From mboxrd@z Thu Jan  1 00:00:00 1970
From: "David S. Miller" <davem@redhat.com>
Subject: Re: route cache DoS testing and softirqs
Date: Tue, 30 Mar 2004 13:30:00 -0800
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Cc: kuznet@ms2.inr.ac.ru, dipankar@in.ibm.com, linux-kernel@vger.kernel.org,
        netdev@oss.sgi.com, Robert.Olsson@data.slu.se, paulmck@us.ibm.com,
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To: Andrea Arcangeli <andrea@suse.de>
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On Tue, 30 Mar 2004 23:14:50 +0200
Andrea Arcangeli <andrea@suse.de> wrote:

> > There are no hardirqs in the case under investigation, remember?
> 
> no hardirqs? there must be tons of hardirqs if ksoftirqd never runs.

NAPI should be kicking in for this workload, and I know for a fact it is
for Robert's case.  There should only be a few thousand hard irqs per
second.

Until the RX ring is depleted the device's hardirqs will not be re-
enabled.