Memory tiering techniques in computing systems

Patent metadata

Field	Value
Publication number	US-12204408-B2
Application number	US-202318154164-A
Country	US
Kind code	B2
Filing date	Jan 13, 2023
Priority date	Jul 9, 2021
Publication date	Jan 21, 2025
Grant date	Jan 21, 2025

Abstract

Techniques of memory tiering include retrieving, from a first tier in a first memory, data from a data portion and metadata from a metadata portion of the first tier upon receiving a request to read data corresponding to a system memory section. The method can then include analyzing the data location information to determine whether the first tier currently contains data corresponding to the system memory section in the received request. In response to determining that the first tier currently contains data corresponding to the system memory section in the received request, transmitting the retrieved data from the data portion of the first memory to the processor in response to the received request. Otherwise, the method can include identifying a memory location in the first or second memory that contains data corresponding to the system memory section and retrieving the data from the identified memory location.

First claim

We claim:

1. A computer-implemented method of memory management, the method comprising:
receiving a request from a processor to read data corresponding to a system memory section from a cache of the processor;
retrieving, from a first section in a first memory, data and metadata, the metadata encoding data location information of multiple system memory sections in the first section of the first memory, a second section of the first memory, and one or more additional sections in a second memory;
analyzing the data location information in the retrieved metadata to determine that the first section in the first memory currently contains data corresponding to the system memory section in the received request; and
in response to determining that the first section in the first memory currently contains data corresponding to the system memory section in the received request, transmitting the retrieved data from the first section in the first memory to the processor in response to the received request.

2. The computer-implemented method of claim 1 , further comprising:
receiving a second request to read data corresponding to the system memory section from a cache of the processor;
retrieving, from the first section in the first memory, second data and second metadata, the second metadata encoding data location information of multiple system memory sections in the first section of the first memory, the second section of the first memory, and one or more additional sections in the second memory; and
analyzing the data location information in the retrieved second metadata to determine that the first section in the first memory does not currently contain data corresponding to the system memory section in the received second request.

3. The computer-implemented method of claim 2 , further comprising, in response to determining that the first section in the first memory currently does not contain data corresponding to the system memory section in the received second request:
further analyzing the data location information in the retrieved second metadata to identify whether the second section in the first memory or a memory location in the second memory contains data corresponding to the system memory section in the received second request; and
retrieving the data from the second section in the first memory or the memory location in the second memory and providing the retrieved data to the processor in response to the received second request.

4. The computer-implemented method of claim 2 , further comprising, in response to determining that the first section in the first memory currently does not contain data corresponding to the system memory section in the received second request:
further analyzing the data location information in the retrieved second metadata to identify whether the second section in the first memory or a memory location in the second memory contains the data corresponding to the system memory section in the received second request;
upon determining that the second section in the first memory contains the data corresponding to the system memory section in the received second request,
retrieving the data from the second section in the first memory and providing the retrieved data to the processor in response to the received second request; and
writing, to the first section in the first memory, the retrieved data from the second section in the first memory.

5. The computer-implemented method of claim 2 , further comprising, in response to determining that the first section in the first memory currently does not contain data corresponding to the system memory section in the received second request:
further analyzing the data location information in the retrieved second metadata to identify whether the second section in the first memory or a memory location in the second memory contains the data corresponding to the system memory section in the received second request;
upon determining that the second section in the first memory contains the data corresponding to the system memory section in the received second request, retrieving the data from the second section in the first memory and providing the retrieved data to the processor in response to the received second request;
writing, to the first section in the first memory, the retrieved data from the second section in the first memory; and
modifying the second metadata in the first memory to indicate that the data corresponding to the system memory section in the received second request is now in the first section of the first memory.

6. The computer-implemented method of claim 2 , further comprising, in response to determining that the first section in the first memory currently does not contain data corresponding to the system memory section in the received second request:
further analyzing the data location information in the retrieved second metadata to identify whether the second section in the first memory or a memory location in the second memory contains the data corresponding to the system memory section in the received second request;
upon determining that the second section in the first memory contains the data corresponding to the system memory section in the received second request, retrieving the data from the second section in the first memory and providing the retrieved data to the processor in response to the received second request;
writing, to the first section in the first memory, the retrieved data from the second section in the first memory; and
writing, to the second section in the first memory, the retrieved data from the first section of the first memory.

7. The computer-implemented method of claim 2 , further comprising, in response to determining that the first section in the first memory currently does not contain data corresponding to the system memory section in the received second request:
further analyzing the data location information in the retrieved second metadata to identify whether the second section in the first memory or a memory location in the second memory contains the data corresponding to the system memory section in the received request;
upon determining that the second section in the first memory contains the data corresponding to the system memory section in the received second request,
retrieving the data from the second section in the first memory and providing the retrieved data to the processor in response to the received second request;
writing, to the first section in the first memory, the retrieved data from the second section in the first memory;
writing, to the second section in the first memory, the retrieved data from the first section of the first memory; and
modifying the second metadata in the first section of the first memory to indicate that:
the data corresponding to the system memory section in the received second request is now in the first section of the first memory; and
the data previously held in the first section of the first memory is now in the second section of the first memory.

8. The computer-implemented method of claim 1 , wherein:
the metadata includes one or more bits; and
the data location information includes combinations of the one or more bits that individually correspond to one of the multiple system memory sections; and
analyzing the data location information includes:
identifying a combination of the one or more bits; and
determining whether the identified combination corresponds to the system memory section in the received request.

9. The computer-implemented method of claim 1 , wherein:
the metadata includes one or more Error Checking and Correction (ECC) bits; and
the data location information includes combinations of the one or more ECC bits that i

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Agarwal Ishwar
• Chrysos George Zacharias
• Rosell Martinez Oscar

Classifications

• G06F12/0811 Primary

  with multilevel cache hierarchies · CPC title

• G06F11/1435

  using file system or storage system metadata · CPC title

• G06F3/0679

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

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F3/0659

  Command handling arrangements, e.g. command buffers, queues, command scheduling · CPC title