From owner-freebsd-questions@FreeBSD.ORG Sat Sep 29 16:10:48 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1D76816A418 for ; Sat, 29 Sep 2007 16:10:48 +0000 (UTC) (envelope-from kris@FreeBSD.org) Received: from weak.local (hub.freebsd.org [IPv6:2001:4f8:fff6::36]) by mx1.freebsd.org (Postfix) with ESMTP id 5A1AF13C455; Sat, 29 Sep 2007 16:10:47 +0000 (UTC) (envelope-from kris@FreeBSD.org) Message-ID: <46FE790A.1000101@FreeBSD.org> Date: Sat, 29 Sep 2007 18:10:50 +0200 From: Kris Kennaway User-Agent: Thunderbird 2.0.0.6 (Macintosh/20070728) MIME-Version: 1.0 To: RW References: <80f4f2b20709240723m121aad88ofaf728f384dd6c20@mail.gmail.com> <20070924184415.7bffd7d2@gumby.homeunix.com.> In-Reply-To: <20070924184415.7bffd7d2@gumby.homeunix.com.> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org Subject: Re: Questions on the scheduler X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 29 Sep 2007 16:10:48 -0000 RW wrote: > The FreeBSD response was to make the kernel more SMP friendly with > finer-grained locking, and to bring-in the ULE scheduler. Dragonfly BSD > was a fork off 4.x by people who thought a more radical kernel rewrite > was needed. Their kernel avoids a lot of the locking problems by using > message queues. Just to clarify, that was the theory and intention behind Dragonfly, but in practise they have yet to achieve it after 4 years and any benefits of their ideas remain unproven. Basically they have achieved no performance gains on SMP and have effectively abandoned working on it. Kris