Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261687AbUKTKjm (ORCPT ); Sat, 20 Nov 2004 05:39:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261685AbUKTKjC (ORCPT ); Sat, 20 Nov 2004 05:39:02 -0500 Received: from ems.hclinsys.com ([203.90.70.242]:32004 "EHLO ems.hclinsys.com") by vger.kernel.org with ESMTP id S261687AbUKTKgJ (ORCPT ); Sat, 20 Nov 2004 05:36:09 -0500 Subject: on the concept of COW From: Jagadeesh Bhaskar P To: LKML Content-Type: text/plain Message-Id: <1100947100.4038.41.camel@myLinux> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 (1.4.5-7) Date: Sat, 20 Nov 2004 16:08:21 +0530 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 918 Lines: 28 Hi, When a process forks, every resource of the parent, including the virtual memory is copied to the child process. The copying of VM uses copy-on-write(COW). I know that COW comes when a write request comes, and then the copy is made. Now my query follows: How will the copy be distributed. Whether giving the child process a new copy of VM be permanent or whether they will be merged anywhere? And shouldn't the operations/updations by one process be visible to the other which inherited the copy of the same VM? How can this work? Can someone please help me on this regard? -- With regards, Jagadeesh Bhaskar P R&D Engineer HCL Infosystems Ltd Pondicherry INDIA - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/