Strange ARC/Swap/CPU on yesterday's -CURRENT

[Matthew D. Fuller]

On Mon, Mar 05, 2018 at 02:39:18PM -0600 I heard the voice of
Larry Rosenman, and lo! it spake thus:
> 
> Yesterday, and I'm seeing really strange slowness, ARC use, and SWAP
> use and swapping.
> 
> Ideas?

Since I updated to the Feb 25 -CURRENT I'm currently running (from
mid-Sept, I believe), I see similar.  It seems like the ARC has gotten
really unwilling to yield, so it grows up in size, and then doesn't
let up under pressure.  I saw programs being actively used constantly
swapping their working set in and out, since they were left with tiny
available memory.

Hard-slappping vfs.zfs.arc_max down a ways mitigated it enough to get
me through the days, but is a pretty gross hackaround...


-- 
Matthew Fuller     (MF4839)   |  fullermd at over-yonder.net
Systems/Network Administrator |  http://www.over-yonder.net/~fullermd/
           On the Internet, nobody can hear you scream.