I''ve found documentation at the Java site that documents using the args array with the hotspot provider. http://java.sun.com/javase/6/docs/technotes/guides/vm/dtrace.html When I try it, I get the usual message that makes it look like you have more than one args array type for one probe spec, (hotspot4585:::method-entry matches an unstable set of probes), when it actually means you have _no_ args arrays define for the probe spec. You can only use the argn built-in variables with USDT providers, right? Is the documentation written that way because there is a plan to change that in the future? Thanks, Chip -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.opensolaris.org/pipermail/dtrace-discuss/attachments/20081020/8a6e5b8a/attachment.html>