From owner-freebsd-stable Sun Apr 1 12:35: 9 2001 Delivered-To: freebsd-stable@freebsd.org Received: from snapper.lansters.com (21-155-124-64.dsl.lan2wan.com [64.124.155.21]) by hub.freebsd.org (Postfix) with ESMTP id 5A4F537B71B; Sun, 1 Apr 2001 12:35:06 -0700 (PDT) (envelope-from lucky@lansters.com) Received: from lucky (lucky.lansters.com [10.1.0.2]) by snapper.lansters.com (8.11.2/8.9.3) with SMTP id f31JZ3h00744; Sun, 1 Apr 2001 15:35:03 -0400 (EDT) (envelope-from lucky@lansters.com) From: "Jason T. Luttgens" To: "'Andrew Hesford'" Cc: "'Mike Smith'" , "'David W. Chapman Jr.'" , Subject: RE: Network performance question Date: Sun, 1 Apr 2001 15:34:35 -0400 Message-ID: <000001c0bae2$c8c7dad0$0200010a@lucky> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.2416 (9.0.2910.0) In-Reply-To: <20010401135622.A16910@cec.wustl.edu> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >> Hmm....so the Linux 2.4.3 kernel is somehow accessing the hardware as to not >> cause hardware failures then? > >That's not it at all. Remember, FreeBSD and Linux can grab packets just >as fast as they come into the interface... the processor is many times >faster than the network card. > >This is definitely a hardware issue, packets are coming too fast to >handle. I'd be willing to bet that Linux simply ignores the interface >errors, rather than reporting them. > >I think what you're seeing is not that Linux handles networking better >than FreeBSD, but instead that FreeBSD is more verbose in its error >reporting. The important thing to remember here is that the card--not >the OS--determines whether or not to drop packets. Even at 100 Mbps, a >typical processor only has to poll the card 1/10 to 1/8 of the time in >order to catch every bit coming in. Good point. One of the things I was using to judge performance was how big of a file the tcpdump on the listening machine recorded under each OS (and the number of packets reported). But maybe this is not the right way to do this.... So, what would be a good way to test the performace differences between Linux 2.2, 2.4 and FreeBSD as a device to capture 100% packets off the wire and not miss any? > >I should point out that virtually every real-world networking test shows >FreeBSD outperforms comparably configured Linux. >-- >Andrew Hesford >ajh3@chmod.ath.cx To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message