HZ kernel option

[jason]

Chad Leigh -- Shire.Net LLC wrote:

> Hi
>
> Ok, I am trying to get a feel for the "HZ" option in the 5.3 
> (RELENG_5) kernel config.
>
> # The granularity of operation is controlled by the kernel option HZ 
> whose
> # default value (100) means a granularity of 10ms (1s/HZ).
> options         HZ=100
>
> For a machine that is running as a server, running apache, roxen, 
> exim, php, some java (server stuff), perl, and then ssh command line 
> stuff, what is a general recommendation for this parameter?  One of 
> the docs mentions that for some network stuff like dummynet, 
> increasing this (making the quantum slice smaller) can give better 
> performance.  Can that be extrapolated to general network server stuff 
> like apache, roxen, exim, etc?
>
> What have people found out in playing with this???
>
> Thanks
> Chad
>
> _______________________________________________
> freebsd-questions at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> To unsubscribe, send any mail to 
> "freebsd-questions-unsubscribe at freebsd.org"
>
The default is now 1000.  If you are using this for device polling, 1000 
is what you want for 100mb, 10000 for 1gb.