JPH09319598A - Low-cost signal mask control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change a signal mask managed in a kernel space from a user space without issuing any system call. SOLUTION: Processor local data 9 prepared for each processor are provided with an area 91 for setting the signal mask of a light wait process(LWP) under operating at that processor. The processor local data 9 corresponding to the active processor are mapped into a specified area 61 in a user process area 6. A user process rewrites a signal mask 62 in this area 61 so that the signal mask managed in the kernel space can be changed from the user space.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal mask control system, and more particularly to a low cost signal mask control system which eliminates system call overhead.

[0002]

2. Description of the Related Art In a user process, a process using a signal may be performed in order to notify an event asynchronously. In such a process, a signal handler that is called when a signal is received is set. For example, the UNIX operating system includes signal (signum, function) as a system call for notifying a process of the occurrence of an asynchronous event. However, signum is an integer type signal number of the action specified by the process, and function is the address of the (user) function to be activated when the process receives the signal.

When performing processing for referencing global data in this signal handler, signals are masked at all points that refer to the global data, and the received signal is temporarily suspended (critical section). ) Need to be established.

However, since the signal mask setting of the process is managed in the kernel space that can be accessed only in the kernel mode, in order to change the signal mask setting, the user process changes the signal mask by the kernel. Therefore, a system call requested to the side is issued. Therefore, if the signal mask is changed frequently, the overhead of the system call causes a great penalty and affects the system performance.

An example of a method for suppressing the overhead due to the system call is disclosed in, for example, Japanese Patent Laid-Open No. 1083/1993.
No. 74 publication. This conventional method eliminates the need to save the register state during user mode execution to the stack space by using an empty register bank when a system call, interrupt, or exception occurs, and when entering the kernel mode, The system call overhead is suppressed.

[0006]

However, although the overhead due to the saving of the register information to the stack can be reduced by the above conventional method, the system call is issued in comparison with the processing amount required for changing the signal mask. The overhead of doing so is large.

This is because the process of changing the signal mask itself is only a process of writing the mask data in a predetermined area, whereas the system call process is the register save / restore process and the exception common part. This is because the amount of processing is large because the processes such as the determination of the exception type and the determination of the system call type in the system call common part are performed.

Therefore, the present invention has been made in view of the above circumstances, and an object thereof is to eliminate the overhead caused by issuing a system call and change the signal mask managed in the kernel space. It is to provide a signal mask control system that enables the above.

[0009]

In order to achieve the above object, the signal mask control method of the present invention enables the signal mask to be changed by rewriting the area of the user process space to which the area of the kernel space is mapped. Is characterized by.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below. The present invention, in its embodiment,
Lightweight process (LWP, also called "lightweight process") UNIX system V Rekease
(See 4.2 MP) sets a signal mask in an area for storing local information for each processor when the operation starts on the processor, and saves the signal mask from the processor local area when the operation ends. (3 in FIG. 1) and the signal mask set in the local area corresponding to the processor when the signal destination light weight process (LWP) is in operation, and if it is not in operation, the light weight process A signal control unit (31 in FIG. 1) that refers to the signal mask of (LWP) and the processor local area of the kernel space corresponding to the processor in which the lightweight process (LWP) is operating are mapped in the user process space, Memory that can be read and written in both user mode and kernel mode And a control unit (4 in FIG. 1).

According to the embodiment of the present invention, the area of the kernel space mapped to the user process space includes:
The signal mask of the light weight process (LWP) in operation is set. By rewriting this setting from the user process space, the signal mask of the lightweight process (LWP) can be changed without issuing a system call.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to describe the embodiment of the present invention described above in more detail, an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a system configuration of an embodiment of the present invention, and shows a configuration of a tightly coupled multiprocessor system in which a main memory is shared among a plurality of processors. Note that, in FIG. 1, a configuration of two processors is shown as the plurality of processors for ease of explanation, but it goes without saying that the present invention is not limited to such a configuration.

Referring to FIG. 1, this embodiment comprises first and second processors 1-1 and 1-2, a main memory 2, a process control unit 3 and a memory control unit 4. It is configured. The process control unit 3 includes a signal control unit 31.
The main memory 2 is provided with a kernel space 5 accessible only from the kernel mode and user process spaces 6-1 to 6-n for each process.

FIG. 2 shows the kernel space 5 in this embodiment.
The internal structure is shown. Referring to FIG. 2, in the kernel space 5, the process includes a plurality of lightweight processes (LWP) that are scheduling units. The kernel space 5 includes process management data 7 provided for each process, LWP management data 8 provided for each lightweight process (LWP), and processor local data 9 provided for each processor. The LWP management data 8 of each lightweight process (LWP) is linked (chained) with the entry of the process management data 7 provided for each process as a header.

The LWP management data 8 includes a CPU number 81 for identifying a processor in which a lightweight process (LWP) is operating and a lightweight process (LWP).
A status flag 82 indicating whether or not (WP) is in operation,
A signal mask setting 83 corresponding to a lightweight process (LWP).

The processor local data 9 is the light weight process (L
This includes an area 91 for storing the signal mask setting of WP).

FIG. 3 schematically shows the relation between the operating light weight process (LWP) and the processor local data in this embodiment. In the figure, reference numerals of LWP management data 8 and processor local data 9 corresponding to the first and second processors 1-1 and 1-2 are “-
1 "and" -2 "are attached.

Referring to FIG. 3, the LWP operating on the processor is controlled by the process controller 3. The signal mask setting 83 of the operating lightweight process (LWP) is set by the process control unit 3 in the processor local data 9 corresponding to the operating processor.
Stored in the signal mask storage area 91.

FIG. 4 schematically shows the relationship between the user process space and processor local data in this embodiment. Referring to FIG. 4, in a specific area 61 of the user process space 6, processor local data 9-1, 9-existing in the kernel space 5 is stored in the kernel space 5 by the memory control unit 4.
Of the two, processor local data corresponding to the operating processor is mapped.

From the user process to this mapping area 6
By reading / writing to 1, the content of the processor local data 9 corresponding to the operating processor can be changed.

Since the processor local data 9 includes the area 91 in which the signal mask of the currently operating lightweight process (LWP) is set, the signal mask 62 in the mapping area 61 corresponding to this is changed. Then, the signal mask can be changed from the user space.

Next, the operation of the embodiment of the present invention will be described with reference to the flowcharts of FIGS. 5, 6 and 7.

FIG. 5 is a flow chart for explaining the processing operation of switching the light weight process (LWP) in the embodiment of the present invention.

Referring to FIG. 5, the process control unit 3 is a lightweight process LW operating in the processor 1.
From P (a) to another lightweight process LWP (b)
When switching (switching) to, the signal mask 91 of the processor local data 9 is saved to the signal mask 83 of the LWP management data 8 of the operating lightweight process LWP (a) (step A1), and the lightweight process LWP (a). The status flag 82 of the LWP management data 8) is changed to "inactive" (step A2).

Then, the processor number 81 of the LWP management data 8 of the newly operating lightweight process LWP (b) is updated to the operating processor number (step A
3), the signal mask 83 of the LWP management data 8 is set to the signal mask 91 of the processor local data 9 (step A4).

L of the lightweight process LWP (b)
The status flag 82 of the WP management data 8 is changed to "in operation" (step A5), and the lightweight process LWP
The context is switched to (b) (step A6).

FIG. 6 is a flow chart for explaining the processing operation of changing the signal mask in the embodiment of the present invention. Referring to FIG. 6, when the user process changes the signal mask, the signal mask 62 in the mapping area 61 of the user process space 6 is rewritten (step A7).

FIG. 7 is a flow chart for explaining the processing operation of the signal mask judgment in the embodiment of the present invention. Referring to FIG. 7, when the signal control unit 31 determines whether the lightweight process (LWP) of the transmission destination masks the signal in the signal transmission processing executed in the kernel mode, the signal control unit 31 Whether or not the light weight process (LWP) is operating on the processor is determined by the light weight process (LWP).
The determination is made by referring to the status flag 82 of the LWP management data 8 of (WP) (step A8).

Destination Lightweight Process (LWP)
Is operating, the signal mask 91 of the processor local data 9 corresponding to the operating processor 1 by referring to the processor number 81 of the LWP management data 8
(Step A9), it is determined whether or not the signal is masked.

On the other hand, the destination lightweight process (L
When WP) is not in operation, the signal mask 83 of the LWP management data 8 for this lightweight process (LWP) is referred to (step A10), and it is determined whether or not the signal is masked. Then, the signal is transmitted or held according to the referenced signal mask.

Next, the function and effect of the embodiment of the present invention will be described.

According to the embodiment of the present invention, since the signal mask for each lightweight process (LWP) managed in the kernel space can be changed from the user space, the overhead caused by issuing the system call is eliminated, and the processing is executed. Will be faster.

[0034]

As described above, according to the present invention,
Since the signal mask managed in the kernel space can be changed directly from the user space without issuing a system call, the signal mask changing process can be speeded up.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a system configuration according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a kernel space according to an embodiment of the present invention.

FIG. 3 is a diagram schematically showing a relationship between LWP and processor local data according to an embodiment of the present invention.

FIG. 4 is a diagram schematically showing a relationship between a user process space and processor local data according to an embodiment of the present invention.

FIG. 5 is a flowchart for explaining a processing operation of the LWP switch according to the embodiment of the present invention.

FIG. 6 is a flowchart for explaining a signal mask changing processing operation according to an embodiment of the present invention.

FIG. 7 is a flowchart for explaining a signal mask determination processing operation according to an embodiment of the present invention.

[Explanation of symbols]

 1 Processor 2 Main Memory 3 Process Control Section 31 Signal Control Section 4 Memory Control Section 5 Kernel Space 6 User Process Space 61 Mapping Area 62 Signal Mask in Mapping Area 7 Process Management Data 8 LWP Management Data 81 Processor Number 82 Status Flag 83 Signal Mask 9 Processor local data 91 Signal mask setting area

Claims (2)

[Claims] 1. A signal mask control system characterized in that a signal mask can be changed by rewriting an area of a user process space formed by mapping a predetermined area of a kernel space. 2. An area for storing a signal mask setting managed in the kernel space is mapped to a user process space so that the area can be read and written from both the user mode and the kernel mode, and the signal mask setting can be performed from the user process. When changing, the user process directly rewrites the mapped predetermined area, and it is not necessary for the user process to issue a system call and request the kernel side to change the setting of the signal mask. Signal mask control method.