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Date: Wed, 3 Oct 2001 10:34:23 +0200 (CEST)
From: Ingo Molnar <mingo@elte.hu>
Reply-To: <mingo@elte.hu>
To: jamal <hadi@cyberus.ca>
Cc: <linux-kernel@vger.kernel.org>, Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
        Robert Olsson <Robert.Olsson@data.slu.se>,
        Benjamin LaHaise <bcrl@redhat.com>, <netdev@oss.sgi.com>,
        Linus Torvalds <torvalds@transmeta.com>,
        Alan Cox <alan@lxorguk.ukuu.org.uk>, Simon Kirby <sim@netnation.com>
Subject: Re: [announce] [patch] limiting IRQ load, irq-rewrite-2.4.11-B5
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On Tue, 2 Oct 2001, jamal wrote:

> [...] please have the courtesy of at least posting results/numbers of
> how this improved things and under what workloads and conditions.
> [...]

500 MHz PIII UP server, 433 MHz client over a single 100 mbit ethernet
using Simon Kirby's udpspam tool to overload the server. Result: 2.4.10
locks up before the patch. 2.4.10 with the first generation irqrate patch
applied protects against the lockup (if max_rate is correct), but results
in dropped packets. The auto-tuning+polling patch results in a working
system and working network, no lockup and no dropped packets. Why this
happened and how it happened has been discussed extensively.

(the effect of polling-driven networking is just an extra and unintended
bonus side-effect.)

	Ingo