Low load average with plenty of cpu-intersive processes

Question

I see loadavg at about 1 with at least 3 processes running at full tile. How can that be?

top - 11:48:32 up 147 days,  5:38,  8 users,  load average: 1.08, 1.11, 1.05
Tasks: 416 total,   4 running, 410 sleeping,   2 stopped,   0 zombie
Cpu0  : 43.3%us, 13.7%sy,  0.0%ni, 43.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu1  : 48.8%us, 12.4%sy,  0.0%ni, 38.8%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu2  :  0.7%us,  0.7%sy,  0.0%ni, 98.3%id,  0.0%wa,  0.0%hi,  0.3%si,  0.0%st
Cpu3  : 99.3%us,  0.7%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu4  :  0.0%us,  0.3%sy,  0.0%ni, 99.7%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu5  :  5.7%us,  0.7%sy,  0.0%ni, 93.6%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu6  :  2.3%us,  0.3%sy,  0.0%ni, 97.4%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu7  :  0.3%us,  0.3%sy,  0.0%ni, 99.0%id,  0.0%wa,  0.0%hi,  0.3%si,  0.0%st
Cpu8  : 38.4%us, 17.4%sy,  0.0%ni, 44.2%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu9  : 43.4%us, 13.5%sy,  0.0%ni, 43.1%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu10 :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu11 :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu12 :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu13 :  0.3%us,  0.3%sy,  0.0%ni, 99.3%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu14 :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu15 :  1.0%us,  0.7%sy,  0.0%ni, 98.3%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:  132145404k total, 88125080k used, 44020324k free,   516476k buffers
Swap:  8388600k total,   620232k used,  7768368k free, 55729064k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
25424 jonathan  20   0 4404m 4.1g 3268 R 99.7  3.3 212:58.17 python2.7
20939 sam       20   0  908m 733m 3376 R 81.2  0.6 603:08.07 python2.7
20987 sam       20   0  908m 732m 3376 R 79.8  0.6 598:49.18 python2.7
25428 jonathan  20   0  774m 164m  15m S 14.2  0.1  24:22.60 java
20996 sam       20   0 98.4m 7780 1880 S  4.3  0.0  17:48.15 vw
20941 sam       20   0  161m  70m 1880 S  3.0  0.1  18:10.03 vw
20940 sam       20   0 98.4m 8068 1880 S  2.6  0.0  18:06.28 vw
20942 sam       20   0 98.4m 8080 1880 S  2.6  0.0  17:39.45 vw
20944 sam       20   0  161m  71m 1880 S  2.6  0.1  17:29.29 vw
20947 sam       20   0  161m  71m 1880 S  2.6  0.1  17:25.58 vw
20959 sam       20   0  161m  70m 1880 S  2.6  0.1  17:28.00 vw
20962 sam       20   0  161m  70m 1880 S  2.6  0.1  17:26.96 vw
20963 sam       20   0 98.4m 8076 1880 S  2.6  0.0  18:07.19 vw
20965 sam       20   0  161m  71m 1880 S  2.6  0.1  18:08.13 vw
20995 sam       20   0  161m  71m 1880 S  2.6  0.1  17:38.67 vw
 6399 root      20   0  558m  19m 5028 S  2.3  0.0   4329:56 BESClient
20945 sam       20   0 98.4m 8068 1880 S  2.3  0.0  17:35.38 vw
20948 sam       20   0 98.4m 8068 1880 S  2.3  0.0  17:26.01 vw
20950 sam       20   0  161m  70m 1880 S  2.3  0.1  17:25.79 vw
20952 sam       20   0 98.4m 8076 1880 S  2.3  0.0  17:32.94 vw
20955 sam       20   0  161m  70m 1880 S  2.3  0.1  17:26.61 vw
20956 sam       20   0 98.4m 8072 1880 S  2.3  0.0  17:34.76 vw
20960 sam       20   0 98.4m 8072 1880 S  2.3  0.0  17:34.04 vw

Adding up CPU loads gives about 300%. The top process list also adds up to about 300%.

Why is load average about 1?

Answer 1

The load average is length of the ready to run task queue, as you have enough idle CPUs, the scheduler has been able at this time to assign every task to a CPU and thus the load average is 1 or at least near it. Only when the scheduler has more ready tasks than it has idle CPUs is the load average greater than 1.