Linux-SMP and shared memory

[Detlef Michael]

Hallo,
does anybody know, if Linux-SMP uses lock-free message buffers??
The background of my question:
 I've got the ch_shmem device of MPICH to work on my system, and I'd like to
 know if it makes sense to try the ch_lfshmem device. The MPICH documentation
 says only, on LINUX systems shared memory devices sometimes will work and
 sometimes not.

Detlef