on my linux appliance based on 3.0.0-14 kernel I got:
RPN:/tmp# ps axuf | grep migration
root 6 92.9 0.0 0 0 ? S Apr23 2788:33 \_ [migration/0]
root 7 99.7 0.0 0 0 ? S Apr23 2993:20 \_ [migration/1]
my top is
RPN:/tmp# top -b -n1
top - 12:03:41 up 2 days, 2:18, 5 users, load average: 25.76, 25.26, 24.73
Tasks: 171 total, 1 running, 168 sleeping, 0 stopped, 2 zombie
Cpu(s): 14.0%us, 12.6%sy, 0.8%ni, 72.0%id, 0.3%wa, 0.0%hi, 0.3%si, 0.0%st
Mem: 1543032k total, 1264728k used, 278304k free, 25308k buffers
Swap: 0k total, 0k used, 0k free, 183168k cached
My question: why processes "migration/N" take so much CPU?