JPH04354035A - Trace method and its device - Google Patents

Abstract

PURPOSE:To clarify the context of trace information collected by a central processing unit and an inputting and outputting device, in a computer system equipped with the central processing unit and the inputting and outputting device. CONSTITUTION:At the time of operating an inputting and outputting operation instruction, and operating an interruption for an operation information or the like, by a central processing unit 1, and an inputting and outputting device 2, a sequence number in sequence number save areas 31 and 27 is stepped, the stepped sequence number and the content of the inputting and outputting operation instruction and the stepped sequence number and the content of the interruption, are set at a channel control block 33-1, and collected in trace areas 32 and 26. The central processing unit 1, and the inputting and outputting device 2 collect the content of the channel control block 33-1 in the trace areas 32 and 26, and set the sequence number set at the channel control block 33-1 at the sequence number save areas 31 and 27.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracing method and apparatus for a computer system equipped with a central processing unit and an input/output device.

0002

[Prior Art] In a computer system having a central processing unit and an input/output device, the operation status of the input/output device is monitored,
For failure analysis when a failure occurs, the contents of input/output operation instructions from the central processing unit to the input/output device, the contents of the operation report from the input/output device to the central processing unit, etc. are collected as trace information. ing. By the way, when the contents of input/output operation instructions, the contents of operation reports, etc. are collected as trace information, conventionally, the time at which the information was collected is added to the collected trace information. When you want to know the operation sequence between the central processing unit and the input/output device, such as when analyzing a failure, you can estimate the context of each trace information based on the collection time added to the trace information. and is conducting an analysis.

0003

[Problems to be Solved by the Invention] As mentioned above, conventionally, when you want to know the operation sequence between a central processing unit and an input/output device, you have to check each trace based on the collection time added to the trace information. Although we try to determine the context of information, there are cases where the context cannot be determined due to the following points. (1) When the times measured by the central processing unit and the input/output device do not match, or when it is impossible to make them match accurately. (2) When the time at which the trace information is collected and input in the central processing unit (3) The central processing unit and the input/output device have different operating timings, and the minimum time increments of the timers that measure time in each device are different. As mentioned above, in the conventional example described above, it may not be possible to determine the context of each trace information, so there is a problem that it may be difficult to analyze the operation sequence between the central processing unit and the input/output device. There was a point.

An object of the present invention is to make it possible to clarify the context of trace information.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides (A) a computer system comprising a central processing unit and an input/output device, wherein the central processing unit is connected to the input/output device; When issuing an input/output operation instruction to the input/output device, the first sequence number is incremented, and the incremented first sequence number and the content of the input/output operation instruction are notified to the input/output device, and the trace area is If there is an interrupt from the input/output device, the contents of the notified interrupt and the sequence number are collected in the trace area, the notified sequence number is made the first sequence number, and the input/output device , when interrupting the central processing unit, increments a second sequence number, notifies the central processing unit of the incremented second sequence number and the contents of the interrupt, and collects it in a trace area. When the contents of the input/output operation instruction and the sequence number are notified from the central processing unit, the contents of the notified input/output operation instruction and the sequence number are collected in the trace area, and the notified sequence number is The second
This is the sequence number.

The present invention also provides a trace device suitable for the method shown in configuration (A), which is used in a computer system including (B) a central processing unit and an input/output device. The central processing unit includes a sequence number save area and a trace area, and when the central processing unit issues an input/output operation instruction to the input/output device, the central processing unit saves the first sequence saved in the first sequence number save area. a first sequence number updating means for incrementing the number; and collecting the first sequence number incremented by the first sequence number updating means and the content of the input/output operation instruction in the trace area; , a first trace collection means for collecting the interrupt contents and sequence number set in the channel control block in the trace area when an interrupt occurs from the input/output device;
The first sequence number incremented by the sequence number updating means of the input/output device and the content of the input/output operation instruction are set in the channel control block, and the driver that issues input/output operation instructions to the input/output device and and a first sequence number setting means for setting the sequence number set in the channel control block as the first sequence number in the first sequence number save area when an interrupt from the output device occurs, the input/output device When interrupting the central processing unit,
a second sequence number updating means for incrementing a second sequence number saved in the second sequence number save area; and the second sequence number incremented by the second sequence number updating means. and the contents of the interrupt are collected in the trace area, and when an input/output operation instruction is issued from the central processing unit, the contents of the input/output operation instruction set in the channel control block and the sequence number are recorded in the trace area. A second trace collection means to collect, a second sequence number incremented by the second sequence number updating means, and the contents of the interrupt are set in a channel control block, and an interrupt is sent to the central processing unit. a second sequence number that sets a sequence number set in the channel control block as a second sequence number in the second sequence number save area when an input/output operation instruction is issued from the central processing unit; sequence number setting means.

[0007]

[Operation] In the configuration (A), when the central processing unit issues an input/output operation instruction to the input/output device, the central processing unit increments the first sequence number and uses the incremented first sequence number as the incremented first sequence number. The content of the input/output operation instruction is notified to the input/output device, and the incremented first sequence number and the content of the input/output operation instruction are collected in the trace area.

When the input/output device is notified of the contents of the input/output operation instruction and the sequence number from the central processing unit, it collects the contents of the notified input/output operation instruction and the sequence number in the trace area, and also sends the notification. The sequence number obtained is set as the second sequence number.

Furthermore, when the input/output device interrupts the central processing unit, it increments the second sequence number and notifies the central processing unit of the incremented second sequence number and the contents of the interrupt. At the same time, collect them in the trace area.

When the central processing unit receives an interrupt from the input/output device, the central processing unit collects the contents of the notified interrupt and the sequence number in a trace area, and sets the notified sequence number as the first sequence number.

In configuration (B), when the central processing unit issues an input/output operation instruction to the input/output device, the first sequence number update means saves the sequence number in the first sequence number save area. The first sequence number is incremented, and the first sequence number incremented by the first trace collection means
The first sequence number and the content of the input/output operation instruction are collected in the trace area, and the first sequence number incremented by the driver and the content of the input/output operation instruction are set in the channel control block. An input/output operation instruction is output to the output device.

When the input/output device receives an input/output operation instruction from the driver, the second sequence number setting means sets the sequence number set in the channel control block as the second sequence number and stores it in the second sequence number save area. The sequence number set in the channel control block and the content of the input/output operation instruction are collected into the trace area by the second trace collection means.

Furthermore, when the input/output device interrupts the central processing unit, the second sequence number updating means increments the second sequence number saved in the second sequence number save area; The second sequence number incremented by the second trace collection means and the contents of the interrupt are collected in the trace area, and the second sequence number and the contents of the interrupt incremented by the bus interface control means are stored in the channel control. After that, the bus interface control means interrupts the central processing unit.

When an interrupt is issued to the central processing unit from the input/output device, the contents of the interrupt and the sequence number set in the channel control block are collected in the trace area by the first trace collection means. The sequence number set in the channel control block by the sequence number setting means of
The sequence number is set as the first sequence number in the sequence number save area.

[0015]

Embodiments Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, in which a central processing unit 1, an input/output device 2, and a memory 3 are connected via a system bus 4.

Memory 3 is sequence number save area 3
1, a trace area 32, and channel control blocks 33-1 and 33-2.

The channel control block 33-1 contains the contents of the input/output operation instruction from the central processing unit 1 to the input/output device 2, a sequence number, or the operation report (interrupt contents) from the input/output device 2 to the central processing unit 1, and the sequence. The number is set. The channel control block 33-2 stores the content and sequence number of an asynchronous interrupt from the input/output device 2 to the central processing unit.

The central processing unit 1 has input/output device control means 11
, a driver 12 , a sequence number updating means 13 ,
Sequence number setting means 14 and trace collection means 15
Contains.

The input/output device control means 11 controls the input/output operations of the input/output device 2 and receives input/output requests from the user.

The driver 12 passes the contents of the input/output operation instruction to the input/output device 2 via the channel control block 33-1, and receives an operation report from the input/output device 2. The driver 12 also receives the contents of an asynchronous interrupt from the input/output device 2 via the channel control block 33-2.

The sequence number updating means 13 is the driver 1
2 issues an input/output operation instruction to the input/output device 2, the sequence number stored in the sequence number save area 31 is incremented by one.

The sequence number setting means 14 is the driver 1
2 sets the sequence number in the channel control block 33-1 to the sequence number save area 31 by receiving an interrupt from the input/output device 2, and sets the sequence number in the channel control block 33-2 to the sequence number save area 31 by receiving an asynchronous interrupt. Set in number save area 31.

The trace collection means 15 records the contents of the channel control block 33-1 as trace information when the driver 12 receives an input/output operation instruction from the input/output device control means 11 or when it receives an interrupt from the input/output device 2. Collected in the trace area 32 as
When receiving an asynchronous interrupt from the input/output device 2, the contents of the channel control block 33-2 are collected in the trace area 32.

The input/output device 2 includes a bus interface control means 21, a trace collection means 22, a sequence number updating means 23, a sequence number setting means 24, an input/output processing means 25, a trace area 26, and a sequence number saving means. Area 27 is included.

The bus interface control means 21 receives the contents of the input/output operation instruction from the central processing unit 1 via the channel control block 33-1, and passes an operation report to the central processing unit 1. The bus interface control means 21 also includes a channel control block 33-2.
The contents of the asynchronous interrupt are passed to the central processing unit 1 via.

When the bus interface control means 21 receives an operation report notification request and an asynchronous notification request from the input/output processing means 25, and when it receives an input/output operation instruction from the central processing unit 1, the trace collection means 22 The contents of the channel control block 33-1 are collected in the trace area 26 as trace information.

When the bus interface control means 21 notifies the central processing unit 1 of an operation report or asynchronous notification, the sequence number updating means 23 changes the sequence number set in the sequence number save area 27 to 1.
step forward

The sequence number setting means 24 stores the sequence number set in the channel control block 33-1 in the sequence number save area 27 when the bus interface control means 21 receives an input/output operation instruction from the central processing unit 1. Set.

FIG. 2 is an explanatory diagram of the operation of the embodiment shown in FIG.

FIG. 3 is a flowchart showing an example of processing when the driver 12 receives an input/output operation instruction from the input/output device control means 11.

FIG. 4 shows the bus interface control means 21.
2 is a flowchart showing an example of processing when receiving an input/output operation instruction from the central processing unit 1. FIG.

FIG. 5 shows the bus interface control means 21.
3 is a flowchart showing an example of processing when receiving an operation report notification request and an asynchronous notification request from the input/output processing means 25;

FIG. 6 is a flowchart showing an example of processing when the driver 12 receives an asynchronous interrupt from the input/output device 2.

FIG. 7 is a diagram showing an example of trace information collected in the trace areas 26 and 32.

The operation of this embodiment will be explained below with reference to the figures.

First, the process performed when the driver 12 in the central processing unit 1 receives an input/output operation instruction for the input/output device 2 from the input/output device control means 11 will be described with reference to FIG.

When the driver 12 receives an input/output operation instruction for the input/output device 2 from the input/output device control means 11, as shown in FIG. The sequence number within is incremented by one step (A1).

Next, the driver 12 sets the contents of the input/output operation instruction from the input/output device control means 11 in the channel control block 33-1 in the memory 3 (A2),
After that, the sequence number save area 31 in the memory 3
The sequence number is extracted from , and the extracted sequence number is also set in the channel control block 33-1 (A3).

Furthermore, the driver 12 has a trace collection means 1.
5 to collect the contents of the input/output operation instruction set in the channel control block 33-1 and the sequence number in the trace area 32 (A4).

Finally, the driver 12 instructs the input/output device 2 to perform the input/output operation set in the channel control block 33-1 via the system bus 4 (A5).

Now, for example, as shown in FIG. 2, "0" is written as a sequence number in the sequence number save area 31.
If an input/output operation instruction is added from the input/output device control means 11 when 1 is set, the sequence number in the sequence number save area 31 is set to "1" by the process of A1 (S1), and A2, A3 The contents of the input/output operation instruction and the sequence number "1" are set in the channel control block 33-1 by the process of A4, and the contents of the input/output operation instruction and the sequence number set in the channel control block 33-1 by the process of A4. is collected in the trace area 32. As a result, as shown in FIG. 7, the trace area 32 contains trace information T1 consisting of the contents of the input/output operation instruction and the sequence number "1".
will be taken.

Next, the bus interface control means 21
from central processing unit 1 to channel control block 3
The operation when an instruction is given to perform the input/output operation of the contents set in 3-1 will be explained with reference to FIG.

When the bus interface control means 21 receives an input/output operation instruction from the central processing unit 1, it first extracts the contents of the input/output operation instruction and a sequence number from the channel control block 33-1, and converts the extracted sequence number into a sequence. The sequence number is set in the sequence number save area 27 using the number setting means 24 (B1).

Next, the bus interface control means 21 uses the trace collection means 22 to collect the contents of the input/output operation instruction and the sequence number taken out from the channel control block 33-1 into the trace area 26 (B
2).

Finally, the bus interface control means 21 notifies the input/output processing means 25 that the input/output operation instruction has been received (B3). This results in
The input/output processing means 25 is the channel control block 3
It performs input/output processing according to the content of the input/output operation instruction set in 3-1, and upon completion of the input/output processing, outputs a notification request containing operation completion information to the bus interface control means 21.

Now, for example, as shown in FIG. 2, when the content of the input/output operation instruction and the sequence number "1" are set in the channel control block 33-1, the If an input/output operation instruction is accepted, the sequence number "1" is saved in the sequence number save area 27 by the process of B1 (S2), and the sequence number "1" is saved in the trace area 26 by the process of B2.
The contents of the received instruction and the sequence number are saved in the trace area 26. As a result, trace area 26
As shown in FIG. 7, trace information T2 consisting of the contents of the acceptance instruction and the trace number "1" is saved.

Next, the operation when the bus interface control means 21 receives a notification request or an asynchronous notification request from the input/output processing means 25 will be explained with reference to FIG.

When the bus interface control means 21 receives a notification request from the input/output processing means 25 (C1 is
In the case of ES), first, the sequence number in the sequence number save area 27 is incremented by 1 using the sequence number updating means 23 (C2).

Next, the bus interface control means 21 sets the operation report contents (operation completion status) included in the notification request added from the input/output processing means 25 in the channel control block 33-1 (C3), and then , extracts the sequence number from the sequence number save area 27, and sets the extracted sequence number in the channel control block 33-1 (C4).

Furthermore, the bus interface control means 21
uses the trace collection means 22 to store the operation report contents and sequence number set in the channel control block 33-1 in the trace area 26 (C5).

Finally, the bus interface control means 21 issues an interrupt to the central processing unit 1 via the system bus 4 to indicate the completion of the operation (C6).

When an asynchronous notification request is received from the input/output processing means 25 (if C1 is NO), first, the sequence number in the sequence number save area 27 is incremented by one using the sequence number updating means 23 ( C7).

[0054] Next, the bus interface control means 21 sends the asynchronous notification contents, such as information indicating a state change of the input/output processing device 25 included in the asynchronous notification request from the input/output processing means 25, to the channel control block 33-2. Set (C8), then sequence number save area 2
7 and sets the extracted sequence number in the channel control block 33-2 (C9).

Furthermore, the bus interface control means 21
uses the trace collection means 22 to collect the asynchronous notification content and sequence number set in the channel control block 33-2 into the trace area 26 (C10).

Finally, the bus interface control means 21 issues an asynchronous interrupt to the central processing unit 1 via the system bus 4 (C11).

Now, for example, as shown in FIG. 2, if a notification request is output from the input/output processing means 25 when the sequence number set in the sequence number save area 27 is "1", the processing of C2 The sequence number in the sequence number area 27 is incremented from "1" to "2" (S3), and the notification content and sequence number "2" are set in the channel control block 33-1 by the processing of C3 and C4. Trace area 2 is created by processing C5.
6, the notification contents and sequence number are collected. As a result, as shown in FIG. 7, trace information T3 consisting of the completion notification contents and the sequence number "2" is collected in the trace area 26.

Next, a processing example of the driver 12 when receiving an interrupt or an asynchronous interrupt from the input/output device 2 will be explained with reference to FIG.

When the driver 12 receives an interrupt from the input/output device 2 (if D1 is YES), it reads the sequence number set in the channel control block 33-1, and sends the read sequence number to the sequence number setting means 14. Use sequence number save area 3
1 (D2).

Next, the driver 12 reads the contents of the operation report such as the operation completion status and the sequence number set in the channel control block 33-1, and sends the read contents of the operation report and the sequence number to the trace collection means 15. Set it in the trace area 32 using (
D3).

Finally, the driver 12 notifies the input/output device control means 11 of the completion of the operation based on the contents of the channel control block 33-1 (D4).

Furthermore, when an asynchronous interrupt is received from the input/output device 2 (when D1 is NO), the sequence number set in the channel control block 33-2 is read, and the read sequence number is sent to the sequence number setting means 14. Sequence number save area 31 using
Save (D5).

Next, the driver 12 reads the asynchronous notification content and sequence number set in the channel control block 33-2, and uses the trace collection means 15 to store the read asynchronous notification content and sequence number in the trace area. 32 (D6).

Finally, the driver 12 sends an asynchronous notification to the input/output device control means 11 based on the contents of the channel control block 33-2 (D7).

For example, suppose that an interrupt notification is received when the sequence number set in the sequence number save area 31 is "2" as shown in FIG.
1 is YES), the sequence number set in the channel control block 33-1 by the processing of D2 is
” is saved in the sequence number save area 31 (
S4) and the processing of D3 collect the notification content and sequence number in the trace area 32. As a result, as shown in FIG. 7, the trace information T consisting of the operation completion notification contents and the sequence number "2" is stored in the trace area 32.
4 is taken.

As described above, according to this embodiment, related trace information is given the same sequence number, so trace information T1, T collected in the central processing unit 1
4 and trace information T2, T collected by input/output device 2
3 can be associated. Furthermore, the sequence number is updated when the central processing unit 1 issues an input/output operation instruction to the input/output device 2, and when the input/output device 2 interrupts or asynchronously interrupts the central processing unit 1. Therefore, the context of the collected trace information can be easily known based on the sequence number added to the trace information.

Next, the operation when the input/output operation instruction from the central processing unit 1 and the asynchronous notification from the input/output device 2 are mixed will be explained.

When some state change occurs in the input/output device 2, an asynchronous notification may be made to report the state to the central processing unit 1.

Now, for example, as shown in FIG. 2, the sequence number "2" is stored in the sequence number save areas 27 and 31.
is set, an asynchronous notification is generated from the input/output processing means 25 to the bus interface control means 21 (S5), and furthermore, in conjunction with this, an input/output operation instruction is generated from the input/output device control means 11 to the driver 12. Suppose that (S6).

The bus interface control means 21 starts the process shown in FIG. 5 when an asynchronous notification is generated. Then, by performing the process of C7, the sequence number set in the sequence number save area 27 is increased by 1 to "3" (S7).

Further, the driver 12 starts the process shown in FIG. 3 when an input/output operation instruction is generated. And A
By performing the process 1, the sequence number set in the sequence number save area 31 is increased by 1 and "
3” (S8).

After that, the bus interface control means 2
1 performs the process of C8, sets the contents of the asynchronous notification in the channel control block 33-2, further processes C9, and sets the sequence number "3" set in the sequence number save area 27 to the channel control block. Set to 33-2. Thereafter, the bus interface control means 21 processes C10, and stores the channel control block 33-2 in the trace area 26.
The content and sequence number of the asynchronous notification set to "
3). As a result, as shown in FIG. 7, the trace area 26 contains the asynchronous notification content and the sequence number "
Trace information T5 consisting of "3" is collected. Thereafter, the bus interface control means 21 performs the process of C11 and issues an asynchronous interrupt to the central processing unit 1 via the system bus 4.

On the other hand, after performing processing A1, the driver 12 performs processing A2 to set the contents of the input/output operation instruction in the channel control block 33-1, and further performs processing A3 to set the contents of the input/output operation instruction in the sequence number save area 31. The saved sequence number "3" is set in the channel control block 33-1. Then driver 1
2 performs process A4 and collects the contents of the input/output operation instruction set in the channel control block 33-1 and the sequence number "3" into the trace area 32. As a result, trace information T6 consisting of input/output operation instruction contents and sequence number "3" is collected in the trace area 32 as shown in FIG. Thereafter, the driver 12 performs the process A5 and issues an input/output operation instruction to the input/output device 2.

The bus interface control means 21 starts the process shown in FIG. 4 upon receiving an input/output operation instruction. Then, by performing process B1, the sequence number "3" set in the channel control block 33-1 is set in the sequence number save area 27, and by further performing process B2, the sequence number "3" set in the channel control block 33-1 is set in the sequence number save area 27. The set acceptance instruction contents and sequence number "3" are collected in the trace area 26. As a result, trace information T7 consisting of the contents of the acceptance instruction and the sequence number "3" is collected in the trace area 26 as shown in FIG. Thereafter, the bus interface control means 21 notifies the input/output processing means 25 of acceptance of the operation instruction by performing processing B3.

Further, the driver 12 starts the process shown in FIG. 6 upon receiving an asynchronous interrupt. And D5
By performing the process, the sequence number "3" set in the channel control block 33-2 is set in the sequence number save area 31 (S10),
By performing the process of D6, the asynchronous notification content and sequence number "3" set in the channel control block 33-2 are collected in the trace area 32. As a result, as shown in FIG. 7, trace information T8 consisting of the asynchronous notification content and the sequence number "3" is collected in the trace area 32. After that, the driver 12 performs the process of D7, and the input/output device control means 11
Perform asynchronous notification.

As described above, according to this embodiment, when processes overlap, trace information T6, T8 collected on the central processing unit 1 side and trace information T5, T7 collected on the input/output device 2 side are will be assigned the same sequence number "3". Therefore, according to this embodiment, it is possible to easily determine at the time of analysis whether or not a crossover has occurred based on whether or not the same sequence numbers are consecutive.

[0077]

[Effects of the Invention] As explained above, the present invention provides input/output operation instructions to an input/output device from a central processing unit.
Notify the input/output device of the incremented first sequence number by incrementing the first sequence number held in the central processing unit and the content of the input/output operation instruction, and send the input/output device to the central processing unit. When an interrupt is performed, the second sequence number held by the input/output device is incremented to notify the central processing unit of the incremented second sequence number and the contents of the interrupt. Replace the second sequence number held by being notified of a sequence number from the central processing unit with the notified sequence number,
When the central processing unit receives a sequence number notification from the input/output device, it replaces the first sequence number it holds with the notified sequence number, and collects the contents of input/output operation instructions, interrupt contents, etc. as trace information. Since the sequence number at that time is added to the trace information, it is possible to reliably determine the context of the trace information based on the sequence number added to the trace information. This has the effect of easily confirming the occurrence of a conflict between an output operation instruction and an asynchronous notification from an input/output device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the invention.

FIG. 2 is an explanatory diagram of the operation of the embodiment of FIG. 1;

FIG. 3 is a flowchart showing an example of processing when the driver 12 receives an input/output operation instruction from the input/output device control means 11;

4 is a flowchart showing an example of processing when the bus interface control means 21 receives an input/output operation instruction from the central processing unit 1. FIG.

FIG. 5 is a flowchart showing an example of processing when the bus interface control means 21 receives an operation report notification request and an asynchronous notification request from the input/output processing means 25;

FIG. 6 is a flowchart showing an example of processing when the driver 12 receives an interrupt from the input/output device 2 and an asynchronous interrupt.

FIG. 7 is a diagram showing an example of trace information collected in trace areas 26 and 32.

[Explanation of symbols]

1...Central processing unit 2...I/O device 3...Memory 4...System bus 11...I/O device control means 12...Driver 13, 23...Sequence number updating means 14, 24...Sequence number setting means 15, 22...Trace collection means 21...Bus interface control means 25...I/O processing means 26, 32...Trace area

Claims (2)

[Claims] Claim 1: In a computer system including a central processing unit and an input/output device, the central processing unit steps forward by a first sequence number when issuing an input/output operation instruction to the input/output device. and notifies the incremented first sequence number and the content of the input/output operation instruction to the input/output device and collects it in a trace area, and when there is an interrupt from the input/output device, the input/output device notifies the input/output operation instruction. The contents of the interrupt and the sequence number are collected in the trace area, and the notified sequence number is set as the first sequence number, and when the input/output device interrupts the central processing unit, The number is incremented, the incremented second sequence number and the contents of the interrupt are notified to the central processing unit, and are collected in a trace area, and the central processing unit increments the contents of the input/output operation instruction and the sequence number. By being notified, the contents of the notified input/output operation instruction and the sequence number are collected in the trace area, and the notified sequence number is stored in the second
A tracing method characterized in that the sequence number is 2. A computer system comprising a central processing unit and an input/output device, comprising first and second sequence number save areas and a trace area, wherein the central processing unit is connected to the input/output device. a first sequence number updating means for incrementing a first sequence number saved in the first sequence number save area when issuing an input/output operation instruction to the first sequence number updating means; The first sequence number incremented by the above and the contents of the input/output operation instruction are collected in the trace area, and at the time of an interrupt from the input/output device, the contents of the interrupt set in the channel control block are collected. a first trace collection means for collecting a sequence number in the trace area, and a first sequence number incremented by the first sequence number updating means and contents of the input/output operation instruction into a channel control block. A driver that configures settings and issues input/output operation instructions to the input/output device, and at the time of an interrupt from the input/output device,
a first sequence number setting means for setting a sequence number set in the channel control block as a first sequence number in the first sequence number save area, the input/output device is configured to be connected to the central processing unit; a second sequence number updating means for incrementing a second sequence number saved in the second sequence number save area; The second sequence number and the contents of the interrupt are collected in the trace area, and when an input/output operation instruction is issued from the central processing unit, the contents and sequence of the input/output operation instruction set in the channel control block are collected. a second trace collection means for collecting a number in the trace area; a second sequence number incremented by the second sequence number updating means and the contents of the interrupt; A bus interface control means that interrupts the central processing unit, and when an input/output operation instruction is issued from the central processing unit, the sequence number set in the channel control block is stored in the second sequence number save area. A tracing device comprising: second sequence number setting means for setting a sequence number.