From owner-freebsd-hackers@FreeBSD.ORG Tue Dec 14 20:50:10 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 61E6416A4CE for ; Tue, 14 Dec 2004 20:50:10 +0000 (GMT) Received: from smtp-vbr10.xs4all.nl (smtp-vbr10.xs4all.nl [194.109.24.30]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9D12943D5F for ; Tue, 14 Dec 2004 20:50:09 +0000 (GMT) (envelope-from wb@freebie.xs4all.nl) Received: from freebie.xs4all.nl (freebie.xs4all.nl [213.84.32.253]) iBEKnxol082584; Tue, 14 Dec 2004 21:49:59 +0100 (CET) (envelope-from wb@freebie.xs4all.nl) Received: from freebie.xs4all.nl (localhost [127.0.0.1]) by freebie.xs4all.nl (8.13.1/8.12.9) with ESMTP id iBEKnxSs001478; Tue, 14 Dec 2004 21:49:59 +0100 (CET) (envelope-from wb@freebie.xs4all.nl) Received: (from wb@localhost) by freebie.xs4all.nl (8.13.1/8.13.1/Submit) id iBEKnsuZ001473; Tue, 14 Dec 2004 21:49:54 +0100 (CET) (envelope-from wb) Date: Tue, 14 Dec 2004 21:49:54 +0100 From: Wilko Bulte To: "Scott M. Ferris" Message-ID: <20041214204954.GC1356@freebie.xs4all.nl> References: <20041214072922.2604543D1D@mx1.FreeBSD.org> <1eea89cd041214114766fd34dc@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1eea89cd041214114766fd34dc@mail.gmail.com> X-OS: FreeBSD 4.11-PRERELEASE X-PGP: finger wilko@freebsd.org User-Agent: Mutt/1.5.6i X-Virus-Scanned: by XS4ALL Virus Scanner cc: hackers@freebsd.org cc: Peter Blok Subject: Re: My project wish-list for the next 12 months X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Dec 2004 20:50:10 -0000 On Tue, Dec 14, 2004 at 01:47:15PM -0600, Scott M. Ferris wrote.. > On Tue, 14 Dec 2004 09:29:19 +0200, Danny Braniss wrote: > > Great!, we seem to be on the same wavelength, im now writing (at about one > > char a minute) the login user program, and somehow - to be discovered -, the > > socket will be passed to the kernel. > > my main efford, at the moment, is a) to &^%$$## understand the RFC (i think > > they used a scrambler) and b) define the data structures. > > How do you plan on handling cases where the user program blocks and > can't login again (because of a page fault for code or data, > allocating a new socket in the kernel, allocating a new socket buffer > in the kernel, etc)? > > One of the major problems any software-only iSCSI initiator has is > dealing with memory deadlocks. The OS may try to write out one or > more pages in order to free up memory. If the iSCSI initiator needs > to allocate memory (directly or indirectly in the TCP stack) in order > to complete that write, you've got a circular dependency where in > order to get free memory you need to have free memory. > Hardware-based iSCSI HBAs solve this by having their own memory and > TCP stack separate from the OS. Software-only iSCSI initiators such Downside: TOE cards are not cheap though.. -- Wilko Bulte wilko@FreeBSD.org