JP2004206424A - Data processing device and data transfer method for data processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a time for processing (CPU time) spent in copy processing by performing data transfer per page. <P>SOLUTION: This data processing device obtains a real address by carrying out the address conversion of a virtual address via an address converting means every time the address is accessed when real memories 601 and 602 are accessed on the basis of the virtual address 601, and uses an address converting system for accessing the real memory on the basis of the obtained real address. The address converting means is equipped with a page management information rewrite means for rewriting page management information. The information rewrite means rewrites page management information 615 and 617 on an address converting table which manages an original position and a destination of transfer of data, and performs data transfer per page in a virtual space. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a data processing device and a data transfer method in the data processing device, and more particularly to a data processing device and a data transfer method in the data processing device capable of quickly moving a large amount of data.
[0002]
[Prior art]
When performing data movement processing on the main storage, normal data copy processing is performed. This process is not a problem when the amount of data to be moved is small. However, in recent years, with an increase in the main storage capacity, the amount of data handled on the main storage has also increased. When the amount of data to be moved increases, the processing time (CPU time) required for copying a large amount of data between main memories increases. Especially when a large amount of data created by a user program is output to a recording medium, data is used between tasks, or data is shared between job steps, data is copied to a common area or an input / output buffer by the system. It is. The processing time required for the data copy increases as the data amount increases, and the CPU processing time is significantly spent on these processes.
[0003]
[Problems to be solved by the invention]
When writing the data created on the main memory by the user program to the recording medium via the data management, the operating system (OS) buffers or blocks the data created by the user program, and then writes the data to the recording medium. Make a data copy to start. However, as the amount of data to be buffered or blocked increases, a large amount of CPU time is spent for data copy processing.
The present invention has been made in view of these problems, and a data processing apparatus and a data processing method capable of shortening the processing time (CPU time) required for data copy processing by performing data movement in page units. A data transfer method in a processing device is provided.
[0004]
[Means for Solving the Problems]
The present invention employs the following means in order to solve the above problems.
[0005]
When the real memory is accessed based on the virtual address, the address is converted by the address conversion means to obtain the real address every time the access is performed, and the real memory is accessed based on the obtained real address. A data processing apparatus using a method, wherein the address conversion means includes a page management information rewriting means for rewriting page management information, wherein the page information rewriting means manages a data transfer source and a transfer destination. The page management information on the table is rewritten, and data is moved in page units in the virtual space.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram illustrating an overview of memory access. When the process a (101) accesses the buffer a (109) using the virtual address, the virtual address is translated (107) through the address translation unit (112) every time the buffer a (109) is accessed, and the real address (108) is converted. Then, the real memory a (109) corresponding to the buffer a is accessed based on the real address. Similarly, when the process b (102) accesses the buffer b (110) using the virtual address, the address conversion unit (112) performs the address conversion (107) in the normal state, and converts the virtual address to the real address (108). After the conversion, the real memory b (110) corresponding to the buffer b is accessed.
[0007]
The address conversion (107) performed by the address conversion unit (112) can also be performed by the OS (111). When the process b (102) accesses the buffer b (110), the address conversion (105) is performed in advance in the OS (111), the virtual address is converted to the real address (106), and then the address conversion unit (112) ), The real memory b (110) corresponding to the buffer b can be directly accessed without performing the address conversion (107).
[0008]
FIG. 2 is a diagram illustrating a computer to which the data movement processing according to the present invention is applied. In this example, a program for outputting data processed and edited by the process a (201) to the auxiliary storage device (211) is provided.
[0009]
When the process a (201) outputs the processed and edited data (203), blocking (temporary storage of data) in the real memory a (212) is performed. When blocking is performed on the real memory a (212), data cannot be written to the main storage device without changing the virtual address. Therefore, the virtual address is translated (208) by the address translation unit (218). The data is converted into an address (209), and data blocking is performed on the real memory a (212) based on the real address.
[0010]
When blocking is performed, the blocking buffer becomes full. Actually, it is sufficient to output the data to the auxiliary storage device (211) when it becomes full. However, since the I / O time (input / output time) of the auxiliary storage device (211) is low, data should be output immediately. Leads to a decrease in throughput. Therefore, data output to the auxiliary storage device (211) is performed asynchronously with the time when the buffer is full.
[0011]
That is, it is necessary not to stop the data output processing of the process a (201) even if the buffer becomes full. As a method of not stopping the data output process, it is necessary to always have a free space in the blocking buffer. As a method for this, a plurality of blocking buffers may be prepared, and when the blocking buffer becomes full, the buffer may be replaced (204). After the replacement of the buffer (204), the I / O control (210) is operated asynchronously in order to output the full buffer to the auxiliary storage device (211).
[0012]
As a method of operating asynchronously, a start notification (205) is sent to the process b (202) in a waiting state. Upon receiving the start notification (205) from the process a (201), the process b (202) starts the process b (202) at the time of receiving the start notification (205). The activated process b (202) receives the full buffer address when receiving the activation notification (205). Next, data is copied (206) from this address to the I / O buffer, and an output request (207) to the auxiliary storage device (211) is issued via the I / O buffer (214). Based on the I / O request (207), the input / output control unit (217) performs output (210) to the auxiliary storage device (211) from the specified address of the I / O buffer (214).
[0013]
Process a (201) and process b (202) operate asynchronously, and a buffer address is used as an interface. The process b (202) performs data copy processing so as to immediately move the contents (213) of the received buffer address to the I / O buffer (214) so as not to be destroyed before issuing the I / O. And the output data is guaranteed. For this purpose, a plurality of I / O buffers (214) are often prepared. Also, in the process a (201), a plurality of blocking buffers (212, 213) are often prepared in order to prevent waiting from occurring in the data output processing.
[0014]
In both the process a (201) and the process b (202), buffer copy processing is performed. The process a (201) corresponds to the process of changing the buffer (204), and the process b (202) corresponds to the copying (206) from the buffer (213) to the I / O buffer (214). As described above, in the copy processing, the processing time increases as the amount of data to be copied increases. This is because the access time required for accessing the main storage device is long even when the CPU performance is improved.
[0015]
FIG. 3 is a diagram illustrating a method of performing address conversion from a virtual address to a real address. To obtain the real address (305) from the virtual address (302), a segment table (303) and a page table (304) are used. The segment table (303) is a table for managing a large area frame on the main memory, and includes one record for each area frame. The start address of the segment table (303) is pointed from the segment table starting point (301). Each record in the segment table (303) indicates the head address of the page table (304) that further manages a large area frame of the main memory managed by one record in the segment table (303) in page units. .
[0016]
The page table (304) is composed of a plurality of records as in the segment table (303), and one record corresponds to one page of the main storage. The virtual address (302) itself includes a segment field, a page field, and a displacement field. The segment field indicates the current record position in the segment table (303), and the page field similarly indicates the current record position in the page table (304). The displacement field indicates the current position in the page.
[0017]
When obtaining the real address (305) from a certain virtual address (302), the virtual address (302) is first divided into a segment field, a page field, and a displacement field. Next, in order to obtain the current position of the segment table (303), the segment field is multiplied by the record length of the segment table (303) (308). In the example of FIG. 3, it is n times (308). Thereafter, the current record position (306) of the segment table (303) can be obtained by adding (309) the value of the segment table start point (301). Next, to determine the current record position of the page table (304), the page field of the virtual address (302) is multiplied (310) by the record length of the page table (304). In the example of FIG. 3, it is m times (310). By adding (311) the page table starting point which is the current position value (306) of the segment table (303) obtained above to the value multiplied by m, the current record position (307) of the page table (304) is obtained. Can be requested.
[0018]
When the current record position (307) of the page table (304) is obtained, the page address value (307) in the record is the page number of the real page. The real address (305) can be obtained by adding the displacement field of the virtual address (302) to this page number. The table structure that can obtain the real address (305) from the virtual address (302) is called an address conversion table.
[0019]
FIG. 4 is a diagram illustrating an outline of a method of exchanging a page table, which is page management information of the address conversion table. In the example of FIG. 4, data copy (404) is performed from buffer a (402) for four pages to buffer b (403) for four pages. In the case of the conventional example, the data transfer is completed by performing a copy process (404) of the data in the buffer a (402) as the transfer source to the buffer b (403) as the transfer destination. In this case, As described above, the CPU time used for the copy processing (404) increases.
[0020]
In the present embodiment, in order to reduce the copy process and suppress the consumption of CPU time, the copy (404) process between buffers is not performed, and the same effect as the copy process is provided.
[0021]
In order to move data without performing a copy process (404) between buffers, a page table managing the page of the source buffer a (402) in the page table group (401) of the address translation table By exchanging (407) and the page management information of the page table (406) managing the pages of the destination buffer b (403) (407), the page movement can be completed.
[0022]
When starting the data transfer process, the page table (405) as the transfer source and the page table (406) as the transfer destination are obtained from each other. After the mutual page tables are obtained, the system performs exclusive control so that the source buffer a (402) and the destination buffer b (403) are not used by other tasks, and then executes the source page table (405). ) And exchange (407) of the page management information of the page table (406) as the movement destination. Thus, the data transfer can be completed without performing the copy process (404).
[0023]
FIG. 5 is a diagram illustrating a method of exchanging page management information in the page table. FIG. 5A shows the page table before information exchange, and FIG. 5B shows the page table after information exchange.
[0024]
FIG. 5A shows a state before the source page a (503) is moved to the destination page b (504). The source page a (503) is managed by the page table (501). I have. The destination page b (504) is managed by the page table (502). The page table a (501) and the page table b (502) store page numbers as page management information. That is, the page number of the real address a of the source page a (503) is stored in the page table a (501), and the page number of the real address b of the destination page b (504) is stored in the page table b (502). Is stored. The page number is uniquely managed for all pages on the main memory. Therefore, the page numbers do not overlap.
[0025]
The method of moving data in this embodiment is to exchange (505) page numbers, which are page management information. Thus, when data is moved from the source page a (503) to the destination page b (504), the page table (501) managing the source page a (503) is used instead of copying the data. ) And the information of the page table (502) managing the destination page b (504) is replaced (505), thereby completing the data transfer.
[0026]
FIG. 5B shows a state after the page numbers of the page table are exchanged by the above-described method. As shown in the figure, since the page numbers of the source and destination page tables (506, 507) have been exchanged, the page table a (506) managing the source page a (508) before the exchange has The page number of the destination page b (509) is stored. Further, the page number of the source page a (508) is stored in the page table b (507) that manages the destination page b (509) before the replacement.
[0027]
Data movement by this method can be realized only by exchanging page numbers. Therefore, the real addresses on the main memory of the source page a (508) and the destination page b (509) are not changed. That is, the page table (506) managing the source page a (508) becomes the page table of the destination page b (509). Therefore, when the user tries to refer to the memory on the main memory where the data exists via the page table a (506), the source page a (508) is referenced before the page number is replaced, but the page number is replaced. Later, the destination page b (509) will be referred to. This eliminates the need to perform copy processing between the source page a (508) and the destination page b (509) where data exists.
[0028]
FIG. 6 is a diagram illustrating a reference path from a virtual address to a real address where data exists. FIG. 6A shows a reference path of the real address before the page table is replaced, and FIG. 6B shows a reference path of the real address after the page table is replaced.
[0029]
In FIG. 6A, when a certain virtual address (601) corresponds to the real address a (602), following the address translation process, a corresponding segment table (604) is obtained from the virtual address (601). , A corresponding page table (605) is obtained from the segment table (604), and a page table (607) managing the real address a (602) is obtained. After performing the address conversion based on these information, the real address is obtained and the real address a (602) is referred to. An arrow (606) shows this process.
[0030]
Next, according to the present embodiment, it is assumed that the data of the real address a (602) is moved (apparently) to the real address b (603). FIG. 6B shows the result. The page table (615) that manages the real address a (609) exchanges page numbers (614) with the page table (616) that manages the real address b (610), so the page table (615) The real page number indicates the real address b (610). By following the above-described address translation process in such a state, the corresponding segment table (611) is obtained from the virtual address (608), the corresponding page table (612) is obtained from the segment table (611), and the real address is further obtained. A page table (615) for managing a is obtained. Address conversion is performed from these pieces of information. Here, the difference from the above is that the page table (615) to be referred is at the same location, but the page number of the page table (615) is different. This is the result of the page number interchange (614). Therefore, the real address obtained as a result of the address conversion (613) is the real address b (610). For this reason, after the page tables are exchanged (614), the virtual address (608) does not change, and only the real pages appear to be replaced.
[0031]
FIG. 7 shows the parameters for exchanging page management information in the page table and the format of command words for exchanging page management information in the page table. FIG. 7A shows a parameter (701) for exchanging the page management information of the page table. The parameter (701) is used when exchanging the page management information by software.
[0032]
In order to exchange page tables with each other, a buffer size (702), a source virtual buffer start virtual address (703), and a destination buffer start virtual address (704) are required. The page table can be exchanged by calling the processing program for exchanging the page table inside the OS by using the parameter (701) storing the information.
[0033]
One parameter (701) is prepared for continuous data in the virtual area to be moved. The buffer size (702) is the total number of bytes of data to be moved, and its value is a multiple of the page length. Note that the buffer size (702) may be the number of pages. However, the page in this case must be a continuous area with virtual addresses. The source buffer top virtual address (703) specifies the source virtual address of the source, and the destination buffer top virtual address (704) specifies the destination virtual address of the destination. Each address must be a page boundary address.
[0034]
FIG. 7B is a diagram illustrating a format of a command word for implementing the exchange of page tables by hardware. Two types of instruction words are prepared, and only the parameter list address (706) can be specified for the instruction word 1 (705). For the parameter list address, an interface having the same format as the parameter (701) that can be implemented by software is prepared, and this address is specified.
[0035]
The instruction word 2 (707) is used when the parameter (701) cannot be prepared. The area size, the starting address of the source buffer, and the starting address of the destination buffer can be specified by the general-purpose register. The address specifies a virtual address for both the source address and the destination address. By issuing these instructions, data moves (apparently) within the hardware. By preparing these methods, data movement can be realized using either software or hardware methods.
[0036]
FIG. 8 is a diagram for explaining data movement processing, and shows a processing flow on the processing program side requesting data movement. First, in step 801, the processing program requesting data movement checks the buffers of the processing source movement source buffer (501) and the movement destination buffer (502). This check is performed to determine whether the buffer length of the source (501) to be moved is a multiple of the page length, is a continuous area, or is a data amount that fits in the buffer size of the destination (502). This is a prior confirmation for exchanging page management information in the page table. If there is a buffer for which the page management information is to be exchanged, the process proceeds to step 809; otherwise, the process ends.
[0037]
Next, in step 809 and subsequent steps, a method for issuing a request for mutual exchange is determined. As shown in FIG. 7, there are three methods for issuing a request for mutual exchange. In the flow shown in FIG. 8, one of three issuing methods is selected. First, in step 809, discrimination can be made in two ways, one using the parameter (701) and the other not using the parameter (701) at the time of mutual exchange. The method using the parameter is a case where the parameter area can be prepared, and the method not using the parameter corresponds to a case where the parameter area cannot be prepared. Here, if the parameter (701) area can be prepared, the process proceeds to step 802; otherwise, the process proceeds to step 803.
[0038]
In step 802, the virtual address and size of the source (501) and destination (502) are set in the parameter (701). In step 810, as a method of issuing the mutual exchange request, either a method of mutually exchanging by software or a method of issuing a command 1 (705) for mutual exchange by hardware is selected. Here, if the method of issuing a request for mutual exchange by software is selected, the process proceeds to step 804, and if the method of issuing (805) the instruction word 1 (705) for mutual exchange by hardware is selected, Proceed to step 805. It should be noted that the method of issuing a request for mutual exchange of page management information in the page table by the software is effective when used when special control is required in the software. Further, the method of issuing a request for mutual exchange using the instruction 1 (705) in hardware is effective when it is used purely for data movement without special control in software. The special control here refers to a program that mainly controls a page table, which is a memory management method, in software. In step 804, mutual exchange of page management information by software is requested. In step 805, a command word 1 (705) is issued to request mutual exchange by hardware.
[0039]
If the parameter (701) is not used or cannot be used in step 809, the virtual addresses and sizes of the source (501) and the destination (502) are set in the general-purpose register in step 803, and the instruction is executed in step 806. Issue word 2 (707) to request mutual exchange.
[0040]
Regardless of the method of issuing any of the mutual exchange requests, a completion report of the exchange processing is issued. In step 807, the completion report is received, and it is confirmed whether or not the mutual exchange of the page management information of the page table has been completed normally. When the transfer is completed normally, the data transfer is completed, the management information of the page table is exchanged between the source (501) buffer and the destination (502) buffer before the transfer, and the state shown in FIG. 5B is completed. I do. If it is confirmed in step 807 that the mutual exchange has been completed normally, the process proceeds to step 801; otherwise, the process proceeds to step 808. In step 808, the processing is interrupted. At this time, a failure occurrence message is output as error processing. In addition, dump output at the time of abnormal termination is performed. If the processing for all the target buffers has been completed normally, the processing is terminated.
[0041]
FIG. 9 is a diagram illustrating the process of exchanging page management information in the page table. The exchange process is performed based on the information stored in the register of the parameter (701) or the instruction word 2 (707) shown in FIG. This processing can be performed by both software and hardware.
[0042]
First, in step 901, the buffer size is obtained from the parameter (701). When the instruction word 2 (707) is used, it can be obtained from the general-purpose register having the area size specified by the first operand. In step 902, it is confirmed whether the obtained buffer size is an integral multiple of the page length. If it is not an integer multiple, information cannot be exchanged in page units, so error processing (processing is interrupted) in step 912. In step 903, the source virtual address is obtained from the parameters. When the instruction word 2 (707) is used, the value is obtained from the general-purpose register at the source address specified by the second operand. In step 904, the validity of the obtained source virtual address is confirmed. Here, it is confirmed whether a real page corresponding to the specified virtual address exists in the main memory. If it does not exist, the designated virtual address becomes an invalid address, and an error process is performed in step 912. When the validity check of the source virtual address is completed in Step 904, the actual address of the page table managing the source buffer is calculated in Step 905.
[0043]
In step 906, the destination virtual address is obtained from the parameter. When the instruction word 2 (707) is used, the value is obtained from the general-purpose register at the destination address specified by the third operand. In step 907, the validity of the obtained destination virtual address is confirmed. Here, it is confirmed whether a real page corresponding to the specified virtual address exists in the main memory. If it does not exist, the designated virtual address becomes an invalid address, and an error process is performed in step 912. When the validity check of the destination virtual address is completed in step 907, the real address of the page table managing the destination buffer is calculated in step 908. When all the validity checks are completed, in step 909, an inter-system lock is secured in order to prevent another process from referring to the buffer during the mutual exchange. After the lock has been secured, in step 910, the page to be replaced is temporarily invalidated. During this time, the page table is replaced, and the invalidated page is validated. After the exchange of page tables is completed, in step 911, the secured system lock is released, and the process ends.
[0044]
As described above, according to the present embodiment, by exchanging only the page management information in the page table of the address conversion table, the same result as when data is moved in units of one page can be obtained. . As a result, the CPU time, which conventionally increases as the amount of data to be copied increases, can be significantly reduced.
[0045]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a data processing apparatus and a data transfer method in the data processing apparatus that can reduce the processing time (CPU time) required for the copy processing.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an outline of memory access.
FIG. 2 is a diagram illustrating a computer to which data movement processing is applied.
FIG. 3 is a diagram illustrating a method of performing address conversion from a virtual address to a real address.
FIG. 4 is a diagram illustrating an outline of a method of exchanging a page table which is page management information of an address conversion table.
FIG. 5 is a diagram illustrating a method of exchanging page management information in a page table.
FIG. 6 is a diagram illustrating a reference path from a virtual address to a real address where data exists.
FIG. 7 is a diagram illustrating data movement processing.
FIG. 8 is a diagram illustrating a process of exchanging page management information in a page table.
FIG. 9 is a diagram illustrating a process of exchanging page management information in a page table.
[Explanation of symbols]
111,216 OS
112,218 Address conversion unit
113, 219 Main storage device
114,215 Computer
211 Auxiliary storage device
301 Segment table origin
302, 601, 608 virtual address
303,604,611 segment table
304 page table
305 real address
401, 605, 612 Page table group
405, 406, 607, 609, 615, 616 Page Table
402 buffer a
403 buffer b
501, 506 Page table a
502, 507 Page table b
503,508 Source page a
504, 509 destination page b

Claims (5)

When the real memory is accessed based on the virtual address, the address is converted by the address conversion means to obtain the real address every time the access is performed, and the real memory is accessed based on the obtained real address. A data processing device using the method,
The address translation means includes a page management information rewriting means for rewriting page management information. The page information rewriting means rewrites page management information on an address translation table which manages a transfer source and a transfer destination of data, and A data processing device for performing data movement in page units on the above. When the real memory is accessed based on the virtual address, the address is converted by the address conversion means to obtain the real address every time the access is performed, and the real memory is accessed based on the obtained real address. A data transfer method in a data processing device using a method,
The address conversion means includes a page management information rewriting means for rewriting page management information,
A data processing apparatus, wherein the page management information rewriting means rewrites page management information on an address conversion table which manages a data transfer source and a transfer destination, and performs page-by-page data movement in a virtual space. Data transfer method. In the description of claim 2,
The processing by the page management information rewriting means includes a step of comparing the capacities of the transfer source memory and the transfer destination memory to confirm in advance the possibility of replacing the page table,
Determining whether it is possible to prepare a parameter area in the memory, and if so, setting the transfer source memory start virtual address, transfer destination memory start virtual address and size as parameters,
A data transfer method in a data processing device, comprising a step of exchanging page management information in a page table using software or hardware. In the description of claim 2,
The processing by the page management information rewriting means includes a step of comparing the capacities of the transfer source memory and the transfer destination memory to confirm in advance the possibility of replacing the page table,
Determining whether it is possible to prepare a parameter area in the memory, and if not possible, setting a transfer source memory start virtual address, transfer destination memory start virtual address and size as parameters in a register; ,
A data transfer method in a data processing device, comprising a step of exchanging page management information using a command for exchanging page management information in a page table. 5. The data transfer method according to claim 2, wherein the first virtual address of the transfer source memory and the first virtual address of the transfer destination memory are each a page boundary address.

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