From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id 399796B00A0 for ; Wed, 8 Jul 2009 23:13:03 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n693QQbg017606 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Thu, 9 Jul 2009 12:26:26 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 247A245DE4E for ; Thu, 9 Jul 2009 12:26:26 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id E987345DE4D for ; Thu, 9 Jul 2009 12:26:25 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id D17941DB8040 for ; Thu, 9 Jul 2009 12:26:25 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 855811DB803C for ; Thu, 9 Jul 2009 12:26:25 +0900 (JST) Date: Thu, 9 Jul 2009 12:24:28 +0900 From: KAMEZAWA Hiroyuki Subject: [PATCH 0/2] ZERO PAGE again v3. Message-Id: <20090709122428.8c2d4232.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" , avi@redhat.com, "akpm@linux-foundation.org" , torvalds@linux-foundation.org, aarcange@redhat.com List-ID: After v2 discussion, I felt that "Go" sign can be given if implemetaion is neat and tiny and overhead seems very small. Here is v3. In this version, - use pte_special() in vm_normal_page() All ZERO_PAGE check will go down to vm_normal_page() and check is done here. Some new flags in follow_page() and get_user_pages(). - per arch use-zero-page config is added. IIUC, archs which have _PAGE_SPECIAL is only x86, powerpc, s390. Because this patch make use of pte_special() check, config to use zero page is added and you can turn it off if necessary. I this patch, only x86 is turned on which I can test. Any comments are welcome. 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