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| author | Johannes Weiner <hannes@cmpxchg.org> | 2010-05-24 14:32:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-25 08:07:00 -0700 |
| commit | 142762bd8d8c46345e79f0f68d3374564306972f (patch) | |
| tree | c33360b872883d24b068ba7b8f01466fccb9dfc9 /mm | |
| parent | 58a9d3d8db06ca2ec31f64ec49ab0aeb89971b85 (diff) | |
| download | lwn-142762bd8d8c46345e79f0f68d3374564306972f.tar.gz lwn-142762bd8d8c46345e79f0f68d3374564306972f.zip | |
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>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c index 833952d8b74d..119b7ccdf39b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -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) |