centos man page for find_or_create_page

FIND_OR_CREATE_PAGE(9)					    Memory Management in Linux					    FIND_OR_CREATE_PAGE(9)

NAME
       find_or_create_page - locate or add a pagecache page

SYNOPSIS
       struct page * find_or_create_page(struct address_space * mapping, pgoff_t index, gfp_t gfp_mask);

ARGUMENTS
       mapping
	   the page's address_space

       index
	   the page's index into the mapping

       gfp_mask
	   page allocation mode

DESCRIPTION
       Looks up the page cache slot at mapping & offset. If there is a page cache page, it is returned locked and with an increased refcount.

       If the page is not present, a new page is allocated using gfp_mask and added to the page cache and the VM's LRU list. The page is returned
       locked and with an increased refcount.

       On memory exhaustion, NULL is returned.

       find_or_create_page may sleep, even if gfp_flags specifies an atomic allocation!

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						    FIND_OR_CREATE_PAGE(9)