Quation about HZ kernel option

[Oliver Fromme]

Artem Kuchin <> wrote:
 > What value of HZ option would you recommend 
 > for a hosting (web) server with a lot of processes
 > (about 900) and polling off (as decided from previous 
 > discussion polling is useless in
 > this situation).

In that case, I would recommend not to override the
default at all (which is 1000).

 > What parts of kernel does this option affect? What
 > depends on it? 

The value of HZ specifies the minimum timing quantum
of the kernel.  It affects the granularity of the
scheduler and all timing-related functions (nanosleep(2)
and others), and the accuracy of dummynet and polling.
I'm sure there are more things.

Basically, the kernel cannot handle time slices smaller
than 1/HZ seconds, for any purpose.

Best regards
   Oliver

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