JP4985478B2 - Information processing device - Google Patents

Description

  The present invention relates to an information processing apparatus.

  In recent years, the trend toward multiple processors and multithreading have increased. In a multiprocessor type and multithread type information processing apparatus, since a plurality of accesses compete for the same storage area, it is common to have an exclusive control function.

  As a technique related to this type of exclusive control, Patent Document 1 discloses an exclusive control method that reduces the processing load by reducing the number of reads of a shared resource by providing an instruction dedicated to a lock request and an instruction dedicated to an unlock request. Are listed.

  Further, in the configuration in which there is one output unit from the execution processing device having a plurality of main memory request sources to the system control device, and the output unit does not accept subsequent processing once the preceding processing is accepted, one main memory request When an unlock request is output from the source, if the lock request output from another main memory request source occupies the output unit, a deadlock occurs. For the purpose of avoiding this, Patent Document 2 describes an exclusive control method in which an unlock request output from one main memory request source is preferentially processed in the execution processing device.

  Patent Document 3 describes an example of a method for determining the execution order of a plurality of competing access requests in a configuration in which a plurality of main storage request sources share one storage device.

Patent Document 4 describes an example of a method of outputting a determination signal dedicated to an atomic instruction when the instruction decoding device decodes the atomic instruction and using it for determining the priority order of instructions to be executed.
JP 60-107170 A JP-A-62-028866 Japanese Patent Laid-Open No. 06-195313 JP 09-146838 A

  However, the technique described in the above document has room for improvement in the following points.

  Generally, the lock acquisition period tends to be extended as the trend toward multiprocessors and multithreading increase. The risk of becoming a bottleneck in system performance in information processing apparatuses is very high.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a high-performance information processing apparatus that shortens the lock acquisition period in an information processing apparatus that performs exclusive control.

  According to the present invention, a control for performing exclusive control when access conflicts from the processing device to the same storage area included in the main storage device, a processing device that executes a predetermined program, and the like. An information processing device comprising: a decoding unit that decodes the predetermined program; and an access control unit that requests access from the processing device to the main storage device. The control device, when an access reception unit that receives an access request from the access control unit and a plurality of access requests received by the access reception unit compete with the same storage area included in the main storage device, The contention control unit that arbitrates the plurality of access requests and selects an access request to be executed, and the access request selected by the contention control unit is the main storage device. And when the unlock request for releasing the lock process accompanying the exclusive control is included in the plurality of access requests, the unlock request is selected with priority over the contention control unit. An information processing apparatus including an unlock priority unit to be provided is provided.

  Here, the configuration including the main storage device, the processing device, and the control device is a general configuration in an information processing device configured such that a plurality of accesses compete for the same storage area. Similarly, the decoding unit and the access control unit included in the processing device, the access receiving unit, the contention control unit, and the access execution unit included in the control device have the same general configuration.

  According to the present invention, when an unlock request for releasing lock processing associated with exclusive control is included in a plurality of competing access requests, the unlock request can be executed with priority.

  In the information processing apparatus, the processing device includes an identification information detection unit that detects identification information of an unlock request from the predetermined program decoded by the decoding unit, and the identification information detection unit that detects the identification information. An identification information control unit that outputs the identification information to the control device in synchronization with the access control unit, the control device from the identification information control unit An identification information receiving unit that receives the identification information may be included.

  According to this configuration, the identification information of the unlock request included in the predetermined program decoded by the processing device can be detected, and the identification information can be transmitted to the control device in synchronization with the access request.

  In the information processing apparatus, the access control unit can directly execute an access request to the main storage device that does not require coherency control between caches.

  According to this configuration, an access request that does not require coherency control between caches can be directly executed from the access control unit to the main storage device without going through the control device.

  The information processing apparatus can be configured using a plurality of processing apparatuses.

  According to this configuration, not only a single processing device (multi-thread method) but also a plurality of processing devices (multi-processor method) can be used.

  In the information processing apparatus, the instruction code for the unlock request may be an arbitrary dedicated code.

  According to this configuration, the unlock request can be identified when a predetermined program is decoded.

  According to the present invention, an unlock request can be preferentially executed from among a plurality of access requests, so that a lock acquisition period can be shortened and a high-performance information processing apparatus is provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(First embodiment)
FIG. 1 is a functional block diagram showing functions of the information processing apparatus according to the embodiment of the present invention.
The information processing apparatus 1 according to the embodiment of the present invention accesses the main storage device 13, the processing device 11 that executes a predetermined program, and the processing device 11 to the same storage area included in the main storage device 13. Is an information processing device that includes a control device 12 that performs exclusive control when there is a conflict, and the processing device 11 includes a decoding unit 111 that decodes a predetermined program, and the processing device 11 to the main storage device 13. An access control unit 112 that requests access. The control device 12 includes an access receiving unit 121 that receives an access request from the access control unit 112, and a plurality of access requests received by the access receiving unit 121 are stored in a main storage device. 13, when there is contention with the same storage area included in 13, a contention control unit 1 that arbitrates a plurality of access requests and selects an access request to be executed. 2, an access execution unit 123 that executes the access request selected by the contention control unit 122 for the main storage device 13, and an unlock request for releasing the lock process associated with the exclusive control is included in the plurality of access requests. The unlock priority unit 124 that causes the contention control unit 122 to select the unlock request with priority.

  The various components of the present invention do not necessarily have to be independent of each other. A plurality of components are formed as a single member, and a single component is formed of a plurality of members. It may be that a certain component is a part of another configuration, a part of a certain component overlaps a part of another component, and the like.

  The main components of the information processing device 1 are the processing device 11, the control device 12, and the main storage device 13, but the information processing device having an exclusive control function has a general configuration.

  As illustrated in FIG. 1, the processing device 11 includes a decoding unit 111 and an access control unit 112.

  The decoding unit 111 decodes a predetermined program to be executed. The predetermined program is not limited to the main storage device 13, and the reading destination is not limited, such as an external device or an external network.

  The access control unit 112 requests access to the main storage device 13. It also requests access to the cache and access when coherency control between the caches is necessary.

  As illustrated in FIG. 1, the control device 12 includes an access receiving unit 121, a contention control unit 122, an access execution unit 123, and an unlock priority unit 124.

  The access receiving unit 121 receives an access request for the main storage device 13 from the processing device 11. It also accepts access when coherency control between caches is required.

  When a plurality of access requests compete for the same storage area included in the main storage device 13, the contention control unit 122 selects an access request to be executed from among the plurality of access requests.

  The access execution unit 123 executes an access request for the main storage device 13.

  When the unlock priority unit 124 acquires the access request information and the unlock request identification information from the access reception unit 121 and identifies that the access request received by the access reception unit 121 is an unlock request, the unlock priority unit 124 The unit 122 is made to select the unlock request with priority. Details of the unlock request identification information acquisition method and the unlock request priority selection method will be described later.

  When receiving a read request, the main storage device 13 returns data to the request source. In the case of a write request, the stored contents are updated.

  Next, an operation flow in the information processing apparatus according to the embodiment of the present invention will be described with reference to FIG.

  First, the processing device 11 reads a program to be executed. As described above, the reading destination does not matter (step S101).

  The decoding unit 111 decodes the read program (step S102).

  The access control unit 112 outputs an access request to the main storage device 13 according to the decoded instruction (step S103).

  The access receiving unit 121 receives an access request. The unlock priority unit 124 acquires information necessary for priority determination of the unlock request from the access reception unit 121, and performs priority determination (step S104).

  When the determination result is priority arbitration (when the determination in S104 is YES), the contention control unit 122 transitions to the priority arbitration state (step S105), and selects the unlock request with priority according to the determination result. When the determination result is normal arbitration (when the determination in S104 is NO), the competition control unit 122 performs normal arbitration (step S106).

  The access execution unit 123 executes the arbitrated access request to the main storage device 13. The main storage device 13 executes arbitrary processing in accordance with the access request (step S107).

(Second Embodiment)
Next, an example of a method for acquiring the above-described unlock request identification information will be specifically described. FIG. 3 is a functional block diagram in which an identification information acquisition dedicated function for an unlock request is added to the information processing apparatus according to the embodiment of the present invention.

  As shown in FIG. 3, in the information processing device 2 according to the embodiment of the present invention, the processing devices 21, 22, 23, and 24 identify the unlock request from a predetermined program decoded by the decoding unit 211. When the identification information is detected by the identification information detection unit 213 that detects information and the identification information detection unit 213, the identification information is output to the control device 25 in synchronization with the access control unit 212. The control device 25 can include an identification information receiving unit 255 that receives identification information from the identification information control unit 214.

  The main components of the information processing device 2 are four processing devices 21, 22, 23, and 24, a control device 25, and a main storage device 26. In the present embodiment, four processing apparatuses are configured, but the number of processing apparatuses may be one or more.

  As illustrated in FIG. 3, the processing device 21 includes a decoding unit 211, an access control unit 212, an identification information detection unit 213, and an identification information control unit 214. The other processing apparatuses 22, 23, and 24 have the same configuration.

  The decoding unit 211 has the same function as that of the decoding unit 111 described above.

  In addition to the function of the access control unit 112 described above, the access control unit 212 can directly execute an access request that does not require coherency control between caches to the main storage device 26. As a result, the number of accesses to the access receiving unit 251 can be reduced.

  The identification information detection unit 213 detects the identification information of the unlock request from the predetermined program decoded by the decoding unit 211. Details of the method for detecting the identification information will be described later.

  The identification information control unit 214 outputs the identification information to the control device 25 in synchronization with the access request output by the access control unit 212 when the identification information detection unit 213 detects the identification information.

  As illustrated in FIG. 3, the control device 25 includes an access receiving unit 251, a contention control unit 252, an access execution unit 253, an unlock priority unit 254, and an identification information receiving unit 255.

  The access receiving unit 251, the contention control unit 252, and the access execution unit 253 have the same functions as the access reception unit 121, the contention control unit 122, and the access execution unit 123, respectively.

  The identification information receiving unit 255 receives the identification information output from the identification information control unit 214.

  The unlock priority unit 254 has the same function as the unlock priority unit 124 described above. However, in this configuration, the identification information receiving unit 255 is a source for obtaining the identification information of the unlock request.

  The main storage device 26 has the same function as that of the main storage device 13 described above.

  An example of the method for detecting the identification information described above will be specifically described.

  When a predetermined program is accompanied by an unlock request, the instruction code for the unlock request is an instruction code dedicated to any unlock request. Each time the program is decoded, the instruction code of the program is compared with the list of instruction codes dedicated to the unlock request, and if they match, it can be identified as an unlock request.

  FIG. 4 is a circuit of an identification information detection unit for realizing the above-described identification information detection method. The decode circuit 311 decodes an instruction code of a predetermined program. The coincidence circuit 312 detects that the instruction code decoded by the decode circuit 311 matches an arbitrary unlock dedicated instruction code.

  A specific example will be described as an example of a method of arbitrating with priority given to the unlock request described above.

  The unlock priority unit 254 obtains a priority determination result from the information acquired from the access reception unit 251 and the identification information reception unit 255 according to the arbitration logic as shown in FIG.

  Requesters A to D in FIG. 5 correspond to the processing devices 21 to 24, respectively. When there is one request source that outputs identification information with unlock identification, the priority determination result is the request source priority. In accordance with this determination, the unlock priority unit 254 causes the contention control unit 252 to preferentially select the request source access request. If all request sources output identification information without unlock identification, or there are a plurality of request sources that output identification information with unlock identification, the priority determination result is normal arbitration. According to this determination, the unlock priority unit 254 causes the contention control unit 252 to perform normal arbitration.

  The operation flow when the method described above with reference to FIGS. 3, 4, and 5 is used will be described with reference to FIG.

  First, the processing device 21 reads a program to be executed. As described above, the reading destination does not matter (step S201).

  The decoding unit 211 decodes the read program (step S202).

  When access requested by the decoded program does not require coherency control between caches (when the determination in S203 is NO), the access control unit 212 directly accesses the main storage device 26 (step S203).

  When the access request requires coherency control between caches (when the determination in S203 is YES), the identification information detection unit 213 detects the identification information of the unlock request from the instruction code of the access request (step S204).

  The access control unit 212 outputs an access request to the main storage device 26. At this time, the identification information control unit 214 acquires the identification information detected by the identification information detection unit 213, and outputs it in synchronization with the access control unit 212 (step S205).

  The access receiving unit 251 and the identification information receiving unit 255 receive an access request and identification information, respectively. The unlock priority unit 254 acquires information necessary for the priority determination of the unlock request from the access reception unit 251 and the identification information reception unit 255, and performs priority determination according to the logic of FIG. 5 (step S206).

  When the determination result is priority arbitration (when the determination in S206 is YES), the contention control unit 252 transitions to the priority arbitration state (step S207), and arbitrates with priority on the unlock request according to the determination result. If the determination result is normal arbitration (if the determination in S206 is NO), the competition control unit 252 performs normal arbitration (step S208).

  The access execution unit 253 executes the arbitrated access request to the main storage device 26. The main storage device 26 executes arbitrary processing in accordance with the access request (step S209).

  As described above, according to the information processing apparatus of the embodiment of the present invention, an unlock request can be preferentially executed from among a plurality of access requests.

  FIG. 7 shows that the lock acquisition period is shorter than that of the conventional processing because the unlock request can be executed with priority given to a plurality of access requests.

  In the conventional processing method, when there are lock requests from a plurality of processing devices, arbitration is performed, and one lock request is selected, and the processing device (CPU # 0) that is the request source of the lock request is selected. The lock is successful. Since this means that the lock on the target storage area is established at the same time as the lock is successful, the processing device that has succeeded in the lock enters the lock acquisition state.

  The lock acquisition state continues until the unlock request requested by the processing device (CPU # 0) is processed. This period is the lock acquisition period. During the lock acquisition period, the other processing devices (CPU #m or CPU #n) do not accept the lock request even if selected at the time of arbitration. Repeat the request again as shown.

  In the conventional processing method, an unlock request cannot be distinguished from other lock requests at the time of arbitration, and they are treated as equivalent. Therefore, when an unlock request and another lock request conflict, the unlock request is always selected. Is not limited. Unlock processing cannot be performed until an unlock request is selected by arbitration, resulting in an extended lock acquisition period.

  On the other hand, in the processing method of the present invention, since the unlock request and other lock requests are distinguished and handled at the time of arbitration, when the unlock request and another lock request conflict, the unlock request is selected, The lock request is carried forward to the next mediation. As a result, the time until the unlock process is performed can be shortened, so that the lock acquisition period can be shortened compared to the conventional processing method, and the performance of the information processing apparatus can be improved.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

  In the present embodiment, the identification information of the unlock request has a dedicated instruction code, but it is only necessary to be able to clearly indicate the identification information, and the method is not limited. For example, a method may be used in which a bit dedicated to identification information is provided and the presence or absence of an unlock request is clearly indicated in bit units.

  In addition, as an identification information acquisition dedicated function for an unlock request, the identification information detection unit, the identification information control unit are described in the processing device, and the identification information receiving unit is provided in the control device. The configuration is not limited to this as long as it can be recognized. For example, depending on the structure and access pattern of data exchanged between the processing device and the control device, the control device can recognize the identification information without detecting the identification information and transmitting it. .

It is a functional block diagram which showed the function of the information processing apparatus which concerns on embodiment. It is a flowchart which shows the operation | movement flow of the information processing apparatus which concerns on embodiment. FIG. 6 is a functional block diagram in which a dedicated function for acquiring identification information of an unlock request is added to the information processing apparatus of FIG. 1 as another embodiment. It is a figure which shows an example of an identification information detection part. It is a figure which shows an example of the arbitration logic which preferentially selects an unlock request at the time of arbitration. It is a flowchart which shows the operation | movement flow of the information processing apparatus in other embodiment. It is a comparison figure of the conventional process and the process of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Information processing apparatus 11 Processing apparatus 111 Decoding part 112 Access control part 12 Control apparatus 121 Access reception part 122 Contention control part 123 Access execution part 124 Unlock priority part 13 Main storage apparatus 2 Information processing apparatus 21-24 Processing apparatus (request origin) A to D)
211 Decoding unit 212 Access control unit 213 Identification information detection unit 214 Identification information control unit 25 Control device 251 Access reception unit 252 Contention control unit 253 Access execution unit 254 Unlock priority unit 255 Identification information reception unit 26 Main storage device 311 Decoding circuit 312 Match circuit

Claims (4)

A main storage device;
A processing device for executing a predetermined program;
A control device that performs exclusive control when access conflicts from the processing device to the same storage area included in the main storage device,
The processor is
A decoding unit for decoding the predetermined program;
An access control unit that requests access from the processing device to the main storage device according to the program decoded by the decoding unit ;
Including
The controller is
An access receiving unit that receives an access request from the access control unit;
When a plurality of access requests received by the access receiving unit compete with the same storage area included in the main storage device, the contention control unit arbitrates the plurality of access requests and selects an access request to be executed;
An access execution unit that executes the access request selected by the contention control unit with respect to the main storage device;
When the plurality of access requests include an unlock request for releasing the lock process associated with the exclusive control, an unlock priority unit that causes the contention control unit to preferentially select the unlock request;
Only including,
The access control unit determines whether an access request to the main storage device according to the program decoded by the decoding unit requires coherency control between caches, and requires coherency control between caches. Execute an access request not to the main storage device directly without going through the control device;
An information processing apparatus characterized by that. The information processing apparatus according to claim 1,
The processor is
From the predetermined program decoded by the decoding unit, an identification information detection unit for detecting identification information of an unlock request;
An identification information control unit that outputs the identification information to the control device in synchronization with the access control unit when the identification information is detected by the identification information detection unit;
The controller is
An information processing apparatus comprising: an identification information receiving unit that receives the identification information from the identification information control unit. The information processing apparatus according to claim 1 or 2 ,
An information processing apparatus comprising a plurality of the processing apparatuses. The information processing apparatus according to any one of claims 1 to 3 ,
An information processing apparatus according to claim 1, wherein an instruction code for the unlock request is an arbitrary dedicated code.

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