From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id D653B6B0082 for ; Wed, 5 Aug 2009 06:18:29 -0400 (EDT) Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n75AIWj2025524 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Wed, 5 Aug 2009 19:18:32 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 8625745DE51 for ; Wed, 5 Aug 2009 19:18:32 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 6577245DE4E for ; Wed, 5 Aug 2009 19:18:32 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 4E38B1DB803F for ; Wed, 5 Aug 2009 19:18:32 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id F3CAC1DB803C for ; Wed, 5 Aug 2009 19:18:31 +0900 (JST) Date: Wed, 5 Aug 2009 19:16:43 +0900 From: KAMEZAWA Hiroyuki Subject: [PATCH] ZERO_PAGE again v5. Message-Id: <20090805191643.2b11ae78.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: "linux-mm@kvack.org" Cc: "linux-kernel@vger.kernel.org" , npiggin@suse.de, hugh.dickins@tiscali.co.uk, "akpm@linux-foundation.org" , torvalds@linux-foundation.org List-ID: Updated from v4 as - avoid to add new arguments to vm_normal_page(). vm_normal_page() always returns NULL if ZERO_PAGE is found. - follow_page() directly handles pte_special and ANON_ZERO_PAGE. Then, amount of changes are reduced. Thanks for advices. Concerns pointed out: - Does use_zero_page() cover all cases ? I think yes.. - All get_user_pages() callers, which may find ZERO_PAGE is safe ? need tests. - All follow_pages() callers, which may find ZERO_PAGE is safe ? I think yes. Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org