Computer system including virtual memory or cache

Patent metadata

Field	Value
Publication number	US-2016202907-A1
Application number	US-201514722606-A
Country	US
Kind code	A1
Filing date	May 27, 2015
Priority date	Jan 14, 2015
Publication date	Jul 14, 2016
Grant date	—

Abstract

According to one embodiment, a computer system includes a first memory unit, a second memory unit having a data transfer rate lower than that of the first memory unit and a controller. The controller controls transfer of unit data. The unit data includes an indicating portion indicating whether the unit data is to be retained in the second memory unit. When the unit data is transferred from the second memory unit to the first memory unit and the unit data is to be retained in the second memory unit, the controller sets a first state to the indicating portion of the respective unit data. When the unit data is transferred from the first memory unit to the second memory unit, the controller writes the respective unit data in which the indicating portion is set to the first state, to the second memory unit.

First claim

What is claimed is:

1 . A computer system comprising:
a first memory unit; a second memory unit having a data transfer rate lower than that of the first memory unit; and a controller configured to control transfer of unit data between the first memory unit and the second memory unit, the unit data comprising an indicating portion indicating whether the unit data is to be retained in the second memory unit, wherein when the unit data is transferred from the second memory unit to the first memory unit and the unit data is to be retained in the second memory unit, the controller sets a first state to the indicating portion of the respective unit data and, when the unit data is transferred from the first memory unit to the second memory unit, the controller writes the unit data in which the indicating portion is set to the first state, to the second memory unit.

2 . The system according to claim 1 , wherein the second memory unit comprises a memory of which data retained therein is destroyed when the data is read.

3 . The system according to claim 2 , wherein when the unit data is not to be retained in the second memory unit, the controller does not set the first state in the indicating portion corresponding to the unit data.

4 . The system according to claim 3 , wherein when the unit data is written after the unit data is transferred from the second memory unit to the first memory unit, the controller sets the first state to the indicating portion of the respective unit data.

5 . The system according to claim 4 , wherein
the controller comprises a first management unit configured to manage a virtual memory space and a virtual address, and to manage transfer of the unit data between the first memory unit and the second memory unit.

6 . The system according to claim 5 , wherein the unit data is contained in a page.

7 . The system according to claim 4 , wherein the controller comprises a second management unit configured to write the unit data to the first memory unit based on a data write request and to read data corresponding to a read request from the second memory unit when data corresponding to the read request is absent in the first memory unit.

8 . The system according to claim 7 , wherein the unit data is data in units of lines of a cache.

9 . A server system comprising a plurality of computer systems of claim 1 mounted therein.

10 . A computer system comprising:
a first memory unit; a second memory unit having a data transfer rate lower than that of the first memory unit; and a controller configured to control transfer of data of a page between the first memory unit and the second memory unit, the page comprising an indicating portion indicating whether the data of the page is to be retained in the second memory unit, wherein in a page-in where the data of the page is transferred from the second memory unit to the first memory unit, when the data of the page is not to be retained in the second memory unit, the controller does not set a first state to the indicating portion of the respective page, and when the data of the page is to be retained in the second memory unit, the controller sets the first state to the indicating portion of the respective page; and after the page-in, when the data of the page is written, the controller sets the first state to the indicating portion of the respective page, and in a page-out where transferring the data of the page from the first memory unit to the second memory unit, the controller writes the data of the page in which the indicating portion is set to the first state, to the second memory unit.

11 . The system according to claim 10 , wherein the second memory unit comprises a memory of which data retained therein is destroyed when the data is read.

12 . The system according to claim 11 , wherein
the controller comprises a management unit configured to manage a virtual memory space and a virtual address, and to manage transfer of the data of the page between the first memory unit and the second memory unit.

13 . A server system comprising a plurality of computer systems of claim 10 mounted therein.

14 . A computer system comprising:
a first memory unit; a second memory unit having a data transfer rate lower than that of the first memory unit; and a controller configured to control transfer of data of a line between the first memory unit and the second memory unit, the line comprising an indicating portion indicating whether the data of the line is to be retained in the second memory unit, wherein in a line-in where the data of the line is transferred from the second memory unit to the first memory unit, when the data of the line is not to be retained in the second memory unit, the controller does not set a first state to the indicating portion of the respective line, and when the data of the page is to be retained in the second memory unit, the controller sets the first state to the indicating portion of the respective line; and after the line-in, when the data of the line is written, the controller sets the first state to the indicating portion of the respective line, and in a page-out where the data of the line is transferred from the first memory unit to the second memory unit, the controller writes the data of the line in which the indicating portion is set to the first state, to the second memory unit.

15 . The system according to claim 14 , wherein the second memory unit comprises a memory of which data retained therein is destroyed when the data is read.

16 . The system according to claim 15 , wherein
the controller comprises a management unit configured to write the data of the line in the first memory unit based on a data write request and read, when data corresponding to a read request is absent in the first memory unit, data corresponding to the read request from the second memory unit.

17 . A server system comprising a plurality of computer systems of claim 14 mounted therein.

Assignees

• Toshiba Kk

Inventors

• Kanno Shinichi
• Yoshida Hideki

Classifications

• G06F3/0647

  Migration mechanisms · CPC title

• G06F3/061 Primary

  Improving I/O performance · CPC title

• G06F3/0683

  Plurality of storage devices · CPC title

• G06F12/1009

  using page tables, e.g. page table structures · CPC title

• G06F12/109

  for multiple virtual address spaces, e.g. segmentation (G06F12/1036 takes precedence) · CPC title