公开(公告)号：GB2597634A

公开(公告)日：2022-02-02

申请号：GB202116905

申请日：2020-04-28

Applicant: IBM

Inventor： LOKESH MOHAN GUPTA ,  BETH ANN PETERSON ,  KEVIN JOHN ASH ,  KYLER ANDERSON

IPC: G06F12/00

Abstract: A method for improving cache hit ratios for selected volumes when using synchronous I/O is disclosed. In one embodiment, such a method includes establishing, in cache, a first set of non-favored storage elements from non-favored storage areas. The method further establishes, in the cache, a second set of favored storage elements from favored storage areas. The method calculates a life expectancy for the non-favored storage elements to reside in the cache prior to eviction. The method further executes an eviction policy for the cache wherein the favored storage elements are maintained in the cache for longer than the life expectancy of the non-favored storage elements. A corresponding system and computer program product are also disclosed.

公开(公告)号：GB2591424B

公开(公告)日：2021-11-10

申请号：GB202106810

申请日：2019-09-30

Applicant: IBM

Inventor： LOKESH GUPTA ,  KYLER ANDERSON ,  KEVIN JOHN ASH ,  MATTHEW BORLICK

IPC: G06N3/08 ,  G06F12/08

Abstract: A machine learning module receives inputs comprising attributes of a storage controller, where the attributes affect performance parameters for performing stages and destages in the storage controller. In response to an event, the machine learning module generates, via forward propagation, an output value that indicates whether to fill holes in a track of a cache by staging data to the cache prior to destage of the track. A margin of error is calculated based on comparing the generated output value to an expected output value, where the expected output value is generated from an indication of whether it is correct to fill holes in a track of the cache by staging data to the cache prior to destage of the track. An adjustment is made of weights of links that interconnect nodes of the plurality of layers via back propagation to reduce the margin of error.

公开(公告)号：GB2584064B

公开(公告)日：2021-04-14

申请号：GB202014835

申请日：2019-02-15

Applicant: IBM

Inventor： MATTHEW BORLICK ,  LOKESH GUPTA ,  KEVIN JOHN ASH ,  KARL ALLEN NIELSEN

IPC: G06F11/10 ,  G06F3/06

Abstract: In one embodiment, virtual storage drives are allocated to RAID arrays so that no two virtual storage drives of a RAID array are mapped to the same physical storage drive. In another aspect, error handling routines are limited to virtual storage drives impacted by an error in a physical storage drive so that virtual storage drives of the physical storage drive not impacted by the error are bypassed. In yet another aspect, cache operations to a target virtual storage drive may be throttled as a function of both a limit imposed on cache operations directed to the RAID array to which the virtual storage drive is allocated, and a separate limit on cache operations directed to a group of virtual storage drives which are mapped to the same physical storage drive as the target virtual storage drive. Other features and aspects may be realized, depending upon the particular application.

公开(公告)号：GB2578080B

公开(公告)日：2020-09-09

申请号：GB202002167

申请日：2018-07-19

Applicant: IBM

Inventor： KYLER ANDERSON ,  KEVIN JOHN ASH ,  MATTHEW JOSEPH KALOS ,  BETH ANN PETERSON ,  LOKESH MOHAN GUPTA

IPC: G06F12/0871 ,  G06F3/06

Abstract: Provided are a computer program product, system, and method for using a track format code in a cache control block for a track in a cache to process read and write requests to the track in the cache. A track format table associates track format codes with track format metadata. A determination is made as to whether the track format table has track format metadata matching track format metadata of a track staged into the cache. A determination is made as to whether a track format code from the track format table for the track format metadata in the track format table matches the track format metadata of the track staged. A cache control block for the track being added to the cache is generated including the determined track format code when the track format table has the matching track format metadata.

公开(公告)号：GB2602404B

公开(公告)日：2022-11-09

申请号：GB202203249

申请日：2020-09-03

Applicant: IBM

Inventor： LOKESH MOHAN GUPTA ,  KEVIN JOHN ASH ,  BRIAN ANTHONY RINALDI ,  KYLER ANDERSON ,  MATTHEW KALOS

IPC: G06F13/16 ,  G06F3/06 ,  G06F12/02 ,  G06F13/42

Abstract: A method to dynamically switch between data transfer techniques includes receiving an I/O request and computing a cost of executing the I/O request using a memory copy data transfer technique. The memory copy data transfer technique copies cache segments associated with the I/O request from cache memory to a permanently mapped memory, which is permanently mapped to a bus address window. The method also computes a cost of executing the I/O request using a memory mapping data transfer technique. The memory mapping data transfer technique temporarily maps cache segments associated with the I/O request from the cache memory to the bus address window. The method uses one of the memory copy data transfer technique and the memory mapping data transfer technique to transfer cache segments associated with the I/O request, depending on which one is less costly. A corresponding system and computer program product are also disclosed.

公开(公告)号：GB2588037B

公开(公告)日：2022-05-11

申请号：GB202019055

申请日：2019-05-13

Applicant: IBM

Inventor： LOKESH MOHAN GUPTA ,  MATTHEW BORLICK ,  KYLER ANDERSON ,  KEVIN JOHN ASH

IPC: G06N3/04 ,  G06F12/00 ,  G06N3/08

Abstract: Provided are a computer program product, system, and method for using a machine learning module to select one of multiple cache eviction algorithms to use to evict a track from the cache. A first cache eviction algorithm determines tracks to evict from the cache. A second cache eviction algorithm determines tracks to evict from the cache, wherein the first and second cache eviction algorithms use different eviction schemes. At least one machine learning module is executed to produce output indicating one of the first cache eviction algorithm and the second cache eviction algorithm to use to select a track to evict from the cache. A track is evicted that is selected by one of the first and second cache eviction algorithms indicated in the output from the at least one machine learning module.

公开(公告)号：GB2588037A

公开(公告)日：2021-04-14

申请号：GB202019055

申请日：2019-05-13

Applicant: IBM

Inventor： LOKESH GUPTA ,  MATTHEW BORLICK ,  KYLER ANDERSON ,  KEVIN JOHN ASH

IPC: G06F12/00

Abstract: A machine learning module selects one of multiple cache eviction algorithms to use to evict a track from the cache. A first cache eviction algorithm determines tracks to evict from the cache. A second cache eviction algorithm determines tracks to evict from the cache, wherein the first and second cache eviction algorithms use different eviction schemes. At least one machine learning module is executed to produce output indicating one of the first cache eviction algorithm and the second cache eviction algorithm to use to select a track to evict from the cache. A track is evicted that is selected by one of the first and second cache eviction algorithms indicated in the output from the at least one machine learning module.

公开(公告)号：GB2585320A

公开(公告)日：2021-01-06

申请号：GB202017405

申请日：2019-04-01

Applicant: IBM

Inventor： LOKESH GUPTA ,  MATTHEW BORLICK ,  KEVIN JOHN ASH

IPC: G06F12/0866 ,  G06F3/06 ,  G06F12/0895

Abstract: Provided are a computer program product, system, and method for using track locks and stride group locks to manage cache operations. A group of tracks from the storage devices are stored in a cache. Exclusive track locks for tracks in the group in the cache are granted for writes to the tracks in the group in the cache, wherein exclusive track locks can be simultaneously held for writes to different tracks in the cache. An exclusive group lock for the group of tracks in the cache is granted to destage the tracks in the group from the cache to the storage devices. The exclusive group lock is released in response to completing the destage of the tracks in the group in the cache to the storage devices.

公开(公告)号：GB2579329B

公开(公告)日：2020-12-16

申请号：GB202003615

申请日：2018-08-10

Applicant: IBM

Inventor： LOKESH M GUPTA ,  KEVIN JOHN ASH ,  KYLER ANDERSON

IPC: G06F12/0895 ,  G06F12/123

Abstract: A list of a first type of tracks in a cache is generated. A list of a second type of tracks in the cache is generated, wherein I/O operations are completed relatively faster to the first type of tracks than to the second type of tracks. A determination is made as to whether to demote a track from the list of the first type of tracks or from the list of the second type of tracks.

公开(公告)号：GB2579754B

公开(公告)日：2020-12-02

申请号：GB202004608

申请日：2018-08-24

Applicant: IBM

Inventor： LOKESH GUPTA ,  KEVIN JOHN ASH ,  KYLER ANDERSON ,  MATTHEW JOSEPH KALOS

IPC: G06F12/06 ,  G06F12/00

Abstract: A cache hit is generated, in response to receiving an input/output (I/O) command over a bus interface. An update for a metadata track is stored in a buffer associated with a central processing unit (CPU) that processes the I/O command, in response to generating the cache hit. The metadata track is asynchronously updated from the buffer with the stored update for the metadata track in the buffer.