From owner-freebsd-arch@FreeBSD.ORG Sat Apr 19 01:06:01 2003 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9B75B37B401; Sat, 19 Apr 2003 01:06:01 -0700 (PDT) Received: from magic.adaptec.com (magic-mail.adaptec.com [208.236.45.100]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0503A43FBF; Sat, 19 Apr 2003 01:06:01 -0700 (PDT) (envelope-from scott_long@btc.adaptec.com) Received: from redfish.adaptec.com (redfish.adaptec.com [162.62.50.11]) by magic.adaptec.com (8.11.6/8.11.6) with ESMTP id h3J83cZ04954; Sat, 19 Apr 2003 01:03:38 -0700 Received: from btc.btc.adaptec.com ([10.100.0.52]) by redfish.adaptec.com (8.8.8p2+Sun/8.8.8) with ESMTP id BAA13672; Sat, 19 Apr 2003 01:05:43 -0700 (PDT) Received: from btc.adaptec.com (hollin [10.100.253.56]) by btc.btc.adaptec.com (8.8.8+Sun/8.8.8) with ESMTP id CAA07997; Sat, 19 Apr 2003 02:05:39 -0600 (MDT) Message-ID: <3EA10351.3010001@btc.adaptec.com> Date: Sat, 19 Apr 2003 02:05:37 -0600 From: Scott Long User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.2.1) Gecko/20030206 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Bruce Evans References: <200304182047.h3IKlhIZ000817@number6.magda.ca> <20030418214702.GA98907@rot13.obsecurity.org> <20030419165033.V15269@gamplex.bde.org> In-Reply-To: <20030419165033.V15269@gamplex.bde.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit cc: arch@freebsd.org cc: jeff@freebsd.org cc: David Magda cc: Kris Kennaway Subject: Re: config(8) should check if a scheduler is selected X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 19 Apr 2003 08:06:01 -0000 Bruce Evans wrote: > On Fri, 18 Apr 2003, Kris Kennaway wrote: > > >>On Fri, Apr 18, 2003 at 04:47:43PM -0400, David Magda wrote: >> >> >>>If you run config(8) on a kernel configuration file which doesn't >>>have a scheduler selected then it does *NOT* complain. >> >>How is this different to any of the other mandatory kernel components >>or dependencies? You can build a kernel that will refuse to link in >>many ways; missing a scheduler is just a new mistake you might make if >>you forget to read /usr/src/UPDATING. > > > It is the only mandatory option (sic). Kernels with no options (although > they might not be useful) can be built except for this bug. Example of > a minimal config file (before misconfiguration of the configuration of > scheduling). > > %%% > machine i386 > cpu I686_CPU > ident MIN > %%% > The scheduler is (one of) the first core subsystems to be made modular. If by chance the VM system became modular (VM_MACH, VM_UVM =-) you'd have a similar situation there also. I'm afraid that the lack of seatbelts in config(8) for SCHED_xxx will generate a lot of user complaints when 5.1 is released. Since code to implement it has not magically appeared yet, we might have to make due with adding extra eye-catching comments to things like NOTES and GENERIC. > BTW, a minimal kernel is now almost 3 times as large as in FreeBSD-2 due > to general bloat and misconfiguration of configuration in the opposite > way (subsystems much larger than scheduling are standard; you can still > leave out FFS and INET but many less useful subsystems are standard). Some of us remember when 250k FreeBSD kernels were not hard to configure =-) Scott