Problem with irq and printing system

Uwe Laverenz uwe at
Tue Aug 23 21:36:23 GMT 2005

On Tue, Aug 23, 2005 at 09:32:19PM +0200, Jose Luis Alarcon Sanchez wrote:

> Interrupt storm detected on "irq7: lpt0"; throttling interrupt source
> What is the meaning of this message?. Have this problem a solution?.

This is a very annoying "feature" in FreeBSD: printing causes a high
rate of interrupts and the kernel tries to reduce this. AFAIK there are
two possible ways to solve this:

1. To increase the threshold for this interrupt storm detection just add
the following line to your /etc/sysctl.conf:


2. Let the parallel port run via polling instead of interrupts (this
causes high loads), add the following line to your



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