Date: Fri, 8 Oct 2004 12:03:23 -0400 From: David Gilbert <dgilbert@dclg.ca> To: "Gerrit Nagelhout" <gnagelhout@sandvine.com> Cc: David Gilbert <dgilbert@dclg.ca> Subject: RE: Packet passing performance study on exotic hardware. Message-ID: <16742.47691.756741.663266@canoe.dclg.ca> In-Reply-To: <A8535F8D62F3644997E91F4F66E341FC1F1CB9@exchange.sandvine.com> References: <A8535F8D62F3644997E91F4F66E341FC1F1CB9@exchange.sandvine.com>
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>>>>> "Gerrit" == Gerrit Nagelhout <gnagelhout@sandvine.com> 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================
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