Doing profiles of the SunOne appserver on Solaris x86, we see significant attribution to "no Java callstack recorded" -- on the order of 67.5% of all data points. This greatly limits the usefulness of the profile.

We have not observed this on Solaris Sparc.

A sample experiment is at ftp://piccolo.east/pub/analyzer-intel.tar.gz

The JVM in use is 1.4.2_03.