Load Average가 올라가는 이유는 무엇일까요??

top - 10:22:07 up 147 days, 7:36, 1 user, load average: 12.05, 10.29, 9.58
Tasks: 341 total, 1 running, 340 sleeping, 0 stopped, 0 zombie
Cpu0 : 0.3%us, 0.3%sy, 0.0%ni, 97.0%id, 0.0%wa, 0.3%hi, 2.0%si, 0.0%st
Cpu1 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu2 : 0.3%us, 0.3%sy, 0.0%ni, 99.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu3 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu4 : 0.0%us, 0.0%sy, 0.0%ni, 99.7%id, 0.3%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu5 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu6 : 0.3%us, 0.3%sy, 0.0%ni, 99.3%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu7 : 0.0%us, 0.0%sy, 0.0%ni, 99.3%id, 0.7%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 4043180k total, 3613284k used, 429896k free, 256312k buffers
Swap: 1052248k total, 0k used, 1052248k free, 2779980k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
7355 root 15 0 12876 1288 812 R 0.7 0.0 0:00.70 top
1 root 15 0 10352 696 588 S 0.0 0.0 2:09.70 init
2 root RT -5 0 0 0 S 0.0 0.0 0:07.88 migration/0
3 root 34 19 0 0 0 S 0.0 0.0 0:00.36 ksoftirqd/0
4 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/0
5 root RT -5 0 0 0 S 0.0 0.0 0:04.03 migration/1
6 root 34 19 0 0 0 S 0.0 0.0 0:00.23 ksoftirqd/1
7 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/1
8 root RT -5 0 0 0 S 0.0 0.0 0:15.37 migration/2
9 root 34 19 0 0 0 S 0.0 0.0 0:01.53 ksoftirqd/2
10 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/2
11 root RT -5 0 0 0 S 0.0 0.0 0:17.88 migration/3
12 root 34 19 0 0 0 S 0.0 0.0 0:00.54 ksoftirqd/3
13 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/3
14 root RT -5 0 0 0 S 0.0 0.0 0:04.21 migration/4
15 root 34 19 0 0 0 S 0.0 0.0 0:00.62 ksoftirqd/4
16 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/4
17 root RT -5 0 0 0 S 0.0 0.0 0:04.33 migration/5
18 root 34 19 0 0 0 S 0.0 0.0 0:01.29 ksoftirqd/5
19 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/5
20 root RT -5 0 0 0 S 0.0 0.0 0:15.22 migration/6
21 root 34 19 0 0 0 S 0.0 0.0 0:02.97 ksoftirqd/6
22 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/6
23 root RT -5 0 0 0 S 0.0 0.0 0:14.89 migration/7
24 root 34 19 0 0 0 S 0.0 0.0 0:01.55 ksoftirqd/7
25 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/7
26 root 10 -5 0 0 0 S 0.0 0.0 0:00.59 events/0
27 root 10 -5 0 0 0 S 0.0 0.0 0:00.48 events/1
28 root 10 -5 0 0 0 S 0.0 0.0 0:00.38 events/2
29 root 10 -5 0 0 0 S 0.0 0.0 0:00.52 events/3
30 root 10 -5 0 0 0 S 0.0 0.0 0:00.46 events/4
31 root 10 -5 0 0 0 S 0.0 0.0 0:00.48 events/5
32 root 10 -5 0 0 0 S 0.0 0.0 0:00.50 events/6
33 root 10 -5 0 0 0 S 0.0 0.0 0:00.44 events/7
34 root 10 -5 0 0 0 S 0.0 0.0 0:00.00 khelper
73 root 11 -5 0 0 0 S 0.0 0.0 0:00.00 kthread
84 root 10 -5 0 0 0 S 0.0 0.0 0:00.07 kblockd/0
85 root 10 -5 0 0 0 S 0.0 0.0 0:00.56 kblockd/1
86 root 10 -5 0 0 0 S 0.0 0.0 0:00.04 kblock

CPU 사용량은 없고, 음악방송 서버로 사용중에 있습니다.

단순히 트래픽이 많아서 그런걸까요?

Load Average의 값은 어떤방식으로 측정되는건가요?