From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id CAE296B01EF for ; Sat, 17 Apr 2010 03:07:34 -0400 (EDT) Received: from [109.160.183.100] (port=19825 helo=borjch.rnk) by gator1121.hostgator.com with esmtpa (Exim 4.69) (envelope-from ) id 1O327n-000411-I6 for linux-mm@kvack.org; Sat, 17 Apr 2010 02:07:31 -0500 Message-ID: <4BC95E2E.5040801@browserseal.com> Date: Sat, 17 Apr 2010 10:07:26 +0300 From: Sasha Sirotkin MIME-Version: 1.0 Subject: question about COW Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: linux-mm@kvack.org List-ID: There is an "early COW" mechanism in __do_fault() which, if the page is not present and the fault is FAULT_PAGE_WRITE goes ahead and copies the page in order to prevent the next exception. The question - why the code in __do_fault() does not decrease the shared map count of the old page as do_wp_page does ? And while we are at it, while this "early COW" code is much more simple than do_wp_page()? Thanks. -- 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