pfSense

There is a line in vmstat -m for temp that is throwing off the output, it's gigantic

         temp 18446744073709543701 18014398509480065K       - 20798147  16,32,64,128,256,512,1024,2048,4096,8192,16384,32768,65536

Changing the DATA line in kmemusage.sh to this seems to make it work but I'm not sure if it's the best fix.

DATA=`/usr/bin/vmstat -m  | grep -v ' temp ' | /usr/bin/sed -Ee '1s/.*/0/;s/.* ([0-9]+)K.*/\1+/;$s/$/1024*p/' | /usr/bin/dc`

Looks like the value of that entry is unsigned and trying to go negative, which results in an underflow (hits 0 then goes very high). It took about an hour and a half to happen on a running system here. See the attached output which is a loop where it checks the value and sleeps for 30s between checks.

#!/bin/sh

while true; do
  date >> /root/tmp/tempout.txt
  uptime >> /root/tmp/tempout.txt
  vmstat -m | egrep 'nvlist|temp' >> /root/tmp/tempout.txt
  echo "---" >> /root/tmp/tempout.txt
  sleep 30
done

Happens on both CE and Plus so it's not due to plus-specific changes.

Looks like this happens as the value for nvlist increases. Apparently already fixed in FreeBSD: https://cgit.freebsd.org/src/commit?id=a37e0e6de6527a7eaddea8e28f5e4b3427fba1a4

Running a kernel with that commit applied the values are holding steady and not constantly changing as they are on an unpatched kernel. I'm still monitoring it, but it looks good with the patch so far.

Mateusz pushed that patch to devel-12 and plus-devel-12.