From owner-freebsd-newbies Tue Jan 23 18:18: 7 2001 Delivered-To: freebsd-newbies@freebsd.org Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by hub.freebsd.org (Postfix) with ESMTP id F0F7437B400 for ; Tue, 23 Jan 2001 18:17:48 -0800 (PST) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id 9EDCD6AB73; Wed, 24 Jan 2001 12:47:46 +1030 (CST) Date: Wed, 24 Jan 2001 12:47:46 +1030 From: Greg Lehey To: David Johnson Cc: Benjamin Lutz , freebsd-newbies@freebsd.org Subject: Re: Why is the FreeBSD kernel so much bigger than the Linux kernel? Message-ID: <20010124124746.L37060@wantadilla.lemis.com> References: <20010124115812.G37060@wantadilla.lemis.com> <3A6E3583.B5F42F16@acuson.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <3A6E3583.B5F42F16@acuson.com>; from djohnson@acuson.com on Tue, Jan 23, 2001 at 05:53:07PM -0800 Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Sender: owner-freebsd-newbies@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tuesday, 23 January 2001 at 17:53:07 -0800, David Johnson wrote: > Greg Lehey wrote: > >> I have a Linux box here: >> >> [grog@capellorosso /boot]$ ls -l /boot/vmlinux-2.2.16-22 >> -rwxr-xr-x 1 root root 1621492 Aug 23 06:26 /boot/vmlinux-2.2.16-22 >> >> That's not very different. Note that a lot of hardware support in >> Linux is done in loadable modules, while FreeBSD has it in the kernel. > > Your Linux is a default kernel off of some distribution (the -22 gives > it away). A 2.2.16 kernel I just compiled to support only the hardware > actually present on the system weighs in at only 416,492 bytes. That's a > quarter the size you gave. (a FreeBSD kernel compiled for the same > system was over one megabyte). It's also compressed. > Granted, FreeBSD has a different architecture than Linux. Comparing > the sizes of the kernels is like comparing apples and oranges. But > Ben's question was a good one, so I'll expand on it. Does putting > the hardware support into the kernel instead of modules account for > this big of a difference? I don't know. As you say, the comparison isn't too meaningful anyway. I suspect that new things like the CAM layer are much bigger than their old counterparts. My first BSD/386 kernel was only about 600 kB, so there has been a lot of growth. Greg -- Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-newbies" in the body of the message