I have ubuntu running on a multi-core CPU with 32 cores. When I check the cpu usage using top command, sometime it shows more than 100 %, like 340%, 650% etc. I did some investigation and found that its actually a sum of usages across different cores. For example if 1st cpu usages is 20% , 2nd is 30%, 3rd is 40% and remaining are 0% then ‘top’ shows 20+30+40=90%.
Its bit confusing and misleading. I believe the top command should display the CPU usages between 0 to 100 by calculating the usages across all the cores. In my example above, I would expect -(90*100)/3200 =2.8125% . Is this a bug with top command ? should it be considered as an enhancement for future releases? please advise