JP2967687B2 - Advance buffer flush system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-buffer flush system in an input / output system having an input / output buffer common to systems and writing data to a disk device asynchronously with an input / output request of a user program.

[0002]

2. Description of the Related Art An input / output buffer common to systems is provided.
In an input / output system that writes user data to a disk device asynchronously with an input / output request of a user program, a conventional asynchronous output process (delayed output process) is called “UNI.
As described in "7.5 Buffer Management, pp. 217-222" of X4.3BSD Design and Implementation, Nakamura et al., Translator, Maruzen Co., Ltd., issued the third printing on July 20, 1992. Was implemented as follows.

When an asynchronous output request (delayed output request) is made, in the conventional input / output system, the write data is copied to the secured input / output buffer, the output request is completed, and the disk of the data on the input / output buffer is completed. The reflection to the device is performed when any of the following conditions is satisfied.

When a request for an input / output buffer is made when the input / output buffer of the system is full. When a file is closed. Forcible sweeping at regular time intervals (sync processing).

However, in this conventional technique, the writing process is not performed normally, but tends to occur intensively when the conditions are satisfied, and the input / output load is high. In the system, there is a problem that the disk device cannot be effectively used, such as occurrence of an input / output wait.

An object of the present invention is to increase the efficiency of processing for writing user data to a disk device by a user program.

Another object of the present invention is to distribute the input / output load of a disk device in which user data is written by a plurality of user programs.

It is another object of the present invention to improve the efficiency of reading data from a disk device by a user program.

[0008]

According to a first pre-buffer flush system of the present invention, user data included in a user program and a disk device to which the user data is written in accordance with an instruction of the user program. A buffer table including a plurality of input / output buffers, wherein the buffer table is a pre-buffer flush system in an input / output system that writes user data to the disk device asynchronously with an input / output request of a user program. A device management table for storing information on the use status of the input / output buffers in the disk device; and, in response to a request from the user program for writing user data to the disk device, the user data in the buffer table. Write to the output buffer, and check the I / O buffer group in the device management table. An input / output request interface for updating usage status information, and user data stored in the input / output buffer in the buffer table written by the user program to the disk device, and an input / output buffer group in the device management table. And a device management program for updating usage information.

A second pre-buffer flush system according to the present invention is the first pre-buffer flush system according to the first pre-buffer flush system, wherein a change buffer queue which is a column of information indicating an input / output buffer during a write processing request to the disk device; A device management entry for each of the disk devices, including a written buffer queue which is a column of information indicating input / output buffers for which write processing has been completed, and a free buffer which is a column of information indicating reusable input / output buffers. A device management table for storing a queue and writing of the device management entry corresponding to the disk device on the change buffer queue in response to a request for writing user data to the disk device from a user program I / O buffer indicating the same block in the disk unit Copy the user data in the output buffer if there is § terminates the writing process,
When there is an input / output buffer indicating the same block in the disk device as the write destination in the written buffer queue of the device management entry corresponding to the disk device, the user data is copied to the input / output buffer and An input / output buffer is linked to the change buffer queue in the device management entry to end the write processing, and furthermore, any of the device management entry corresponding to the disk device on the written buffer queue or on the change buffer queue. If there is no input / output buffer indicating the same block in the disk device as the write destination, the input / output buffer is taken out from the empty buffer queue and user data is copied to this input / output buffer, and the change buffer in the device management entry is changed. Link to the queue and write The I / O request interface to be completed and the first I / O buffer if there is an I / O buffer linked to the change buffer queue in the device management entry corresponding to the disk device that operates corresponding to the disk device. A device management program for retrieving a buffer, writing the input / output buffer to a disk device, and sequentially linking the input / output buffer to the written buffer queue when the writing process is completed.

A third pre-buffer flush system according to the present invention is the second pre-buffer flush system according to the second pre-buffer flush system, wherein the device corresponding to the disk device is responsive to a data read request from the disk device from a user program. When a corresponding input / output buffer is linked to the written buffer queue of the management entry, the input / output buffer transfers the data of the input / output buffer to the user program and includes the input / output request interface for terminating the reading process.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings.

Referring to FIG. 1, a pre-buffer flush system according to a first embodiment of the present invention comprises: a user program 1 including user data 2 to be input / output;
A plurality of disk devices 7 for inputting / outputting the user data 2
And an input / output system 8 that performs input / output processing in accordance with a request from the user program 1.

The input / output system 8 has a buffer table 3 including a plurality of input / output buffers 31 used as intermediate buffers for data transfer between the disk device 7 and the user data 2, and the user program 1 has issued a write request. At this time, an input / output request program (hereinafter, referred to as an input / output request interface) 4 which is a program for transferring data from the user data 2 to the input / output buffer 31 and a device management used for controlling the buffer table 3 The table 5 corresponds to each disk unit 7, and the input / output buffer 3
A device management program 6 for controlling input / output to / from one disk device 7.

The device management table 5 stores information on each disk device 7
And a free buffer queue 52 linking the device management entry 51 corresponding to the I / O buffer 31 and the input / output buffer 31 for which the write or read processing has been completed.

The device management entry 51 contains the disk device 7
An operation state flag 53 that is present for each disk device and is turned on when the corresponding disk device 7 is in the process of writing or reading, and turned off when the disk device 7 is stopped, and an input / output buffer that holds data to be written to the relevant disk device 7. 31, an input buffer queue 55 linking the input / output buffer 31 that performs read processing to the disk device 7, and an input / output buffer 31 that has completed writing or reading processing to the disk device 7. When the written buffer queue 56 to be linked and the corresponding disk device 7 are in the process of writing or reading,
The block number of the input / output buffer 31 that is currently performing the writing or reading process is stored. If the disk device 7 is not performing the writing or reading process, -1 is stored.
Is stored in the input / output processing block number 57.

Referring to FIG. 2, the input / output buffer 31
Is a buffer queue storing an input / output block number 34 indicating a block number of an input / output processing destination, and a link destination address to an empty buffer queue 52, a change buffer queue 54, an input waiting buffer queue 55, and a written buffer queue 56. A buffer header 32 including a link destination address 35 and a data section 33 are included.

Next, a pre-buffer flush system according to a first embodiment of the present invention will be described with reference to FIGS.

An input / output request interface 4 receiving a write request for user data 2 from the user program 1
First, the disk device 7 to which the user data 2 is to be written and the output block number in the disk device 7 are obtained from the input / output request of the user program 1 (step 41).

Next, the I / O request interface 4 compares the I / O processing block number 57 of the device management entry 51 managing the disk device 7 with the output block number obtained in step 41 (step 42). If the block numbers are the same, the process waits for completion of the input / output processing for the input / output buffer 31 (step 43).

If the input / output request interface 4 determines in step 42 that the block numbers are not the same,
Device management entry 51 managing the disk device 7
It is determined whether or not the input / output buffer 31 linked to the input waiting buffer queue 55 has the same block number as the input / output block number 34 of the buffer header 32 and the output block number obtained in step 41 ( Step 44) If there is a block having the same block number, the process waits for completion of reading from the input / output buffer 31 (step 45).

If the input / output request interface 4 determines in step 44 that the block numbers are not the same,
Device management entry 51 managing the disk device 7
It is determined whether or not the input / output buffer 31 linked to the change buffer queue 54 has the same input / output block number as the output block number obtained in step 41 in the buffer header 32 (step 4
6) If there is a block with the same block number, the user data 2 is transferred to the data section 33 of the input / output buffer 31, and the writing process ends (step 47).

If the input / output request interface 4 determines in step 46 that there is no block with the same block number, the input / output request interface 4 linked to the written buffer queue 56 of the device management entry 51 managing the disk device 7. It is determined whether or not the output buffer 31 has an input / output block number 34 in the buffer header 32 that is the same as the output block number obtained in step 41 (step 48). In this case, the user data 2 is transferred to the data section 33 of the input / output buffer 31 (step 49).
1 is retrieved from the written buffer queue 56 and the empty buffer queue 52, and is linked to the change buffer queue 54 in the device management entry 51 (step 4A).
Further, the operation state flag 53 in the device management entry 51
Is determined to be off (step 4B). If it is off, a start request is issued to the device management program 6 corresponding to the disk device 7, and the writing process is terminated (step 4C).
If it is on, the writing process is terminated (step 4
D).

If the input / output request interface 4 determines in step 48 that there is no block having the same block number, the input / output request interface 4 determines whether or not the input / output buffer 31 is linked to the empty buffer queue 52 (step 4E). If so, one input / output buffer 31 is taken out from the head (step 4F). If the input / output buffer 31 is not linked to the empty buffer queue 52 in step 4E, the process waits until the input / output buffer 31 is linked (step 4G).

The input / output request interface 4 removes the input / output buffer 31 taken out in step 4F from the linked buffer queue 56 (step 4H), and the data section 3 of the input / output buffer 31
The user data 2 is transferred to 3 (step 4I),
The input / output block number 34 is set in the buffer header 32 (step 4J), and the input / output buffer 31 is linked to the change buffer queue 54 in the device management entry 51 (step 4K). Further, it is determined whether or not the operation state flag 53 in the device management entry 51 is off (step 4).
L) If it is off, a start request is issued to the device management program 6 corresponding to the disk device 7, and the writing process is terminated (step 4M). If it is on, the writing process is terminated (step 4N).

When the device management program 6 corresponding to the disk device 7 receives the activation request from the input / output request interface 4, it releases the waiting state and
Then, the operation status flag 53 in the device management entry 51 corresponding to "1" is turned on (step 61). Next, the device management program 6 determines whether there is an unprocessed input / output buffer 31 in the input waiting buffer queue 55 in the device management entry 51 corresponding to the disk device 7 (step 62).
If there is no unprocessed input / output buffer 31, it is further determined whether or not the input / output buffer 31 is linked to the change buffer queue 54 (step 63). The operation state flag 53 in the management entry 51 is turned off (step 6).
4) Wait for an activation request from the input / output request interface 4 (step 65).

When the device management program 6 determines in step 63 that the input / output buffer 31 linked to the change buffer queue 54 exists, the writing process from the input / output buffer 31 to the disk device 7 is performed. (Step 66), and waits for an end notification from the disk device 7 (Step 67). Device management program 6
Then, upon receiving a write completion notification from the disk device 7, the I / O buffer 31 is removed from the change buffer queue 54 (step 68), and the I / O buffer 31 is written into the written buffer queue 56 and the empty buffer queue 56. Linking to step 52 (step 69), step 61
Return to

Thus, the processing of the pre-buffer flush system according to the first embodiment of the present invention is completed.

The pre-buffer flush system according to the first embodiment of the present invention writes user data to a disk device asynchronously with an input / output request of the user program, thereby enabling user data to be written by the user program. This has the effect of increasing the efficiency of write processing to the disk device and distributing the input / output load of the disk device in which user data is written by a plurality of user programs.

The pre-buffer flush system according to the second embodiment of the present invention is different from the pre-buffer flush system according to the second pre-buffer flush system in that when the user program 1 issues a read request,
And an input / output request interface 4 which is a program for transferring data to the memory.

Next, a pre-buffer flush system according to a second embodiment of the present invention will be described with reference to FIGS. 1, 2, and 6 to 8. FIG.

An input / output request interface 4 receiving a read request for user data 2 from the user program 1
First, the disk device 7 from which the user data 2 is to be read and the input block number in the disk device 7 are obtained from the input / output request of the user program 1 (step 141).

Next, the I / O request interface 4 compares the I / O processing block number 57 of the device management entry 51 managing the disk device 7 with the input block number obtained in step 141 (step 142). If the block numbers are the same, the process waits for completion of the input / output processing for the input / output buffer 31 (step 143).

If the input / output request interface 4 determines in step 142 that the block numbers are not the same, the input / output request interface 4 linked to the input wait buffer queue 55 of the device management entry 51 managing the disk device 7. The input / output block number 34 of the buffer header 32 of the buffer 31 is compared with the input block number obtained in step 141 (step 144). If the block numbers are the same, the completion of reading from the input / output buffer 31 is waited for (step 144). 145).

If the input / output request interface 4 determines in step 144 that the block numbers are not the same, the input / output buffer linked to the change buffer queue 54 of the device management entry 51 that manages the disk device 7 In step 31, the input / output block number 34 of the buffer header 32 is compared with the input block number obtained in step 141 (step 146). Unit 33, and finishes the reading process (step 1).
47).

If the input / output request interface 4 determines at step 146 that the block numbers are not the same, the input / output request interface 4 linked to the written buffer queue 56 of the device management entry 51 managing the disk device 7. In the buffer 31, the input / output block number 34 of the buffer header 32 is compared with the input block number obtained in step 141 (step 148).
Is transferred, and the reading process is terminated (step 149).

If the input / output request interface 4 determines in step 148 that the block numbers are not the same, the input / output request interface 4 determines whether the input / output buffer 31 is linked to the empty buffer queue 52 (step 14A). If so, one input / output buffer 31 is extracted from the head of the written buffer queue 56 (step 14B). If the input / output buffer 31 is not linked to the empty buffer queue 52 in step 14A,
Wait until the input / output buffer 31 is linked (step 14C).

The input / output request interface 4 sets the input / output block number 34 in the buffer header 32 of the input / output buffer 31 extracted in step 14B (step 14D), and stores the input / output buffer 31 in the input of the device management entry 51. Link to the waiting buffer queue 55 (step 14E).

The input / output request interface 4 determines whether or not the operation status flag 53 of the device management entry 51 is off (step 14F). If it is off, the input / output request interface 4 sends the device management program 6 corresponding to the disk device 7 to the device management program 6. A start request is issued by designating the disk device 7 (step 14G), and the reading process by the device management program 6 is waited for (step 14H). If the operation state flag 53 is on in step 14F, the process waits for a read process (step 14I).

When the reading of the input / output buffer 31 from the disk device 7 is completed and the input / output request interface 4 is started by the device management program 6 and the waiting is released, the input / output request interface 4 transfers the data from the input / output buffer 31 to the user data 2. (Step 14J), and the input / output buffer 3
1 to the empty buffer queue 52 of the device management entry 51
(Step 14K), and terminates the reading process.

When the device management program 6 corresponding to the disk device 7 receives the activation request from the input / output request interface 4, it releases the waiting state and turns on the operation state flag 53 in the device management entry 51 (step 61). ). Next, the device management program 6 determines whether or not there is an unprocessed input / output buffer 31 in the input waiting buffer queue 55 in the device management entry 51 corresponding to the disk device 7 (step 62). If there is, the input / output block number 34 of the input / output buffer 31 is stored in the input / output processing block number 57 of the device management entry 51 managing the disk device 7 (step 6).
A) The disk device 7 for the input / output buffer 31
A request to read out data from the disk device 7 is made to the disk device 7 (step 6B), and an end notification from the disk device 7 is waited for (step 6C).

When the device management program 6 receives the notification of the end of reading data from the disk device 7, the device management program 6 sets the I / O processing block number 57 of the device management entry 51 managing the disk device 7 to -1. The input / output buffer 31 is processed (step 6D), the input / output request interface 4 waiting for completion is activated (step 6E), and the process returns to step 61.

Thus, the processing of the pre-buffer flush system according to the second embodiment of the present invention is completed.

The pre-buffer flush system according to the second embodiment of the present invention has the effect of increasing the efficiency of reading data from a disk device by a user program.

[0044]

As described above, according to the present invention, the output buffer can be written to the disk as much as possible in advance while increasing the operation rate of the disk device. This has the effect of preventing the number from increasing and improving the throughput of the entire system under a high load input / output environment.

[Brief description of the drawings]

FIG. 1 is a block diagram showing first and second embodiments of the present invention.

FIG. 2 is a diagram showing contents of an input / output buffer 31 in the first and second embodiments of the present invention.

FIG. 3 is a flowchart showing a partial process of the input / output request interface 4 according to the first embodiment of the present invention.

FIG. 4 is a flowchart showing processing of the remaining portion of the input / output request interface 4 in the first embodiment of the present invention.

FIG. 5 is a flowchart showing processing of an apparatus management program 6 according to the first embodiment of the present invention.

FIG. 6 is a flowchart showing a partial process of the input / output request interface 4 according to the second embodiment of the present invention.

FIG. 7 is a flowchart showing processing of the remaining part of the input / output request interface 4 in the second embodiment of the present invention.

FIG. 8 is a flowchart showing processing of an apparatus management program 6 according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 User program 2 User data 3 Buffer table 31 I / O buffer 32 Buffer header 33 Data part 34 I / O block number 35 Buffer queue link destination address 4 I / O request interface 5 Device management table 51 Device management entry 52 Empty buffer queue 53 Operation status flag 54 Change buffer queue 55 Input waiting buffer queue 56 Buffer queue already written 57 I / O processing block number 6 Device management program 7 Disk unit 71 Block 8 I / O system

Claims (2)

(57) [Claims] [Claim 1, further comprising a buffer table containing input-output buffers of multiple between the user disk device data is written by an instruction of the user program of the user data Toko included in the user program, user program a pre-buffer flush system in the output system for writing user data to the output request and asynchronous Nico disk device, input and output in the write request to said disk device
Change buffer queue and previous, which are columns of information indicating the buffer
When the write process to the disk device has been
A written buffer that is a sequence of information indicating the output buffer
Device management entry for each disk device including
And a column of information indicating reusable I / O buffers.
That a device management table for storing the free buffer queue, in accordance with the user data write request to the disk device from the user program, in the disk device
The change buffer queue of the corresponding device management entry.
Indicates the same block in the disk device as the write destination
If there is an input / output buffer, user data
Copy to the output buffer and finish the write process.
The device management entry corresponding to the disk device
The same directory as the write destination is written in the written buffer queue.
If there is an I / O buffer that indicates a block in the disk device
Copies the user data into this input / output buffer and
The I / O buffer is changed in the device management entry.
Link to the buffer queue, finish the writing process, and
To the device management entry corresponding to the disk device
The written buffer queue or the modified buffer
The same disk drive as the writing destination
If there is no input / output buffer indicating
Retrieve I / O buffer from empty buffer queue and use
User data into this input / output buffer and
Link to the change buffer queue in the entry and write
An input / output request interface for ending the loading process, and operating in response to the disk device,
The change buffer queue in the corresponding device management entry.
If there is an I / O buffer linked to the
Take out the head I / O buffer and put it in this I / O buffer
Write processing to the disk device for
The already writing the input and output buffer during the write process is completed
And a device management program for sequentially repeating linking to a buffer queue . 2. An input / output request interface according to claim 1, wherein
Data from the disk device from the user program
Data corresponding to the disk device in response to a data read request.
The written buffer key of the device management entry
If the corresponding I / O buffer is linked on the
In this case, the data in this input / output buffer is
2. The pre-buffer flush system according to claim 1 , wherein the data is transferred to the RAM and the read processing is terminated .