From owner-freebsd-hackers Wed Nov 18 03:14:16 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id DAA18622 for freebsd-hackers-outgoing; Wed, 18 Nov 1998 03:14:16 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from www.scancall.no (www.scancall.no [195.139.183.5]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id DAA18617 for ; Wed, 18 Nov 1998 03:14:14 -0800 (PST) (envelope-from Marius.Bendiksen@scancall.no) Received: from super2.langesund.scancall.no [195.139.183.29] by www with smtp id KBNAKNAJ; Wed, 18 Nov 98 11:13:46 GMT (PowerWeb version 4.04r6) Message-Id: <3.0.5.32.19981118121341.00975ac0@mail.scancall.no> X-Sender: Marius@mail.scancall.no X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.5 (32) Date: Wed, 18 Nov 1998 12:13:41 +0100 To: Matthew Dillon , Terry Lambert From: Marius Bendiksen Subject: Re: FreeBSD on i386 memory model Cc: rnordier@nordier.com, freebsd-hackers@FreeBSD.ORG In-Reply-To: <199811172208.OAA29032@apollo.backplane.com> References: <199811171806.LAA03809@usr09.primenet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > The only differences between a normal call gate and an > interrupt is that an interrupt disables interrupts on call > (cli equivalent), while a call gate does not, and a Ehrm. Allow me to note that, unless I'm way off mark here, there is a difference between an interrupt gate and a trap gate. One of these does indeed disable interrupts; the other does not. I believe it is the trap gate which does not. > call gate has extra garbage to handle argument copying > (which we don't use), while an interrupt does not. The part about argument copying yields an extra layer of isolation, by giving you the ability to stick everything on a completely different stack. > There are constructs that make call gates sound like a > walk in the park, though... a task gate, for example. > What a holy mess. I doubt the divinities played a hand in the creation of *that* particular mechanism. > Interrupt gates are definitely faster. Okay. I seemed to recall it being the other way around. Obtw; are they only faster upon entry, or do they return quicker, too? --- Marius Bendiksen, IT-Trainee, ScanCall AS To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message