wired memory leak?

[Greg Troxel <gdt%lexort.com@localhost>]

I have a pretty normal system, 9th generation i7 with 32 GB of RAM.  The
only semi-odd thing is that I run ZFS.  Less odd, the nextcloud sync
client and syncthing.  It was crashy on NetBSD 10, but was solid on
NetBSD 11 as soon as I updated.  (11 has fixes for flushing dirty mmap'd
pages and some other locking issues, so this is not surprising.) I've
been updating every month or so along NetBSD 11.

I was rebuilding NetBSD on various branches, one at a time with -j2
(should be not really noticeable).  I noticed firefox was very laggy,
and then I noticed in top that the system was io bound and paging hard.
Wired memory had begun to consume 75% of RAM.

  Memory: 307M Act, 121M Inact, 24G Wired, 52M Exec, 306M File, 343M Free
  Swap: 40G Total, 660M Used, 39G Free / Pools: 6949M Used / Network: 4K In, 3K Out

After rebooting, it was "only" a few hundred MB.

Just now, after not particularly  hard use

  5:43PM  up 1 day,  8:13, 27 users, load averages: 0.38, 0.65, 0.52

  Memory: 12G Act, 777M Inact, 2070M Wired, 523M Exec, 9301M File, 3701M Free
  Swap: 40G Total, 40G Free / Pools: 12G Used / Network: 10K In, 6K Out

which is not trouble yet but heading in the wrong direction.  I had not
started syncthing, trying to simplify.

I was the first time, I think, running kernel from September 29, and now
am on sources from October 28 about 12Z.

I do not remeber this happneing before.  I suspect that I updated to
NetBSD 11 in May or June; I can't remember my last zfs lockup.

I do have 12 GB in pools, but I suspect that's a lot of ZFS ARC that
does get freed under memory pressure.

Another 11 system that is my dom0 for pkg builders, also ZFS, after 24h
of uptime (it's stable; I've just done a build/update/reboot pass.)

  Memory: 2199M Act, 1097M Inact, 19M Wired, 110M Exec, 1948M File, 413M Free
  Swap: 40G Total, 40G Free / Pools: 5818M Used / Network: 74K In, 150K Out

A NetBSD 10 system that's been up 30 days:

  Memory: 2476M Act, 1355M Inact, 17M Wired, 192M Exec, 1662M File, 311M Free
  Swap: / Pools: 639M Used / Network: 40G In, 39G Out

which is starting to be a pattern.

So:

  Is anyone else seeing excessive/growing wired memory?

  Other than vmstat -s to see the wired page count, anything I should be
  watching?