Re: [PATCH 1/2] mm: introduce page reference manipulation functions

[Joonsoo Kim <iamjoonsoo.kim@lge.com>]

On Mon, Nov 09, 2015 at 01:45:37PM +0200, Kirill A. Shutemov wrote:
> On Mon, Nov 09, 2015 at 05:00:32PM +0900, Joonsoo Kim wrote:
> > 2015-11-09 16:53 GMT+09:00 Sergey Senozhatsky
> > <sergey.senozhatsky.work@gmail.com>:
> > > 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?
> > 
> > Hello,
> > 
> > I used that page_count_ before but change my mind.
> > I think that ref is more relevant to this operation.
> > Perhaps, it'd be better to change page_count()/set_page_count()
> > to page_ref()/set_page_ref().
> 
> What about get_page() vs. page_cache_get() and put_page() vs.
> page_cache_release()? Two different helpers for the same thing is annyoing
> me for some time (plus PAGE_SIZE vs. PAGE_CACHE_SIZE, etc.).
> 
> If you want coherent API you might want to get them consitent too.

In fact, consistent naming is out of interest of this patchset. :)

Thanks.