Synchronously performing commit records operations

Patent metadata

Field	Value
Publication number	US-2019073142-A1
Application number	US-201715696052-A
Country	US
Kind code	A1
Filing date	Sep 5, 2017
Priority date	Sep 5, 2017
Publication date	Mar 7, 2019
Grant date	—

Abstract

Provided are techniques for synchronously performing commit records operations. A local copy of a commit records message is built for a Non-Volatile Storage (NVS) track, with a valid indicator set to indicate that this commit records message is valid and has not been processed yet. A Direct Memory Access (DMA) chain is executed to transfer customer data from a host to real segments and alternate segments of a track buffer and to transfer the local copy of the commit records message to a mail message structure of a mail message array. At DMA completion, an NVS manager is synchronously called to perform a commit records operation with the commit records message in the mail message structure. In response to the commit records operation completing, there is an indication that a new write DMA is allowed to proceed for the NVS track.

First claim

What is claimed is:

1 . 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:
building a local copy of a commit records message for a Non-Volatile Storage (NVS) track, with a valid indicator set to indicate that this commit records message is valid and has not been processed yet; executing a Direct Memory Access (DMA) chain to transfer customer data from a host to real segments and alternate segments of a track buffer and to transfer the local copy of the commit records message to a mail message structure of a mail message array; at DMA completion, synchronously calling an NVS manager to perform a commit records operation with the commit records message in the mail message structure; and in response to the commit records operation completing, indicating that a new write DMA is allowed to proceed for the NVS track.

2 . The computer program product of claim 1 , wherein the commit records structure comprises: a track identifier, a track buffer, a start sector, an end sector, an end of track sector, the valid indicator, and a use real or alternate segments indicator.

3 . The computer program product of claim 1 , wherein the program code is executable by the at least one processor to perform:
building the DMA chain.

4 . The computer program product of claim 1 , wherein the program code is executable by the at least one processor to perform:
executing the commit records operation to update a real sector structure and an alternate sector structure indicating whether new data for each record is stored in real segments or alternate segments, reset the valid indicator to indicate that the commit records message has been processed, and synchronously return control.

5 . The computer program product of claim 1 , wherein the program code is executable by the at least one processor to perform:
during any of an Initial Microcode Load (IML) and an Error Handling Behavior (EHB), examining the mail message structure to determine whether the commit records message has the valid indicator set to indicate that the mail message structure is to be processed; and in response to determining that the valid indicator is set to indicate that the mail message structure is to be processed, re-processing the commit records message.

6 . The computer program product of claim 1 , wherein the mail message structure is preserved across a power loss and Error Handling Behavior (EHB) in Non-Volatile Storage.

7 . 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: building a local copy of a commit records message for a Non-Volatile Storage (NVS) track, with a valid indicator set to indicate that this commit records message is valid and has not been processed yet; executing a Direct Memory Access (DMA) chain to transfer customer data from a host to real segments and alternate segments of a track buffer and to transfer the local copy of the commit records message to a mail message structure of a mail message array; at DMA completion, synchronously calling an NVS manager to perform a commit records operation with the commit records message in the mail message structure; and in response to the commit records operation completing, indicating that a new write DMA is allowed to proceed for the NVS track.

8 . The computer system of claim 7 , wherein the commit records structure comprises: a track identifier, a track buffer, a start sector, an end sector, an end of track sector, the valid indicator, and a use real or alternate segments indicator.

9 . The computer system of claim 7 , wherein the operations further comprise:
building the DMA chain.

10 . The computer system of claim 7 , wherein the operations further comprise:
executing the commit records operation to update a real sector structure and an alternate sector structure indicating whether new data for each record is stored in real segments or alternate segments, reset the valid indicator to indicate that the commit records message has been processed, and synchronously return control.

11 . The computer system of claim 7 , wherein the operations further comprise:
during any of an Initial Microcode Load (IML) and an Error Handling Behavior (EHB), examining the mail message structure to determine whether the commit records message has the valid indicator set to indicate that the mail message structure is to be processed; and in response to determining that the valid indicator is set to indicate that the mail message structure is to be processed, re-processing the commit records message.

12 . The computer system of claim 7 , wherein the mail message structure is preserved across a power loss and Error Handling Behavior (EHB) in Non-Volatile Storage.

13 . A method, comprising:
building, using a processor of a computer, a local copy of a commit records message for a Non-Volatile Storage (NVS) track, with a valid indicator set to indicate that this commit records message is valid and has not been processed yet; executing a Direct Memory Access (DMA) chain to transfer customer data from a host to real segments and alternate segments of a track buffer and to transfer the local copy of the commit records message to a mail message structure of a mail message array; at DMA completion, synchronously calling an NVS manager to perform a commit records operation with the commit records message in the mail message structure; and in response to the commit records operation completing, indicating that a new write DMA is allowed to proceed for the NVS track.

14 . The method of claim 13 , wherein the commit records structure comprises: a track identifier, a track buffer, a start sector, an end sector, an end of track sector, the valid indicator, and a use real or alternate segments indicator.

15 . The method of claim 13 , further comprising:
building the DMA chain.

16 . The method of claim 13 , further comprising:
executing the commit records operation to update a real sector structure and an alternate sector structure indicating whether new data for each record is stored in real segments or alternate segments, reset the valid indicator to indicate that the commit records message has been processed, and synchronously return control.

17 . The method of claim 13 , further comprising:
during any of an Initial Microcode Load (IML) and an Error Handling Behavior (EHB), examining the mail message structure to determine whether the commit records message has the valid indicator set to indicate that the mail message structure is to be processed; and in response to determining that the valid indicator is set to indicate that the mail message structure is to be processed, re-processing the commit records message.

18 . The method of claim 13 , wherein the mail message structure is preserved across a power loss and Error Handling Behavior (EHB) in Non-Volatile Storage.

Assignees

• IBM

Inventors

• Ash Kevin J
• Gupta Lokesh M
• Kalos Matthew J
• Peterson Beth A
• Rasor Louis A

Classifications

• G06F9/466

  Transaction processing · CPC title

• G06F13/4282

  on a serial bus, e.g. I2C bus, SPI bus (on daisy chain buses G06F13/4247) · CPC title

• G06F13/4022

  using switching circuits, e.g. switching matrix, connection or expansion network (G06F13/4009 takes precedence) · CPC title

• G06F3/0679

  Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP] · CPC title

• G06F13/28 Primary

  using burst mode transfer, e.g. direct memory access {DMA}, cycle steal (G06F13/32 takes precedence) · CPC title