From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,5bcf30769d6d9599 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-09-02 13:38:06 PST Path: archiver1.google.com!newsfeed.google.com!newsfeed.stanford.edu!news.tele.dk!small.news.tele.dk!194.213.69.151!news.algonet.se!algonet!newspeer.clara.net!news.clara.net!news5-gui.server.ntli.net!ntli.net!news6-win.server.ntlworld.com.POSTED!not-for-mail From: "chris.danx" Newsgroups: comp.lang.ada References: <20010829113230.0ae3febd.tonygair@blueyonder.co.uk> <9miteo$t7r$1@nh.pace.co.uk> Subject: Re: ADA os talk X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.50.4807.1700 X-MIMEOLE: Produced By Microsoft MimeOLE V5.50.4807.1700 Message-ID: <4twk7.28692$wX5.3722280@news6-win.server.ntlworld.com> Date: Sun, 2 Sep 2001 21:16:52 +0100 NNTP-Posting-Host: 213.104.121.104 X-Complaints-To: abuse@ntlworld.com X-Trace: news6-win.server.ntlworld.com 999461824 213.104.121.104 (Sun, 02 Sep 2001 21:17:04 BST) NNTP-Posting-Date: Sun, 02 Sep 2001 21:17:04 BST Organization: ntlworld News Service Xref: archiver1.google.com comp.lang.ada:12641 Date: 2001-09-02T21:16:52+01:00 List-Id: > Why not set a goal of a kernel that handles scheduling of processes & tasks > on from one to N processors? Presume that you have memory and some device > from which the kernel can boot. Presume that it needs to execute at least > one application (what ultimately becomes the API - maybe device drivers?) in > "privileged" mode. On x86 this is ok for monolithic kernels but if it's real privileged mode in a microkernel, then performance will take a hit. If you fake privileged mode and run things in "user mode" with a user level IPC, then the hit will be much less. Check out L4 for info on it. Note that on other systems, the hit of the context switch (which are more frequent in microkernels) is not so bad and this scheme may not be necessary. Chris