I am not a dtrace expert but I like to play with its fantastic features. Brendan Gregg has published an extremely good book available on amazon web site : http://www.amazon.com/dp/0132091518. Really worth reading.

dtrace PROBE arguments type

Solaris# dtrace -lvn  zfs_remove:entry
ID   PROVIDER            MODULE                          FUNCTION NAME
41249        fbt               zfs                        zfs_remove entry
Probe Description Attributes
Identifier Names: Private
Data Semantics:   Private
Dependency Class: Unknown
Argument Attributes
Identifier Names: Private
Data Semantics:   Private
Dependency Class: ISA
Argument Types
args[0]: vnode_t *
args[1]: char *
args[2]: cred_t *
args[3]: caller_context_t *
args[4]: int