US 6,687,905 B1 · Multiple port input/output job scheduling

Abstract

A multi-port adapter and method for scheduling jobs at the adapter input/output ports. A plurality of queues are provided, each associated with one of the input/output ports. A processor arranges the jobs in each of the queues in a normal queued order for selection by the associated port. Upon selecting a next job for one of the ports, the processor determines the number of queued jobs of each of the queues for each of the other ports; and determines whether the number of queued jobs of each queue for the other ports is less than a threshold. If the number of jobs is less than the threshold, the processor selects the next job for the one port from the jobs in the queue for the one port identified as one that may be conducted in out of queue order, e.g., having attached heuristic information; else, selects the next job for the one port from the jobs in the queue for the one port on the normal queued basis. The identified job may be part of an operation involving two of the ports, and gives the job priority so that another port is less likely to have to be idle while waiting for the one port.

Claims40

Dependent claims

A method for scheduling input/output jobs for multiple ports of a controller, said controller having a queue of said jobs for each of said ports, each said queue arranging said jobs in a queued order for selection by said associated port, comprising the steps of:

identifying, based on predetermined criteria, ones of said jobs as ones that may be conducted out of queue order;
upon selecting a next job for one of said ports, determining the number of said queued jobs of each said queue for each other of said ports;
determining whether said number of queued jobs of each said queue for said other ports is less than a threshold;
and
if said number of jobs is less than said threshold, selecting said next job, for said one port from said jobs in said queue for said one port, having said out of queue order identification;
else, selecting said next job for said one port from said jobs in said queue for said one port on said queued basis.

3 more elements

A data storage system selecting jobs to be performed by said data storage system, comprising:

a plurality of data storage subsystems;
and
an intermediate controller comprising:
a plurality of input/output ports, each coupled to one of said data storage subsystems;
a plurality of queues, each associated with one of said input/output ports;
and
at least one processor, said processor:
identifies, based on predetermined criteria, ones of said jobs as ones that may be conducted out of queue order;
arranges said jobs in each of said queues in a queued order for selection by said associated input/output port;
upon selecting a next job for one of said input/output ports, determines the number of said queued jobs of each said queue for each other of said input/output ports;
determines whether said number of queued jobs of each said queue for said other input/output ports is less than a threshold;
if said number of jobs is less than said threshold, selects said next job for said one input/output port, from said jobs in said queue for said one input/output port, having said out of queue order identification;
else, selects said next job for said one input/output port from said jobs in said queue for said one input/output port on said queued basis;
and
operating said data storage system to conduct said next selected job at said one input/output port.

12 more elements

A job scheduling computer program product usable with a programmable computer having computer readable program code embodied therein, for use with multiple ports of a controller, said controller having a queue of jobs for each of said ports, each said queue arranging said jobs in a queued order for selection by said associated port, comprising:

computer readable program code which causes a computer processor to identify, based on predetermined criteria, ones of said jobs as ones that may be conducted out of queue order;
computer readable program code which causes a computer processor to arrange said jobs in each of said queues in a queued order for selection by said associated port;
computer readable program code which causes a computer processor to, upon selecting a next job for one of said ports, determine the number of said queued jobs of each said queue for each other of said ports;
computer readable program code which causes a computer processor to determine whether said number of queued jobs of each said queue for said other ports is less than a threshold;
and
computer readable program code which causes a computer processor to, if said number of jobs is less than said threshold, select said next job, for said one port from said jobs in said queue for said one port, having said out of queue order identification;
else, select said next job for said one port from said jobs in said queue for said one port on said queued basis.

4 more elements

Dependencies are inferred from the claim text.

Multiple port input/output job scheduling

Life of this patent

Multiple port input/output job scheduling

Life of this patent

Abstract

Claims40