Extreme high load average is shown but actual load is low

Issue

• sar shows the following strange load average, CPU usage is low.

  00:00:01      runq-sz  plist-sz   ldavg-1   ldavg-5  ldavg-15   blocked
  00:10:01            8      5205      4.73  41475.94 2099919.40         0
  00:20:01            2      5178      4.60   5567.83 1100355.00         0
  00:30:01            3      5181      3.45    749.94 576585.05         0
  00:40:01            5      5206      4.14    104.00 302130.97         1
  00:50:01            3      5233      4.50     18.62 158318.51         0
  01:00:01            6      5190 470763.00 18999430.29 15157625.34         0
  01:10:01            5      5193     24.39 2548489.10 7942559.38         0
  01:20:01            3      5192      3.25 341843.95 4161882.60         0
  01:30:01            6      5179      2.52  45855.57 2180817.35         0
  01:40:01            3      5168      3.35   6154.11 1142744.68         0
  01:50:01            3      5166      3.38    828.36 598796.89         0
  02:00:01           21      5183      3.48    114.14 313769.75         1
  02:10:01           10      5171      3.14     18.60 164416.59         0
  02:20:01            2      5166 2499079.78 26555240.08 16875205.23         0
  02:30:01            2      5173    114.96 3561986.51 8842566.82         0
  02:40:01            3      5168      3.88 477789.99 4633484.62         0
  02:50:01            4      5181      4.88  64092.15 2427936.29         0
  03:00:01           18      5203      3.88   8600.09 1272234.16         1
  03:10:01            7      5179      4.11   1157.73 666649.93         0
  03:20:01           18      5187      5.63    160.26 349325.57         0
  03:30:01            3      5180      5.84     26.21 183048.20         0
  03:40:01            8      5187 4567393.00 11598615.59 21260021.08         0
  

• top also shows the similar load average.