top 中的 load average 對 performance 的真正影響為何?
通常聽到的說法是, 如果 CPU 有 4 顆, load average 超過 8 (CPU 個數的兩倍) 的時候, 代表 CPU 的 loading 很重, 但往往此時還有 idle, 也許是 10% ~ 20%, 雖然有 idle 但真的覺得慢
The first CPU-related information is present on the very first line: the load average. The load average is a number that corresponds to the average number of runnable processes on the system. The load average is often listed as three sets of numbers (as seen here), which represent the load average for the past 1, 5, and 15 minutes, indicating that the system in this example was not very busy.