small patch for numactl. Comments?

[Scott Long]

> On Nov 14, 2017, at 10:21 AM, Larry McVoy <lm at mcvoy.com> wrote:
> 
> On Tue, Nov 14, 2017 at 06:10:34PM +0100, Mateusz Guzik wrote:
>>> I'm wacking LMbench to be numa aware and this patch would help me make
>>> sure that when you are a numa machine you could insist that people 
>>> run the benchmark via numactl (imma gonna blog about numa, it sucks
>>> unless you are numa aware).
>>> 
>> 
>> Well, I think the right thing to do is to query the existing policy and
>> complain when it turns out nothing is set. Perhaps exit by default and
>> add a switch to proceed anyway.
> 
> As already stated, that means #ifdef-ing portable code.  Not a fan of that.
> 
> I believe someone already approved env var approach anyway.

FWIW, communicating state via environment variables is not a common pattern in
the core FreeBSD userland tools.  It’s a bit more common in the contributed tools.
That’s probably why people are wishy-washy about your proposal.  That said,
there’s no architectural rule against what you’re proposing, it’s useful, and it’s not
invasive and needing long discussion.

Scott