Replacement Of SSK Instruction In A Paging Environment
Original Publication Date: 1979-Oct-01
Included in the Prior Art Database: 2005-Feb-20
System control programs with multiple virtual spaces (MVS) perform a page-in operation. In order to do this, processor hardware (which does not differentiate page-ins from other store operations) automatically turns on the change bit in the storage protection array. As a result, the control program must then issue a SSK (set system key) instruction after each page-in to reset the change bit. In a 4-kilobyte page environment, two SSK instructions are executed after each page-in. In the processor, each SSK will initiate a table lookaside buffer (TLB) search, and for a multiprocessor (MP), each SSK requires synchronization of both processors and searches of both TLBs.