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[PATCH] mm: unbloat get_futex_key

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The follow_page changes in get_futex_key have left it with two almost
identical blocks, when handling the rare case of a futex in a nonlinear vma.
get_user_pages will itself do that follow_page, and its additional
find_extend_vma is hardly any overhead since the vma is already cached.  Let's
just delete the follow_page block and let get_user_pages do it.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Hugh Dickins 2005-11-23 13:37:38 -08:00 committed by Linus Torvalds
parent 7b6ac9dffe
commit cc3327e7df
1 changed files with 0 additions and 15 deletions
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15
kernel/futex.c
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@ -201,21 +201,6 @@ static int get_futex_key(unsigned long uaddr, union futex_key *key)
* from swap. But that's a lot of code to duplicate here
* for a rare case, so we simply fetch the page.
*/
/*
* Do a quick atomic lookup first - this is the fastpath.
*/
page = follow_page(mm, uaddr, FOLL_TOUCH|FOLL_GET);
if (likely(page != NULL)) {
key->shared.pgoff =
page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
put_page(page);
return 0;
}
/*
* Do it the general way.
*/
err = get_user_pages(current, mm, uaddr, 1, 0, 0, &page, NULL);
if (err >= 0) {
key->shared.pgoff =