[mythtv-users] CPU Load vs. CPU Utilization (uptime and top)

[Keith Pyle]

On 08/03/12 22:13, Greg Grotsky wrote:
> When I launch top, I see:
>
> top - 21:11:01 up  2:28,  4 users,  load average: 1.91, 1.62, 1.36
> Tasks: 232 total,   1 running, 231 sleeping,   0 stopped,   0 zombie
> Cpu(s):  0.6%us,  0.2%sy,  0.0%ni, 96.8%id,  2.3%wa,  0.0%hi,  0.1%si,
> 0.0%st
> Mem:  132010188k total, 23824268k used, 108185920k free,   180384k buffers
> Swap:        0k total,        0k used,        0k free, 21094840k cached
>
>    PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
>   3223 spikeygg  20   0 2593m  44m  10m S    4  0.0   4:03.10 mythbackend
>   2918 spikeygg  20   0  516m  22m  10m S    1  0.0   1:21.19 unity-panel-ser
>   2920 spikeygg  20   0  417m 7680 3464 S    1  0.0   0:58.63 hud-service
>   5693 spikeygg  20   0  422m  15m  10m S    1  0.0   0:21.20 indicator-multi
>   2032 spikeygg  20   0 27324 3124  624 S    1  0.0   0:22.39 dbus-daemon
>   2338 spikeygg  20   0 1371m  92m  36m S    1  0.1   1:47.21 compiz
>   3239 spikeygg  20   0 1104m  10m 5548 S    1  0.0   1:31.26 mythlogserver
>    122 root      20   0     0    0    0 S    0  0.0   0:05.24 kworker/1:1
>   1233 mysql     20   0 2269m  70m 8088 S    0  0.1   0:08.79 mysqld
>   1288 root      20   0  206m  66m  10m S    0  0.1   2:22.10 Xorg
>   1568 nobody    20   0 21480 1412 1064 S    0  0.0   0:11.89 LCDd
>   2934 spikeygg  20   0  412m 5340 3952 S    0  0.0   0:26.34 indicator-appli
>   5502 spikeygg  20   0  904m 293m  35m S    0  0.2   2:09.67 firefox
>   6457 spikeygg  20   0 17468 1416  968 R    0  0.0   0:00.48 top
>      1 root      20   0 24544 2544 1352 S    0  0.0   0:02.63 init
>      2 root      20   0     0    0    0 S    0  0.0   0:00.00 kthreadd
>      3 root      20   0     0    0    0 S    0  0.0   0:00.25 ksoftirqd/0
>
> What gives, any idea why I have load averages of nearly 2 when the CPU is
> basically idle with 1 running job??
Load is the number of running processes, plus processes that want to run 
(in the run queue), plus the number of uninterruptible sleeping 
processes.  The last group is typically those processes waiting for I/O 
operations to complete.  You have several processes that could be doing 
I/O, like mythbackend, mythlogserver and mysqld.  So, a load average of 
just less than 2 seems reasonable.

Keep in mind that the load is not determined continuously, but is 
calculated from samples taken at intervals and averaged over 1, 5, and 
15 minutes.  Due to the possibility of sampling error, the load numbers 
may not exactly reflect activity you otherwise observe.

Keith