Enables priority paging feature, provided cachefree is greater than lotsfree. This variable is available for systems running the Solaris 2.6 release, with at a minimum, revision 10 of patch 105181 installed, and for systems running the Solaris 7 release. By default, this feature (cachefree equals lotsfree) is disabled.
Value of lotsfree unless priority_paging is set, which means cachefree is 2 times lotsfree
lotsfree to physical memory on system
If less than lotsfree, it is reset to the value of lotsfree.
Should always be enabled unless the system is tight on memory, and does excessive I/O where the contents of the files are needed in the future.