From owner-freebsd-hackers Fri Apr 5 18: 0:45 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by hub.freebsd.org (Postfix) with ESMTP id 3B6B637B405 for ; Fri, 5 Apr 2002 18:00:36 -0800 (PST) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id 995C878319; Sat, 6 Apr 2002 11:30:33 +0930 (CST) Date: Sat, 6 Apr 2002 11:30:33 +0930 From: Greg 'groggy' Lehey To: Doug White Cc: Alessandro de Manzano , Alfred Perlstein , hackers@FreeBSD.ORG Subject: Re: Is a debug kernel slower than a non-debug one ? Message-ID: <20020406113033.I81917@wantadilla.lemis.com> References: <20020405220831.B14188@libero.sunshine.ale> <20020405141702.V36072-100000@resnet.uoregon.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020405141702.V36072-100000@resnet.uoregon.edu> User-Agent: Mutt/1.3.23i Organization: The FreeBSD Project Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.FreeBSD.org/ X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Friday, 5 April 2002 at 14:18:38 -0800, Doug White wrote: > On Fri, 5 Apr 2002, Alessandro de Manzano wrote: > >> On Fri, Apr 05, 2002 at 12:00:05PM -0800, Alfred Perlstein wrote: >> >> Wow, thanks for the super-fast answer! :)) >> >> >>>> on my production servers' kernel so in the very rare case of crash I'll >>>> got a crash dump ( I'ld use also options DDB_UNATTENDED) and could >>>> immediately have a backtrace report. >>>> >>>> ..Am I crazy ? :-)) >>> >>> I don't think you'll notice a difference for most stuff, this is how >> >> does the "-g" option (GCC option I guess) disable the "-O" optimizing >> option ? >> If "-g" simply attach the symbols and similar debug info to the >> executable I guess the kernel should not be slower, but I don't know >> GCC very well... > > Note that the kernel binary with debugging symbols is left in > /sys/compile/MYKERNEL/kernel.debug while the actual kernel is stripped > before installation into /kernel. > > If the debugging kernel was actually loaded it would be gigantic :) No, since the transition to ELF, none of the debugging information gets loaded into core. Try it. > This is all detailed in the Handbook section on kernel debugging, > btw. Hmm, that needs to be fixed, then. Greg -- See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message