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

[Rodney W. Grimes]

> On Tue, Mar 06, 2018 at 08:40:10AM -0800, Rodney W. Grimes wrote:
> > > On Mon, 5 Mar 2018 14:39-0600, Larry Rosenman wrote:
> > > 
> > > > Upgraded to:
> > > > 
> > > > FreeBSD borg.lerctr.org 12.0-CURRENT FreeBSD 12.0-CURRENT #11 r330385: Sun Mar  4 12:48:52 CST 2018     root at borg.lerctr.org:/usr/obj/usr/src/amd64.amd64/sys/VT-LER  amd64
> > > > +1200060 1200060
> > > > 
> > > > Yesterday, and I'm seeing really strange slowness, ARC use, and SWAP use and swapping.
> > > > 
> > > > See http://www.lerctr.org/~ler/FreeBSD/Swapuse.png
> > > 
> > > I see these symptoms on stable/11. One of my servers has 32 GiB of 
> > > RAM. After a reboot all is well. ARC starts to fill up, and I still 
> > > have more than half of the memory available for user processes.
> > > 
> > > After running the periodic jobs at night, the amount of wired memory 
> > > goes sky high. /etc/periodic/weekly/310.locate is a particular nasty 
> > > one.
> > 
> > I would like to find out if this is the same person I have
> > reporting this problem from another source, or if this is
> > a confirmation of a bug I was helping someone else with.
> > 
> > Have you been in contact with Michael Dexter about this
> > issue, or any other forum/mailing list/etc?  
> Just IRC/Slack, with no response.
> > 
> > If not then we have at least 2 reports of this unbound
> > wired memory growth, if so hopefully someone here can
> > take you further in the debug than we have been able
> > to get.
> What can I provide?  The system is still in this state as the full backup is slow.

One place to look is to see if this is the recently fixed:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=222288
g_bio leak.

vmstat -z | egrep 'ITEM|g_bio|UMA'

would be a good first look

> > > Limiting the ARC to, say, 16 GiB, has no effect of the high amount of 
> > > wired memory. After a few more days, the kernel consumes virtually all 
> > > memory, forcing processes in and out of the swap device.
> > 
> > Our experience as well.
> > 
> > ...
> > 
> > Thanks,
> > Rod Grimes                                                 rgrimes at freebsd.org
> Larry Rosenman                     http://www.lerctr.org/~ler

-- 
Rod Grimes                                                 rgrimes at freebsd.org