Date: Fri, 12 May 2006 21:58:09 -0400 From: Kris Kennaway <kris@obsecurity.org> To: Dmitry Pryanishnikov <dmitry@atlantis.dp.ua> Cc: freebsd-stable@FreeBSD.org, Robert Watson <rwatson@FreeBSD.org> Subject: Re: RELENG_4 -> 5 -> 6: significant performance regression Message-ID: <20060513015809.GA18438@xor.obsecurity.org> In-Reply-To: <20060512232806.Q35558@atlantis.atlantis.dp.ua> References: <20060427160536.M96305@atlantis.atlantis.dp.ua> <20060502181118.M92256@fledge.watson.org> <20060512232806.Q35558@atlantis.atlantis.dp.ua>
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--KsGdsel6WgEHnImy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, May 12, 2006 at 11:32:44PM +0300, Dmitry Pryanishnikov wrote: >=20 > Hello! >=20 > On Tue, 2 May 2006, Robert Watson wrote: > >>options INVARIANTS > >>options INVARIANT_SUPPORT > > > >In FreeBSD 5.x and FreeBSD 6.x, the INVARIANTS option has been=20 > >significantly expanded to test a much larger set of invariants, and also= =20 > >incorporate kernel use-after-free checking, which involves memory=20 > >scrubbing. This is great for catching bugs, but it will have a=20 > >significant performance impact, especially for kernel-intensive loads. >=20 > So maybe it's time to add, say, >=20 > options INVARIANTS_EXTENDED >=20 > for these new and expensive checks, and leave only basic and cheap (yet > effective for bug hunting) asserts enabled when only >=20 > options INVARIANTS >=20 > is defined? No, they are all effective for bug hunting. You just need to be aware that it is incompatible with performance. Kris --KsGdsel6WgEHnImy Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQFEZT0xWry0BWjoQKURAsQxAKDQaF/Q7mL5aMt4a45MqKDmhgBP+wCg82BL nSYJ3OooAiLI8E4E8a15QLY= =ujRL -----END PGP SIGNATURE----- --KsGdsel6WgEHnImy--
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