Date: Sun, 14 Jan 2001 13:00:17 +0100 From: Erik Trulsson <ertr1013@student.uu.se> To: Peter Wemm <peter@netplex.com.au> Cc: Poul-Henning Kamp <phk@critter.freebsd.dk>, Wilko Bulte <wkb@freebie.demon.nl>, John Baldwin <jhb@FreeBSD.org>, cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/conf GENERIC Message-ID: <20010114130017.A1612@student.uu.se> In-Reply-To: <200101141115.f0EBFBQ89810@mobile.wemm.org>; from peter@netplex.com.au on Sun, Jan 14, 2001 at 03:15:11AM -0800 References: <28586.979469127@critter> <200101141115.f0EBFBQ89810@mobile.wemm.org>
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On Sun, Jan 14, 2001 at 03:15:11AM -0800, Peter Wemm wrote: > Poul-Henning Kamp wrote: > > In message <20010114114418.A46703@freebie.demon.nl>, Wilko Bulte writes: > > >On Sun, Jan 14, 2001 at 02:11:11AM -0800, John Baldwin wrote: > > >> jhb 2001/01/14 02:11:10 PST > > >> > > >> Modified files: > > >> sys/i386/conf GENERIC > > >> Log: > > >> Remove I386_CPU from GENERIC. Support for the 386 seriously pessimizes > > >> performance on other x86 processors. Custom kernels can still be built > > >> that will run on the 386. > > > > > >Does this mean installation won't run on 386 anymore? > > > > It would be trivial to add i386 to the install kernel, and > > probably worthwhile. > > No, because simply doing that leaves you with an unbootable machine. > > Anyway, I defy anybody to do a standard CDROM or boot floppy install on a > 386 and stay sane. Everybody that I know of that does this sort of thing > does one of the following type things: > My experience with doing a normal install on a 386 is that it isn't too bad. Granted, last time I did a normal install (as opposed to build/installworld) was with 3.2 but anyway. > 1: cross builds from a fast machine to a small image and dd's it to disks. > Remember, 99% of 386's cannot handle more than 528MB IDE disks. Most (all?) 386's can handle large IDE disks just fine. The BIOS might not be able to handle anything above the 528MB limit, but that just means that the / partition must be within the 528 MB limit. (Yes, I have a 386 whose BIOS can't handle large disks with a 1.2 GB IDE disk. Works like a charm.) > > 2: install on a fast machine using sysinstall, and strip the hell out of > the kernel, world etc. Then transport the disk to a 386. Building > a 5.0 kernel on a *486* takes forever these days, let alone a 386. > > Remember, 386's were essentially ISA-only. I think we should send people > to 2.2.x if they want to run on an ISA-only i386. 5.0 will *seriously > suck* on typical 386 hardware. My personal experience is that it > *seriously sucks* on a 486 right now (yes, I have one running right now, > and a 486DX33 w/ 64M of ram is **painful**). > > In fact, it was near impossible to run on a 486-33 w/ 12MB ram when I tried > it about 12 months ago on what was then -current. I was eventually able to Huh? I am running 4.2-stable on a 386 with 8MB RAM right now and it works fine. It is not a speed demon exactly but as gateway/firewall it it works fine. It doesn't even need to use any swap during boot/login. (The kernel is quite stripped down but anyway.) (Alright, world/kernel builds are done on a faster machine and then installed over NFS.) > tune things down enough (maxusers 5, 2 gettys, etc) to get it to the point > that it didn't lock up the VM system during a compile. i386 *pc* hardware > that supports more than 16MB was pretty rare if I recall. Embedded systems > are a different issue, but I doubt many people use the FreeBSD cdrom and > sysinstall to set up an embedded micro-OS install... Heck, even picobsd > uses its own kernel configs. > > Yes, we could make an alternate 386 kernel, and a 386 boot disk etc. But > I really dont think it is worth while. The user experience would be rather > uninspiring - I think we'd be far better pointing them to 2.2.x. In fact, > another net-only point release of 2.2.x to fix the known security holes > would probably be less cumulative effort than it would take to keep i386 > a viable 'GENERIC' option for the SMPng kernel over the next 6-12 months. 2.2.x ? Why not at least 3.x ? (3.2 was AFAIK the last release that could be installed on a machine with 8MB RAM or less.) > > The bottom line is that I feel the time is just about right to yank i386 > entirely, not just taking it out of GENERIC. But I wont push for that > (yet :-). But ending the expensive runtime cost of i386 support in > GENERIC is well overdue I feel. The cost of slowing down copyin()/copyout() > etc is just not worth it. > I don't agree. Removing 386 support from GENERIC I can live with (although I don't like it much) but removing 386 support entirely would be a bad idea IMNSHO. I don't have any experience with -current but -stable works fine on 386 and I don't see any reason not to use those old computers for something useful. Better to have separate configs for 386 and 486-and-above. -- <Insert your favourite quote here.> Erik Trulsson ertr1013@student.uu.se To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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