Date: Mon, 22 Jan 2001 02:55:41 -0800 From: Kris Kennaway <kris@FreeBSD.org> To: cjclark@alum.mit.edu Cc: questions@FreeBSD.org Subject: Re: small program eats lot of memory Message-ID: <20010122025541.B84078@citusc17.usc.edu> In-Reply-To: <20010121203207.F10761@rfx-216-196-73-168.users.reflex>; from cjclark@reflexnet.net on Sun, Jan 21, 2001 at 08:32:07PM -0800 References: <14955.1209.195848.394006@guru.mired.org> <01012121054701.03293@buffy> <20010121152246.X10761@rfx-216-196-73-168.users.reflex> <20010121165041.A76170@citusc17.usc.edu> <20010121203207.F10761@rfx-216-196-73-168.users.reflex>
next in thread | previous in thread | raw e-mail | index | archive | help
--/WwmFnJnmDyWGHa4
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
On Sun, Jan 21, 2001 at 08:32:07PM -0800, Crist J. Clark wrote:
> > No, I believe he is correct. If you have two shared programs in
> > memory, the VM system will only have one copy of the libc code shared
> > between them (similarly with any other common libraries).
>=20
> That's really something if it's true. I don't see any mention of
> features like that on rtld(1).
It's a generic feature of the VM system which shared libraries happen
to incidentally benefit from. If you map the same object more than
once, it only maintains one copy of it in VM, until one of the users
dirties a page (changes something), at which point the page is copied
("copy on write").
Kris
--=20
NOTE: To fetch an updated copy of my GPG key which has not expired,
finger kris@FreeBSD.org
--/WwmFnJnmDyWGHa4
Content-Type: application/pgp-signature
Content-Disposition: inline
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.4 (FreeBSD)
Comment: For info see http://www.gnupg.org
iD8DBQE6bBGsWry0BWjoQKURAvWnAKDzBOgXq9r6aWTHxkXfnCVcx9IIgACeN8eL
j3xBsYoKmjyHxiYYsJzvJ98=
=sxQi
-----END PGP SIGNATURE-----
--/WwmFnJnmDyWGHa4--
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010122025541.B84078>