Data transfer between virtual addresses

• US 20030033431A1
• Filed: 08/02/2002
• Published: 02/13/2003
• Est. Priority Date: 08/07/2001
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Shinomiya, Kiyoshi
• Granted Patent: US 6,928,529 B2
• Time in Patent Office: Days
• US Class Current: 709/245
• CPC Class Codes: G06F 12/1027 using associative or pseudo-associative address translation means, e.g. translation look-aside buffer [TLB]
• CPC Class Codes: G06F 12/1072 Decentralised address translation, e.g. in distributed shared memory systems
• CPC Class Codes: G06F 2212/654 Look-ahead translation

Abstract

When a first computer instructs transfer of data from the first computer to a second computer, a transmitting device in the first computer instructs the second computer to perform pre-read of a translation look-aside buffer, which contains a transfer-destination virtual address, in concurrence with read-out of initial data or of initial data for which the transfer-destination address has exceeded a page boundary, thereby causing virtual-address translation information to be pre-registered in a translation look-aside buffer from an address translation table of the second computer. When the second computer instructs transfer of data from the first computer to the second computer, a receiving device in the first computer instructs the second computer to perform pre-read of a translation look-aside buffer, which contains a transfer-destination virtual address, in concurrence with read-out of initial data or of initial data for which the transfer-destination address has exceeded a page boundary, thereby causing virtual-address translation information to be pre-registered in the translation look-aside buffer from an address translation table of the second computer.

Claims

1. A system for transferring data between virtual addresses, said system comprising a plurality of computers each equipped with a central processing unit;

a main memory for storing data;

an address translation table holding address information for translating a virtual address to a real address;

a transmitting device for reading out, and transmitting to a switched network interconnecting said plurality of computers, data from said main memory, said transmitting device incorporating a translation look-aside buffer holding a portion of the translation information of said address translation table; and

a receiving device for receiving, and writing to said main memory, data from the switched network, said receiving device incorporating a translation look-aside buffer holding a portion of the translation information of said address translation table;

the data in said main memories being transferred between said plurality of computers via the switched network upon designating addresses of a data-transfer source and data-transfer destination by the virtual addresses;

translation information associated with the virtual addresses of the data-transfer source and data-transfer destination being registered in the translation look-aside buffers from said address translation table internally of said transmitting and receiving devices within said computers; and

an address translation from the virtual addresses to the real addresses being performed using the translation information registered in the translation look-aside buffers;

wherein

if data in said main memory of one of said computers equipped with said transmitting device is transmitted to said receiving device within another one of said computers, said transmitting device, in concurrence with read-out of data from said main memory provided within the computer equipped with said transmitting device, instructs said receiving device provided within said another computer to pre-register the translation information corresponding to the virtual address of the data-transfer destination in the translation look-aside buffer provided within said another computer.

2. The system according to claim 1, wherein

if said receiving device receives a remote-read instruction, which is issued from the transmitting device provided within a computer constituting a requesting source, for transferring data from said main memory provided within the computer equipped with said receiving device, said receiving device, in concurrence with read-out of data from said main memory provided within the computer equipped said this receiving device, instructs said receiving device provided within the computer constituting the requesting source to pre-register the translation information corresponding to the virtual address of the destination-transfer destination in the translation look-aside buffer provided within the computer constituting the requesting source.

3. The system according to claim 2, wherein

said transmitting device and said receiving device perform the address translation on a per-page basis, where a page is the size of a predetermined memory space in said main memory.

4. The system according to claim 3, wherein

if data in said main memory of one of said computers equipped with said transmitting device is transmitted to said receiving device within another one of said computers, said transmitting device instructs said receiving device provided within said another computer to pre-register the translation information in the translation look-aside buffer when data transmission starts and instructs said receiving device provided within said another computer to pre-register the translation information in the translation look-aside buffer when a virtual address in said main memory within said other computer causes a page boundary to be exceeded.

5. The system according to claim 4, wherein

when said transmitting device transmits a transfer request to another computer in order for data in said main memory provided within said another computer to be transferred to the main memory provided within the computer equipped with said transmitting device serving as a transfer destination, said transmitting device sends said receiving device provided in said another computer a transfer request, obtained by attaching a flag designating pre-registration of address conversion information to a packet, if a virtual address of the transfer destination that constitutes a transfer requesting source causes a page boundary to be exceeded, and said receiving device in said other computer transmits a packet, which instructs said receiving device in the computer that sent the transfer request to pre-register the translation information in the translation look-aside buffer, only if the flag designating pre-registration has been attached to the packet.

6. The system according to claim 1, wherein

when said transmitting device instructs that the translation information is to be pre-registered in the translation look-aside buffer, said transmitting device transmits a TLB pre-read packet containing the virtual address of a data-transfer destination.

7. The system according to claim 2, wherein

when said receiving device instructs that the translation information is to be pre-registered in the translation look-aside buffer, said receiving device transmits a TLB pre-read packet containing the virtual address of a data-transfer destination.

8. The system according to claim 1, wherein

said transmitting device provided within said one computer is adapted to generate a TLB pre-read packet including at least a transfer-destination virtual address, on receipt of a remote-write instruction issued by the central processing unit provided within said one computer, said remote-write instruction requesting said transmitting device provided within said one computer to execute data transfer from said transmitting device provided within said one computer to said receiving device provided within said another computer to transmit the generated TLB pre-read packet to the receiving device provided within said another computer, thereby requesting the receiving device provided within said another computer to perform a pre-read operation of the transfer look-aside buffer provided within said another computer, and

said transmitting device provided within said one computer translates a transfer-source virtual address to a transfer-source real address by using the transfer look-aside buffer provided within said one computer, while said receiving device provided within said another computer, on receipt of the TLB pre-read packet transferred from said transmitting device, performs indexing of the transfer look-aside buffer provided within said another computer by the transfer-destination virtual address contained in the TLB pre-read packet received to translate the virtual address to a real address.

9. The system according to claim 8, wherein

said transmitting device provided within said one computer, after executing an address translation from the transfer-source virtual address to the transfer-source real address, reads data from the transfer-source real address of the main memory to generate a remote-write packet including a transfer-destination virtual address and data read out from said main memory for transferring said remote-write packet to said receiving device provided within said another computer, and

said receiving device provided within said another computer, on receipt of the remote-write packet transferred from said transmitting device provided within said one computer, performs an address translation of a transfer-destination virtual address to a transfer-destination real address by using indexing of the transfer look-aside buffer by the transfer-destination virtual address contained in the remote-write packet to translates the transfer-destination virtual address to a transfer-destination real address.

10. The system according to claim 1, wherein

said transmitting device is adapted to generate a remote-read packet including at least a transfer-source virtual address and a transfer-destination virtual address, on receipt of a remote-read instruction issued by the central processing unit provided within said one computer, said remote-read instruction requesting a data transfer from said receiving device provided within said another computer to said receiving device provided within said one computer to transmit the generated remote-read packet to the receiving device provided within said another computer,

said receiving device within said another computer, is adapted so that said receiving device, on receipt of the remote-read packet transferred from said transmitting device provided within said one computer, generates a TLB pre-read packet including at least a transfer-destination virtual address to send the generated TLB pre-read packet to the receiving device provided within said one computer, and

said receiving device provided within said another computer performs an address translation from a transfer-source virtual address to a transfer-source real address by using the transfer look-aside buffer provided within said another computer, while said receiving device provided within said one computer, on receipt of the TLB pre-read packet transferred from said receiving device provided within said another computer, performs indexing of the transfer look-aside buffer provided within said one computer by the transfer-destination virtual address contained in the TLB pre-read packet received to translate the virtual address to a real address.

11. The system according to claim 10, wherein

said receiving device provided within said another computer, after executing an address translation from the transfer-source virtual address to the transfer-source real address, reads data from the transfer-source real address of the main memory provided within said another computer to generate a remote-write packet including at least a transfer-destination virtual address contained in the remote-read packet received and data read out from said main memory provided within said another computer for transferring said remote-write packet to said receiving device provided within said one computer, and

said receiving device provided within said one computer, on receipt of the remote-write packet transferred from said transmitting device provided within said another computer, performs an address translation from a transfer-destination virtual address to a transfer-destination real address by using indexing of the transfer look-aside buffer by the transfer-destination virtual address contained in the remote-write packet received to translates the transfer-destination virtual address to a transfer-destination real address.