From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936246AbYEVJgr (ORCPT ); Thu, 22 May 2008 05:36:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933808AbYEVJgi (ORCPT ); Thu, 22 May 2008 05:36:38 -0400 Received: from ns.miraclelinux.com ([219.118.163.66]:37624 "EHLO mail.miraclelinux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932070AbYEVJgh (ORCPT ); Thu, 22 May 2008 05:36:37 -0400 Message-ID: <48353D60.2050704@miraclelinux.com> Date: Thu, 22 May 2008 18:31:12 +0900 From: Hirofumi Nakagawa User-Agent: Thunderbird 2.0.0.12 (X11/20080213) MIME-Version: 1.0 To: Andrew Morton CC: linux-kernel@vger.kernel.org, Andi Kleen Subject: Re: [RFC][PATCH 0/1] MAZE: Mazed processes monitor References: <48297FD0.2090905@miraclelinux.com> <20080513084157.098ae2dc.akpm@linux-foundation.org> In-Reply-To: <20080513084157.098ae2dc.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-PMX-Version: 5.3.1.294258, Antispam-Engine: 2.5.1.298604, Antispam-Data: 2008.5.22.21216 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Andrew, Thank you for your comment and review. > The immediate quesstion is, of course, "why does this need to be done > in-kernel?". I am unable to answer that from the provided changelog > information, and I should be able to do that. It needs to be done in kernel because excessive CPU cycle usage is directly detected watching kernel internal task_struct.state. It's hard to get that information outside the kernel. Additionally, this patch's aim is to implement a CGL (Carrier Grade Linux) requirement (AVL.14.0). There are specs that can not be implemented outside the kernel. These are; - Communication between the monitoring process and the kernel - Ability to define policy based on process events including process/thread creation and exit, and, - Ability to set the CPU cycle threshold to a resolution of one millisecond. Thanks. Hirofumi Nakagawa