From owner-freebsd-stable Fri Aug 9 6:10:13 2002 Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B413037B400 for ; Fri, 9 Aug 2002 06:10:09 -0700 (PDT) Received: from tesla.distributel.net (nat.MTL.distributel.NET [66.38.181.24]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1E59843E6E for ; Fri, 9 Aug 2002 06:10:09 -0700 (PDT) (envelope-from bmilekic@unixdaemons.com) Received: (from bmilekic@localhost) by tesla.distributel.net (8.11.6/8.11.6) id g79DA8K87158; Fri, 9 Aug 2002 09:10:08 -0400 (EDT) (envelope-from bmilekic@unixdaemons.com) Date: Fri, 9 Aug 2002 09:10:08 -0400 From: Bosko Milekic To: Mario Pranjic Cc: freebsd-stable@FreeBSD.ORG Subject: Re: SMP kernel: FreeBSD vs. Linux 2.4.x Message-ID: <20020809091008.A87124@unixdaemons.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: ; from mario.pranjic@irb.hr on Fri, Aug 09, 2002 at 02:13:31PM +0200 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, Aug 09, 2002 at 02:13:31PM +0200, Mario Pranjic wrote: > Hi! > > I just wanted to ask your opinion about this issue. > > If I'm well informed, current FreeBSD SMP kernel is slower that Linux > 2.4.x. I don't know about Linux 2.4.x. However, FreeBSD -STABLE employs a "Big Giant Lock" around the kernel, so that if you have two processes that want to do work in the kernel (e.g., system call), one will have to wait for the other to leave the kernel before it does anything. > Can anyone tell me just how much slower it really is? This is a really interesting question, actually. I would be interested to see some REAL WORLD numbers comparing single-processor, dual-processor and, for example, four-processor machines. It's tough to benchmark properly, so I'm a little skeptical with this statement. > FreeBSD 5.0 will have a 'true' SMP kernel, but it has been scheduled for > November. Almost 4 months waiting. 5.0 will ship with the infrastructure of a multi-threaded kernel. However, it will take a few releases before you can really see the big advantages it brings. 5.0 will also bring a hoard of new things that will take some time to settle and become really useful. Notably, KSEs will allow for some really flexible/performant threading once they settle in. Several in-kernel mechanisms will also become more and more advantageous as the Giant lock is further unwound. > Thanks! > > > Mario Pranjic, dipl.ing. > sistem administrator > Knjiznica, Institut Rudjer Boskovic > ------------------------------------- > e-mail: mario.pranjic@irb.hr > ICQ: 72059629 > tel: +385 1 45 60 954 (interni: 1293) > ------------------------------------- Cheers, -- Bosko Milekic * bmilekic@unixdaemons.com * bmilekic@FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message