From owner-freebsd-chat Wed Dec 8 17:38:41 1999 Delivered-To: freebsd-chat@freebsd.org Received: from mail.enteract.com (mail.enteract.com [207.229.143.33]) by hub.freebsd.org (Postfix) with ESMTP id C263415102; Wed, 8 Dec 1999 17:38:38 -0800 (PST) (envelope-from dscheidt@enteract.com) Received: from shell-1.enteract.com (dscheidt@shell-1.enteract.com [207.229.143.40]) by mail.enteract.com (8.9.3/8.9.3) with SMTP id TAA61811; Wed, 8 Dec 1999 19:36:58 -0600 (CST) (envelope-from dscheidt@enteract.com) Date: Wed, 8 Dec 1999 19:36:57 -0600 (CST) From: David Scheidt To: Brett Glass Cc: Alfred Perlstein , Roelof Osinga , Jonathon McKitrick , Kris Kennaway , freebsd-chat Subject: Re: Yahoo hacked last night In-Reply-To: <4.2.0.58.19991208182954.048a3460@localhost> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Wed, 8 Dec 1999, Brett Glass wrote: > At 06:19 PM 12/8/1999 , Alfred Perlstein wrote: > > >> So, Intel had no incentive to make the instructions which manipulated > > > segments fast. To this day, Pentiums support them only for downward > > > compatibility and to allow the implementation of VMs. The segmentation > > > instructions are microcoded rather than hardwired, and can cause > > > expensive pipeline stalls or (worse) flushes if you use them. > > > >So they really can only be done in page sized chunks... :) > > No, you just have to be willing to take a hit of about 60 cycles > per function call, worst case. The thing is, with clock speeds > ready to hit 1 MHz, this is getting to be a trivial amount of > overhead. > > --Brett Glass > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-chat" in the body of the message > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message