]);
        for (nr = i + 1; nr < npages; nr++) {
John Hubbard Jan. 11, 2022, 7:44 a.m. UTC | #3 
On 1/9/22 20:24, Matthew Wilcox (Oracle) wrote:
> Convert the only caller to work on folios instead of pages.
> This removes the last caller of put_compound_head(), so delete it.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>   include/linux/mm.h |  4 ++--
>   mm/gup.c           | 38 ++++++++++++++++++--------------------
>   2 files changed, 20 insertions(+), 22 deletions(-)
> 

Reviewed-by: John Hubbard <jhubbard@nvidia.com>


thanks,
diff mbox series

Patch

diff --git a/include/linux/mm.h b/include/linux/mm.h
index c103c6401ecd..1ddb0a55b5ca 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -216,10 +216,10 @@  int overcommit_policy_handler(struct ctl_table *, int, void *, size_t *,
 
 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
-#define page_nth(head, tail)	(page_to_pfn(tail) - page_to_pfn(head))
+#define folio_nth(folio, page)	(page_to_pfn(page) - folio_pfn(folio))
 #else
 #define nth_page(page,n) ((page) + (n))
-#define page_nth(head, tail)	((tail) - (head))
+#define folio_nth(folio, tail)	((tail) - &(folio)->page)
 #endif
 
 /* to align the pointer to the (next) page boundary */
diff --git a/mm/gup.c b/mm/gup.c
index 0cf2d5fd8d2d..1cdd5f2887a8 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -156,12 +156,6 @@  static void gup_put_folio(struct folio *folio, int refs, unsigned int flags)
 	folio_put_refs(folio, refs);
 }
 
-static void put_compound_head(struct page *page, int refs, unsigned int flags)
-{
-	VM_BUG_ON_PAGE(PageTail(page), page);
-	gup_put_folio((struct folio *)page, refs, flags);
-}
-
 /**
  * try_grab_page() - elevate a page's refcount by a flag-dependent amount
  *
@@ -204,20 +198,21 @@  void unpin_user_page(struct page *page)
 }
 EXPORT_SYMBOL(unpin_user_page);
 
-static inline struct page *compound_range_next(unsigned long i,
+static inline struct folio *gup_folio_range_next(unsigned long i,
 		unsigned long npages, struct page *start, unsigned int *ntails)
 {
-	struct page *next, *page;
+	struct page *next;
+	struct folio *folio;
 	unsigned int nr = 1;
 
 	next = nth_page(start, i);
-	page = compound_head(next);
-	if (PageHead(page))
+	folio = page_folio(next);
+	if (folio_test_large(folio))
 		nr = min_t(unsigned int, npages - i,
-			   compound_nr(page) - page_nth(page, next));
+			   folio_nr_pages(folio) - folio_nth(folio, next));
 
 	*ntails = nr;
-	return page;
+	return folio;
 }
 
 static inline struct folio *gup_folio_next(unsigned long i,
@@ -326,15 +321,18 @@  EXPORT_SYMBOL(unpin_user_pages_dirty_lock);
 void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages,
 				      bool make_dirty)
 {
-	unsigned long index;
-	struct page *head;
-	unsigned int ntails;
+	unsigned long i;
+	struct folio *folio;
+	unsigned int nr;
 
-	for (index = 0; index < npages; index += ntails) {
-		head = compound_range_next(index, npages, page, &ntails);
-		if (make_dirty && !PageDirty(head))
-			set_page_dirty_lock(head);
-		put_compound_head(head, ntails, FOLL_PIN);
+	for (i = 0; i < npages; i += nr) {
+		folio = gup_folio_range_next(i, npages, page, &nr);
+		if (make_dirty && !folio_test_dirty(folio)) {
+			folio_lock(folio);
+			folio_mark_dirty(folio);
+			folio_unlock(folio);
+		}
+		gup_put_folio(folio, nr, FOLL_PIN);
 	}
 }
 EXPORT_SYMBOL(unpin_user_page_range_dirty_lock);