From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030301AbXCSQKL (ORCPT ); Mon, 19 Mar 2007 12:10:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030332AbXCSQKL (ORCPT ); Mon, 19 Mar 2007 12:10:11 -0400 Received: from embla.aitel.hist.no ([158.38.50.22]:44791 "HELO embla.aitel.hist.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1030317AbXCSQKK (ORCPT ); Mon, 19 Mar 2007 12:10:10 -0400 Message-ID: <45FEB50E.2040104@aitel.hist.no> Date: Mon, 19 Mar 2007 17:06:38 +0100 From: Helge Hafting User-Agent: Icedove 1.5.0.9 (X11/20061220) MIME-Version: 1.0 To: Avi Kivity CC: davids@webmaster.com, "Linux-Kernel@Vger. Kernel. Org" Subject: Re: is RSDL an "unfair" scheduler too? References: <45FEAB60.7090704@argo.co.il> In-Reply-To: <45FEAB60.7090704@argo.co.il> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Avi Kivity wrote: > > A fairly contrived example, but I see your point. Of course any > system can be broken. I think that user-level scheduling is good for > real multi user systems, where 'user' means a person, not an > artificial entity. It's also good for a multi application server, > where typically each service runs (or can be made to run) as a > separate user. For a not so contrived example, look at email delivery. Some mailservers do all work as root (or some fixed email user) Some servers will switch to the UID of the user receiving the message, limiting the damage in case of buffer overflow etc. A fair amount of work is then done as that user - running the message through virus/spam-checks and then perhaps procmail. Helge Hafting