Device polling performance

Mike Tancsa mike at
Sat Sep 25 07:17:15 PDT 2004

At 09:57 AM 25/09/2004, TM4525 at wrote:
>     As long as all your interfaces support polling, you should see
>hardly see any interrupt usage at all, as that is the whole point of
>polling.  You can allocate more or less CPU cycles to flinging packets
>around via various sysctl settings.  See the polling man pages for
>more info
>     ---Mike
>Thanks, but that doesn't answer the question. Since polling cycles don't 
>seem to be shown under any usage category, how do you know what your 
>system usage is when polling is enabled? It seems like a big negative to me.

Read the MAN page.  There is a whole section there on a number of MIB 
variables that display various statistics around polling.  50% of the CPU 
cycles are allocated to the system by default.  If that 50% is used up, it 
will show up in top under system processes in top.

Given a decent CPU, you wont see very much of a load average at all in the 
200Kpps / 100Mb range.



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