Yes, the virtual file /proc/[pid]/stat
seems to have this info: man 5 proc
:
/proc/[pid]/stat
Status information about the process. This is used by ps(1). It is
defined in /usr/src/linux/fs/proc/array.c.
(...fields description...)
processor %d (since Linux 2.2.8)
CPU number last executed on.
on my dual core:
cat /proc/*/stat | awk '{printf "%-32s %d\n", $2 ":", $(NF-5)}'
(su): 0
(bash): 0
(tail): 1
(hd-audio0): 1
(chromium-browse): 0
(bash): 1
(upstart-socket-): 1
(rpcbind): 1
..though I can't say if it's pertinent and/or accurate..