From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 23 May 2001 02:01:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 23 May 2001 02:00:53 -0400 Received: from wiprom2mx1.wipro.com ([203.197.164.41]:45028 "EHLO wiprom2mx1.wipro.com") by vger.kernel.org with ESMTP id ; Wed, 23 May 2001 02:00:44 -0400 Message-ID: <3B0B533B.B902EE85@wipro.tcpn.com> Date: Wed, 23 May 2001 11:35:47 +0530 From: "Shashi Kiran T.R." Organization: Wipro Ltd X-Mailer: Mozilla 4.76 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, Shashi.Kiran@wipro.com Subject: Kernel memory mapped into user process Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi , I have a proposition at hand to optimize getting system time by avoiding the system call(gettimeofday()) overhead. This can be implemented by keeping a read-only page of kernel memory mapped into user processes for reading quickly. A kernel process can keep that page up-to-date. I did some browsing of this mailing list archives to get the following related topics: * mapping user space buffer to kernel address space * Direct I/O * Zero Copy IO None of these seem to specifically address my problem. So can the experienced please throw some light on the issues involved in having a read-only page of kernel memory mapped into user process. Any help/suggestions will be much appreciated. Please CC your comments to "trsk@wipro.tcpn.com" Thanks and Regards, Shashi