Date: Mon, 11 Mar 2019 10:36:17 +0100 (CET) From: samir.otmane@numericable.fr To: "Kevin P. Neal" <kpn@neutralgood.org> Cc: freebsd-questions@freebsd.org Subject: Re: Re: Barebone kernel options request Message-ID: <ea-mime-5c862c11-6ae6-37e66a16@webmail.numericable.fr> In-Reply-To: <20190311023130.GA3936@neutralgood.org>
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Hi Kevin, Thanks for the answer. Actually my ISP webmail is kinda buggy, i apologize for multiple mail send= ing. I'm already aware of kernel compilation options through NOTES file, and ye= ah i'm using amd64 arch. As peoples told me and as i'm actually thinking of it is i might be a litt= le exaggerating about overhead stuff, but yet i'd like to choose what i wan= t to. Samir. ---- Message d'origine ---- De : "Kevin P. Neal" <kpn@neutralgood.org> =C0 : samir.otmane@numericable.fr Objet : Re: Barebone kernel options request Date : 11/03/2019 03:31:30 CET Copie =E0 : freebsd-questions@freebsd.org On Sun, Mar 10, 2019 at 02:09:37PM +0100, samir.otmane@numericable.fr wrot= e: > Hello everyone, >=20 > For my purpose, i would like to get a very barebone FreeBSD kernel ( For= instance i don't want jaling, i'll want to get rid of unwanted overhead ),= but i don't know how to do so. >=20 > IRC chatters told me that it would be very challenging to do so. >=20 > I found that page ( https://www.freebsd.org/cgi/man.cgi?query=3Dsrc.conf= ) but it only disables user-land program building, not kernel-land code. Three emails to the same list is two email too many. Just one email would be sufficient, and if you get no response another single email a reasonabl= e period of time later. I don't know if this community has a definition of "reasonable period of time", though. The LLVM community's is roughly "a week or so". Anyway. On to business: What you want is to build a custom kernel. The GENERIC kernel config file is, for the 64-bit amd64 host, located at: /usr/src/sys/amd64/conf/GENERIC You didn't say what host, but the other hosts are at guessable locations based on that path, and the filename to look for is "GENERIC". You'll need to copy that file and edit out the stuff you don't want. This will probably take some research and trial and error. Note that this may not be granular enough. I don't know if you can remove jailing, for example. But I don't know that jailing actually increases the overhead in a measureable way if you aren't using it. So it may not be worth your time to bother with it. This goes double if it requires special patches to the kernel that you have to maintain forever and incur the cost forever. You'll need to do the cost/benefit analysis yourself. I don't know the current correct method of building custom kernels. It's no doubt docuemented, and maybe someone will chime in here. --=20 "A method for inducing cats to exercise consists of directing a beam of invisible light produced by a hand-held laser apparatus onto the floor ... in the vicinity of the cat, then moving the laser ... in an irregular way fascinating to cats,..." -- US patent 5443036, "Method of exercising a cat= " _______________________________________________ freebsd-questions@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.or= g"
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