Fast cache demotions in storage controllers with metadata
AssigneeInternational Business Machines Corporation
InventorsKyler A. Anderson, Kevin J. Ash, Lokesh M. Gupta
Life of this patent
Estimating the term…
Abstract
Provided are techniques for fast cache demotions in storage controllers with metadata. A track in a demotion structure is selected. In response to determining that the track in the demotion structure does not have invalidate metadata set, demoting the track from cache. In response to determining that the track has invalidate metadata set, the track is moved from the demotion structure to an invalidate metadata structure. One or more tasks are created to process the invalidate metadata structure, wherein each of the one or more tasks selects a different track in the invalidate metadata structure, invalidates metadata for that track, and demotes that track.
Claims21
1-18. (canceled)
A computer program product, the computer program product comprising a computer readable storage medium having program code embodied therewith, the program code executable by at least one processor to perform:
- storing a demotion structure and an invalidate metadata structure;
- determining that a track in the demotion structure has invalidate metadata set;
- determining whether the track is to be moved to the invalidate metadata structure;
- in response to determining that the track is to be moved to the invalidate metadata structure,
- moving the track from the demotion structure to the invalidate metadata structure;
- and
- creating a task to process the invalidate metadata structure asynchronously by invalidating metadata for the track and demoting the track from cache;
- and
- in response to determining that the track is not to be moved to the invalidate metadata structure, skipping movement of the track from the demotion structure to the invalidate metadata structure.
A computer system, comprising:
- one or more processors, one or more computer-readable memories and one or more computer-readable, tangible storage devices;
- and
- program instructions, stored on at least one of the one or more computer-readable, tangible storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, to perform operations comprising:
- storing a demotion structure and an invalidate metadata structure;
- determining that a track in the demotion structure has invalidate metadata set;
- determining whether the track is to be moved to the invalidate metadata structure;
- in response to determining that the track is to be moved to the invalidate metadata structure,
- moving the track from the demotion structure to the invalidate metadata structure;
- and
- creating a task to process the invalidate metadata structure asynchronously by invalidating metadata for the track and demoting the track from cache;
- and
- in response to determining that the track is not to be moved to the invalidate metadata structure, skipping movement of the track from the demotion structure to the invalidate metadata structure.
A computer-implemented method, comprising:
- storing a demotion structure and an invalidate metadata structure;
- determining that a track in the demotion structure has invalidate metadata set;
- determining whether the track is to be moved to the invalidate metadata structure;
- in response to determining that the track is to be moved to the invalidate metadata structure,
- moving the track from the demotion structure to the invalidate metadata structure;
- and
- creating a task to process the invalidate metadata structure asynchronously by invalidating metadata for the track and demoting the track from cache;
- and
- in response to determining that the track is not to be moved to the invalidate metadata structure, skipping movement of the track from the demotion structure to the invalidate metadata structure.
Dependencies are inferred from the claim text.