mongod will use the mincore() kernel function (or the similar Windows QueryWorkingSetEx() API) on platforms where we have provided support in a src/mongo/util/processinfo_<platform>.cpp file to enable better runtime decisions about when to throw a PageFaultException.
We do not provide a processinfo_*.cpp file for Solaris/SmartOS, though Solaris has support for mincore() (according to http://www.opensolarisforum.org/man/man2/mincore.html) and has supported the mincore() function since Solaris 9 (according to http://fossies.org/linux/privat/libsigsegv-2.10.tar.gz:a/libsigsegv-2.10/src/stackvma-mincore.c).
The missing support results in a warning message being displayed by mongod in the Solaris/SmartOS build, and in the jstests/block_check_supported.js test reporting failure (because Solaris is not being excluded from testing):
It would be good to add a src/mongo/util/processinfo_solaris.cpp file (similar to the Linux version) to enable this support. If required, the structure of this support allows this to be a runtime test.