Re: High CPU utilization of hostap

From: Jouni Malinen (
Date: 2002-04-30 03:16:15 UTC

On Mon, Apr 29, 2002 at 07:06:30PM -0700, Happy Camper wrote:

> Downloaded the latest driver Prism2-2002-04-24.tar.gz and installed. It
> all worked beautifully. Much much easier than I thought. I only have one
> concern. The CPU utlization. It uses 40% of my 2GHz Intel P4 during use.

If you use the default configuration, TX path has a busy wait loop of about 150 usec for every packet. This will use a lot of CPU no matter how fast your CPU is..

I have implemented alternative TX path handling that uses command completion interrupt instead of busy wait. This should reduce the CPU usage a lot, but it has not yet been fully tested so it is not the default compilation option in the current release. If you would like to test it, you can uncomment following line in driver/modules/prism2_config.h:


(i.e., change it into)


Jouni Malinen                                            PGP id EFC895FA

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