From owner-freebsd-questions Sat Jun 30 12: 2:43 2001 Delivered-To: freebsd-questions@freebsd.org Received: from gull.mail.pas.earthlink.net (gull.mail.pas.earthlink.net [207.217.121.85]) by hub.freebsd.org (Postfix) with ESMTP id 91EC037B405 for ; Sat, 30 Jun 2001 12:02:40 -0700 (PDT) (envelope-from cjc@earthlink.net) Received: from blossom.cjclark.org (dialup-209.245.134.21.Dial1.SanJose1.Level3.net [209.245.134.21]) by gull.mail.pas.earthlink.net (EL-8_9_3_3/8.9.3) with ESMTP id MAA04517; Sat, 30 Jun 2001 12:02:38 -0700 (PDT) Received: (from cjc@localhost) by blossom.cjclark.org (8.11.4/8.11.3) id f5UJ2ah08119; Sat, 30 Jun 2001 12:02:36 -0700 (PDT) (envelope-from cjc) Date: Sat, 30 Jun 2001 12:02:36 -0700 From: "Crist J. Clark" To: David Leimbach Cc: questions@freebsd.org Subject: Re: Kernel options for faster loopback? Message-ID: <20010630120236.E348@blossom.cjclark.org> Reply-To: cjclark@alum.mit.edu References: <20010629114724.A1074@mpi-plusplus.mpi-softtech.com> <20010629235736.C348@blossom.cjclark.org> <20010630103533.A548@mutt.home.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010630103533.A548@mutt.home.net>; from dleimbac@earthlink.net on Sat, Jun 30, 2001 at 10:35:33AM -0500 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sat, Jun 30, 2001 at 10:35:33AM -0500, David Leimbach wrote: > > The reason for me asking this is that FreeBSD has really shitty performance > when it comes to using loopback for any kind of communications. > > Its about 8x faster on Linux to use the loopback device for communication > between processes of parallel jobs using an MPI library. I'd be curious what you are using to benchmark this. I in your previous mail, you said your ping(1)s on the loopback were slow. That's what was so funny. OTOH, if you have some meaningful measurements showing the bandwidth on the loopback is slow, that would be interesting. Also, there are better mechanisms for interprocess communications. Ways to avoid the overhead of the network stack completely. -- Crist J. Clark cjclark@alum.mit.edu To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message