From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 25 Sep 2001 17:29:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 25 Sep 2001 17:28:56 -0400 Received: from hermes.csd.unb.ca ([131.202.3.20]:23209 "EHLO hermes.csd.unb.ca") by vger.kernel.org with ESMTP id ; Tue, 25 Sep 2001 17:28:42 -0400 X-WebMail-UserID: newton Date: Tue, 25 Sep 2001 18:38:31 -0300 From: Chris Newton To: Andrew Morton Cc: linux-kernel X-EXP32-SerialNo: 00003025, 00003442 Subject: RE: excessive interrupts on network cards Message-ID: <3BB11992@webmail1> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: WebMail (Hydra) SMTP v3.61.08 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Yea, it is a single port card... I had meant to mention that in the email I sent out... ie: that it wasn't reporting correctly... but, I didnt really think it was related, since the eepro was doing the same thing. As for comparing with ifconfig, I ran 'watch 1 ifconfig -a', and sure enough, I have about ~7000-7500 packets coming in right now. And, the 'procinfo -D', reports ~21000-22000 interrupts per second. Other sources I have used to confirm packet rate... include output from 'sniffer', a flow generator that was monitoring that link, and the hub this machine is plugged into. the hub has 3 active ports.. port 1 is one side of our internet conenction (out to our provider), port 2 was from the hub over to our main router... port 3 is a mirror of the IN on port 1 and the OUT on port 2 to port 3. Comparing, and verifying, showed port 3 getting 10K packets (this afternoon, which obviously drops at night, which it is here now), and down to 7K now. Chris >===== Original Message From Andrew Morton ===== >Chris Newton wrote: >> >> Hi, >> >> I 'think' the number of interrupts being generated for the network traffic I >> monitor, is excessive. Having talked quikly with Donald Becker, he indicated >> that I should be seeing a little less than the number of RX/TX packets/s on a >> wire, in terms of interrupts/s. That, however, is not what I am seeing. I am >> seeing 3 times as many interrupts/s as I am seeing packets/s. >> >> I have used three network devices to look at the stream I am monitoring, and >> it is usually aorund 5K packet/s IN, and 5K out, fed full duplex into a single >> 3Com 3c982 (2.4.10 kernel reports that anyways). However, watching: > >3c982 is a dual-port server NIC. Is your card dual-port? If not, it's probably >a 3c980, and I goofed :) > >> 'procinfo -D', reports on the order of 30,000 interrupts per second. > >That does sound rather high. You should compare the interrupt rate >with the packet rate from `ifconfig' or /proc/net/dev. > >Normally, 3c59x will show approx three Tx packets per interrupt >and one Rx packet per interrupt. It varies with workload, but >it tends to vary in the "good" direction - at higher packet >rates, we do more work in a single interrupt and the interrupt-per-packet >rate falls.