ntpd segfaults on start

[Konstantin Belousov]

On Sat, Sep 07, 2019 at 08:45:21AM -0700, Cy Schubert wrote:
> I've been able to set the memlock rlimit as low as 20 MB. The issue is 
> letting it default to 0 which allows ntp to mlockall() anything it wants. 
> ntpd on my sandbox is currently using 18 MB.

Default stack size on amd64 is 512M, and default stack gap percentage is
3%. This means that the gap can be as large as ~17MB. If 3MB is enough
for the stack of the main thread of ntpd, then fine.