Why A Linux Process Is Too Busy To Be Attached (ptrace or so)?

Question

On multi-core RHEL6, there is a FIFO realtime process in a deadloop, so it occupies all the CPU resources on the core (process is bound to the core). However, the other cores are pretty fine.

At this time, pstack for the process in deadloop failed to print anything. At the same time, pstack for any other processes works well.

Could anyone please help to let me know why?

Thanks!

Answer 1

try in this way, put the debuger command in a free core with taskset -c corenumber /path/command and after this try change the scheduling class in fifo of your debug process using chrt command

I think you found this problem, because the fifo process cannot be stoped by normal process