flycast:
I think the inability to get fractions od seconds from the Linux processor is a bug. Is there a place where one can do a bug report for the Yun in the hopes that it can get resolved on the next release?
It's not a bug. It's an unimplemented feature. Part of the reason Linux can run on so many platforms is that it is modular. You can't expect all features to be present in all kernels/shells. Especially in an embedded release.