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, 16 Jan 2002 17:41:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 16 Jan 2002 17:41:43 -0500 Received: from baghira.han.de ([212.63.63.2]:6148 "EHLO baghira.han.de") by vger.kernel.org with ESMTP id ; Wed, 16 Jan 2002 17:41:31 -0500 To: linux-kernel@vger.kernel.org Path: jum From: jum@anubis.han.de (Jens-Uwe Mager) Newsgroups: hannet.ml.linux.rutgers.linux-kernel Subject: Re: [patch] O(1) scheduler-H6/H7/I0 and nice +19 Date: 16 Jan 2002 22:41:17 GMT Organization: At Home Message-ID: In-Reply-To: NNTP-Posting-Host: anubis.han.de X-Trace: baghira.han.de 1011220877 12441 212.63.63.3 (16 Jan 2002 22:41:17 GMT) X-Complaints-To: usenet@baghira.han.de NNTP-Posting-Date: 16 Jan 2002 22:41:17 GMT User-Agent: slrn/0.9.6.4 (Linux) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 16 Jan 2002 03:00:45 GMT, Robert Love wrote: >On Tue, 2002-01-15 at 21:04, Davide Libenzi wrote: > >> On 15 Jan 2002, Robert Love wrote: >> > This isn't a bad idea, as long as we don't use it as a crutch or >> > excuse. That is, answer scheduling problems with "properly nice your >> > tasks" -- the scheduler should be smart enough, to some degree. >> > >> > FWIW, Solaris actually implements a completely different scheduling >> > policy, SCHED_INTERACT or something. It is for windowed tasks in X -- >> > they get a large interactivity bonus. > >> Now ( with 2.5.3-pre1 ) intractivity is *very good* but SCHED_INTERACT >> would help *a lot* to get things even more right. > >I looked it up; its called class IA. I don't know if it grows from a >limitation of their scheduler (i.e. they can't calculate priority and be >as fair to interactive tasks as us) or if it offers a fundamental >advantage. I suspect their are a myriad of things things we can do with >an interactive/GUI scheduling policy. > >One thing this is, since their kernel is preemptible, it marks processes >that very much always deserve a scheduling boost based on interactivity, >and thus their interactivity is quite nice. I would believe the IA class is a hack to maintain good interactive performance for the X window apps if the scheduler does not maintain this itself in the TS (time sharing class). The standard Solaris scheduler is not favoring I/O bound programs properly, especially if these are driven by network connections. I have several programs that are of the type poll() - recv() - work a little - send() type loops and these get slow to a crawl if run in the TS class if the foreground process (also in TS) is compute bound. -- Jens-Uwe Mager