2022-01-10 04:25:35

by Matthew Wilcox

[permalink] [raw]
Subject: [PATCH v2 25/28] gup: Convert compound_next() to gup_folio_next()

Convert both callers to work on folios instead of pages.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
---
mm/gup.c | 41 ++++++++++++++++++++++-------------------
1 file changed, 22 insertions(+), 19 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index b5786e83c418..0cf2d5fd8d2d 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -220,20 +220,20 @@ static inline struct page *compound_range_next(unsigned long i,
return page;
}

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

- page = compound_head(list[i]);
+ folio = page_folio(list[i]);
for (nr = i + 1; nr < npages; nr++) {
- if (compound_head(list[nr]) != page)
+ if (page_folio(list[nr]) != folio)
break;
}

*ntails = nr - i;
- return page;
+ return folio;
}

/**
@@ -261,17 +261,17 @@ static inline struct page *compound_next(unsigned long i,
void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages,
bool make_dirty)
{
- unsigned long index;
- struct page *head;
- unsigned int ntails;
+ unsigned long i;
+ struct folio *folio;
+ unsigned int nr;

if (!make_dirty) {
unpin_user_pages(pages, npages);
return;
}

- for (index = 0; index < npages; index += ntails) {
- head = compound_next(index, npages, pages, &ntails);
+ for (i = 0; i < npages; i += nr) {
+ folio = gup_folio_next(i, npages, pages, &nr);
/*
* Checking PageDirty at this point may race with
* clear_page_dirty_for_io(), but that's OK. Two key
@@ -292,9 +292,12 @@ void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages,
* written back, so it gets written back again in the
* next writeback cycle. This is harmless.
*/
- if (!PageDirty(head))
- set_page_dirty_lock(head);
- put_compound_head(head, ntails, FOLL_PIN);
+ if (!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_pages_dirty_lock);
@@ -347,9 +350,9 @@ EXPORT_SYMBOL(unpin_user_page_range_dirty_lock);
*/
void unpin_user_pages(struct page **pages, unsigned long npages)
{
- unsigned long index;
- struct page *head;
- unsigned int ntails;
+ unsigned long i;
+ struct folio *folio;
+ unsigned int nr;

/*
* If this WARN_ON() fires, then the system *might* be leaking pages (by
@@ -359,9 +362,9 @@ void unpin_user_pages(struct page **pages, unsigned long npages)
if (WARN_ON(IS_ERR_VALUE(npages)))
return;

- for (index = 0; index < npages; index += ntails) {
- head = compound_next(index, npages, pages, &ntails);
- put_compound_head(head, ntails, FOLL_PIN);
+ for (i = 0; i < npages; i += nr) {
+ folio = gup_folio_next(i, npages, pages, &nr);
+ gup_put_folio(folio, nr, FOLL_PIN);
}
}
EXPORT_SYMBOL(unpin_user_pages);
--
2.33.0



2022-01-11 07:41:37

by John Hubbard

[permalink] [raw]
Subject: Re: [PATCH v2 25/28] gup: Convert compound_next() to gup_folio_next()

On 1/9/22 20:24, Matthew Wilcox (Oracle) wrote:
> Convert both callers to work on folios instead of pages.
>
> Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
> ---
> mm/gup.c | 41 ++++++++++++++++++++++-------------------
> 1 file changed, 22 insertions(+), 19 deletions(-)

Reviewed-by: John Hubbard <[email protected]>


thanks,
--
John Hubbard
NVIDIA

>
> diff --git a/mm/gup.c b/mm/gup.c
> index b5786e83c418..0cf2d5fd8d2d 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -220,20 +220,20 @@ static inline struct page *compound_range_next(unsigned long i,
> return page;
> }
>
> -static inline struct page *compound_next(unsigned long i,
> +static inline struct folio *gup_folio_next(unsigned long i,
> unsigned long npages, struct page **list, unsigned int *ntails)
> {
> - struct page *page;
> + struct folio *folio;
> unsigned int nr;
>
> - page = compound_head(list[i]);
> + folio = page_folio(list[i]);
> for (nr = i + 1; nr < npages; nr++) {
> - if (compound_head(list[nr]) != page)
> + if (page_folio(list[nr]) != folio)
> break;
> }
>
> *ntails = nr - i;
> - return page;
> + return folio;
> }
>
> /**
> @@ -261,17 +261,17 @@ static inline struct page *compound_next(unsigned long i,
> void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages,
> bool make_dirty)
> {
> - unsigned long index;
> - struct page *head;
> - unsigned int ntails;
> + unsigned long i;
> + struct folio *folio;
> + unsigned int nr;
>
> if (!make_dirty) {
> unpin_user_pages(pages, npages);
> return;
> }
>
> - for (index = 0; index < npages; index += ntails) {
> - head = compound_next(index, npages, pages, &ntails);
> + for (i = 0; i < npages; i += nr) {
> + folio = gup_folio_next(i, npages, pages, &nr);
> /*
> * Checking PageDirty at this point may race with
> * clear_page_dirty_for_io(), but that's OK. Two key
> @@ -292,9 +292,12 @@ void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages,
> * written back, so it gets written back again in the
> * next writeback cycle. This is harmless.
> */
> - if (!PageDirty(head))
> - set_page_dirty_lock(head);
> - put_compound_head(head, ntails, FOLL_PIN);
> + if (!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_pages_dirty_lock);
> @@ -347,9 +350,9 @@ EXPORT_SYMBOL(unpin_user_page_range_dirty_lock);
> */
> void unpin_user_pages(struct page **pages, unsigned long npages)
> {
> - unsigned long index;
> - struct page *head;
> - unsigned int ntails;
> + unsigned long i;
> + struct folio *folio;
> + unsigned int nr;
>
> /*
> * If this WARN_ON() fires, then the system *might* be leaking pages (by
> @@ -359,9 +362,9 @@ void unpin_user_pages(struct page **pages, unsigned long npages)
> if (WARN_ON(IS_ERR_VALUE(npages)))
> return;
>
> - for (index = 0; index < npages; index += ntails) {
> - head = compound_next(index, npages, pages, &ntails);
> - put_compound_head(head, ntails, FOLL_PIN);
> + for (i = 0; i < npages; i += nr) {
> + folio = gup_folio_next(i, npages, pages, &nr);
> + gup_put_folio(folio, nr, FOLL_PIN);
> }
> }
> EXPORT_SYMBOL(unpin_user_pages);