Does the kernel assign CPU affinity automatically?

[Yuri]

I noticed that my particularly large process always runs on the same CPU 
through its lifetime (based on top). This process doesn't use cpuset(1) 
or cpuset(2), and cpuset(1) only shows the all-inclusive set:

$ cpuset -g -p 11511
pid 11511 mask: 0, 1, 2, 3, 4, 5, 6, 7

Does the kernel assign CPU affinity automatically in some cases? There 
seems to be some factor besides 'cpuset' that determines affinity.



Thanks,

Yuri