JP2000242548A - Request sender identification method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To process a request as request from the same request transmission source at a request reception destination even when a different signal line is used owing to a fault occurring in the route of request transmission by specifying the request transmission source without depending upon the signal line used to transmit the request. SOLUTION: In addition to request contents 102, a computer system has in a request 101 a physical ID (name given by a signal line, which the request is transmitted to, specifying the transmission source of the request) 104 or a physical ID 105 and absolute ID information (information needed to generate an absolute ID) 106. Further, the absolute ID (name which is independent of the signal line and unique to an individual request transmission source) 108 is generated in a process step 107 from the ID information 103 and the request transmission source is specified by using the absolute ID 108. Consequently, the transmission source can be specified without depending upon the signal line where the request is sent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a computer system, and more particularly to a computer system having a redundant configuration.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG. The computer system is composed of a plurality of parts. In the case of FIG. 2, the computer system 201 includes a memory management unit 202, a central processing unit 203, intermediate control devices 206 and 207, and input / output devices 204 and 205. Also, they are connected to the signal lines 208 to 214
It is connected by. Central processing unit 203, input / output device 2
04 and 205 send a memory access request to the memory management unit 202, and a response to the request is returned if necessary. At that time, the memory management unit 207 uses a signal line from which the request has been sent in order to identify the source of the request.

For example, in the memory management unit 202, the source of a request sent from the input / output device 204 via the intermediate control device 206 is processed as a signal 208 and a signal 213. As described above, the transmission source of the request is specified not by the transmission source itself but by the signal line to which the request is transmitted.

[0004]

The method described in the prior art has no problem when there is only one signal line from the source of the request to the destination of the request. However, a problem arises in a computer system having a plurality of paths in view of improving availability and load distribution. For example, the computer system 201 of FIG.
The signal line 2 depends on whether the path from the memory management unit 202 to
08 and 213 or the signal lines 209 and 214.
Then, the memory management unit 202 determines that the request is from a different place even though the request is originally from the same input / output device 204.

[0005] Further, it is assumed that another part attempts to perform processing in place of a failure at the request transmission source. Some requests secure and release common resources in the computer system, such as exclusive access to a memory area, and only requests that secure resources to secure exclusiveness can be performed. If the failed request source has secured resources, the resources cannot be released because other request sources cannot release the resources.

As described above, a problem arises if the source of a request is determined by the signal line from which the request was sent. An object of the present invention is to provide means for specifying a source of a request without depending on a signal line to which the request has been sent.

[0007]

Means for Solving the Problems The name given by the signal line to which the request used to specify the source of the request and which is described in the prior art is transmitted is called a physical ID. On the other hand, a name unique to each request source and independent of the signal line is called an absolute ID. The information required to generate the absolute ID is called absolute ID information.

Means for solving the problem will be described with reference to FIG. In order to achieve the object described in the problem to be solved by the invention, the present invention relates to a computer system, in which a request 101
Physical ID 104 or physical I
Request 101 with absolute ID information 106 in addition to D105
And from the ID information 103 to the processing step 107
Is used to generate an absolute ID 108, and the request source is specified by the absolute ID 108.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, a hardware configuration of a computer system using the first embodiment of the present invention will be described with reference to FIG. The computer system 201 includes at least a memory management unit 202, a central processing unit 203,
It comprises input / output devices 204 and 205 and intermediate control devices 206 and 207. Memory management unit 202
Are the central processing unit 203 and the input / output devices 204 and 205
Manages commonly accessed memory.

Since the input / output devices 204 and 205 have a physical distance from the memory management unit 202, they once access the memory managed by the memory management unit 202 via the intermediate control device 206 or 207. These two
02 to 207 are connected by signal lines 208 to 214, respectively. Although the signal lines 208 to 214 are represented by a single line in FIG. 2, the signal lines are actually composed of a plurality of signal lines and can transmit a lot of information at the same time and can transmit information in two directions.

Next, a basic processing operation of the computer system 201 will be described. Central processing unit 203
The access to the memory from is transmitted to the memory management unit 202 via the signal line 212. This process is called request transmission. In response to this request, the memory management unit 202 returns an access result to the central processing unit 203 via the signal line 212. For example, in the case of a request to read the contents of the memory, the read memory contents are returned. This process is called advance transmission. When the input / output devices 204 and 205 perform request transmission, they are performed once via the intermediate control device 206 or 207. In the case of the input / output device 204, a request is transmitted to the intermediate control device 206 via the signal line 208, and subsequently, the weekly control device 206 transmits a request to the scale management unit 202 via the signal line 213.

The advance transmission is the reverse of the above, and the memory management unit 202 transmits the signal via the signal line 213 to the intermediate control device 2.
06, and then the intermediate control unit 206
8 to the input / output device 204. The same applies to the case where the input / output device 204 passes through the intermediate control device 207 or the case where the input / output device 205 is used. Some types of requests do not have advance transmission.

Next, a mechanism for returning the advance transmission to the source of the request transmission will be described with reference to FIGS. In FIG. 2, a port for receiving a request signal transmitted from a signal line 208 to a signal line 214 is called a port, and is numbered. The port of signal line 208 in intermediate control device 206 is port (0) 215, signal line 21
Port 0 is port (1) 216. Similarly, the port of the signal line 209 in the intermediate control device 207 is connected to the port (0) 21
7. The port of the signal line 211 is the port (1) 218. The port of the signal line 211 in the memory control device 202 is a port
(00) 219, the port of signal line 213 is port (10) 22
0, the port of the signal line 214 is the port (11) 202.

Referring to FIG. 3, the mechanism of the advance transmission returned to the request transmission source will be described with reference to FIG. 2 while showing the data format of the request transmitted at the time of request transmission. When a request is transmitted from the input / output device 204 via the signal line 208, the request data 3
01 has only the request content 304. Upon receiving the request 301, the intermediate control device 215 generates request data 302 to which the number 0 of the port (0) 215 to which the request data 301 has been transmitted is added to the request data 301. Request data 30
The physical ID (C) 305 in 2 is the port number. The intermediate control device 206 transmits the request data 302 via the signal line 213. Memory management unit 202
Is the port (1) from which the request data 302 was sent.
0) The number 220 is added, and the request data 303 is generated. Physical ID (A) 307 and Physical ID (B) 306
Is the number of the port (10) 220.

When performing advanced transmission, ports 215 to 221 to be transmitted are selected based on the physical IDs 305 to 307 added to the request data 302 and 303. First, the memory management unit 202 checks the physical ID (A) 307 and the physical ID of the request data 303.
Based on (B) 206, the port (10) 220 is selected, and the advanced data 309 including the advanced content 308 corresponding to the request content 304 and the physical ID (C) 305 not used for selecting the port this time is transmitted. . Upon receiving the advance data 309, the intermediate control device 206 selects the port (0) 215 based on the physical ID (C) 305, transmits the advance data 310 including only the advanced content 308, and transmits it to the original request data 301. Received by the input / output device 204.

As described above, the request transmission and the advance transmission are associated with the physical IDs 305 to 307, that is, the ports 215 to 22 that have received the request.
It is determined by the number of 1. Although only the advance transmission response has been described here, the memory management unit 2
In 02, the source of the request is also determined based on the physical IDs 305 to 307. That is, the signal transmission path itself is used to specify the source of the request.

Now, such a computer system 20
1 will be described. Intermediate control device 20
6 and 207 can be seen as being duplicated. That is, the input / output devices 204 and 205 can transmit a request and receive an advance if there is any one of the intermediate control devices 206 and 207. This is because computer system 20 does not work if either intermediate control system 206 or 207 fails due to a failure.
1 means that it operates, and it can be said that the configuration is resistant to failure. In addition, since it is possible to select one of the intermediate controllers 206 and 207 that has no processing available, it can be said that load distribution is easily performed.

Now, a problem arises. I / O device 2
04 transmits the request via the intermediate control device 206, the physical IDs 404 to 406 of the request data 401 in the memory management unit, and the input / output device 2
The contents of the physical IDs 408 to 410 of the request data 402 in the memory management unit in the case where the request has been transmitted via the intermediate control device 207 are different. As a result, the memory management unit 202 cannot determine that the request data 401 and 402 are the same request source. For example, if the request data 401 requests exclusive memory access control only for the request source, the request data 402 is determined to be a different request source, and memory access becomes impossible. This is because an attempt was made to specify the request transmission source by a physical ID which is a physical thing called a passed signal line.

In the present invention, the determination is made based not on the physical ID but on the absolute ID of the request transmission source. This absolute ID is called an absolute ID. In this embodiment, the absolute ID is obtained as follows. Physical ID (A) 4
06 or 409, and physical ID (C) 404 or 40
8 is an absolute ID. According to this method, the absolute ID of the request data 401 is “10” and the request data 402
Is also "10", and can be determined to be the same request transmission source.

The method of obtaining the absolute ID can vary depending on the connection of the signal line. The case of the configuration of the computer system 501 similar to that of FIG. 2 as shown in FIG. 5 will be described. 2, the memory management unit 502, the central processing unit 503, the input / output management units 504 and 505, the intermediate control units 506 and 507, the signal lines 508 to 514,
It consists of ports 515 to 521.

The difference between FIG. 5 and FIG. 2 lies in the connection destination ports 516 to 518 of the signal lines 509 to 511. In the case of such a connection, when the input / output device 504 transmits a request via the intermediate control device 506 as shown in FIG.
1 and the request data 602 in the memory management unit when the input / output device 504 transmits the request via the intermediate control device 507. In the case of a configuration such as the computer system 501, the absolute ID is obtained as follows.

One digit of the absolute ID is a physical ID (A) 606 or 609. The remaining one digit of the absolute ID is physical (B)
605 or 609 and physical ID (C) 604 or 60
8 and exclusive OR. Then request data 6
The absolute ID of “01” becomes “10” due to “the exclusive OR of the value 1 of the physical ID (A) 606” and the value 0 of the physical ID (B) 605 and the value 0 of the physical ID (C) 604. The absolute ID of the request data 602 is “10” due to “the exclusive OR of the value 1 of the physical (A) 610” and the value 1 of the physical ID (B) 609 and the value 1 of the physical ID (C) 608. Become. As a result, the two request data 601 and 602 can be determined to be the same request source.

As described above, according to the present invention, in a computer system having a plurality of sets of signal lines for transmitting a request, no matter which signal line is used to transmit the request, the request receiving destination It can be determined that the request is from the same request source. This allows
It is possible to construct a computer system that transmits a request while avoiding a group of signal lines that cannot be used due to a failure or the like and is resistant to failure. In addition, since requests can be transmitted and received using a set of vacant signal lines, a computer system in which non-dispersion is easily performed can be constructed.

Next, a second embodiment of the present invention will be described.

FIG. 7 shows the configuration of a computer system 701 in which the present invention is implemented. Memory management unit 70
2. It comprises a central processing unit 703, an input / output unit 704, an intermediate control unit 705, and an auxiliary control unit 706, each of which is connected by signal lines 707 to 711, and a part of which is connected by ports 712 to 715 to which signal line 707 711
It can be determined whether the request came from.
The operation of request transmission and advance transmission in this computer system 701 is the same as that of the computer system 201 of the above-described embodiment.

The request 801 is transmitted from the input / output device 704 to the memory management unit 70 via the intermediate control device 705.
It was sent to 2. Request 801 includes absolute ID information 804 to 80 in addition to request content 803.
5, a proxy bit 806, and physical IDs 807 to 808. The physical ID (B) 807 and the physical ID (A) 808 are the signal lines 707 and 709 to which the request 801 was sent, respectively.
(0) 712 and port (1) 715 which are the receiving ports of
Represents the number. The proxy bit 806 is used for calculating the absolute ID, and will be described later in detail. Absolute ID information 80
4 and 805 are not necessary for obtaining the absolute ID as described later, and thus may be arbitrary values. The method for obtaining the absolute ID in the present embodiment is as follows.
Is an absolute ID, and if it is 1, the absolute ID information is an absolute ID. " In the case of request 801, proxy bit 8
Since the value of 06 is 0, the absolute ID becomes 10 by the physical IDs 807 and 808.

Subsequently, it is assumed that the input / output device 704 has failed and cannot transmit a request, and has secured a right called a lock for exclusively accessing a memory in the management unit 702. This lock is for the purpose of exclusive access to the memory.
Central processing unit 703 that is a request source other than 04
The request cannot be released. Only the request from the input / output device 704 can be released.

However, the input / output device 704 cannot transmit a request due to a failure. for that reason,
The lock is not released, the central processing unit 703 cannot access the locked memory, and the computer system 702 goes down. For this reason, there is a computer system in which this lock is released by using a special method for the occurrence of a failure that is not a request.

In the computer system 701 of this embodiment, this lock is released by a request. It is the auxiliary control device 706 that transmits a request to release the lock secured by the input / output device 704. Auxiliary control device 70
6 transmits a request 802 to the memory management unit 702 via the intermediate control device 705. The request 802 in FIG. 8 includes a request content 809 instructing release of the lock, physical IDs 813 and 814, and a proxy bit 81.
2. There are absolute ID information 810 and 811.

The physical IDs 813 and 814 correspond to the request 8
The numbers correspond to the numbers of the port (1) 713 and the port (1) 715, which are the reception ports of the signal lines 710 and 709 used for the transmission of “02”. The proxy bit 812 is set to 1 because it is a proxy for the input / output device 704. The absolute ID information 810 and 811 is 10 indicating the input / output device 704.

The absolute ID of such a request 802 is
The surrogate bits 81
Since the value of 2 is 1, the absolute ID information 810 and 81
It becomes 10 from 1. In the memory management unit 702, a request 801 for locking from the input / output device 704 is issued.
Since the absolute ID of the transmission source of the request 802 and the absolute ID of the transmission source of the request 802 for releasing the lock from the auxiliary control device 706 are the same, the lock applied by the request 801 is released by the request 802.

As described above, according to the present invention, it is possible to release a lock secured by a failed request source by a request from another request source. This makes it possible to construct a computer system that is resistant to failure.

The proxy bit 806 or 812 is not an independent bit, but the request content 803 or 8
09 may be included. That is, a method may be used in which either the physical ID or the absolute ID information is used as the absolute ID based on the value of the request content 803 or 809.

The method described in the present embodiment can be similarly applied to a computer system 901 in which a memory management unit 902 and 903 are duplicated as shown in FIG. The computer system 901 includes two memory management units 902 and 903 and a central processing unit 90.
4. Input / output device 905, intermediate control device 906, auxiliary control device 907, and signal lines 908 to 913 connecting them
And a port 91 which is a receiving port for the signal lines 908 to 913.
4 to 919. The memory management units 902 and 903 operate synchronously from the request transmission side, but their internal operations are asynchronous.
The request sender sends a request to both memory management units 902 and 903 as needed.

In the memory management units 902 and 903 thus duplexed, if the lock is simultaneously released from the outside by a method other than the request transmission, the internal operation is asynchronous, and the memory access by the lock is performed. The exclusive processing of may be different. That is, since the processing timing of a certain request is different between the memory management units 902 and 903, the same request is processed by the memory management unit 902 before the lock is released, after the lock is released by the memory management unit 903, or vice versa. The access process will be different.
Therefore, in such a computer system 901, it is necessary for the request source other than the one that caused the failure to release the lock by the request.

As described above, according to the present invention, a synchronous operation is performed from the viewpoint of the request transmitting side, but even in a computer system having a memory management unit that operates asynchronously, a failure occurs. Can be strong.

[0038]

According to the present invention, in a computer system having a redundant configuration, the source of a request can be specified without depending on the signal line used for transmitting the request.
Thus, even if a failure occurs in the request transmission route and a request is transmitted using a different signal line, the request receiving destination can process the request as a request from the same request transmission source. Further, even if a failure occurs in a certain request source and a resource common to the computer system is maintained, another request source can release the resource instead. This makes it possible to construct a computer system that is resistant to failure.

[Brief description of the drawings]

FIG. 1 shows the structure of a request and the absolute I which outlines the present invention.
The figure of the D generation method.

FIG. 2 is a configuration diagram of a computer system which is an application example of the present invention.

FIG. 3 is a diagram of a data structure of a request.

FIG. 4 is a diagram of a data structure of a request.

FIG. 5 is a configuration diagram of a computer system which is an application example of the present invention.

FIG. 6 is a diagram of a data structure of a request.

FIG. 7 is a configuration diagram of a computer system as an application example of the present invention.

FIG. 8 is a diagram of a data structure of a request.

FIG. 9 is a configuration diagram of a computer system which is an application example of the present invention.

[Explanation of symbols]

101 request, 102 request content, 103
... ID information, 104, 105 ... physical ID, 106 ... absolute ID information, 107 ... processing steps, 108 ... absolute ID,
201 computer system, 202 memory management unit, 203 central processing unit, 204, 205 input / output device, 208-214 signal line, 215-221 port, 301-303 request, 304 request content, 305 -307: Physical ID, 308: Advanced contents, 309, 310: Advanced, 401, 402
... request, 403, 407 ... request, 404-
406, 408-410: physical ID, 501: computer system, 502: memory management unit, 503:
Central processing unit, 504, 505 ... I / O unit, 506
507: Intermediate control device, 508-514: Signal line, 51
5-521 ... port, 601, 602 ... request, 6
03,607 ... request contents, 604-606,60
8-610: Physical ID, 701: Computer system, 702: Memory management unit, 703: Central processing unit, 704: Input / output device, 705: Intermediate control device, 70
6. auxiliary control device, 707-710 ... signal line, 711-
714 ... port, 801, 802 ... request, 80
3,809 ... Request contents, 804-805,810
-811: absolute ID information, 806, 812: proxy bit, 807-808, 813-814: physical ID, 90
DESCRIPTION OF SYMBOLS 1 ... Computer system, 902-903 ... Memory management unit, 904 ... Central processing unit, 905 ... Input / output device, 906 ... Intermediate control device, 907 ... Auxiliary control device, 9
08-913 ... signal line, 914-919 ... port.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinichi Mitsuhashi 1 Horiyamashita, Hadano-shi, Kanagawa F-term, General-purpose Computer Division, Hitachi, Ltd. 5B060 KA02 KA03 KA07

Claims (1)

[Claims] A computer system comprises at least a request source, a request destination, and a signal line connecting the request source and the request destination. The request includes at least the request content and "request source" called ID information. Requesting the request receiving destination at least on the basis of the calculation result of the ID information at the request receiving destination.