If you’re running pfsense check your memory usage. Netgate enabled the pcscd service by default a while back, which will be fixed in 2.6.0 see here. One of the problems is that pcscd has a memory leak which is causing issues for some people, see here.
This is what my system looked like when I started digging into it.
last pid: 891; load averages: 0.90, 0.77, 0.78 up 64+22:00:17 02:18:37
76 processes: 1 running, 75 sleeping
CPU: 2.3% user, 0.0% nice, 1.2% system, 0.5% interrupt, 96.0% idle
Mem: 2264M Active, 2039M Inact, 2227M Laundry, 1019M Wired, 554M Buf, 273M Free
Swap: 4096M Total, 2159M Used, 1937M Free, 52% Inuse
PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU COMMAND
9896 root 3 20 0 4557M 2389M select 4 54:08 0.04% pcscd
Since I’m not using ipsec or a smart card I killed it using service pcscd stop. There is a patch available and more reading here.
Memory usage is back to normal now.
last pid: 1587; load averages: 0.32, 0.48, 0.57 up 64+22:11:00 02:29:20
75 processes: 1 running, 74 sleeping
CPU: 3.9% user, 0.0% nice, 1.2% system, 0.9% interrupt, 94.0% idle
Mem: 2189M Active, 1952M Inact, 8152K Laundry, 1007M Wired, 561M Buf, 2666M Free
Swap: 4096M Total, 21M Used, 4075M Free