working of migrate_page (exported) function in mm/migrate.c linux Kernel

Hi, Anybody knows the working of this function "migrate_page" (not "migrate_pages") defined in mm/migrate.c file (linux 2.6) This function is exported so can be used in a Kernel module. Is it used somewhere ? Can it be used to migrate a page to a different NUMA node from kernel module and How to use it?  Is there a function/way in kernel which can be used to migrate page to different NUMA node from Kernel module (not userspace)? Ajay