Chasing OOM Issues - good sysctl metrics to use?

hello -

on my workstation running CURRENT (amd64/32g of ram) i've been running 
into a scenario where after 4 or 5 days of daily use I get an OOM event 
and both chromium and firefox are killed.  then in the next day or so 
the system will become very unresponsive in the morning when i unlock my 
screensaver in the morning forcing a manual power cycle.

one thing i've noticed is growing swap usage but plenty of free and 
inactive memory as well as a GB or so of memory in the Laundry state 
according top.  my understanding is that seeing swap usage grow over 
time is expected and doesn't necessarily indicate a problem.  but what 
concerns me is the system locking up while seeing quite a bit of disk 
i/o (maybe from paging back in?).

in order to help chase this down i've setup the 
prometheus_sysctl_exporter(8) to send data to a local prometheus 
instance.  the goal is to examine memory utilizaton over time to help 
detect any issues. so my question is this:

what OID's would be useful to help see to help diagnose weird memory 
issues like this?

i'm currently looking at:
sysctl_vm_domain_0_stats_laundry
sysctl_vm_domain_0_stats_active
sysctl_vm_domain_0_stats_free_count
sysctl_vm_domain_0_stats_inactive_pps


thanks in advance - and i'd be happy to share my data if anyone is 
interested :)
-pete

-- 
Pete Wright
pete@nomadlogic.org
@nomadlogicLA