From owner-freebsd-current@FreeBSD.ORG Wed Nov 30 12:22:32 2005 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7A2CC16A41F; Wed, 30 Nov 2005 12:22:32 +0000 (GMT) (envelope-from doconnor@gsoft.com.au) Received: from smtp3.adl2.internode.on.net (smtp3.adl2.internode.on.net [203.16.214.203]) by mx1.FreeBSD.org (Postfix) with ESMTP id 616F743D5E; Wed, 30 Nov 2005 12:22:29 +0000 (GMT) (envelope-from doconnor@gsoft.com.au) Received: from midget.dons.net.au (ppp134-41.lns2.adl2.internode.on.net [59.167.134.41]) by smtp3.adl2.internode.on.net (8.12.9/8.12.6) with ESMTP id jAUCMB3w026143; Wed, 30 Nov 2005 22:52:12 +1030 (CST) (envelope-from doconnor@gsoft.com.au) Received: from [10.0.2.99] (inchoate.dons.net.au [10.0.2.99]) (authenticated bits=0) by midget.dons.net.au (8.13.4/8.13.3) with ESMTP id jAUCM9wX046788 (version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=NO); Wed, 30 Nov 2005 22:52:11 +1030 (CST) (envelope-from doconnor@gsoft.com.au) From: "Daniel O'Connor" To: freebsd-current@freebsd.org Date: Wed, 30 Nov 2005 22:51:52 +1030 User-Agent: KMail/1.8.2 References: <6861.1133349506@critter.freebsd.dk> In-Reply-To: <6861.1133349506@critter.freebsd.dk> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart3804233.csohxlyASA"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Message-Id: <200511302252.05741.doconnor@gsoft.com.au> X-Spam-Score: 0 () X-Scanned-By: MIMEDefang 2.52 on 59.167.134.41 Cc: Poul-Henning Kamp , Jason Evans , current@freebsd.org Subject: Re: New libc malloc patch X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Nov 2005 12:22:32 -0000 --nextPart3804233.csohxlyASA Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Wed, 30 Nov 2005 21:48, Poul-Henning Kamp wrote: > In message <20051130111017.GA67032@galgenberg.net>, Ulrich Spoerlein writ= es: > >I just read that mmap() part and have to wonder: Is it possible to > >introduce something like the guard pages that OpenBSD has implemented? > >I'd love to try this out and see the dozens of applications that fail > >due to off-by-one bugs. > > Guard-pages are very expensive and that is why I have not adopted > OpenBSD's patch. > > I would advocate that people use one of the dedicated debugging malloc > implementations (ElectricFence ?) instead of putting too much overhead > into our default malloc. Electric fence is right. Although it IS slow, an order of magnitude or more= =20 usually. Also if you do use it you'll probably have to bump up the=20 vm.max_proc_mmap sysctl or it will fail to allocate memory. Another good one is valgrind (and it detects more problems to boot :) > For all practical purposes, the options J, A, X & Z are the most commonly > used. =2D-=20 Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C --nextPart3804233.csohxlyASA Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQBDjZlt5ZPcIHs/zowRAnhxAKCp2p5SYlq0IC2fB4xM+I/lSW0XAQCeIApz HTETzLR6SBVsz4evY6IcZbk= =4c4c -----END PGP SIGNATURE----- --nextPart3804233.csohxlyASA--