JP2010128743A - Buffer management method, buffer management device, and buffer management program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy a requirement that, in the case that a plurality of peripheral devices are connected, a method and a device are required for dynamically adjusting a buffer size to achieve the best performance as a whole. <P>SOLUTION: A buffer management device comprising a data processing device 30, a plurality of peripheral devices 60 connected to the data processing device 30, a plurality of device drivers 32a for controlling the input/output of data, and a buffer management part 40 for managing a buffer size performs initial processing for determining whether or not the buffer size according to information concerning the buffer size declared from the specific device driver 32a of the plurality of the device drivers 32a can be secured, and changes the buffer size dynamically according to the proportion of the throughput of the specific device driver 32a to the throughput of an operation in the whole device driver 32a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a buffer management method, a buffer management device, and a buffer management program for dynamically managing a buffer so that throughput is maximized when a buffer of a limited size is shared by a plurality of peripheral devices. is there.

FIG. 4 is an explanatory diagram showing a conventional general data processing apparatus 10.
The data processing apparatus 10 is, for example, a personal computer (hereinafter referred to as “PC”) or the like, to which a plurality of peripheral devices (I / O) 15 or the like are connected. The data processing apparatus 10 includes a central processing unit (hereinafter referred to as “CPU”) 11, a read only memory (hereinafter referred to as “ROM”) 12, a random access memory (hereinafter referred to as “RAM”) 13, a data bus 14, and the like. It is configured.

  When inputting / outputting a large amount of data between the data processing device 10 and the peripheral device 15, a buffer is secured on the RAM 13, and a direct memory access such as a hard disk or the like does not pass through the CPU 11 by DMA (Direct Memory Access). Data is transferred between the peripheral device 15 and the RAM 13. In this method, the data bus 14 is occupied during data transfer by DMA. As a result, there is a problem that the overall processing speed is reduced. In order to solve this problem, a buffer management apparatus as shown in FIG. 5 has been proposed.

  FIG. 5 is a schematic configuration diagram showing a buffer management device using the data processing device 10 of FIG.

  In this buffer management device, a shared memory 20 is connected between the data processing device 10 and a plurality of peripheral devices (I / O) 15 (= 15-1 to 15-n: n is an integer). On the shared memory 20, buffers 21 (= 21-1 to 21-n) are provided corresponding to the peripheral devices 15, respectively. The buffer 21 temporarily stores data input / output between the data processing device 10 and the peripheral device 15. Further, the ROM 12 stores device drivers 12a (= 12a-1 to 12a-n) corresponding to the peripheral devices 15 as programs for performing input / output with the peripheral devices 15.

  In this case, since the data bus 14 is not used at the time of data transfer, the processing of the CPU 1 is not temporarily stopped, and it is possible to suppress a decrease in the overall processing speed.

  However, since it is necessary to prepare a dedicated shared memory 20 in terms of hardware, only a small area can be secured as compared with the case where a buffer is secured on the RAM 3. When this method is adopted, the overall processing speed is affected by how efficiently the shared memory 20 having a limited predetermined memory capacity is used.

  For example, when the shared memory 20 is limited in this way and there is one connected peripheral device 15, the entire shared memory 20 can be occupied by the peripheral device 15, so the peripheral device 15 and the device driver 12a are It is possible to allocate the maximum buffer 21 within an allowable range, and it is expected that the best performance under a given condition can be obtained.

  However, when the shared memory 20 is limited and a plurality of peripheral devices 15 are connected, it is necessary to allocate a buffer 21 to each peripheral device 15 in consideration of the following points.

  (1) When a plurality of device drivers 12a try to secure the buffer 21, a conflict occurs. However, in order to prevent buffer resources from being biased to a specific device driver 12a, the size of the buffer 21 to be allocated must be reduced. I must.

  (2) On the other hand, in order to improve the throughput of the input / output processing of the device driver 12a, it is desirable that the buffer size is large.

  (3) Further, in the case of a system having a hot swap structure in which peripheral devices 15 can be dynamically added and deleted while the system is turned on, what kind of peripheral devices 15 are connected. As a result, the optimum allocation of the buffer 21 changes.

  (4) Some peripheral devices 15 have very rare opportunities for data input / output, and it is useless to assign the buffer 21 to such devices in a fixed manner.

  When the shared memory 20 is shared by a plurality of peripheral devices 15, considerations such as the above (1) to (4) are necessary. However, in the current technology, the buffer 21 having a certain size is fixedly fixed. It is difficult to determine the buffer size so as to maximize the overall performance.

  Such buffer management methods, devices, and the like are described in the following documents.

JP-A-11-282744 Japanese Patent Laying-Open No. 2005-303458

  Patent Document 1 discloses a buffer acquisition unit that selects a buffer having a size most suitable for the request in accordance with a buffer acquisition request sent by the business program and delivers the buffer to the program, and a buffer designated according to a buffer return request sent by the program. Return means for returning the management information as an unused buffer, and a block changing means for updating the management information by instructing the buffer acquisition means and the buffer return means to perform expansion and reduction of the buffer block. And a buffer usage frequency inspection unit that periodically refers to the buffer management information file, monitors the usage status for each buffer size, and updates the management index corresponding to the usage status. Has been.

  Patent Document 2 discloses a buffer for storing data based on information on a data input / output speed when data is input / output to / from a buffer memory in a communication device that stores the data in the buffer memory once before or after data transmission. A communication device is described that includes a buffer size calculation unit that determines a size, and a buffer memory management control unit that sets a buffer area in which data can be stored based on the buffer size determined by the buffer size calculation unit. .

  As described above, when the buffer capacity at the time of data input / output is limited and a plurality of peripheral devices 15 are dynamically added or deleted, the overall performance is maximized. What is needed is a method and apparatus for dynamically adjusting the buffer size.

  However, in the conventional technique, a buffer having a certain size is fixedly allocated, and it is difficult to determine the buffer size so as to maximize the overall performance.

  On the other hand, although the invention of Patent Document 1 is a technique for dynamically changing the buffer size according to the buffer size required by the business program, the buffer size is dynamically changed so as to maximize the throughput of the entire system. It is not a thing.

  The invention of Patent Document 2 is a technique for calculating a buffer size using communication parameters such as a data transfer rate and a data transfer period acquired from an external computer or the like, and dynamically calculates the throughput of a connected device. This is not a technique for determining the buffer size.

  The buffer management method of the present invention includes a data processing device that processes data, a plurality of peripheral devices that input / output data to / from the data processing device, and between the data processing device and the plurality of peripheral devices. A buffer for temporarily storing the data to be input / output in the device, a plurality of device drivers provided for each of the peripheral devices, and controlling the input / output of the data, based on the throughput of the operation in the device driver, A buffer management method using a buffer management unit that manages a buffer size, and whether a buffer size according to information about the buffer size reported from a specific device driver of the plurality of device drivers can be secured The initial processing to determine whether or not the overall throughput of the device driver Depending on the ratio of the throughput of the particular device driver, and having a changing process for dynamically changing the buffer size.

  The buffer management device of the present invention includes a data processing device that processes data, a plurality of peripheral devices that input / output data to / from the data processing device, and between the data processing device and the plurality of peripheral devices. A buffer for temporarily storing the data to be input / output in the device, a plurality of device drivers provided for each of the peripheral devices, and controlling the input / output of the data, based on the throughput of the operation in the device driver, A buffer management device comprising a buffer management unit for managing a buffer size, wherein a buffer size according to information on the buffer size reported from a specific device driver of the plurality of device drivers can be secured; The initial processing of whether or not, to the throughput of the operation in the entire device driver Wherein in proportion to the throughput of a particular device driver, and wherein the dynamically changing the buffer size.

  A buffer management program according to the present invention includes a data processing device that processes data, a plurality of peripheral devices that input and output data to and from the data processing device, and the data processing device and the plurality of peripheral devices. A buffer for temporarily storing the data to be input / output in the device, a plurality of device drivers provided for each of the peripheral devices, and controlling the input / output of the data, based on the throughput of the operation in the device driver, A buffer management program using a buffer management unit that manages a buffer size, and whether a buffer size according to information on the buffer size reported from a specific device driver of the plurality of device drivers can be secured Initial processing for determining whether or not the device and the operation of the entire device driver Wherein in proportion to the throughput of a specific device driver for throughput, and wherein the buffer management program for functioning the process of changing the buffer size for dynamically changing the buffer size.

According to the buffer management method, buffer management device, and buffer management program of the present invention, when a shared memory of a limited size is used as a buffer by a plurality of device drivers, the buffer management device calculates the throughput of each device driver. In addition, since the buffer size is dynamically determined in accordance with the ratio of the throughput of the device driver to the throughput of the entire operation, the performance of the entire system can be made more efficient.

  Further, at this time, the buffer size is determined by the buffer management apparatus in a centralized manner, so that each device driver does not have to perform any special processing regarding the buffer management, so that the design of the device driver is prevented from being complicated. It is done.

  The best mode for carrying out the invention will become apparent from the following description of the preferred embodiments when read in conjunction with the accompanying drawings. However, the drawings are only for explanation and do not limit the scope of the present invention.

(Configuration of Buffer Management Device of Embodiment 1)
FIG. 1 is a schematic configuration diagram illustrating a buffer management device using the data processing device 30 according to the first embodiment of the present invention.

  The buffer management device includes a data processing device 30 such as a PC, and the data processing device 30 includes a plurality of peripheral devices 60 (= 60-1 to 60-n) such as a printer via a buffer management unit 40. Is connected. The data processing device 30 includes a CPU 31 that controls the entire device, a program memory 32 that stores various programs, a data memory 33 such as a RAM that stores working data, and the like. It is connected to the. A buffer management unit 40 is connected to the data bus 34.

  The buffer management unit 40 includes a shared memory 41 and a control unit 43 that controls the entire buffer management unit 40 by a program, and is connected to various peripheral devices 60 (= 60-1 to 60-n). Yes. For example, M1 (42-1), M2 (42-2), and M3 (42-3) in FIG. 1 are used as the buffer 42 by each device driver in input / output with each peripheral device 60. Used for sharing.

  The control unit 43 includes a processing time measuring unit 43a that measures the input / output processing time of the device driver 32a (= 32a-1 to 32a-n), a throughput calculating unit 43b that calculates the throughput of the device driver 32a, It has a buffer size calculation means 43c for calculating the buffer size in accordance with the ratio of the throughput of the device driver 32a to the throughput and two registers, and these are interconnected with various registers for each peripheral device described later. Yes.

  One of the registers of the control unit 43 is a buffer allocation size register (total) (hereinafter referred to as “BAR (total)”) 43d that stores the total sum of the buffers 42 allocated to each device driver. The other register is a throughput register (overall) (hereinafter referred to as “TPR (overall)”) 43e that stores the sum total of the throughput of each device driver.

  Next, various registers will be described. Various registers are prepared for each peripheral device 60 connected to the buffer management device 40. A buffer request size (MIN) register (hereinafter referred to as “BRR (MIN)”) 44 (= 44-1 to 44-n) stores a minimum buffer size requested by the device driver 32a to the buffer management unit 40. This is the register to set. A buffer request size (MAX) register (hereinafter referred to as “BRR (MAX)”) 45 (= 45-1 to 45-n) sets the maximum buffer size requested by the device driver to the buffer management unit 40. Register.

  The buffer allocation size register (hereinafter referred to as “BAR”) 46 (= 46-1 to 46-n) is set with the buffer size calculated by the buffer size calculation means 43c, and notifies the device driver 32a of the value. This register is used for A buffer transfer byte number register (hereinafter referred to as “BTR”) 47 (= 47-1 to 47-n) is a register for setting the transfer byte number when the device driver 32a performs input / output processing. A buffer transfer response counter (hereinafter referred to as “BTC”) 48 (= 48-1 to 48-n) is a counter in which the processing time measuring means 43a counts the clock while the device driver 32a is performing input / output processing. is there.

  A throughput register (hereinafter referred to as “TPR”) 49 (= 49-1 to 49-n) is a throughput of the device driver 32a calculated by the throughput calculation unit 43b as a result of the input / output processing performed by the device driver 32a. Is a register for storing. A buffer transfer control register (hereinafter referred to as “BCR”) 50 (= 50-1 to 50-n) is a register for the device driver 32a to notify the buffer management unit 40 of the start of input / output.

(Buffer management method of Embodiment 1)
(A) Initial operation in the buffer management apparatus of the first embodiment

  FIG. 2 is a flowchart showing an initial operation in the buffer management apparatus of FIG.

  The operation of the initial process in the buffer management apparatus of the first embodiment is composed of the following steps. The device driver 32a (for example, the device driver 32a-1) corresponding to a certain peripheral device 60 (for example, the peripheral device 60-1) sets the minimum value of the requested buffer size to BRR (MIN) before exchanging data for the first time. In 44-1, the maximum value is written in the BRR (MAX) 45-1, and a buffer to be used is requested to the buffer management unit 40 (step S1).

  The buffer management device 40 refers to the BRR (MIN) 44-1 (step 2) and checks whether the buffer can be allocated (step 3). When the allocation is impossible (NO), “0” is set in the BAR 46-1 and the process is terminated (step 4). The device driver 32a refers to the BAR 46-1, and if it is “0”, the buffer allocation has failed, so the buffer size is reduced and a retry is performed.

  When buffer allocation is possible (YES), the buffer management unit 40 refers to the BRR (MIN) 44-1 and sets the minimum value set therein to the BAR 46-1 (step S5). At this time, the sum of the buffer sizes assigned to each device driver 32a is recalculated and set in the BAR (total) 43d.

  The device driver 32a secures the buffer 42 having the size set in the BAR 46-1 (step S6), sets the input / output request in the BCR 50-1 (step S7), and notifies the buffer management unit 40 of the start of input / output. To do.

  When receiving the input / output request, the buffer management unit 40 clears the BTC 48-1 (step S8) and starts data transfer. The processing time measuring unit 43a counts the clock during data transfer and adds it to the BTC 48-1 (step S9). Until the input / output is completed, the BTC 48-1 count in step S9 is repeated. When the input / output is completed (step S10), the processing time measuring unit 43a stops the clock counting (step S11) and determines the number of transferred bytes. Set to BTR 47-1 (step 12).

  Next, the throughput calculation unit 43b calculates the throughput Ta of the device driver by dividing the transfer byte number Ba set in the BTR 47-1 by the processing time Pa set in the BTC 48-1, thereby calculating the TPR 49- 1 is set (step S13). For example, if the number of transfer bytes Ba = 1000 bytes and the processing time Pa = 200 milliseconds, the throughput Ta = Ba / Pa = 1000 / 0.2 = 5000 [bytes / second].

Subsequently, the overall throughput Tsum is calculated (step S14). The total throughput is the sum of the input / output processing throughputs Ti in all the peripheral devices 60 sharing the shared memory 41, and is expressed by the following equation.
Tsum = ΣTi (1)

  When the throughput Ta is calculated, equation (1) is recalculated and the overall throughput Tsum is updated. Tsum is set and stored in the TPR (total) 43e. The peripheral device 60-1 has been described above as an example, but the same applies to processing for other peripheral devices.

(B) Second and subsequent operations in the buffer management apparatus of the first embodiment FIG. 3 is a flowchart showing the second and subsequent operations in the buffer management apparatus of FIG. 1, and the elements common to the elements in FIG. The common code | symbol is attached | subjected.

  The second and subsequent operations in the buffer management apparatus of the first embodiment are configured by the following steps. The device driver 32a requests the buffer management unit 40 for the buffer 42 before exchanging the second and subsequent data (step S21). The buffer size calculation unit 43c calculates the buffer size by multiplying the overall buffer size by the ratio of the throughput of the device driver to the overall operation throughput (step 22), and sets the calculation result in the BAR 46-1 (step S23). .

For example, if the overall buffer size is MS and the buffer size given to the device driver is MSa,
MSa = MS × (Ta / Tsum) (2)
It is.

For example, MS = 3000 [bytes], Ta = 5000 [bytes / second],
If Tsum = 50,000 [bytes / second], MSa = 3000 × (5000 / 50,000) = 300 [bytes] from equation (2)
It becomes.

  The device driver 32a secures the buffer 42 having the size set in the BAR 46-1 (step S6), sets the input / output request in the BCR 50-1 (step S7), and notifies the buffer management unit 40 of the start of input / output. To do. The operations after Step 6 are almost the same as the operations of the device driver and buffer management unit 40 shown in FIG. Although the peripheral device 60-1 has been described as an example, the same applies to the processing for other peripheral devices.

(Effect of Example 1)
According to the buffer management method, the buffer management apparatus, and the buffer management program of the first embodiment, when the shared memory 41 having a limited size is used as the buffer 42 by the plurality of device drivers 32a, the buffer management unit 40 Since the throughput of each device driver 32a is calculated and the buffer size is dynamically determined according to the ratio of the throughput of the device driver 32a to the overall operation throughput, the performance of the entire system can be made more efficient.

  Further, at this time, since the buffer size is determined by the buffer management unit 40 in a centralized manner, each device driver does not need to perform special processing regarding the buffer management 32a, so that the design of the device driver 32a is complicated. It can be suppressed.

(Modification)
The present invention is not limited to the above-described embodiments, and various usage forms and modifications are possible. For example, the following forms (a) to (c) are available as usage forms and modifications.

  (A) In the first embodiment, the buffer management unit 40 is described as being realized by program control, but may be realized by various circuits.

  (B) The CPU 31, the program memory 32, the data memory 33, the data bus 34, and the buffer management unit 40 of the first embodiment may be realized by one large-scale integrated circuit.

  (C) In the first embodiment, the program or the like is described as being stored in the program memory 32. However, the program may be loaded from the hard disk to the data memory 33 and executed.

It is a schematic block diagram which shows the buffer management apparatus using the data processor 30 in Example 1 of this invention. 3 is a flowchart showing an initial operation in the buffer management device of FIG. 1. 3 is a flowchart showing the second and subsequent operations in the buffer management device of FIG. 1. It is explanatory drawing which shows the conventional general data processing apparatus. FIG. 5 is a schematic configuration diagram showing a buffer management device using the data processing device 10 of FIG. 4.

Explanation of symbols

30 Data processing unit 31 Central processing unit 32 Program memory 32a Device driver 33 Data memory 34 Data bus 40 Buffer management unit 41 Shared memory 42 Buffer 43 Control unit 43a Processing time measurement unit 43b Throughput calculation unit 43c Buffer size calculation unit 60 Peripheral device

Claims (10)

A data processing device for processing data;
A plurality of peripheral devices for inputting / outputting data to / from the data processing device;
A buffer for temporarily storing the data input / output between the data processing device and the plurality of peripheral devices;
A plurality of device drivers that are provided for each of the peripheral devices and control input / output of the data;
A buffer management unit for managing the buffer size based on the operation throughput in the device driver;
A buffer management method using
An initial process for determining whether or not a buffer size according to information on the buffer size reported from a specific device driver of the plurality of device drivers can be secured;
A change process for dynamically changing the buffer size according to a ratio of the throughput of the specific device driver to the throughput of the operation in the entire device driver;
A buffer management method comprising: The change process is
A processing time measurement process for measuring a processing time from the start to the completion of the operation;
Throughput calculation processing for calculating the throughput of the operation from the processing time and the transfer data amount of the operation;
A buffer size calculation process for calculating a buffer size used in the next operation based on the throughput;
The buffer management method according to claim 1, further comprising:   3. The buffer management method according to claim 2, wherein the throughput calculation process calculates the throughput of the operation by dividing the transfer data amount by the processing time.   The buffer size calculation process obtains the sum of the throughput of the operation in the plurality of device drivers, divides the throughput of the operation in the specific device driver by the sum, and according to the calculation result, 4. The buffer management method according to claim 2, wherein a buffer size used in the operation is calculated. A data processing device for processing data;
A plurality of peripheral devices for inputting / outputting data to / from the data processing device;
A buffer for temporarily storing the data input / output between the data processing device and the plurality of peripheral devices;
A plurality of device drivers that are provided for each of the peripheral devices and control input / output of the data;
A buffer management unit for managing the buffer size based on the operation throughput in the device driver;
A buffer management device comprising:
An initial process is performed to determine whether or not a buffer size corresponding to the information on the buffer size reported from a specific device driver among the plurality of device drivers can be secured, and the specification with respect to the operation throughput of the entire device driver A buffer management apparatus that dynamically changes the buffer size according to a throughput ratio of the device driver. The buffer management unit
A processing time measuring means for measuring a processing time from the start to the completion of the operation;
Throughput calculating means for calculating the throughput of the operation from the processing time and the transfer data amount of the operation;
Buffer size calculation means for calculating a buffer size to be used in the next operation based on the throughput;
The buffer management device according to claim 5, further comprising:   7. The buffer management apparatus according to claim 6, wherein the throughput calculation means calculates the throughput of the operation by dividing the transfer data amount by the processing time.   The buffer size calculation means obtains a sum of the throughput of the operation in the plurality of device drivers, divides the throughput of the operation in the specific device driver by the sum, and according to the calculation result, 8. The buffer management apparatus according to claim 6, wherein a buffer size used in the operation is calculated.   The buffer according to any one of claims 6 to 8, wherein the processing time measuring means is a circuit that counts a clock from the start to the completion of the operation to measure the processing time. Management device. A data processing device for processing data;
A plurality of peripheral devices for inputting / outputting data to / from the data processing device;
A buffer for temporarily storing the data input / output between the data processing device and the plurality of peripheral devices;
A plurality of device drivers that are provided for each of the peripheral devices and control input / output of the data;
A buffer management unit for managing the buffer size based on the operation throughput in the device driver;
A buffer management program using
An initial process for performing a process as to whether or not a buffer size according to information on the buffer size reported from a specific device driver of the plurality of device drivers can be secured;
Buffer size change processing that dynamically changes the buffer size according to the ratio of the throughput of the specific device driver to the throughput of operation in the entire device driver;
A buffer management program to make it work.

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