From: kuznet@ms2.inr.ac.ru
Message-Id: <200404081338.RAA16267@yakov.inr.ac.ru>
Subject: Re: route cache DoS testing and softirqs
To: andrea@suse.de (Andrea Arcangeli)
Date: Thu, 8 Apr 2004 17:38:27 +0400 (MSD)
Cc: kuznet@ms2.inr.ac.ru, Robert.Olsson@data.slu.se (Robert Olsson),
       dipankar@in.ibm.com (Dipankar Sarma),
       davem@redhat.com (David S. Miller), linux-kernel@vger.kernel.org,
       netdev@oss.sgi.com, paulmck@us.ibm.com, akpm@osdl.org
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	=?ISO-8859-1?Q?=D0=D2?= 01, 2004 03:16:57 
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Hello!

> This sounds reasonable. However as a start I was thinking at having
> hardirq run only the softirq they posted actively, and local_bh_enable
> run only the softirq that have been posted by the critical section (not
> from hardirqs happening on top of it).

To all that I remember Ingo insisted that the run from local_bh_enable() 
is necessary for softirqs triggered by hardirqs while softirqs are disabled.
Otherwise he observed random delays and redundant scheduler activity
breaking at least tux fast path.

Alexey
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