Messages in this thread | | | Date | Mon, 9 Nov 2015 16:53:37 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH 1/2] mm: introduce page reference manipulation functions |
| |
Hi,
On (11/09/15 16:23), Joonsoo Kim wrote: [..] > +static inline int page_count(struct page *page) > +{ > + return atomic_read(&compound_head(page)->_count); > +} > + > +static inline void set_page_count(struct page *page, int v) > +{ > + atomic_set(&page->_count, v); > +} > + > +/* > + * Setup the page count before being freed into the page allocator for > + * the first time (boot or memory hotplug) > + */ > +static inline void init_page_count(struct page *page) > +{ > + set_page_count(page, 1); > +} > + > +static inline void page_ref_add(struct page *page, int nr) > +{ > + atomic_add(nr, &page->_count); > +}
Since page_ref_FOO wrappers operate with page->_count and there are already page_count()/set_page_count()/etc. may be name new wrappers in page_count_FOO() manner?
> +static inline void page_ref_sub(struct page *page, int nr)
for example, page_count_sub(), etc.
-ss
> +{ > + atomic_sub(nr, &page->_count); > +} > + > +static inline void page_ref_inc(struct page *page) > +{ > + atomic_inc(&page->_count); > +} > + > +static inline void page_ref_dec(struct page *page) > +{ > + atomic_dec(&page->_count); > +} > + > +static inline int page_ref_sub_and_test(struct page *page, int nr) > +{ > + return atomic_sub_and_test(nr, &page->_count); > +} > + > +static inline int page_ref_dec_and_test(struct page *page) > +{ > + return atomic_dec_and_test(&page->_count); > +} > + > +static inline int page_ref_dec_return(struct page *page) > +{ > + return atomic_dec_return(&page->_count); > +} > + > +static inline int page_ref_add_unless(struct page *page, int nr, int u) > +{ > + return atomic_add_unless(&page->_count, nr, u); > +} > + > +static inline int page_ref_freeze(struct page *page, int count) > +{ > + return likely(atomic_cmpxchg(&page->_count, count, 0) == count); > +} > + > +static inline void page_ref_unfreeze(struct page *page, int count) > +{ > + VM_BUG_ON_PAGE(page_count(page) != 0, page); > + VM_BUG_ON(count == 0); > + > + atomic_set(&page->_count, count); > +}
| |