High kswapd

Good morning,

Ubuntu 16.04.6 LTS
PostgreSQL 9.6.5

On one of our database servers, we're regularly seeing kswapd at the top of
"top" output, regularly using over 50 %CPU. We should have well over 80GB
of available memory according to "free -m".

# free -m
total used free shared buff/cache
available
Mem: 125910 41654 820 857 83435
82231
Swap: 511 448 63

We've already got vm.swappiness and vm.zone_reclaim_mode set to 0, and NUMA
is disabled from what I can see:

# dmesg | grep -i numa
[ 0.000000] No NUMA configuration found

We are using HugePages and things look good there as well. Curious what
would be causing kswapd to run hot like it is, or if it is a red herring as
I look into high CPU usage on this box (although, again, it is the
single-highest CPU user).

--
Don Seiler
www.seiler.us