Date: Mon, 29 May 2006 01:18:11 -0400 From: Kris Kennaway <kris@obsecurity.org> To: gnn@FreeBSD.org Cc: freebsd-atm@FreeBSD.org, Robert Watson <rwatson@FreeBSD.org>, freebsd-arch@FreeBSD.org Subject: Re: Locking netatm Message-ID: <20060529051811.GA60877@xor.obsecurity.org> In-Reply-To: <m23betzb33.wl%gnn@neville-neil.com> References: <20060528230058.GA836@lucy.pool-70-17-33-65.pskn.east.verizon.net> <m23betzb33.wl%gnn@neville-neil.com>
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--Kj7319i9nmIyA2yE Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, May 29, 2006 at 01:52:48PM +0900, gnn@FreeBSD.org wrote: > > So my question is, were network interrupts disabled when mucking > > with the atm_timeq list because a generated interrupt can modify > > structures within the list? This use is probably very > > netatm-specific. I'm still studying the timeout code to understand > > what it's doing. > >=20 >=20 > The spl() calls haven't disabled real interrupts, as far as I know, > for quite a while. They acted as general code locks to prevent > simultaneous access to data structures while an update was in > progress. In terms of the timeq, the locks were acting as a mutex now > would to protect the list during an update. Actually the spl calls have all been NOPs since the early 5.0 days, and they were just left in an mnemonic placeholders showing which code/data sections need to be protected. Kris --Kj7319i9nmIyA2yE Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQFEeoQTWry0BWjoQKURAk94AJ41qSIQle1p3QJpxfY+eZ6nrN21jgCeLlvP auY7U0HK7miLNQHDLpfOgMc= =WY96 -----END PGP SIGNATURE----- --Kj7319i9nmIyA2yE--
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