US 2015/0089509 A1Published application

Data processing resource management

AssigneeInternational Business Machines Corporation

InventorsTheresa M. Brown, Nedlaya Y. Francisco, Suguang Li, Beth A. Peterson, Raul E. Saba

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Abstract

In accordance with one aspect of the present description execution of a particular command by a data processor such as a storage controller, may include obtaining priority over a resource which is also associated with execution of another command, setting a timer for the duration of a dynamically set timeout period, and detecting a potential deadlock condition as a function of expiration of the dynamically set timeout period before execution of the particular command is completed. In one embodiment, the particular command releases priority over the resource upon detection of the potential deadlock condition, and then reobtains priority over the resource in a retry of the command. It is believed that such an arrangement can relieve a potential deadlock condition, allowing execution of one or more commands including the particular command to proceed. Other features and aspects may be realized, depending upon the particular application.

Claims21

Dependent claims

A method, comprising:

monitoring the duration of time between receipt of a first command from a command initiator and receipt of a second command from said command initiator and associated with said first command;
dynamically setting a timeout period as a function of said monitored duration of time;
receiving a plurality of additional commands including a third command from said command initiator and partially executing said plurality of additional commands wherein partially executing the third command includes setting a timer for the duration of said dynamically set timeout period and obtaining priority over a first resource which is also associated with execution of a command of said plurality of additional commands other than said third command;
detecting a deadlock condition as a function of expiration of said dynamically set timeout period before execution of the third command is completed, wherein the deadlock condition results from completion of execution of the third command being blocked by another command of said plurality of additional commands having obtained priority over a second resource which is also associated with execution of the third command;
releasing priority of the third command over the first resource upon detection of said deadlock condition;
and
reobtaining priority of the third command over the first resource.

4 more elements

A system for use with a host having a command initiator, comprising:

at least one storage subsystem including at least one storage unit and at least one storage controller adapted to access and control storage units of the at least one storage subsystem wherein the storage subsystem includes a plurality of resources and a timer;
and
at least one computer readable storage medium having computer readable program code embodied therein that is enabled to cause operations to be performed, the operations comprising:
monitoring the duration of time between receipt of a first command from a command initiator and receipt of a second command from said command initiator and associated with said first command;
dynamically setting a timeout period as a function of said monitored duration of time;
receiving a plurality of additional commands including a third command from said command initiator and partially executing said plurality of additional commands wherein partially executing the third command includes setting a timer for the duration of said dynamically set timeout period and obtaining priority over a first resource which is also associated with execution of a command of said plurality of additional commands other than said third command;
detecting a deadlock condition as a function of expiration of said dynamically set timeout period before execution of the third command is completed, wherein the deadlock condition results from completion of execution of the third command being blocked by another command of said plurality of additional commands having obtained priority over a second resource which is also associated with execution of the third command;
releasing priority of the third command over the first resource upon detection of said deadlock condition;
and
reobtaining priority of the third command over the first resource.

7 more elements

A computer program product for use with a host having a command initiator, and for managing data storage operations in connection with at least one storage subsystem including at least one storage unit and at least one storage controller adapted to access and control storage units of the at least one storage subsystem wherein the storage subsystem includes a plurality of resources and a timer;

the computer program product comprising at least one computer readable storage medium having computer readable program code embodied therein that is enabled to cause operations to be performed, the operations comprising:
at least one storage subsystem including at least one storage unit and at least one storage controller adapted to access and control storage units of the at least one storage subsystem wherein the storage controller includes a plurality of resources and a timer;
and
at least one computer readable storage medium having computer readable program code embodied therein that is enabled to cause operations to be performed, the operations comprising:
monitoring the duration of time between receipt of a first command from a command initiator and receipt of a second command from said command initiator and associated with said first command;
dynamically setting a timeout period as a function of said monitored duration of time;
receiving a plurality of additional commands including a third command from said command initiator and partially executing said plurality of additional commands wherein partially executing the third command includes setting a timer for the duration of said dynamically set timeout period and obtaining priority over a first resource which is also associated with execution of a command of said plurality of additional commands other than said third command;
detecting a deadlock condition as a function of expiration of said dynamically set timeout period before execution of the third command is completed, wherein the deadlock condition results from completion of execution of the third command being blocked by another command of said plurality of additional commands having obtained priority over a second resource which is also associated with execution of the third command;
releasing priority of the third command over the first resource upon detection of said deadlock condition;
and
reobtaining priority of the third command over the first resource.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/037,367Filed 26 Sep 2013
Published: 26 Mar 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G06F 9/5016
The resources being hardware resources other than CPUs, Servers and Terminals: the resource being the memory
G06F 9/524
Program synchronisation; Mutual exclusion, e.g. by means of semaphores: deadlock detection or avoidance
G06F 11/14
Responding to the occurrence of a fault, e.g. fault tolerance: error detection or correction of the data by redundancy in operations
G06F 11/1451
Management of the data involved in backup or backup restore: by selection of backup contents