Re: [PATCHv4 14/39] thp, mm: rewrite delete_from_page_cache() tosupport huge pages

[Kirill A. Shutemov]

Dave Hansen wrote:
> On 06/07/2013 08:10 AM, Kirill A. Shutemov wrote:
> > +	/*
> > +	 * When we add a huge page to page cache we take only reference to head
> > +	 * page, but on split we need to take addition reference to all tail
> > +	 * pages since they are still in page cache after splitting.
> > +	 */
> > +	init_tail_refcount = PageAnon(page) ? 0 : 1;
> 
> What's the "init" for in the name?

initial_tail_refcount?

> In add_to_page_cache_locked() in patch 12/39, you do
> > +       spin_lock_irq(&mapping->tree_lock);
> > +       for (i = 0; i < nr; i++) {
> > +               page_cache_get(page + i);
> 
> That looks to me to be taking references to the tail pages.  What gives? :)

The point is to drop this from add_to_page_cache_locked() and make distribution
on split.

-- 
 Kirill A. Shutemov
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