kstats are data structures maintained by various kernel subsystems and drivers. They provide a mechanism for exporting data from the kernel to user programs without requiring that the program read kernel memory or have superuser privilege. For more information, see kstat(1M) or kstat(3KSTAT).
kstat data structures with system_pages name in the unix module do not report statistics for cachefree. cachefree is not supported, starting in the Solaris 9 release.