mm: document follow_page()

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Izik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2010-05-24 14:32:39 -07:00 committed by Linus Torvalds
parent 58a9d3d8db
commit 142762bd8d

View File

@ -1227,8 +1227,17 @@ int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
}
EXPORT_SYMBOL_GPL(zap_vma_ptes);
/*
* Do a quick page-table lookup for a single page.
/**
* follow_page - look up a page descriptor from a user-virtual address
* @vma: vm_area_struct mapping @address
* @address: virtual address to look up
* @flags: flags modifying lookup behaviour
*
* @flags can have FOLL_ flags set, defined in <linux/mm.h>
*
* Returns the mapped (struct page *), %NULL if no mapping exists, or
* an error pointer if there is a mapping to something not represented
* by a page descriptor (see also vm_normal_page()).
*/
struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
unsigned int flags)