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Unformatted text preview: Open Sources: Voices from the Open Source Revolution 1st Edition January 1999 1-56592-582-3, Order Number: 5823 280 pages, $24.95 Appendix A The Tanenbaum-Torvalds Debate What follows in this appendix are what are known in the community as the Tanenbaum/Linus "Linux is obsolete" debates. Andrew Tanenbaum is a well-respected researcher who has made a very good living thinking about operating systems and OS design. In early 1992, noticing the way that the Linux discussion had taken over the discussion in comp.os.minix, he decided it was time to comment on Linux. Although Andrew Tanenbaum has been derided for his heavy hand and misjudgements of the Linux kernel, such a reaction to Tanenbaum is unfair. When Linus himself heard that we were including this, he wanted to make sure that the world understood that he holds no animus towards Tanenbaum and in fact would not have sanctioned its inclusion if we had not been able to convince him that it would show the way the world was thinking about OS design at the time. We felt the inclusion of this appendix would give a good perspective on how things were when Linus was under pressure because he abandoned the idea of microkernels in academia. The first third of Linus' essay discusses this further. Electronic copies of this debate are available on the Web and are easily found through any search service. It's fun to read this and note who joined into the discussion; you see user- hacker Ken Thompson (one of the founders of Unix) and David Miller (who is a major Linux kernel hacker now), as well as many others. To put this discussion into perspective, when it occurred in 1992, the 386 was the dominating chip and the 486 had not come out on the market. Microsoft was still a small company selling DOS and Word for DOS. Lotus 123 ruled the spreadsheet space and WordPerfect the word processing market. DBASE was the dominant database vendor and many companies that are household names today--Netscape, Yahoo, Excite--simply did not exist. From: [email protected] (Andy Tanenbaum) Newsgroups: comp.os.minix Subject: LINUX is obsolete Date: 29 Jan 92 12:12:50 GMT I was in the U.S. for a couple of weeks, so I haven't commented much on LINUX (not that I would have said much had I been around), but for what it is worth, I have a couple of comments now. As most of you know, for me MINIX is a hobby, something that I do in the evening when I get bored writing books and there are no major wars, revolutions, or senate hearings being televised live on CNN. My real job is a professor and researcher in the area of operating systems. As a result of my occupation, I think I know a bit about where operating are going in the next decade or so. Two aspects stand out: 1. MICROKERNEL VS MONOLITHIC SYSTEM Most older operating systems are monolithic, that is, the whole operating system is a single a.out file that runs in 'kernel mode.' This binary contains the process management, memory management, file system and the rest. Examples of such systems are UNIX, MS-DOS, VMS, MVS, OS/360, rest....
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- Spring '11
- monolithic kernel, Linux kernel, Microkernel