vm_lowmem is prevented every 2**31 ticks

[Ryan Stone]

On Wed, Aug 5, 2015 at 7:59 PM, Ian Lepore <ian at freebsd.org> wrote:

> If you're measuring elapsed time, please use getbinuptime() rather than
> the time of day clock (which can be stepped arbitrarily).
>
> Hey wait a sec... if it's currently some_ticks/hz it's counting seconds,
> right?  So no need to mess with bintimes, if whole seconds are good
> enough just use the global time_uptime.
>

i thought that there was such a variable, but a quick search didn't turn it
up.  Thanks.  (And thanks for also catching my potential mistake in not
using uptime -- that would have been embarrassing)

I've put the potential fix up for review here:
https://reviews.freebsd.org/D3439