From owner-freebsd-hackers Fri Apr 7 9: 4:33 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from lince.tdnet.com.br (lince.tdnet.com.br [200.236.148.6]) by hub.freebsd.org (Postfix) with ESMTP id 498A937BEBE for ; Fri, 7 Apr 2000 09:04:22 -0700 (PDT) (envelope-from kernel@tdnet.com.br) Received: from tdnet.com.br [200.236.148.100] by lince.tdnet.com.br with ESMTP (SMTPD32-5.00) id AA9D981501B8; Fri, 07 Apr 2000 12:11:25 -0300 Message-ID: <38EDDBC4.51F2414D@tdnet.com.br> Date: Fri, 07 Apr 2000 12:59:48 +0000 From: Gustavo V G C Rios X-Mailer: Mozilla 4.7 [en] (X11; I; FreeBSD 4.0-STABLE i386) X-Accept-Language: en MIME-Version: 1.0 To: Nick Sayer Cc: Alfred Perlstein , freebsd-hackers@FreeBSD.ORG Subject: Re: Is traditional unixes kernel really stable ? References: <38ED128C.22C3AA28@tdnet.com.br> <20000406192206.N22104@fw.wintelcom.net> <38ED233E.74716D02@tdnet.com.br> <20000406230234.B4381@fw.wintelcom.net> <38EDD209.421EF9B0@tdnet.com.br> <38EE0536.F2305A40@quack.kfu.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Nick Sayer wrote: > > Gustavo V G C Rios wrote: > > > Why not starting a microkernel arch? > > IMHO the microkernel is the emperor's new clothes (so is OOP, but that, > I suspect, I won't > get quite so much agreement on). > > Context switching has been mentioned, but in addition to that, the real > problem is that it > really doesn't change anything. It may somewhat simplify a non-critical > driver like a serial > port or a mouse or the like, but if a SCSI HBA driver crashes, it's > likely going to make > life for the microkernel very hairy, just like it would a full kernel. > > And a driver bug can cause the hardware to wedge the machine whether the > driver is in > protected or user mode too. > > Most people who I talk to who bring up microkernel do it because they > see the process of compiling > a FreeBSD kernel and think that microkernels are somehow the opposite of > that. If that's the > case, they should believe that Solaris is a microkernel, which it > patently is not. > > NT comes closer, with its rings of protection, but you can hardly call > that a picture of > stabiliy. Yeah! I had started to study OS (UNIX Internals: the new frontiers) internals. That book tell the same about microkernel, but when i downloaded QNX demo disk i got confused. If microkernel has such a drawnbacks, why QNX is so fast and reliable? Should you download it too, and realize what i mean. Thanks a lot for the patience. PS: I am just a beginner, so, don't take me wrong. The fact is that i am really confused about what books say about microkernel and what in that single demo floppy. I would be really glad to have some here to kindly clarify it to me. -- If you're happy, you're successful. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message