Patent · US Expired

Pass-through for I/O channel subsystem call instructions for accessing shared resources in a computer system having a plurality of operating systems

US5600805A · kind A · utility

152Cited by
6References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 15, 1992
Grant dateFeb 4, 1997
Priority date
Expiry dateJun 15, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F13/126
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Enables any OS of plural OSs within any of plural logical-resource partitions (LPARs) of a CEC to use interpretive execution for synchronously-executable CHSC (channel subsystem call) commands. A CHSC command authorization mask (CCAM) is provided to control which CHSC commands are allowed to execute interpretively (with pass-through), and which commands are executed with hypervisor intervention (as all prior CHSC commands did). By enabling interpretive execution of those commands which can successfully operate with pass-through, significant system efficiency is obtained. And by disabling interpretive execution for a subset of CHSC commands (which are not allowed to execute with pass-through) potential system failures may be prevented. Thus, interpretive execution may be restricted differently among the OSs in a CEC. Novel CHSC command execution now handles multiple images of shared I/O resources by use of image identifiers, which could not be done before. The information requested by any OS issuing a CHSC command is filtered and optionally compacted by the I/O subsystem responding to the command by only providing information obtained from control blocks associated with the OS which…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.