svn commit: r284959 - in head: . share/man/man4 share/man/man9 sys/conf sys/dev/glxsb sys/dev/hifn sys/dev/random sys/dev/rndtest sys/dev/safe sys/dev/syscons sys/dev/ubsec sys/dev/virtio/random sy...

[Scott Long]

> On Jul 25, 2015, at 2:10 AM, Mark R V Murray <markm at FreeBSD.org> wrote:
> 
> 
>> On 25 Jul 2015, at 06:06, Scott Long <scott4long at yahoo.com> wrote:
>> 
>>> I’m working on a premise of “tools, not policy”. I’d like there to be
>>> enough harvesting points for the box owner to get the warm fuzzies.
>>> If they choose to use less, fine by me.
>>> 
>> 
>> Sure, and that’s not an unreasonable goal, but the devil is in the details.
> 
> Yes, indeed!
> 
>> It’s an unfortunate fact of modern CPU architecture that even something
>> as simple and innocent as a run-time control that checks a variable can
>> cause significant performance problems, thanks to the penalty of cache
>> misses and bus contention between lots of CPU cores.  Maybe these
>> “extended” collection points should be controlled with a compile-time
>> option?
> 
> They can. I’ve coded it already, but not tested it properly, and will
> commit in a week or two. :-)

What you posted this morning for review is a great start.  Thanks for the
productive conversation on this.

Scott