JPH07210321A - Disk controller - Google Patents

Abstract

(57) [Abstract] [Purpose] The purpose of the disk controller is to eliminate the waiting for rotation in order to improve the data transfer rate. [Arrangement] In the disk control device 3 that reads a record from the disk device 4 and stores it in the memory 25 by the CKD-EX command, and transfers the data read from the memory 25 to the host device 23, the LR specified by the DX command.
Based on the number of times the command is issued, the number of records that is twice the number of times the maximum number of records that can be designated by the LR command is read from the disk device 4 and stored in the memory 25.
A control means 24 for transferring the data read from the memory 25 to the higher-level device 23 by the RD command is provided, and the data transfer from the disk device 4 to the memory 25 is continuously executed regardless of the analysis of the LR command after the second time. ,
The data transfer from the memory 25 to the host device 23 is configured to analyze all LR commands and extract and execute the data in the designated range.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk control device, and more particularly to a disk control device capable of improving a data transfer rate with a host device.

One of the important factors for improving the performance required of a magnetic disk device is how to increase the data transfer rate with a host device. Among the magnetic disk devices, the factors that hinder the increase in the data transfer speed are the seek operation for positioning the head on the target track and the machine such as rotation waiting for positioning the head on the target sector. It is a system operation.

Therefore, as one means for increasing the data transfer rate of the magnetic disk device, there is a reduction in the waiting time for the disk to rotate. Therefore, it is desired to speed up the access to the magnetic disk device and improve the data transfer speed without generating the waiting for rotation.

[0004]

2. Description of the Related Art FIG. 8 is a diagram for explaining an example of CCW. From channel to magnetic disk controller, for example, CKD-EX (extended form of count key data)
When an asynchronous data read is instructed by the command set and the number of records to be read is 1, CCW (channel command word) as shown in FIG. 8A is transmitted.

That is, a DX command (notifying the use condition of a command following this command) and an LR command following this DX command (operation regulation of the command following this command, seek address for positioning the head, this CCW) Notification of the number of processed records etc.) and this LR
Following the command, an RD command (instructing to read the data portion of the record in which the head is positioned) is sent once.

Further, for example, the number of records to be read is 25.
When it is 6, CCW as shown in FIG. 8 (B) is transmitted. That is, the DX command, the LR command following this DX command, and the RD command following this LR command are 2
55 times, then again LR command and this LR
The RD command is sent once after the command.

[0007]

As described above, the conventional C
When reading records by the KD-EX command set, the number of records that can be instructed to be read by one LR command is limited. For example, the number of records to be read is 25.
When the number of records exceeds 5 (for example, the number of records that can be recorded in one track), as shown in FIG. 8B, one LR command cannot instruct to read all the records, and it is necessary to reissue the LR command. is there.

However, if the channel reissues the LR command again, the magnetic disk controller will
By the time the analysis of this LR command is completed, the head of the magnetic disk device records the target record [2 in the case of FIG.
Position of the 56th record]
There is a problem that a disk rotation wait occurs and the data transfer rate of the magnetic disk device decreases.

In view of such a problem, the present invention aims to improve the data transfer rate of the magnetic disk device by preventing the disk from waiting for rotation when reading data from the magnetic disk device. Has an aim.

[0010]

FIG. 1 is a block diagram for explaining the principle of the present invention. The disk control device 3 receives the CKD-EX command set sent from the host device 23, reads a plurality of continuous records from the disk device 4 over a plurality of tracks, stores them in the memory 25, and The data read from the memory 25 is asynchronously transferred to the host device 23.

The operation mode to be executed added to the parameter of one DX command and the CKD-E
Based on the number of LR commands chained in the X command set, the number of times the LR command is issued is recognized in advance,
The number of records that is equal to the maximum number of records that can be designated by the LR command is read from the disk device 4 and sequentially stored in the memory 25, and the data read from the memory 25 by the RD command is stored in the upper device 23. There is provided a control means 24 for sequentially transferring to.

Data transfer from the disk device 4 to the memory 25 is continuously executed regardless of the analysis of the LR command from the second time onward, and the data is transferred to the memory 25.
Data transfer from the host device 23 to
By analyzing the R command, the data in the specified range is extracted and executed.

Further, the disk control device 3 uses the CK
First C sent before issuing D-EX command set
A memory area 26 required in advance is secured in the memory 25 based on the range of tracks specified by CW, and the records of tracks within the specified range are sequentially read from the disk device 4 and stored. CK
The data in the record designated by the D-EX command set is read from the secured memory area 26 and sequentially transferred to the higher-level device 23, and by the second CCW sent following the CKD-EX command set. A control means 24 for opening the secured memory area 26 is provided.

Then, the data transfer from the disk device 4 to the memory area 26 is sequentially and successively executed for each record of the tracks within the range specified by the first CCW, and the data transfer from the memory area 26 to the memory area 26 is performed. Data transfer to the host device 23 is executed based on the CKD-EX command set, and then the reserved memory area 26 is released by the second CCW that is subsequently transmitted.

Further, the disk control device 3 uses the CK
Based on the range of the track specified by the CCW sent before the D-EX command set is issued, a memory area 26 required beforehand is secured in the memory 25 and the disk device 4 within the specified range. The records of the tracks are sequentially read and stored, and at the same time, the CKD-E
The control means 24 is provided for reading the data in the record designated by the X command set from the secured memory area 26 and sequentially transferring it to the host device 23, and then releasing the secured memory area 26.

Then, the data transfer from the disk device 4 to the memory area 26 is successively and successively executed for each record of the tracks within the range designated by the CCW, and the data transfer from the memory area 26 to the host device 2 is performed.
The data transfer to the memory 3 is performed based on the CKD-EX command set, and then the secured memory area 26
Open up.

[0017]

With the above-described structure, the data transfer from the disk device 4 to the memory 25 or the memory area 26 is performed by continuously reading the required number of records, and therefore the LR command may be reissued. However, waiting for the disk to rotate does not occur.

Then, the data transfer from the memory 25 or the memory area 26 to the host device 23 is interrupted for the time during which the control means 24 analyzes the LR command, but this time is shorter than the rotation waiting time of the disk. Since the data to be transferred to the disk is stored in the memory 25 or the memory area 26, it can be immediately read and transferred, and the data transfer speed of the disk device can be improved as compared with the conventional case.

When the memory area 26 is used as a cache memory, it can be prevented from being erased without an instruction from the host device 23. Furthermore,
It is also possible to eliminate the need to issue a new CCW for erasing the memory area 26 secured on the memory 25.

[0020]

2 is a block diagram of a circuit showing an embodiment of the present invention, and FIG. 3 is a detailed block diagram of each functional unit.

The disk controller 3 is composed of a plurality of functional units, and the channel adapters 6 and 7 are shown in FIG.
With the configuration as shown in FIG. 1, the processor 16 reads the program stored in the control memory 17 to operate, and the start I / O from the channel 1 or 2 via the interface circuit 14.
The CCW sent together with the O command is received and the data is transferred between the channel 1 and the channel 2, and the common bus control circuit 15 is controlled to transfer the data between the functional units via the common bus 12. I do.

The device adapters 8 and 9 have a structure as shown in FIG. 3A, and the processor 16 reads the program stored in the control memory 17 to operate, and the processor 16 reads the program from the disk device 4 or 5 via the interface circuit 14. Command is sent and data is transferred to and from the disk device 4 or 5, and
The common bus control circuit 15 is controlled to transfer data with other functional units via the common bus 12.

The resource manager 10 has a configuration as shown in FIG. 3B, and the processor 19 operates by reading the program stored in the control memory 18, and controls the common bus control circuit 20 to operate the common bus 12. All the CCWs from the channel 1 or 2 are received and stored in the RAM 21 via the centralized management of this CCW and each start I /
The data transfer processing instruction is given to the channel adapter 6 or 7 and the device adapter 8 or 9 for each O instruction.

The control information for each received start I / O command, the control information for each channel path, and the disk device 4
And the control information of 5 are stored in the RAM 21, and other functional units pass through the RAM access control circuit 22 and
Can be accessed and the above information can be read, and this information is centrally managed.

Next, the operation when the number of times the LR command is issued is specified as the parameter of the DX command will be described. For example, when the channel 1 sends a start I / O command to the channel adapter 6 and sends a DX command, the processor 16 of the channel adapter 6 sends this D
Parse the X command.

The parameter of this DX command indicates the reading of data and the number of times the LR command is issued. That is, as shown in FIG. 8B, for example, the maximum number of records that can be designated by one LR command is 255, and the number of records to be read designated by channel 1 is 2.
If it is 56, it means that the LR command is reissued once.

Therefore, since the channel adapter 6 has to reissue the LR command once, the number of records read from the disk device to the shared memory 11 is 255 × 2 = 510.
Recognize that.

The channel adapter 6 continues to the channel 1
Parses the LR command sent from the disk device 4 to read data from the disk device 4, record-based processing, the first record position to be read, and the number of records to be transferred to the channel 1 by this LR command (255) Recognize.

Here, when the channel adapter 6 obtains the right to use the common bus 12 from the resource manager 10, the RAM 21 of the resource manager 10 passes through the common bus 12.
As a result of analyzing the DX command and the LR command,
That is, the machine number of the disk device 4, the access start position, that is, the cylinder address, the head address, the record address, and the number of records (510) to be transferred from the disk device 4 to the shared memory 11 are stored.

Therefore, the resource manager 10 instructs the processor 16 of the device adapter 8 to read the data, and the device adapter 8 reads the cylinder address, the head address, the record address and the number of records to be processed from the RAM 21 of the resource manager 10. Then, the disk device 4 is controlled to position the designated head at the designated record, and the designated number of records (510) are sequentially read and written in the shared memory 11.

The resource manager 10 uses the shared memory 1
When the device adapter 8 starts writing a record to 1, the channel adapter 6 is instructed to start data transfer.
Therefore, the channel adapter 6 receives the RD command sent from the channel 1 in parallel with the process in which the device adapter 8 writes the record in the shared memory 11, and the designated head stored in the shared memory 11 is received. When the data recorded in the data portion of the record is sequentially read from the record, it is transferred to the channel 1.

The channel adapter 6 receives the first received L
When the data transfer to the channel 1 having the number of records (255) designated by the R command is completed, the next LR command is sent from the channel 1, so that the LR command sent next is analyzed.

Therefore, although the data transfer is suspended,
During this time, the device adapter 8 continues the operation of reading the record from the disk device 4 and writing it in the shared memory 11.

That is, the RAM 2 of the resource manager 10
The record write processing of the device adapter 8 is continuously executed until the writing of the number of records (510) read from 1 to the shared memory 11 is completed or the data transfer completion is notified from the channel adapter 6. It

The LR command analysis processing time of the channel adapter 6 is short, and as described above, in the write operation to the shared memory 11 of the device adapter 8, since the disk rotation wait does not occur, when the LR command analysis time elapses, Immediately, the data transfer of the channel adapter 6 to the channel 1 of the number of records designated by this LR command is started.

After the data transfer of the number of records designated by the LR command is completed, the channel adapter 6
When the channel 1 is notified of the completion of the data transfer, the device adapter 8 is notified of the completion of the data transfer. Therefore, if the record is continuously read from the disk device 4 at this point, the device adapter 8 cancels the read process. To do.

The operations of the channel 2, the channel adapter 7, the device adapter 9, and the disk device 5 are the same as those described above, and detailed description thereof will be omitted. Next, the operation when using two new CCWs will be described.

FIG. 4 is a diagram for explaining an example of the command set of the present invention. As shown in FIG. 4, the channel 1 specifies the range of tracks to be read together with the start I / O command before issuing the conventional CKD-EX command set.
The CW is sent to the channel adapter 6.

The processor 16 of the channel adapter 6 is
When this CCW is analyzed and the range of the track designated by the parameter is recognized, the right to use the common bus 12 is obtained from the resource manager 10, and the shared memory 1
A memory area having the required capacity is secured on the upper part of the table.

Then, the channel adapter 6 stores the machine number and cylinder address of the disk device 4 and the range of tracks to be processed in the RAM 21 of the resource manager 10 via the common bus 12.

The channel adapter 6 continues to the channel 1
Together with the start I / O instruction, the conventional CKD shown in FIG.
-When the EX command set is sent out, first the DX command is analyzed, the use condition of the subsequent command is recognized, the LR command received subsequently is analyzed, and data is read from the disk device 4. , Record-by-record processing, the position of the first record to be read, and the number of records to be read (255).

The resource manager 10 instructs the processor 16 of the device adapter 8 to read the data, and the device adapter 8 reads the cylinder address and the range of the track to be processed from the RAM 21 of the resource manager 10 according to this instruction. By controlling the disk device 4, the head corresponding to the head track of the specified range of the specified cylinder is positioned at the head record, and the records of the tracks in the specified range are sequentially read out. , The operation of writing in the memory area secured by the channel adapter 6 on the shared memory 11 is started.

Therefore, the channel adapter 6 receives the RD command sent by the channel 1, as shown by RD in FIG. 4, in parallel with the process in which the device adapter 8 writes a record in the memory area on the shared memory 11. Each time, from the record stored in the memory area secured on the shared memory 11 to the next record from the first record specified by the LR command, the data is sequentially recorded in the data part of each record. When the existing data is read, it is transferred to channel 1.

When the data transfer of the number of records (255) designated by the first LR command from the channel adapter 6 is completed, as shown by LR in FIG.
Since the next LR command is sent from, the channel adapter 6 analyzes the next sent LR command.

Therefore, although the data transfer is suspended,
In the meantime, the device adapter 8 continues the operation of reading the record from the disk device 4 and writing it in the memory area of the shared memory 11.

That is, the RAM 2 of the resource manager 10
The record writing process of the device adapter 8 is continuously executed until the writing of a plurality of records determined by the range of the tracks read from 1 to the memory area on the shared memory 11 is completed.

The LR command analysis processing time of the channel adapter 6 is short, and as described above, in the write operation of the device adapter 8, there is no disk rotation waiting time.
As soon as the R command analysis time has elapsed, this LR
The data transfer of the channel adapter 6 to the channel 1 of the number of records designated by the command is started.

After the data transfer of the number of records designated by the LR command is completed, the channel adapter 6
When the completion of data transfer is notified from the channel 1, it is checked whether or not the start I / O command is received, and if not received, the data reading process is terminated while the reserved memory area remains on the shared memory 11.

As shown in CCW of FIG. 4, when releasing the memory area secured on the shared memory 11, the channel 1 sends to the channel adapter 6 a CCW for instructing the release of the memory area together with the start I / O instruction. Send out.

Therefore, when the CCW shown in FIG. 4 is received together with the start I / O instruction, the channel adapter 6 releases the reserved memory area on the shared memory 11. The operations of the channel 2, the channel adapter 7, the device adapter 9, and the disk device 5 are the same as above, and detailed description thereof will be omitted.

Next, the operation when one new CCW is used will be described. In this case, the CCW shown in FIG. 4 is not sent from the channel 1 to the channel adapter 6, and when the channel adapter 6 is notified of the completion of the data transfer from the channel 1, it makes its own judgment regardless of the instruction from the channel 1. Then, the memory area secured on the shared memory 11 is released.

The other operations are the same as the operations when two new CCWs are used. 5, 6 and 7 are flowcharts for explaining the operation of FIG. Figure 5 is DX
The operation when the number of times the LR command is issued is specified in the command is shown.

The channel adapter monitors the reception of the start I / O command in step (1),
When the command is received, the reception of the DX command is waited in step (2).

When the DX command is received, the CA (channel adapter) analyzes the DX command in step (3) to recognize the number of times the LR command is issued, and recognizes the number of records continuously read from the disk device. The LR command that is subsequently received is analyzed to read data, perform processing in record units, and recognize the start record position and the number of records to be transferred to the CH (channel).

Then, in step (4), the result of analyzing the DX command and the LR command is stored in the RAM of the RM (resource manager). In step (5), the DA (device adapter) is instructed by the RM to read the R of the RM.
Based on the analysis result read from the AM, the operation of continuously reading and storing the number of records designated in the shared memory from the disk device is started.

In step (6), the CA reads data from the shared memory in response to the RD command sent by the CH and transfers the data to the CH according to the instruction from the RM. When the CA receives the next LR command in step (7), it suspends data transfer while parsing this LR command.

Then, in step (8), the CA resumes the read process immediately after the next LR command analysis is completed,
The data of the number of records designated by the LR command is sequentially read from the shared memory corresponding to the RD command and transferred to the CH.

Then, in step (9), it is checked whether the data transfer is completed. If there is no completion notification from the channel, step (7)
When the completion notification is received, the CA notifies the DA of the completion of the data transfer in step (10), and the DA executes the step.
If the record reading from the disk device is continuing in (11), this reading process is stopped.

FIG. 6 shows the operation when two CCWs are used. Channel adapter starts in step (1) I
The reception of the / O command is monitored, and the reception of the start I / O command waits for the CCW reception in step (2).

When the CCW is received, the CA analyzes the CCW in step (3), recognizes the range of the track to be read, secures a memory area having a required capacity on the shared memory, and the CA of the disk device. The machine number, the cylinder address, and the range of the track to be processed are stored in the RAM of the RM.

When the CA receives the CKD-EX command set in step (4), it analyzes the DX command and the LR command, reads the data from the disk device and processes it in record units, and reads the record position and the record. Recognize numbers.

Here, the DA is based on the contents read from the RAM of the RM according to the instruction of the RM in the step (5), and each track within the designated range in the memory area secured by the CA of the shared memory from the disk device. Then, the operation of sequentially reading and storing the respective records is started.

In step (6), the CA, in parallel with the process of writing a record in the memory area of the DA, reads the data in the data portion of each record from the memory area and transfers it to the CH each time an RD command is received. To do.

When the CA receives the next LR command in step (7), it suspends data transfer while parsing this LR command. Then, in step (8), the CA restarts the reading process immediately after the next LR command analysis is completed,
The data of the number of records designated by the LR command is sequentially read from the memory area corresponding to the RD command and transferred to the CH.

Then, it is checked in step (9) whether or not the data transfer is completed. If there is no completion notification from the channel, step (7)
When the completion notification is received, it is checked in step (10) whether the start I / O command is received.

When the start I / O command is received, the step
When the CCW is received in (11) and the CCW is received, the CA releases the memory area secured in the shared memory in step (12).

If the start I / O command is not received in step (10), the CA ends the read process in step (13), leaving the reserved memory area on the shared memory. Figure 7
Shows the operation when one CCW is used. FIG. 7 is different from FIG. 6 only in the operation after step (10). When the completion of data transfer is notified in step (9), step (1
At 0), the CA releases the secured memory area on the shared memory and ends the read processing.

[0068]

As described above, the present invention is a CKD-E.
When the data of the disk device is transferred to the channel by the X command set, the disk rotation wait does not occur even if the LR command is reissued, so that the data transfer speed of the disk device can be improved.

Further, when the memory area secured on the shared memory is used as a cache memory, it is possible to prevent the memory area from being erased unless there is an instruction from the channel. Na C
It is also possible not to issue the CW.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating the principle of the present invention.

FIG. 2 is a block diagram of a circuit showing an embodiment of the present invention.

FIG. 3 is a detailed block diagram of each functional unit.

FIG. 4 is a diagram illustrating an example of a command set of the present invention.

FIG. 5 is a flowchart explaining the operation of FIG. 2 (No. 1).

FIG. 6 is a flowchart (part 2) explaining the operation of FIG. 2;

FIG. 7 is a flowchart (part 3) explaining the operation of FIG. 2;

FIG. 8 is a diagram illustrating an example of CCW.

[Explanation of symbols]

 1, 2 channels 3 disk controller 4, 5 disk device 6, 7 channel adapter 8, 9 device adapter 10 resource manager 11 shared memory 12 common bus 14 interface circuit 15, 20 common bus control circuit 16, 19 processor 17, 18 control Memory 21 RAM 22 RAM Access control circuit 23 Upper device 24 Control means 25 Memory 26 Memory area

Claims (3)

[Claims] 1. A CKD-EX command set sent by a higher-level device (23) is received, a plurality of consecutive records are read from a disk device (4) over a plurality of tracks, and are stored in a memory (25). In the disk controller (3) for storing and asynchronously transferring the data read from the memory (25) to the upper device (23), the operation mode to be executed added to the parameter of one DX command and the Based on the number of LR commands chained in the CKD-EX command set, the number of issuances of the LR command is recognized in advance, and the number of records that is twice the number of issuances of the maximum number of records that can be designated by the LR command is stored in the disk device ( 4) and stores it in the memory (25) sequentially, and a control means (24) for sequentially transferring the data read from the memory (25) by the RD command to the upper device (23). The data transfer from the disk device (4) to the memory (25) is continuously executed regardless of the analysis of the LR command after the second time, and the data transfer from the memory (25) to the upper device (23) is performed.
The disk control device is characterized in that data transfer to and from is executed by analyzing all LR commands to extract data in a specified range. 2. A CKD-EX command set sent by a higher-level device (23) is received, a plurality of continuous records over a plurality of tracks is read from the disk device (4), and is stored in a memory (25). In the disk controller (3) which stores the data and asynchronously transfers the data read from the memory (25) to the host device (23), the first CCW transmitted before the issuance of the CKD-EX command set. Based on the range of tracks specified by, the memory area (26) required beforehand is secured on the memory (25), and the records of the tracks within the specified range are sequentially transferred from the disk device (4). The data in the record designated by the CKD-EX command set is read out from the secured memory area (26) and sequentially transferred to the higher-level device (23), and the CKD-EX is read out and stored.
The control means (2) for releasing the secured memory area (26) by the second CCW sent after the command set.
4) is provided, and data transfer from the disk device (4) to the memory area (26) is sequentially and successively executed for each record of tracks within the range specified by the first CCW, Data transfer from the area (26) to the upper device (23) is executed based on the CKD-EX command set, and then the secured memory area (26) is released by the second CCW that is subsequently transmitted. A disk control device characterized by performing. 3. A CKD-EX command set sent by a higher-level device (23) is received, a plurality of consecutive records are read from a disk device (4) over a plurality of tracks, and are stored in a memory (25). In the disk controller (3) that stores the data and asynchronously transfers the data read from the memory (25) to the higher-level device (23), it is designated by the CCW sent before the issuance of the CKD-EX command set. Based on the range of the track, a memory area (26) required in advance is secured in the memory (25) and the records of the tracks within the specified range are sequentially read from the disk device (4) and stored. With the CK
After the data in the record designated by the D-EX command set is read from the secured memory area (26) and sequentially transferred to the upper device (23), the secured memory area
A control means (24) for releasing (26) is provided, and the data transfer from the disk device (4) to the memory area (26) is successively performed for each record of the track within the range designated by the CCW. The data transfer from the memory area (26) to the upper device (23) is performed based on the CKD-EX command set, and then the secured memory area (26) is released. Disk controller.