[ntp:questions] Re: Locking memory in ntp

Michael Sierchio kudzu at tenebras.com
Fri Sep 26 14:58:24 UTC 2003


Maarten Wiltink wrote:
> Gopal wrote in message ...
> 
> 
>>Ntpd has a mlockall() function call which locks all the current and
>>future memory.  Why do we need to lock the memory.
> 
> 
> 
> To prevent page faults, which can cause unnecessary variation in
> the response time to receiving timestamps.

Does it help to point out that mlockall() is a wish and a prayer?
There are per-process and per-machine limits on how many pages
may be locked in memory...

IOW the only guaranteed way of locking all pages in physmem is
to run without swap.




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