decreasing interrupt CPU load

Oleg Gawriloff barzog at telecom.by
Fri Oct 22 07:04:23 PDT 2004


Hello, Steven!
You wrote to "Oleg Gawriloff" <barzog at telecom.by>; 
<freebsd-performance at freebsd.org> on Fri, 22 Oct 2004 14:04:46 +0100:

>When you say not working are you seeing no more that
>HZ interrupts per second? After compiling in you did
>enable it with the sysctl?
After recompiling kernel with
options         HZ=1000
options         DEVICE_POLLING
and kern.polling.enable=1 number of interrupts shown in systat -v 1 does not 
change (about 5k). CPU interrupt load does not changes as well. Also RTT in 
ping increases from 2ms to 20ms. After disabling polling RTT goes back to 
2ms. So we decided that polling does not work on i82550 in SMP.

With best regards, Oleg Gawriloff. 



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