From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751112AbVKUWFL (ORCPT ); Mon, 21 Nov 2005 17:05:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751117AbVKUWFL (ORCPT ); Mon, 21 Nov 2005 17:05:11 -0500 Received: from gold.veritas.com ([143.127.12.110]:59307 "EHLO gold.veritas.com") by vger.kernel.org with ESMTP id S1751112AbVKUWFK (ORCPT ); Mon, 21 Nov 2005 17:05:10 -0500 Date: Mon, 21 Nov 2005 20:33:29 +0000 (GMT) From: Hugh Dickins X-X-Sender: hugh@goblin.wat.veritas.com To: Andrew Morton cc: linux-kernel@vger.kernel.org Subject: [PATCH 2/5] mm: unbloat get_futex_key In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 21 Nov 2005 20:33:18.0970 (UTC) FILETIME=[CECC3DA0:01C5EEDA] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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 --- kernel/futex.c | 15 --------------- 1 files changed, 15 deletions(-) --- 2.6.15-rc2/kernel/futex.c 2005-11-20 19:44:23.000000000 +0000 +++ linux/kernel/futex.c 2005-11-21 18:50:20.000000000 +0000 @@ -201,21 +201,6 @@ static int get_futex_key(unsigned long u * 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 =