Date: Thu, 10 Dec 2009 16:52:27 +0100 From: Christian Brueffer <brueffer@FreeBSD.org> To: Mel Flynn <mel.flynn+fbsd.hackers@mailing.thruhere.net> Cc: freebsd-hackers@freebsd.org, Linda Messerschmidt <linda.messerschmidt@gmail.com> Subject: Re: Superpages on amd64 FreeBSD 7.2-STABLE Message-ID: <20091210155226.GA59257@serenity> In-Reply-To: <200912071620.03371.mel.flynn%2Bfbsd.hackers@mailing.thruhere.net> References: <237c27100911260714x2fcb194ew1e6ce11e764efd08@mail.gmail.com> <867htduvwh.fsf@ds4.des.no> <237c27100911260911w2674b79ds8ac447e900324dce@mail.gmail.com> <200912071620.03371.mel.flynn%2Bfbsd.hackers@mailing.thruhere.net>
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--gBBFr7Ir9EOA20Yy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Dec 07, 2009 at 04:20:03PM +0100, Mel Flynn wrote: > On Thursday 26 November 2009 18:11:10 Linda Messerschmidt wrote: >=20 > > I did not mean to suggest that we were asking for help solving a > > problem with squid rotation. I provided that information as > > background to discuss what we observed as a potential misbehavior in > > the new VM superpages feature, in the hope that if there is a problem > > with the new feature, we can help find/resolve it or, if this is > > working as intended, hopefully gain some insight as to what's going > > on. >=20 > I tend to agree with this, though I don't know the nitty gritty of the=20 > implementation, it seems that: > a) superpages aren't copied efficiently (at all?) on fork and probably ot= her=20 > workloads > b) vfork is encouraged for memory intensive applications, yet: > BUGS > This system call will be eliminated when proper system sharing mecha= nisms > are implemented. Users should not depend on the memory sharing sema= ntics > of vfork() as it will, in that case, be made synonymous to fork(2). >=20 FYI, this comment has been removed a couple of weeks ago in HEAD and the STABLE branches. - Christian --=20 Christian Brueffer chris@unixpages.org brueffer@FreeBSD.org GPG Key: http://people.freebsd.org/~brueffer/brueffer.key.asc GPG Fingerprint: A5C8 2099 19FF AACA F41B B29B 6C76 178C A0ED 982D --gBBFr7Ir9EOA20Yy Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkshGToACgkQbHYXjKDtmC1oEgCdF6W6Xt2lfK+HBdiIv+Vc/5XG jgYAn2OULbuj8pPu9AMNlJRGBCdbx4Gr =YPjW -----END PGP SIGNATURE----- --gBBFr7Ir9EOA20Yy--
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