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, 31 Jul 2001 08:22:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 31 Jul 2001 08:22:49 -0400 Received: from foobar.isg.de ([62.96.243.63]:21770 "HELO mail.isg.de") by vger.kernel.org with SMTP id ; Tue, 31 Jul 2001 08:22:46 -0400 Message-ID: <3B66A318.1E530A35@isg.de> Date: Tue, 31 Jul 2001 14:22:48 +0200 From: Thomas Mischke Organization: IS Innovative Software AG X-Mailer: Mozilla 4.77 [de] (X11; U; Linux 2.4.6-pre8 i686) X-Accept-Language: de-DE, de, en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Tulip and Interrupt mitigation Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Original-Recipient: rfc822;linux-kernel-outgoing Hello, the tulip driver (as of 2.4.7, maybe earlyer versions too) has code in tulip_interrupt to switch to interrupt mitigation on heavy network load. The problem is: I have heavy network load, my system (Athlon 900 MHz with 1 GB) spends 100% of the time in the interrupt, but it does not switch to mitigation. If I force the card to mitigation (by changing the code of tulip driver) I don't loose any packets and get 20% idle time. Great! I don't use CONFIG_NET_HW_FLOWCONTROL because sometimes my network goes down for about 5 seconds. This does not happen without CONFIG_NET_HW_FLOWCONTROL. The problem seems to be the following: Mitigation is switched on if we receive (or send) a lot of packets during a single interrupt. But this never happens. During an interrupt I receive or send about 5 packets, so no mitigation is started. But the interrupt is called very quickly after leaving again, seeing another 5 packets and so on. My tulip cards use 21143 chips. Thanks in advance, Thomas Mischke