Use of pool servers reveals unacceptable crash rate in async DNS

[Hal Murray]

esr at thyrsus.com said:
> After discussion with Daniel about the performance and security issues I
> deleted the memlock code. As the comment explains:

I think changes like that are worthy of a general announcement.

> on modern systems, which swap so seldom
>     that many people don't bother with swap partitions

I think you have extrapolated from some modern systems to our whole target 
environment.  I don't remember any discussion supporting memlock not being 
interesting/important.

I'd be a lot happier if you had a plan for what to do if it turned out to be 
a problem and/or a way to verify that we don't need it or detect that it 
causes trouble.

Consider ntpd running on an old system that is mostly lightly loaded and 
doesn't have a lot of memory.  I could easily imagine ntpd getting swapped 
out when some load did come along.  I don't know how to evaluate if that will 
cause problems and I don't think we have a test environment that is likely to 
blunder into it.

I poked around a bit.  Linux and NetBSD and FreeBSD all have getrusage().  I 
didn't notice any differences.  It covers page faults and CPU usage.  When 
I'm in the right mood, I'll add another file parallel to sysstats to collect 
that sort of data.  The CPU usage will probably be interesting even if page 
faults are boring.

-- 
These are my opinions.  I hate spam.