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authorHugh Dickins <hugh@veritas.com>2005-11-23 16:37:38 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2005-11-23 19:08:38 -0500
commitcc3327e7dfc16a9a3e164075234c869867a59e45 (patch)
treed120c13540a7fa4769c0bf53eb12628a76366631
parent7b6ac9dffe6f4dd8776908b234ac1410ed15f112 (diff)
[PATCH] mm: unbloat get_futex_key
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>
-rw-r--r--kernel/futex.c15
1 files changed, 0 insertions, 15 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index aca8d10704f6..5872e3507f35 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -201,21 +201,6 @@ static int get_futex_key(unsigned long uaddr, union futex_key *key)
201 * from swap. But that's a lot of code to duplicate here 201 * from swap. But that's a lot of code to duplicate here
202 * for a rare case, so we simply fetch the page. 202 * for a rare case, so we simply fetch the page.
203 */ 203 */
204
205 /*
206 * Do a quick atomic lookup first - this is the fastpath.
207 */
208 page = follow_page(mm, uaddr, FOLL_TOUCH|FOLL_GET);
209 if (likely(page != NULL)) {
210 key->shared.pgoff =
211 page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
212 put_page(page);
213 return 0;
214 }
215
216 /*
217 * Do it the general way.
218 */
219 err = get_user_pages(current, mm, uaddr, 1, 0, 0, &page, NULL); 204 err = get_user_pages(current, mm, uaddr, 1, 0, 0, &page, NULL);
220 if (err >= 0) { 205 if (err >= 0) {
221 key->shared.pgoff = 206 key->shared.pgoff =