From owner-freebsd-current@FreeBSD.ORG Fri Oct 8 16:03:30 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 37A7616A4E3 for ; Fri, 8 Oct 2004 16:03:30 +0000 (GMT) Received: from ox.eicat.ca (ox.eicat.ca [66.96.30.35]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0C42143D41 for ; Fri, 8 Oct 2004 16:03:30 +0000 (GMT) (envelope-from dgilbert@daveg.ca) Received: by ox.eicat.ca (Postfix, from userid 66) id 78D87B8A4; Fri, 8 Oct 2004 12:03:29 -0400 (EDT) Received: by canoe.dclg.ca (Postfix, from userid 101) id C95D61D1CCD; Fri, 8 Oct 2004 12:03:23 -0400 (EDT) From: David Gilbert MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16742.47691.756741.663266@canoe.dclg.ca> Date: Fri, 8 Oct 2004 12:03:23 -0400 To: "Gerrit Nagelhout" In-Reply-To: References: X-Mailer: VM 7.17 under 21.5 (beta17) "chayote" (+CVS-20040321) XEmacs Lucid cc: freebsd-current@freebsd.org cc: David Gilbert Subject: RE: Packet passing performance study on exotic hardware. X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Oct 2004 16:03:30 -0000 >>>>> "Gerrit" == Gerrit Nagelhout writes: Gerrit> David Gilbert Wrote: >> - with polling and excessive packets, it doesn't "receive" the >> full load of packets. In netstat -w, they show as input "errors" >> although the number of "errors" isn't strictly related to the >> number of dropped packets. It's just some large number that >> generally increases with the number of dropped packets. >> Gerrit> In em_update_stats_counters, errors is calculated as follows: Gerrit> /* Rx Errors */ ifp-> if_ierrors = adapter-> dropped_pkts + stats.rxerrc + stats.crcerrs + stats.algnerrc adapter-> + stats.rlec + adapter->stats.rnbc + stats.mpc + adapter-> adapter->stats.cexterr; Gerrit> The extra errors you are talking about come from doing mpc + Gerrit> rnbc. Only mpc (missed packet count) (and the other errors of Gerrit> course) should be used. Rnbc is an indication of the internal Gerrit> buffer filling up, but not yet dropping packets, and should Gerrit> not be included. That does explain it. I did, BTW increase to the 4096 sized ring as my cards supported it. It seems to me that the bottle neck is the time required to send preventing the driver from getting back to the receive queue. Dave. -- ============================================================================ |David Gilbert, Independent Contractor. | Two things can only be | |Mail: dave@daveg.ca | equal if and only if they | |http://daveg.ca | are precisely opposite. | =========================================================GLO================