JPH11167528A - Time-out control method for data processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a real link error from occurring owing to the delay of recovery due to the overhead of a recovering process by the time-out generation of command execution as to the data processing system consisting of processors and a coupling device mechanism. SOLUTION: Time-out transmission (34) is received over a fast channel of the coupling device mechanism and then after mechanism stop control (43) makes a time-out response (35), a mechanism stop response state is entered. Command transmission (31) after the time-out response (35) makes a mechanism stop response (55) under the mechanism stop control (43) to reject command reception. The mechanism stop response is reset when the command execution control (44) maintains the security and consistency of data to reduce a recovering process after the time-out generation and eliminate the delay of the recovering process, thereby preventing a link error from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timeout control method for a data processing system, and more particularly to a high-speed channel failure handling during execution of a command in a coupling device mechanism.

[0002]

2. Description of the Related Art Conventionally, as disclosed in JP-A-6-89241, when a response to a command issued between a processing unit and a coupling device mechanism is not received within a predetermined time, control and control within the coupling device mechanism are performed. With respect to maintaining consistency, there is known a technique in which an operating system running on a processing device issues a command to a coupling device mechanism to utilize the function.

[0003] JP-A-6-89241 describes that if a response from a command is not received within 300 ms,
An interface control check (ICC) is reported from the I / S channel to the requesting program. At this time, the command being executed either completes execution or is canceled and the state of the coupling facility is returned to the state before receiving the command, and control and coordination within the coupling facility are performed. Sexual preservation was maintained.

[0004]

In the above prior art,
If there is no response to the command issued from the operating system running on the processing device to the coupling device within 300 ms, a timeout IFCC report is sent from the I / S channel on the processing device to the coupling device. No consideration was given to the overhead of recovery processing when a timeout was reported.

[0005] Since the coupling device mechanism is a device shared by a plurality of processing devices, an overhead of processing for completing a command being executed or returning to a state before execution due to recovery processing of a timeout generated in a certain processing device. In some cases, a command from another processing device may time out.

In the recovery processing after the detection of the timeout,
Due to the overhead of the response process to the timeout,
There is also a problem that a true link error of the high-speed channel occurs due to delay of the recovery process of the timeout within 10 ms within a predetermined time after the occurrence of the timeout. An object of the present invention is to reduce the overhead of a timeout recovery method in a coupling device, to eliminate the influence of time over from a processing device linked to the coupling device mechanism on other processing devices, and to realize a true The purpose is to avoid link errors.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to provide a method for recovering from a timeout after a high-speed channel of a coupling device receives a timeout failure report from a processing device, and the high-speed channel processes a timeout response. Achieved by responding to the device.

The high-speed channel that has timed out to the processing device has means for rejecting reception of a new command after the time-out response to the high-speed channel in order to synchronize with the command execution program in the coupling device mechanism. Another object of the present invention is to reduce the overhead of the recovery process while maintaining the consistency by using a command processing program in the coupling device mechanism.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system environment diagram according to the present invention. The coupling device mechanism (10) includes a plurality of processing devices (20),
Each high-speed channel is coupled. The processing device (20) transmits a command (31) to the coupling device mechanism (10) using the high-speed channel between the coupling device mechanisms (10) as a message path (30), and transmits data (32) according to the type of command to be transmitted. Do. After receiving the command from the processing device (20), the coupling device mechanism (10) processes the command under the command execution control of the coupling device mechanism (10), and responds to the command (33). This is a data processing system that performs transmission (32).

FIG. 2 is a block diagram showing an outline of processing when a high-speed channel in the coupling device mechanism (10) detects a timeout.

The coupling device mechanism (10) comprises a high-speed channel device (11) and a command execution control device (12) for executing commands. The high-speed channel device (11) includes a command transmission / reception control (40), a command discrimination control (41), a timeout control (42), and a mechanism suspension control (43). The command execution control device (12) includes a command execution control (44). The command (31) sent from the processing device is
It is received by the command transmission / reception control (40) of the high-speed channel device (11), and is sent to the command discrimination control (41). The command discrimination control (41) discriminates the type of the command transmitted from the processing device, and reports the command reception to the command execution control (44). After finishing the command processing, the command execution control (44) issues a command response request to the command determination device (41) of the high-distant channel device as a command response. Upon receiving this request, the command discrimination control (41) requests the command transmission / reception control (40) for command response processing and ends the command processing. But,
If the command execution control (44) does not respond to the command (31) from the processing device within a predetermined time, a timeout transmission (34) is transmitted from the processing device. The command transmission / reception control (40) sends the transmitted command to the command determination control (41), and the command determination control (41)
When it is confirmed that the timeout has occurred, the control is transferred to the timeout control (42). Timeout control (42)
Changes the high-speed channel device (11) to the failure occurrence status and sends a timeout occurrence notification to the command execution control (44).
Then, the control is shifted to the mechanism suspension control (43). When the mechanism suspension control (43) receives the notification from the timeout control (42), the high-speed channel device (11) refuses to receive the command and transitions to the mechanism suspension response state. Thereafter, the mechanism external pressure control (43) returns a timeout response (35) via the command transmission / reception control (40).

After the high-speed channel device (11) transits to the mechanism suspension response state, even if a new command transmission (31) after the timeout response (35) is received, the command discrimination control (41) performs the mechanism suspension control. (43) The control is shifted to the above, and the command makes a mechanism suspension response (36). The command transmission (31) received in the mechanism stop state is not notified to the command execution control (44). This mechanism suspension response state is maintained until a command for canceling the mechanism suspension response from the command execution control (44) reaches the mechanism suspension control (43).

When the mechanism suspension release notification is received from the command execution control (44), the mechanism suspension response state is released, and a new command transmission (31) from the processing device is performed before the timeout transmission (34). (10) It becomes possible to receive.

FIG. 3 is a block diagram for canceling the high-speed channel mechanism suspension response state after the command execution control receives a timeout notification.

High-speed channel (68) for command execution control
An interrupt handler (60) for receiving a command reception notification including a timeout notification from the server, multiple command execution tasks (65) for executing the notified command, and shared among command execution tasks (65) during command execution There is shared data (67). The shared data (67) has an exclusive control (66) for referring and updating by a plurality of command execution tasks (65). In addition, the command execution task switches tasks by dispatch control (63) by task switching, and can execute a plurality of notified commands. The command response control (64) controls a command response to the executed command. The device management block (61) is a control block for managing all notification information from the high-speed channel (68). The mechanism pause release control (62) is a control for releasing the mechanism pause response of the high-speed channel (68) at the time of timeout.

Since the mechanism suspension release control (62) is started from various controls in the command execution control, there are a plurality of date points for each control to be started. Interrupt handler (60)
When a timeout occurs after a command is received from the high-speed channel (68), if the command received earlier has not been executed by the command execution task (65), After truncating the previously received command, the interrupt handler (60) notifies the mechanism pause release control (62) and notifies the high-speed channel (68) of the release of the mechanism pause response.
Upon receiving the notification from the interrupt handler (60), the mechanism suspension release control (62) notifies the high-speed channel (68) of the suspension of the mechanism and restores the high-speed channel (68) to the state before the timeout occurred. Also, the interrupt handler (60)
Sets the timeout notification generation information in the device management block (61) if the command has already been executed by the command execution task (65). In this case, the command execution task (6
It is used in the method described later during the execution of 5). Also, when the timeout occurrence information is set in the device management block (61), if the mechanism suspension release automatic response information is set by the processing method of the command execution task (65), it is determined that the mechanism suspension release automatic response is possible. In addition to setting the timeout occurrence information, it requests the mechanism suspension release control (62) to issue a mechanism suspension release notification. Thereafter, the interrupt handler (60) sets the information indicating that the suspension of the mechanism has been canceled in the device management block (61).

When the command execution task temporarily leaves the control by another method including task switching, and when the dispatch control (63) operates, the mechanism suspension release control (62) is automatically responded to the mechanism suspension release control (62). There is a way to set. Command execution gusuku (65) is shared data (67)
When a task is switched to another command execution task (65) by a task switching method that includes a state in which exclusive control (66) enters an exclusive control wait state due to reference or update of
This is a method of activating the mechanism-pause release control (62) to operate the mechanism-pause release automatic response method, and releasing the mechanism-pause release automatic response method when dispatching is performed again. When the mechanism suspension release automatic response function is set, the mechanism suspension release control (62) is operated before switching the task to another command execution task (66) in the dispatch control (63). The mechanism pause release control (62) refers to the device management block (61) if the activation is from the dispatch control, and if the timeout occurrence information has already been set in the interrupt handler (60), the mechanism pause response is released. The notification is sent to the high-speed channel (68), and the code that has been notified of the cancellation of the mechanism suspension response is set in the device management block (61). If no time-out has occurred, set the code of the automatic stop function for canceling the suspension of the mechanism in the device management block (61). These code settings may be identifiable codes of 1 byte or more or pits of 1 bit or more. The mechanism suspension release control (62) that has completed these controls returns control to the dispatch control (63) and continues the task switching operation, whereby the mechanism suspension release automatic response function becomes operable. To release the automatic suspension function for canceling the suspension of the mechanism, when re-dispatching to the original command execution task (65) again, the dispatch control (63) releases the release request for the automatic response function for the cancellation of the suspension of the mechanism set at the time of task switching Notify the control (62). Upon receiving this notification, the mechanism suspension release control (62) releases the mechanism suspension release automatic response function of the device management block (61), and stores information on the timeout during operation of the mechanism suspension release automatic response function in the device management block (61). Set to 61). Thereafter, the command execution task (65) only needs to restart the command execution, and does not need to perform the same processing when a timeout occurs. The command execution task (65) can determine whether or not the automatic suspension cancellation automatic response due to the occurrence of the timeout has been activated by the automatic suspension cancellation automatic response function by referring to the device management block (61).

If a timeout occurs during the operation of the automatic suspension function for canceling the suspension of the mechanism, the interrupt handler (60) refers to the device management block (61) and checks whether the automatic response function for the cancellation of the mechanism suspension is in operation. At this time, if the automatic suspension function of the mechanism pause release is operating, the interrupt handler (6
0) activates the mechanism suspension release control (62) and causes the high-speed channel (68) to notify the mechanism suspension release notification. Thereafter, the interrupt handler (60) sets, in the device management block (61), a code indicating that all the recovery due to the timeout has been completed by the mechanism pause release automatic response function.

The command execution task (65) executes a command response control (64) in response to a command response at the end of command execution.
Is activated, the command response control (64) or the device management block (61) is referred to check whether a timeout has occurred and a mechanism suspension release notification has been notified. If neither of them has occurred, a command response of command execution end is performed. However, if a timeout has occurred, and if the mechanism suspension release notification has not yet been executed, the mechanism suspension release control ( 62) is started and there is no command response. If the notification of the suspension of the mechanism has already been notified, the command response control (64) ends the process without performing the command response and the notification of the release of the mechanism suspension.

In addition, there is a method of directly checking whether a timeout has occurred or not by the command execution task (65). If the command execution task (65) is executing a command and the command execution is interrupted or aborted, the consistency of the shared data can be maintained, so refer to the device management block (61) Check whether a timeout has occurred. If the timeout has not occurred, the command execution task (65) continues the command execution processing. If the timeout has occurred, the mechanism suspension release control (62) is activated to notify the mechanism suspension release and perform the command execution. Execute suspend processing. Alternatively, after executing the command execution suspending process, a notification of the suspension of the mechanism is issued. The order of the processing at this time can be arbitrarily changed depending on the type of the command being executed. Even if the command execution task (65) confirms that a timeout has occurred, depending on the progress of the command execution, the process is continued until a command response without activating the mechanism suspension release control (62), and the command response control (64 The method for issuing a mechanism suspension release notification in ()) can also be selected.

FIGS. 4 to 6 are processing block diagrams showing the flow of processing of the mechanism suspension release control. FIG. 4 shows activation from an interrupt handler, FIG. 5 shows activation from dispatch control,
FIG. 6 shows a command response control and a processing method at the time of startup from a command execution task.

FIG. 4 is a flow chart of a process when the mechanism suspension release control is activated from an interrupt handler when a timeout occurs. There are two types of activation from the interrupt handler. There are times when the command received is not yet processed by the command execution task, and times when the command is being executed. When activated from the interrupt handler, first, it is determined whether or not the command received before the occurrence of the timeout is being executed by the command execution task (70). If the command is being executed, it is determined whether or not the automatic stop function for canceling the suspension of the mechanism is operating (71). If the system is being activated, the mechanism suspension release (72) is operated. Otherwise, a timeout has occurred, and the device management block is updated in the device management information update (73). If it is determined in the command execution (70) that the command is not yet executed in the command execution task, the mechanism suspension release notification (72) is activated to update the device management information (73) and end the processing.

FIG. 5 is a flow chart of the processing when the dispatch control activates the mechanism pause release control. The activation from the dispatch control is at the time of setting and releasing of the automatic suspension release automatic response. When activated from the dispatch control, a judgment is made of a mechanism suspension release automatic response request (80). When the request from dispatch control is an automatic response setting request,
It is determined whether or not the automatic suspension release automatic response has already been set (81), and if it has been set, the timeout occurrence determination (83) is operated. If not, the device management block is updated to be in the mechanism suspension release automatic response state (82). If a timeout has already occurred, a mechanism suspension release notification (84) is performed at the time of requesting a mechanism suspension release automatic response setting request, and an apparatus management block is updated (85). If no timeout has occurred, the process ends.

If the request from the dispatch control is an automatic response release request, the mechanism suspension release automatic response function is released (86), and it is determined whether the mechanism suspension release automatic response function has already been operated (87). If the automatic suspension cancel response has already been executed, the device management information is updated (88); otherwise, the process ends.

FIG. 6 is a flow chart of the command suspension control and the command execution task at the time of occurrence of a timeout when the horizontal suspension request is released. If started from the command response control or the command execution task, it is first determined whether or not the mechanism suspension response has been released (90), and if it has been released, the processing is terminated. If not, it is determined whether a timeout has occurred (91), and if no timeout has occurred, the process ends. If a time-out has occurred, the mechanism suspension response is released (92), the device management information in the device management block is updated (93), and the process ends.

[0026]

As described above, according to the present invention, the timeout failure that occurs during execution of the command execution task in the coupling device mechanism can be prevented by providing the high-speed channel mechanism suspension response function. Timeout recovery processing is not required. The command execution control in the coupling equipment mechanism only needs to notify the high-speed channel of the notification of the cancellation of the mechanism halt response, thereby minimizing the overhead due to timeout recovery processing and preventing the occurrence of chained timeouts during timeout recovery processing. And a true link error due to a delay in the timeout recovery process is avoided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall environment for implementing the present invention.

FIG. 2 is a block diagram illustrating a timeout control method of a high-speed channel device.

FIG. 3 is a block diagram showing a method for canceling a mechanism halt response of a high-speed channel.

FIG. 4 is a flowchart showing a method for notifying a mechanism suspension response from an interrupt handler.

FIG. 5 is a flowchart showing a method for setting and canceling a mechanism suspension response cancellation automatic response method from dispatch control.

FIG. 6 is a flowchart showing a method of determining occurrence of a timeout and notifying a mechanism suspension response cancellation.

[Explanation of symbols]

 10: Coupling device 20: Processing device 30: Message path 68: High-speed channel

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Otsuji 5030 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Software Development Division, Hitachi, Ltd. (72) Inventor Takao Nakajima 5030 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Koji Masuda 5030 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Software Development Division, Hitachi, Ltd.

Claims (3)

[Claims] At least one processing device for executing a data processing program is connected to a coupling device mechanism via a channel device having a time-out processing means, and between the plurality of processing devices and the coupling device mechanism. In the timeout control method for a data processing system in which a command is transmitted and received, a command is transmitted from the processing device, and a limit of a predetermined time is waited for waiting for a response from the coupling device mechanism to be completed. When a response waiting time for a command transmission between the device mechanisms exceeds a predetermined time, the channel device of the coupling device mechanism responds to the processing device that the integrated device mechanism is inactive, and receives a command to the coupling device mechanism. Timeout control method for a data processing system, wherein a timeout is rejected. 2. A timeout control method for a data processing system according to claim 1, wherein said command execution program in said coupling device mechanism releases a mechanism suspension response to a high-speed channel connected to said coupling device mechanism. Characteristic timeout control method for a data processing system. 3. A timeout control method for a data processing system according to claim 1, wherein a timeout recovery method at the time of command execution is used to cancel a mechanism suspension response, and said mechanism is executed during execution of a command in said coupling device mechanism. A timeout control method for a data processing system, wherein a pause response is released during execution of a command.