US 11,144,462 B2 · Wait classified cache writes in a data storage system

Abstract

In one embodiment, a task control block (TCB) for allocating cache storage such as cache segments in a multi-track cache write operation may be enqueued in a wait queue for a relatively long wait period, the first time the task control block is used, and may be re-enqueued on the wait queue for a relatively short wait period, each time the task control block is used for allocating cache segments for subsequent cache writes of the remaining tracks of the multi-track cache write operation. As a result, time-out suspensions caused by throttling of host input-output operations to facilitate cache draining, may be reduced or eliminated. It is appreciated that wait classification of task control blocks in accordance with the present description may be applied to applications other than draining a cache. Other features and aspects may be realized, depending upon the particular application.

Claims24

Dependent claims

A method, comprising:

classifying a task control block for allocating cache storage for writing tracks of a chain of tracks of a multi-track cache write operation in a selected wait class of a plurality of different wait classes of task control blocks having an associated wait time of a selected duration of a plurality of different durations of time;
queueing a classified task control block in a wait queue wherein the task control block is queued classified in the selected wait class;
and
allocating cache storage for a cache, for writing in the cache a track of the multi-track cache write operation using the task control block classified in the selected wait class after the task control block has been in the wait queue for a duration of time at least equal to the selected duration of time.

1 more element

A computer program product for use with a host and a primary data storage system having a primary storage controller and a primary device controlled by the primary storage controller and configured to store data, and at least one secondary data storage system having a secondary storage controller and a secondary device controlled by the secondary storage controller and configured to store data, wherein the secondary storage controller has a processor and a cache and wherein the computer program product comprises a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor of the secondary storage controller to cause processor operations, the processor operations comprising:

classifying a task control block for allocating cache storage for writing tracks of a chain of tracks of a multi-track cache write operation in a selected wait class of a plurality of different wait classes of task control blocks having an associated wait time of a selected duration of a plurality of different durations of time;
queueing a classified task control block in a wait queue wherein the task control block is queued classified in the selected wait class;
and
allocating cache storage for a cache, for writing in the cache a track of the multi-track cache write operation using the task control block classified in the selected wait class after the task control block has been in the wait queue for a duration of time at least equal to the selected duration of time.

1 more element

A system for use with a host and a primary data storage system having a primary storage controller and a primary device controlled by the primary storage controller and configured to store data, the system comprising:

at least one secondary data storage system having a secondary storage controller and a secondary device controlled by the secondary storage controller and configured to store data, wherein the secondary storage controller has a processor, a cache and a computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor of the secondary storage controller to cause processor operations, the processor operations comprising:
classifying a task control block for allocating cache storage for writing tracks of a chain of tracks of a multi-track cache write operation in a selected wait class of a plurality of different wait classes of task control blocks having an associated wait time of a selected duration of a plurality of different durations of time;
queueing a classified task control block in a wait queue wherein the task control block is queued classified in the selected wait class;
and
allocating cache storage for a cache, for writing in the cache a track of the multi-track cache write operation using the task control block classified in the selected wait class after the task control block has been in the wait queue for a duration of time at least equal to the selected duration of time.

2 more elements

Dependencies are inferred from the claim text.

Wait classified cache writes in a data storage system

Life of this patent

Wait classified cache writes in a data storage system

Life of this patent

Abstract

Claims24