Re: High CPU utilization of hostap


From: Wim Lewis (wiml_at_omnigroup.com)
Date: 2002-04-30 19:25:22 UTC


On Tuesday, April 30, 2002, at 12:06 PM, Happy Camper wrote:

> Using this technique I do see a 10% improvement in CPU utilization on
> average.  But the avg. CPU utilization of 25% on a P4 2GHz is still a
> cause for concern.  Could this mean a potential 100% CPU utilization
> on a P3 500MHz?

[....]

No; what's happening is that the cpu (no matter how fast) is stuck waiting for a (slow) I/O operation to complete. It'd probably still take 25% of the CPU on a P2-200.

> --- Jouni Malinen <jkmaline_at_cc.hut.fi> wrote:

>> 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..


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