From owner-freebsd-doc Wed Jul 12 17: 3:34 2000 Delivered-To: freebsd-doc@freebsd.org Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by hub.freebsd.org (Postfix) with ESMTP id 41EA237B756; Wed, 12 Jul 2000 17:03:29 -0700 (PDT) (envelope-from grog@wantadilla.lemis.com) Received: (from grog@localhost) by wantadilla.lemis.com (8.9.3/8.9.3) id JAA04587; Thu, 13 Jul 2000 09:33:24 +0930 (CST) (envelope-from grog) Date: Thu, 13 Jul 2000 09:33:24 +0930 From: Greg Lehey To: Ben Smithurst Cc: doc@FreeBSD.ORG Subject: Re: small update to handbook about debug kernels Message-ID: <20000713093324.A4094@wantadilla.lemis.com> References: <20000711131846.L11000@strontium.scientia.demon.co.uk> <20000712103922.A29642@wantadilla.lemis.com> <20000712145451.D11000@strontium.scientia.demon.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0pre2i In-Reply-To: <20000712145451.D11000@strontium.scientia.demon.co.uk> 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-doc@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Wednesday, 12 July 2000 at 14:54:51 +0100, Ben Smithurst wrote: > Greg Lehey wrote: > >> I think you should look from the viewpoint of the modern kernel: >> >> If you are using version 2 or 3 of FreeBSD, you will need to strip >> the kernel manually... Note that if you run an a.out kernel with >> debugging symbols, the whole kernel will be loaded into memory... > > Is this better: > > If you are using FreeBSD 3 or earlier, you should make a stripped > copy of the debug kernel, rather than installing the large debug > kernel itself: > > &prompt.root; cp kernel kernel.debug > &prompt.root; strip -g kernel > > This stage isn't necessary, but it is recommended. (In > FreeBSD 4 and later releases this step is performed automatically > at the end of the kernel make process.) > When the kernel has been stripped, either automatically or by > using the commands above, you may install it as usual by typing > make install. > > If you install and boot the debug kernel, without stripping > it as described above, symbol table lookup time for some programs > will drastically increase. Note also that older releases of > FreeBSD (up to but not including 3.1) used a.out kernels by > default, which must have their symbol tables permanently resident > in physical memory. With the larger symbol table in an unstripped > debug kernel, this is wasteful. Recent FreeBSD releases use ELF > kernels where this is no longer a problem. > > ? It's a bit longer, but has a bit more detail, I think. That looks a lot better. I don't think it's too long. Only one thing: does the symbol lookup time increase sufficiently to be noticeable? I don't have any experience with this myself. I'd personally play safe and not mention it. 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-doc" in the body of the message