I'm running Ubuntu 13.10 on a laptop. Recently, after waking from sleep, I noticed the computer was quite warm, checked top and discovered 1.00 load average. I shutdown Chrome, various daemons, no effect.
I rebooted and fired up a terminal and checked top again, and watched the load quickly spike to 1.75, and slowly settle down back to around 1.0 - 1.2:
top - 09:49:17 up 36 min, 2 users, load average: 1.01, 1.10, 1.01
Tasks: 267 total, 1 running, 266 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.9 us, 0.4 sy, 0.0 ni, 98.6 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem: 8069288 total, 2885572 used, 5183716 free, 123652 buffers
KiB Swap: 7711332 total, 0 used, 7711332 free, 1661816 cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1420 root 20 0 589m 144m 131m S 3.4 1.8 0:36.49 Xorg
6233 user1 20 0 986m 83m 31m S 2.7 1.1 0:19.89 chrome
3708 user1 20 0 749m 19m 12m S 1.8 0.3 0:06.58 gnome-terminal
3526 user1 20 0 1350m 67m 28m S 1.4 0.9 0:26.19 compiz
4014 user1 20 0 1022m 126m 52m S 1.1 1.6 0:44.34 chrome
I checked /proc/loadavg manually, same story:
sudo cat /proc/loadavg
1.20 1.16 0.99 3/614 6254
ps auxwwwf doesn't show any process consuming more than 6.0% of CPU.
iostat:
avg-cpu: %user %nice %system %iowait %steal %idle
0.63 0.00 0.13 0.00 0.00 99.25
Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
scd0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
free -m:
total used free shared buffers cached
Mem: 7880 2841 5039 0 120 1651
-/+ buffers/cache: 1068 6811
Swap: 7530 0 7530
Clearly some process is saturating CPU, but it doesn't seem to show up on the process list. Some sort of hidden Linux filesystem checker? Rootkit? Any ideas how to find the process in question?