Hardware flush assist

Patent metadata

Field	Value
Publication number	US-10489298-B2
Application number	US-201515747755-A
Country	US
Kind code	B2
Filing date	Jul 28, 2015
Priority date	Jul 28, 2015
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

An apparatus for assisting a flush of a cache is described herein. The apparatus comprises processing element. The processing element is to probe a cache line at an offset address and write the cache line at the offset address to a non-volatile memory in response to a flush instruction at a first address.

First claim

What is claimed is:

1. A system for a hardware flush assist, comprising:
a cache;
a memory;
a home agent, wherein the home agent is to detect a flush instruction on the cache at an address; and
a memory controller, wherein the memory controller comprises a hardware engine, and the hardware engine is to snoop a region of the cache at an offset of the address, and write the region to the memory at the offset of the address, wherein the offset is a value such that a traversal time across a clean region of the cache from the address to the offset plus the address is less than an amount of time that a dirty flush is completed at the non-volatile memory.

2. The system of claim 1 , wherein the memory controller is the home agent.

3. The system of claim 1 , wherein the home agent is to detect a plurality of flush instructions on the cache at a plurality of addresses, and the hardware engine is to snoop a region of the cache at an offset of each of the plurality of addresses, and write the region to the memory at the offset of each of the plurality of addresses.

4. The system of claim 1 , wherein the snoop is speculative.

5. A method for a hardware flush assist, comprising:
detecting a flush instruction at address N;
snooping a memory location at the address N plus a selected offset; and pre-flushing a region of memory at the address N plus the offset, wherein the offset is selected such that a traversal time across a clean region of the cache from the address to the offset plus the address is less than an amount of time that a dirty flush is completed at the non-volatile memory.

6. The method of claim 5 , wherein pre-flushing the region of memory is performed prior to a next flush instruction directed the address plus the offset.

7. The method of claim 5 , wherein the snooping is concurrent with the flush instruction.

8. An apparatus for a hardware flush assist, comprising:
a processing element, wherein the processing element is to:
detect a flush instruction on a cache at an address;
snoop a region of the cache at an offset of the address; and
write the region to the memory at the offset of the address, wherein the offset is a value such that a traversal time across a clean region of the cache from the address to the offset plus the address is less than an amount of time that a dirty flush is completed at the non-volatile memory.

9. The apparatus of claim 8 , wherein the offset address is to be calculated as an offset of an address N received for a flush.

10. The apparatus of claim 8 , wherein the processing element includes a hardware engine.

11. The apparatus of claim 8 , wherein flush instructions are monitored by the processing element.

12. The apparatus of claim 8 , wherein the snoop and write is non-blocking.

Assignees

• Hewlett Packard Entpr Dev Lp

Inventors

• Sherlock Derek Alan
• Walker Shawn

Classifications

• G06F12/0873

  Mapping of cache memory to specific storage devices or parts thereof · CPC title

• G06F12/0817

  using directory methods · CPC title

• G06F12/0804 Primary

  with main memory updating (G06F12/0806 takes precedence) · CPC title

• G06F12/0862 Primary

  with prefetch · CPC title

• G06F12/0891

  using clearing, invalidating or resetting means · CPC title