Hello , I am not Linux and Unix expert so maybe this is a simple question to be answered , I am just not sure. I have a sever with 8 cores (running CENTOS) that executes a batch job once a day for few minutes . I tried to monitor the CPU usage foreach core when the batch is executed using the top command and then pressing '1'.
There I saw something really strange (for me). Initially I saw that job being executed in Cpu5 (it was obvious because it is a job that needs almost 100% of the CPU that is executed) , then Cpu5 usage dropped and Cpu1 usage starting to raise , and then Cpu1 was 100%. That happened several times switching other CPU cores as well (randomly as far as I can tell).
Could a single job that is not using threads change in what CPU core is executed? Is that normal? And if so why is it happening?
Thank you for your responses in advance.