diff options
| author | John Hubbard <jhubbard@nvidia.com> | 2021-09-02 14:53:51 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-03 09:58:11 -0700 |
| commit | 54d516b1d62ff8f17cee2da06e5e4706a0d00b8a (patch) | |
| tree | 6e48db6d78f717ec959dbdf9009ffd313a042a89 /mm/gup.c | |
| parent | 3967db22ba324939762f618f0d654b13317ca7a4 (diff) | |
mm/gup: small refactoring: simplify try_grab_page()
try_grab_page() does the same thing as try_grab_compound_head(..., refs=1,
...), just with a different API. So there is a lot of code duplication
there.
Change try_grab_page() to call try_grab_compound_head(), while keeping the
API contract identical for callers.
Also, now that try_grab_compound_head() always has a caller, remove the
__maybe_unused annotation.
Link: https://lkml.kernel.org/r/20210813044133.1536842-3-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/gup.c')
| -rw-r--r-- | mm/gup.c | 35 |
1 files changed, 5 insertions, 30 deletions
@@ -124,8 +124,8 @@ static inline struct page *try_get_compound_head(struct page *page, int refs) * considered failure, and furthermore, a likely bug in the caller, so a warning * is also emitted. */ -__maybe_unused struct page *try_grab_compound_head(struct page *page, - int refs, unsigned int flags) +struct page *try_grab_compound_head(struct page *page, + int refs, unsigned int flags) { if (flags & FOLL_GET) return try_get_compound_head(page, refs); @@ -208,35 +208,10 @@ static void put_compound_head(struct page *page, int refs, unsigned int flags) */ bool __must_check try_grab_page(struct page *page, unsigned int flags) { - WARN_ON_ONCE((flags & (FOLL_GET | FOLL_PIN)) == (FOLL_GET | FOLL_PIN)); + if (!(flags & (FOLL_GET | FOLL_PIN))) + return true; - if (flags & FOLL_GET) - return try_get_page(page); - else if (flags & FOLL_PIN) { - int refs = 1; - - page = compound_head(page); - - if (WARN_ON_ONCE(page_ref_count(page) <= 0)) - return false; - - if (hpage_pincount_available(page)) - hpage_pincount_add(page, 1); - else - refs = GUP_PIN_COUNTING_BIAS; - - /* - * Similar to try_grab_compound_head(): even if using the - * hpage_pincount_add/_sub() routines, be sure to - * *also* increment the normal page refcount field at least - * once, so that the page really is pinned. - */ - page_ref_add(page, refs); - - mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_ACQUIRED, 1); - } - - return true; + return try_grab_compound_head(page, 1, flags); } /** |