From owner-freebsd-questions@FreeBSD.ORG  Mon Apr 10 05:55:37 2006
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
X-Original-To: freebsd-questions@freebsd.org
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 1B2FA16A401
	for <freebsd-questions@freebsd.org>;
	Mon, 10 Apr 2006 05:55:37 +0000 (UTC)
	(envelope-from oliver-forward@charter.net)
Received: from mxsf09.cluster1.charter.net (mxsf09.cluster1.charter.net
	[209.225.28.209])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 5E0AB43D7C
	for <freebsd-questions@freebsd.org>;
	Mon, 10 Apr 2006 05:55:36 +0000 (GMT)
	(envelope-from oliver-forward@charter.net)
Received: from mxip28a.cluster1.charter.net (mxip28a.cluster1.charter.net
	[209.225.28.187])
	by mxsf09.cluster1.charter.net (8.12.11/8.12.11) with ESMTP id
	k3A5tYa3016186
	for <freebsd-questions@freebsd.org>; Mon, 10 Apr 2006 01:55:34 -0400
Received: from 24-205-236-185.dhcp.snlo.ca.charter.com (HELO linux.linux)
	([24.205.236.185])
	by mxip28a.cluster1.charter.net with ESMTP; 10 Apr 2006 01:55:34 -0400
X-IronPort-AV: i="4.04,105,1144036800"; 
	d="scan'208"; a="996820015:sNHT124037726"
From: Oliver Iberien <oliver-forward@charter.net>
To: freebsd-questions@freebsd.org
Date: Sun, 9 Apr 2006 22:55:32 -0700
User-Agent: KMail/1.9.1
References: <200604071332.57717.oliver-forward@charter.net>
	<20060408132247.1df00a38@localhost>
In-Reply-To: <20060408132247.1df00a38@localhost>
MIME-Version: 1.0
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200604092255.33239.oliver-forward@charter.net>
Cc: 
Subject: Re: Setting max interrupts per second (WAS printing on firefox)
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 10 Apr 2006 05:55:37 -0000

On Saturday 08 April 2006 04:22, Fabian Keil wrote:
> Oliver Iberien <oliver-forward@charter.net> wrote:
> > [snip] The printer (Xerox N17, local,
> > parallel port) started cycling through waiting-processing-waiting
> > messages. Rebooting, I saw a message about an IRQ storm on the
> > printer port being "throttled". Killing the job took care of this.
> >
[snip]
>
> The default value of hw.intr_storm_threshold is easily reached
> by a printer connected through the parallel port.
>
> Have a look at: <http://www.lemis.com/grog/diary-dec2005.html#8>.
>
> Fabian

Thanks for this. Here's the relevent text from that weblog: 

>  As a result, once more harnessed my veteran HP LaserJet 6MP to echunga.
> Printing went at a snail's pace. Finally I discovered the message:
> Interrupt storm detected on "irq7: lpt0"; throttling interrupt source
>
>  It proved to be a new interrupt throttling feature in the system: the
> sysctl variable hw.intr_storm_threshold sets the maximum number of
> interrupts per second on any interrupt level. The default value is 500,
> woefully inadequate for a PostScript printer on a parallel port, which can
> generate over 100,000 interrupts a second. Fixed that: === root@echunga
> (/dev/ttyp1) ~ 130 -> sysctl hw.intr_storm_threshold  
> hw.intr_storm_threshold: 500 
> === root@echunga (/dev/ttyp1) ~ 131 -> sysctl hw.intr_storm_threshold=200000
> hw.intr_storm_threshold: 500 -> 200000 
>
>  Unfortunately, this effectively disables the interrupt storm detection
> system-wide. The values should be per interrupt.

Does anyone have any idea what an optimum number would be? 

Oliver