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From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no>
To: Robert Watson <rwatson@FreeBSD.org>
References: <477C82F0.5060809@freebsd.org> <863ateemw2.fsf@ds4.des.no>
	<20080104002002.L30578@fledge.watson.org> <86wsqqaqbe.fsf@ds4.des.no>
	<20080104110511.S77222@fledge.watson.org>
Date: Fri, 04 Jan 2008 13:34:33 +0100
In-Reply-To: <20080104110511.S77222@fledge.watson.org> (Robert Watson's
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Cc: freebsd-current@freebsd.org, Jason Evans <jasone@freebsd.org>,
	Poul-Henning Kamp <phk@FreeBSD.org>
Subject: Re: sbrk(2) broken
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Robert Watson <rwatson@FreeBSD.org> writes:
> Dag-Erling Sm=C3=B8rgrav <des@des.no> writes:
> > Robert Watson <rwatson@FreeBSD.org> writes:
> > > The right answer is presumably to introduce a new LIMIT_SWAP, which
> > > limits the allocation of anonymous memory by processes, and size it to
> > > something like 90% of swap space by default.
> > Not a good solution on its own.  You need a per-process limit as
> > well, otherwise a malloc() bomb will still cause other processes to
> > fail randomly.
> That was what I had in mind, the above should read RLIMIT_SWAP.

You don't want the default to be so high.  You want a low default, with
the possibility for the admin to increase the limit for a particular
user in login.conf or similar without rebooting (which is currently not
possible since the default datasize =3D=3D maxdsiz, which can only be
changed in the kernel config or loader.conf)

You may also want to have a collective limit for unprivileged users, so
root will still be able to log in if something goes wrong.

DES
--=20
Dag-Erling Sm=C3=B8rgrav - des@des.no