Access control method and computer system
AssigneeFujitsu Limited
InventorTomoo Shirota
Life of this patent
Estimating the term…
Abstract
An access control method for a computer system in which a plurality of clusters share a storage unit, includes predefining an access instruction with exclusive right in addition to an access instruction that is issued with respect to the storage unit from the plurality of clusters, and monitoring, in the storage unit, based on the access instruction with exclusive right transferred from an arbitrary cluster, an access state of an other cluster and executing access instructions with exclusion if a region accessed by an access instruction from the other cluster overlaps a region accessed by the access instruction with exclusive right.
Claims10
An access control method for a computer system in which a plurality of clusters share a storage unit, comprising:
- predefining an access instruction with exclusive right in addition to an access instruction that is issued with respect to the storage unit from the plurality of clusters;
- storing, in a register within the storage unit, a table rewrite instruction that is transferred from at least one of the plurality of clusters and instructs rewriting of the table;
- and
- determining, in the storage unit, a priority order of an access instruction transferred from an arbitrary cluster and an access instruction transferred from another cluster,
- wherein the determining waits for the access instruction transferred from the other cluster to end when the access instruction transferred from the arbitrary cluster is an access instruction with exclusive right and accesses an address that overlaps an address of an access instruction that is being executed, and
- wherein the determining waits for execution of the table rewrite instruction stored in the register to end when the access instruction transferred from the arbitrary cluster is an access instruction with exclusive right and accesses an address that does not overlap an address of an access instruction that is being executed but overlaps an address of the table rewrite instruction.
A computer system comprising:
- a plurality of clusters;
- and
- a storage unit shared by the plurality of clusters,
- wherein an access instruction with exclusive right is predefined in addition to an access instruction that is issued with respect to the storage unit from the plurality of clusters,
- wherein the storage unit includes a register configured to store a table rewrite instruction that is transferred from at least one of the plurality of clusters and instructs rewriting of the table, and a priority determination circuit configured to determine a priority order of an access instruction transferred from an arbitrary cluster and an access instruction transferred from another cluster,
- wherein the priority determination circuit waits for the access instruction transferred from the other cluster to end when the access instruction transferred from the arbitrary cluster is an access instruction with exclusive right and accesses an address that overlaps an address of an access instruction that is being executed, and
- wherein the priority determination circuit waits for execution of the table rewrite instruction stored in the register to end when the access instruction transferred from the arbitrary cluster is an access instruction with exclusive right and accesses an address that does not overlap an address of an access instruction that is being executed but overlaps an address of the table rewrite instruction.
Dependencies are inferred from the claim text.