JP5347451B2 - Multiprocessor system, conflict avoidance program, and conflict avoidance method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multiprocessor system, a contention avoidance program and a contention avoidance method, allowing scheduling for avoiding resource contention to a process of using a resource after detecting the resource that is a factor of the resource contention. <P>SOLUTION: The multiprocessor system 100 includes: a contention detection part 12 for detecting the resource contention based on a request for a lock and/or a latency time after the request of the lock to the resource used by another process operating on another CPU when one process operating on one CPU of a plurality of CPUs uses the resource; an avoidance target specification part 13 for specifying the resource of a detected contention target as an avoidance target; and an execution CPU determination part 7 for determining whether or not each process is a process using the resource of the avoidance target when uprising of each process, and allocating the one CPU of the plurality of CPUs to each uprising process. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a multiprocessor system equipped with a multiprocessor that executes parallel processing by a plurality of processors, a conflict avoidance program, and a conflict avoidance method.

In recent server products and the like, multiprocessor systems that perform parallel processing using a plurality of CPUs are becoming common. In these systems, an OS (operating system) repeats an operation (scheduling) in which a large number of processes necessary for operation take turns and each CPU (central processing unit) has an execution right. .
Each process requires various resources (a memory, a disk, a network, a buffer, etc.) in the process of executing processing on the multiprocessor.

  In addition, when waking up a process that has been paused, in consideration of the effectiveness of the memory cache, priority is given to execution in the CPU that was previously executed, and there is a significant difference in the number of wait queues for each CPU. In this case, the queues to be connected are changed and selected so that the load on each CPU becomes equal.

  For example, as a conventional scheduling method for a multiprocessor system, a method is disclosed in which a process running on a multiprocessor system is scheduled using a criterion of “processing characteristics” determined based on the processing time and the like. . In particular, this conventional scheduling method for a multiprocessor system determines the processing characteristics in advance for each process, and is applicable when the processing time of the process measured during operation tends to exceed the processing characteristics. A method of stopping a process or changing a scheduling algorithm related to the process has been proposed (see, for example, Patent Document 1).

In addition, a conventional shared resource conflict detection method is disclosed in which an interrupt is generated when multi-thread conflict is detected, and a process is stopped (suspended) or other process switching is performed to avoid the conflict. (For example, refer to Patent Document 2).
JP-A-6-119300 JP 2004-252670 A

However, the scheduling method for the conventional multiprocessor system is to change to another scheduling algorithm based on simply exceeding the processing time without specifying which resource contention affects the delay. There was a problem that there was no guarantee that resource competition would be resolved.
Further, the conventional shared resource conflict avoidance method has a problem that there is a high possibility that the influence of overhead generated every time interrupt processing or process switching is executed becomes large.

  In particular, the conventional scheduling method and shared resource conflict avoidance method for a multiprocessor system only avoids resource conflict on an ad hoc basis by stopping or halting a process when a conflict is detected. There is a high possibility that the same type of resource competition will occur immediately, and there is a problem that it is not a permanent countermeasure.

In the multiprocessor system according to the present invention, when one process operating on one processor among a plurality of processors uses resources, the other process operating on the other processor is used. Based on the lock request for the resource and / or the waiting time after the lock request, a conflict detection unit that detects a resource conflict and a resource that is a conflict target in the detected resource conflict should avoid resource conflict. The avoidance target identifying unit that is identified as a target, and whether each process is a process that uses the avoidance target resource upon wakeup of each process, and for each process that is woken up based on the determination result Te, among the plurality of processors, and executing CPU determining unit for assigning the one processor, when the waiting The basis, the total waiting time calculating unit for accumulating the waiting time for each resource has a table for each resource, an information storage unit for storing processor information and latency information corresponding to the resource of the respective table, the The avoidance target specifying unit specifies a resource having a total waiting time exceeding a predetermined reference value as a avoidance target resource based on an accumulation result for each resource by the total waiting time calculating unit, and the execution processor determining unit Determines whether the process is a process that uses the avoidance resource for the resource used by the process to be woken up based on the identified avoidance target resource, and the process to be woken up is avoided When the target resource is used, the waiting time corresponding to the resource to be avoided is stored in the information storage unit. The processor corresponding to a predetermined waiting time, which is allocated shall for the process to be the wake-up.

  The present invention has been made in order to solve the above-described problems. A first object of the present invention is to detect a resource that causes resource competition, and then perform resource competition for a process that uses the resource. The present invention provides a multiprocessor system, a contention avoidance program, and a contention avoidance method capable of performing scheduling for avoiding the above.

  The second purpose is to anticipate resources that are subject to resource contention and avoid them by scheduling in advance, thereby avoiding resource contention itself and generating interrupt processing and process switching that can be overhead. The present invention provides a multiprocessor system, a conflict avoidance program, and a conflict avoidance method capable of operating a system efficiently.

  A third object of the present invention is to provide a multiprocessor capable of implementing permanent countermeasures against resource contention by scheduling so as to avoid resource contention when a process wakes up based on information collected periodically. A system, a conflict avoidance program, and a conflict avoidance method are provided.

  The disclosed multiprocessor system can reduce processing associated with waiting for resources to be released (CPU occupancy due to busy waits and task switching processing), and can allocate the corresponding CPU resources to processing of another process. There is an effect that the processing efficiency can be improved.

  Here, the present invention can be implemented in many different forms. Therefore, it should not be interpreted only by the description of the following embodiments. In addition, the same reference numerals are given to the same elements throughout the embodiments.

  In each embodiment, the system will be mainly described. However, as will be apparent to those skilled in the art, the present invention can also be implemented as a program and method usable on a computer. In addition, the present invention can be implemented in hardware, software, or software and hardware embodiments. The program can be recorded on any computer-readable medium such as a hard disk, CD-ROM, DVD-ROM, optical storage device, or magnetic storage device. Furthermore, the program can be recorded on another computer via a network.

(First embodiment of the present invention)
FIG. 1 is a schematic diagram illustrating the main configuration of the multiprocessor system according to the first embodiment, FIG. 2A is an explanatory diagram illustrating an example of information recorded in a process execution storage unit, and FIG. FIG. 2C is an explanatory diagram showing an example of information recorded in the CPU process information storage unit, and FIG. 3 is a diagram before conflict avoidance in the multiprocessor system. FIG. 4 is a sequence diagram showing the update procedure of the resource exclusive information storage unit and the CPU process information storage unit, FIG. 5 is a sequence diagram showing the update procedure of the process execution storage unit, and FIG. FIG. 7A is an explanatory diagram showing another example of information recorded in the process execution storage unit, and FIG. 7B is a resource example. 7 is an explanatory diagram showing another example of information recorded in the exclusive information storage unit, FIG. 7C is an explanatory diagram showing another example of information recorded in the CPU process information storage unit, and FIG. It is a flowchart which shows the procedure of the conflict avoidance at the time of process wakeup.

  In FIG. 1, a multiprocessor system 100 includes a process wake-up unit 1, a wait queue 2, an execution queue 3, an execution queue connection unit 4, and a processor (CPU) 5, which are the same components as those of a conventional multiprocessor system. Yes.

The process wake-up unit 1 wakes up the paused process (hereinafter referred to as the dormant process 6) to the execution CPU determination unit 7 to be described later based on the release of resources by the process operating on the processor 5. Notify
The waiting queue 2 holds data of a process to which a CPU is not assigned in a first-in first-out (FIFO) list structure.

  The execution queue 3 holds process data in a first-in first-out (FIFO) list structure. When the holding process acquires the execution right of the CPU, the process data is sent to the corresponding CPU.

  The execution queue connection unit 4 reads the data of the process to be woken up from the waiting queue 2 based on the CPU allocation result by the execution CPU determination unit 7 to be described later, and applies the corresponding pause process to the execution queue 3 of the allocated CPU. 6 is connected.

  In addition, the multiprocessor system 100 includes an execution CPU determination unit 7 in which a new function to be described later is added to the execution CPU determination unit that is a component of the conventional multiprocessor system.

  The execution CPU determination unit 7 wakes up each process based on resource identification information and avoidance target information stored in the source exclusive information storage unit 11 described later for the resources used by the process to be woken up. Is a process that uses the resource to be avoided.

  In addition, when the process to be woken up uses the avoidance target resource, the execution CPU determination unit 7 stores the waiting time information in the table corresponding to the avoidance target resource, which is stored in the CPU process information storage unit 14 to be described later. Among them, the CPU corresponding to the shortest waiting time is assigned to the process to be woken up. That is, the execution CPU determination unit 7 assigns one CPU among a plurality of CPUs to each process to wake up based on the determination result.

  The multiprocessor system 100 is a process execution storage unit 8, an exclusive information collection unit 9, a total waiting time calculation unit 10, a resource exclusive information storage unit that are newly added components to the conventional multiprocessor system. 11, a conflict detection unit 12, an avoidance target identification unit 13, and a CPU process information storage unit 14.

  For example, as shown in FIG. 2A, the process execution storage unit 8 identifies each process when the process operates with the execution right of one CPU and uses any resource. Information (hereinafter referred to as a process ID), information for identifying a CPU that operates each process (hereinafter referred to as a CPU ID), information for identifying a resource used by each process (hereinafter referred to as a resource ID), In addition, information on a waiting time until each process requests a resource lock and acquires the lock (hereinafter referred to as wait time information) is stored. Note that the CPU ID and process ID can be obtained from the process information held in the memory. Examples of the resource ID include a resource name, an identification number, or an exclusive variable corresponding to the resource.

  The exclusive information collection unit 9 periodically monitors information (CPUID, process ID, resource ID, waiting time information) recorded in real time in the process execution storage unit 8 and records it within a predetermined period in a fixed period. The updated information is updated in a predetermined column of a table in the resource exclusion information storage unit 11 and the CPU process information storage unit 14 to be described later.

  When a new resource ID is recorded in the process execution storage unit 8, a new field is created in a table of the resource exclusive information storage unit 11 described later to record predetermined information, and a CPU process described later A new table is created in the information storage unit 14 and predetermined information is recorded. When a new combination of resource ID and process ID is recorded in the process execution storage unit 8, a new column is created in a table of a CPU process information storage unit 14 to be described later and predetermined information is recorded. To do.

  The total waiting time calculation unit 10 calculates a total waiting time (hereinafter referred to as a total waiting time) obtained by integrating the waiting time for each resource of the resource ID based on the resource ID and the waiting time information from the exclusive information collecting unit 9. Then, the resource exclusive information storage unit 11 is updated (newly recorded).

  For example, as shown in FIG. 2B, the resource exclusion information storage unit 11 stores information on total waiting time (hereinafter referred to as total waiting time information), and resources whose total waiting time exceeds a predetermined reference value. On the other hand, information that is identified as an avoidance target resource (hereinafter referred to as avoidance target information), and target value information (hereinafter referred to as target value information) whose target value is the total waiting time corresponding to the avoidance target resource. ) Are stored in association with each resource of the resource ID. The predetermined reference value is tuned according to the system environment. For example, in the multiprocessor system 100 that requires real-time performance, a setting in units of msec to μsec is assumed.

  The conflict detection unit 12 detects that the total waiting time exceeds a predetermined reference value based on the total waiting time information recorded in the resource exclusion information storage unit 11, and outputs the detection result to the avoidance target specifying unit 13. To do. That is, the conflict detection unit 12 detects resource conflicts by a plurality of CPUs.

  The avoidance target identification unit 13 records the avoidance target information for the resource whose total waiting time exceeds a predetermined reference value in the resource ID of the resource exclusion information storage unit 11, and records the total waiting time as target value information. To do. That is, the avoidance target identification unit 13 identifies a resource that is a competition target in the resource conflict detected by the conflict detection unit 12 as an avoidance target that should avoid the resource conflict.

  In the present embodiment, there is one resource to be avoided, and information is recorded in the initial stage for the avoidance target and target value fields of the resource exclusion information storage unit 11, and the total waiting time is predetermined. When there are a plurality of resources exceeding the reference value, the avoidance target information and the target value information are recorded for the one resource having the longest total waiting time.

  In addition, the information recorded in the avoidance target and target value fields of the resource exclusion information storage unit 11 indicates that the process using the avoidance target resource will later use another resource, and the other resource's This is held until the total waiting time exceeds the target value of the resource to be avoided.

  For example, as shown in FIG. 2C, the CPU process information storage unit 14 has a table for each resource of the resource ID, and stores the CPU ID, process ID, and waiting time information corresponding to the resource ID of each table. Store.

Next, a processing procedure for avoiding resource contention in the multiprocessor system 100 according to the present embodiment will be described.
In the following description, a case where a total of three processors 5 (CPU # 0, CPU # 1, CPU # 2) are mounted as the multiprocessor system 100 according to the present embodiment will be described. It is not limited to the number.

  First, the operation of a general process when the avoidance target information is not set in the resource exclusion information storage unit 11 and before the avoidance of resource conflict according to the present invention functions will be described.

  In the multiprocessor system 100, various processes are switched such that one process occupies the execution right of the CPU for a certain period of time on each CPU and the process is switched to another process when the process is completed. Parallel processing by a plurality of CPUs is performed.

  In addition, the process that has finished processing is extinguished or transitions to a dormant state. However, the dormant process 6 that has transitioned to the dormant state is eventually woken up from another process and connected to the execution queue 3 prepared for each CPU. Transition to the execution wait state.

  The process connected to the execution queue 3 is taken out from the execution queue 3 when the timing of scheduling comes and acquires the execution right of the corresponding CPU again. In general, such a series of operations is referred to as process scheduling, and mainly implements an OS scheduler function.

When processes on different CPUs require the same resource at the same time, it is necessary to perform exclusive processing between the processes.
As the exclusive processing, the multiprocessor system 100 according to the present embodiment employs the following spin lock mechanism.

First, each process is running on the CPU and calls a spin lock function when resources are required.
In this spin lock function, a process that requires a resource refers to a global (can be referred to from any process) exclusive flag and checks whether there is a process that has acquired the resource at the present time.

  If the exclusion flag is off (no other process has acquired the resource), the process that needs the resource turns on the exclusion flag corresponding to its own process and starts using the resource. .

  If the exclusive flag is on (there is another process that has acquired the resource), the process that needs the resource repeats the reference of the exclusive flag while idling the CPU by loop processing or the like. . Further, when it is confirmed that the resource is released from another process and the exclusive flag is turned off, the process that needs the resource starts using the resource with the exclusive flag corresponding to the self process turned on.

  In the multiprocessor system 100 according to the present embodiment, the case where spin lock is used as exclusive processing will be described. However, the present invention is not limited to spin lock, and examples include mutex and semaphore. Can be mentioned. This mutex is a method in which a waiting process keeps the execution right of the CPU as in the case of spin lock.

  On the other hand, when there is another process that has acquired the resource when the resource is requested, the semaphore temporarily transfers the CPU execution right to another process and pauses the process that requested the resource. It differs from spinlock in that it is forced to transition to a state. The semaphore is a method in which the hibernation process 6 is woken up again when the desired resource is released, re-acquires the right to execute the CPU, and the desired resource can be used.

  Note that the spin lock is a busy wait process by the loop processing during the waiting time. Therefore, in a situation where resource competition is intense and the period until the resource is secured becomes long, the CPU resource is greatly increased. It is wasted and inefficient.

  In addition, semaphores involve processing overhead associated with task switching for operations such as process pause, stop, and wake-up, so in situations where resource contention frequently occurs, the overhead associated with process switching increases accordingly. And must be inefficient. In particular, in recent multiprocessor systems, the inefficiency due to resource competition cannot be ignored as the number of installed processors increases.

For this reason, in the multiprocessor system 100 according to the present embodiment, a new process to be described later is added in order to make the exclusive process such as the spin lock function effectively.
Here, in describing the newly added processing, for example, as shown in FIG. 3, it is assumed that a CPU execution right acquisition state and a resource occupation state by each process are assumed.

  In FIG. 3, process D, process C, and process G are executed in sequence on CPU # 0 within a certain period (here, the range of times T1 to T4), and process B is executed on CPU # 1. And process F are executed in order, and process A and process E are executed in sequence on CPU # 2.

In FIG. 3, in the course of processing by each process, the process A, the process B, and the process C use the resource α, the process F and the process G use the resource β, and the process D and the process E use the resource γ. Assume that is used.
In particular, the movement of the process B will be described. The process B is operating on the CPU # 1, and issues a lock acquisition request for the resource α at the time T2.

However, at time T2, since the resource α is already used by the process A, the process B enters a “waiting” state. In this embodiment, since the spin lock is adopted as the exclusive processing, the process B keeps wasting the CPU while idling during the “waiting” state.
Eventually, when the process A releases the lock of the resource α at the time T3, the process B can acquire the lock of the resource α, and the process B can use the resource α.

  With respect to the CPU execution right acquisition state and the resource occupancy state by each process as described above, the OS of the multiprocessor system 100 allows the process to execute the execution right on each CPU and allocate any resource during operation. Each time it is used, the CPU ID, resource ID, and waiting time information corresponding to the process are recorded in the process execution storage unit 8 in real time.

  That is, during the period from time T1 to time T4 shown in FIG. 3, the CPU ID, resource ID, and waiting time information are recorded in the process execution storage unit 8, as shown in FIG.

  In FIG. 2A, the line surrounded by a thick line frame is data recorded at the time T3 while the process B shown in FIG. 3 is operating on the CPU. The waiting time information “135” indicates that the time from the time T2 at the time of lock acquisition request to the time T3 at the time of lock acquisition (difference between T3 and T2) is 135 msec.

  For process A, process D, process E, and process F shown in FIG. 3, since the waiting time information is a short time of “15” or “25”, a desired resource is used when a lock acquisition request is made. This indicates that there is no other process, the resource lock can be acquired immediately, and only the running time, excluding the idling time.

  Then, as shown in FIG. 4, the exclusive information collection unit 9 periodically monitors information recorded in real time in the process execution storage unit 8 (step S101), and records it within a predetermined period in a fixed period. The updated information is updated in the CPU process information storage unit 14 (step S102).

  In addition, the exclusive information collection unit 9 updates the information recorded within a predetermined period in a certain period to the resource exclusive information storage unit 11 via the total waiting time calculation unit 10 (step S103). The total waiting time calculating unit 10 calculates the total waiting time based on the resource ID and the waiting time information from the exclusive information collecting unit 9 and updates the resource waiting time to the resource exclusive information storage unit 11.

  That is, in the information shown in FIG. 2A, as shown in FIG. 2B, the resource ID and the total waiting time information are recorded in the resource exclusive information storage unit 11. In the information shown in FIG. 2A, the resource ID, process ID, and waiting time information are recorded in the CPU process information storage unit 14, as shown in FIG.

  Then, the conflict detection unit 12 refers to the total waiting time information recorded in the resource exclusion information storage unit 11 (step S104), detects that the total waiting time exceeds a predetermined reference value, and specifies an avoidance target. The detection result is output to the unit 13 (step S105).

  When the predetermined reference value is set to 200 msec, for example, in FIG. 2B, the total waiting time information corresponding to the resource ID “α” is “360” msec. Exceeding the value, the resource α becomes a target for avoiding resource contention.

  The avoidance target specifying unit 13 records the avoidance target information as an avoidance target of resource contention for the resource whose total waiting time exceeds a predetermined reference value in the resource exclusion information storage unit 11, and sets the total waiting time as the target value. Information is recorded (step S106).

That is, in the information shown in FIG. 2A, as shown in FIG. 2B, the avoidance target information column corresponding to the resource ID “α” is marked, and the total waiting time is shown in the target value information column. Information “360” is copied.
Then, when the processes A to G shown in FIG. 3 operating on the CPU finish the target processing, the execution right of the CPU is handed over to other processes, and then the process is suspended.

Hereinafter, the case where the avoidance target information is set in the resource exclusion information storage unit 11 and the resource conflict avoidance according to the present invention functions will be described with reference to FIG.
First, the process wake-up unit 1 activates the execution CPU determination unit 7 and transmits a connection request for the execution queue 3 on the basis of an instruction from another process in response to an arbitrary event (step S201).
The execution CPU determination unit 7 refers to the resource exclusion information storage unit 11 (step S202), and recognizes the avoidance target resource (here, resource α) (step S203).

  Next, the execution CPU determination unit 7 refers to the table corresponding to the avoidance target resource (resource α in this case) in the CPU process information storage unit 14 (step S204).

  Then, the execution CPU determination unit 7 determines whether or not the process to be woken up is a process (here, the process A, the process B, or the process C) that uses the resource to be avoided (here, the resource α). To do.

  Here, for example, when the processes to wake up are processes D to G, the execution CPU determination unit 7 determines that the process is irrelevant to the resource α to be avoided and follows the existing scheduling method. The execution queue connection unit 4 is notified (a queue connection request is made).

  According to the existing scheduling method, the process to wake up is normally reconnected to the execution queue 3 of the CPU that operated last time. However, when the number of processes on the execution queue 3 of each CPU is extremely uneven, the number of processes waiting in the execution queue 3 is small so as to reduce the unevenness of the execution queue 3 according to the existing load balancing function. In some cases, it is connected to the execution queue 3 of another CPU.

  When the processes to wake up are processes A to C, the execution CPU determination unit 7 determines that the process is related to the resource α to be avoided. Then, the execution CPU determination unit 7 performs the previous processing on the CPU # 2 in which the process A having the shortest waiting time information of 15 msec in the table corresponding to the resource α to be avoided in the CPU process information storage unit 14 operates. The process B and the process C not operating on the CPU # 2 are aggregated (step S205).

  That is, when the process to wake up is the process A, the execution queue connection unit 4 is notified so as to be connected to the execution queue 3 of the CPU # 2 as in the previous case. Also, when the processes to wake up are the process B and the process C, the execution queue connection unit 4 is notified so as to connect to the execution queue 3 of the same CPU # 2 as the process A (step S206).

  Then, the execution queue connection unit 4 refers to the data in the waiting queue 2, wakes up a predetermined pause process 6 (here, process B), and enters the execution queue 3 (here, execution queue 3 of CPU # 2). Connect (step S207).

  The process that wakes up (here, process B) waits on the execution queue 3 (step S208), and acquires the execution right of the CPU (here, CPU # 2) (step S209). A lock acquisition request is transmitted to α) (step S210). Also, the resource (here, resource α) transmits that the lock has been acquired (step S211).

  The process (here, process B) requests the CPU ID and process ID in the process information from the memory (step S212), and the CPU ID (here, CPU # 2) and process ID (here, B). ) Is acquired (step S213).

  The process (here, process B) uses a resource (here, resource α) for a predetermined process (step S214). When the predetermined process is completed, the process (here, resource α) is performed. An unlock request is transmitted (step S215). Further, the resource (here, resource α) transmits that the lock has been released (step S216).

Then, the process (here, process B) records the information (CPUID, process ID, resource ID, waiting time information) of its own process (here, process B) in the process execution storage unit 8 (step S217). .
Then, the process (here, process B) ends the process (step S218) and enters a dormant state.

  Therefore, for example, as shown in FIG. 6, in the period from time T4 to time T5, which is a time after this (after time T4 in FIG. 5), a process A that uses a resource α that needs to avoid resource contention. Process B and Process C are all integrated and operated by CPU # 2. The process D, the process G, and the process F operate on the same CPU (CPU # 0 or CPU # 1) as the previous time, and the process E changes from the previous CPU # 2 to the CPU # by the existing load balance function. 1 to operate on CPU # 1.

  As described above, the multiprocessor system 100 according to the present embodiment uses processes (here, process B and process C) that use resources (here, resource α) that need to avoid resource contention by the resource contention avoidance operation. ), The resource (here, resource α) can be acquired immediately after the resource request, and the waiting time that has occurred can be greatly reduced. Moreover, it becomes possible to allocate the CPU resource vacancy associated therewith to other processes (here, process H, process I and process J).

Here, after that, resource contention related to resources (hereinafter referred to as avoidance target resources) other than the resources that are currently targeted for avoiding resource conflicts (hereinafter referred to as current avoidance target resources) becomes intense, and the avoidance target candidate resources Consider a case where the total waiting time information corresponding to the resource ID exceeds a predetermined reference value.
When a process using the avoidance target candidate resource is woken up, of course, it is a CPU aggregation target, but the following processing is performed.

  First, when a process using the current avoidance target resource is included as a process using the avoidance target candidate resource, the execution CPU determination unit 7 sets the total waiting time information corresponding to the avoidance target candidate resource and Compare the target value information of the current avoidance target resource copied during the previous setting as the avoidance target of resource conflict.

  When the total waiting time information corresponding to the avoidance target resource exceeds the target value information corresponding to the current avoidance target resource, the execution queue is re-executed even for the process using the current avoidance target resource. Among the tables corresponding to the avoidance target candidate resources in the CPU process information storage unit 14, the processes corresponding to the shortest waiting time information are collected in the CPU that is operating.

  In this case, the execution CPU determination unit 7 outputs the determination result to the avoidance target specifying unit 13, and the avoidance target specifying unit 13 in the resource exclusion information storage unit 11 avoids the avoidance target information and the target corresponding to the current avoidance target resource. The value information is deleted, and predetermined information is recorded in the avoidance target information and target value information corresponding to the avoidance target candidate resource.

  On the other hand, when the total waiting time information corresponding to the avoidance target resource is lower than the target value information corresponding to the current avoidance target resource, the avoidance candidate for the process using the current avoidance target resource Removed from CPU aggregation target for resources. In other words, the process that is using the current avoidance target resource continues to operate on the CPU that is aggregated when avoiding resource contention regarding the current avoidance target resource.

  Specifically, as shown in FIG. 7B, due to the effect of avoiding resource contention, the total waiting time corresponding to the resource α is shortened from “360” to “40”, and the total waiting time corresponding to the resource δ. It can be seen that the time “240” exceeds the predetermined reference value “200”.

  In this case, when the target value information “360” corresponding to the resource α is compared with the total waiting time information “240” corresponding to the resource δ, the target value information corresponding to the resource α is the total waiting time corresponding to the resource δ. Since it exceeds the time information, the past scheduling is prioritized, and the CPU is not aggregated based on the resource δ this time.

Hereinafter, the process described so far will be described with reference to the flowchart shown in FIG.
First, the process wake-up unit 1 activates the execution CPU determination unit 7 and transmits a connection request for the execution queue 3 based on an instruction from another process at an event trigger (step S1).
The execution CPU determination unit 7 refers to the resource exclusion information storage unit 11 (step S2), and determines whether there is a resource exceeding a predetermined reference value (step S3).

  If it is determined in step S3 that there is no resource exceeding the predetermined reference value, the execution CPU determination unit 7 transmits a connection request to the execution queue 3 of the same CPU as the previous time to the execution queue connection unit 4. (Step S4). That is, the execution CPU determination unit 7 notifies the execution queue connection unit 4 (makes a queue connection request) so as to follow the existing scheduling method.

  The execution queue connection unit 4 wakes up and connects the pause process 6 to the designated execution queue 3 (step S5), this process waits on the execution queue 3, and then acquires the execution right of the CPU. Become. Since the subsequent processing is almost the same as Step S210 to Step S218 shown in FIG. 5 (not limited to the process B, resource α, and CPU # 1), description thereof will be omitted.

  If it is determined in step S3 that there is a resource exceeding the predetermined reference value, the execution CPU determination unit 7 refers to a table corresponding to the excess resource in the CPU process information storage unit 14 (step S3). S6).

Then, the execution CPU determination unit 7 determines whether or not the process to be woken up is a process that uses an excess resource (step S7).
If it is determined in step S7 that the process does not use the excess resource, the process proceeds to step S4 described above.

  If it is determined in step S7 that the process uses the excess resource, the execution CPU determination unit 7 determines that the resource used in the past by the process in the referenced resource table is the current one. It is determined whether it is an avoidance target (step S8).

  If it is determined in step S8 that it is not an avoidance target, the execution CPU determination unit 7 operates the process with the shortest waiting time information in the table corresponding to the avoidance target resource in the CPU process information storage unit 14. The CPU decides to consolidate and sends a connection request to the execution queue 3 to the execution queue connection unit 4 (step S9).

  If it is determined in step S8 that the target is an avoidance target, the execution CPU determination unit 7 includes target value information of a resource (current avoidance target resource) that is a current avoidance target due to resource competition in the past, The total waiting time information of currently competing resources (avoidance target candidate resources) is compared (step S10).

Then, the execution CPU determination unit 7 determines whether or not the total waiting time of the avoidance target candidate resource is equal to or greater than the target value of the current avoidance target resource (step S11).
If it is determined in step S11 that the total waiting time of the avoidance target candidate resource is not equal to or greater than the target value of the current avoidance target resource, the process proceeds to step S4 described above.

  If it is determined in step S11 that the total waiting time of the avoidance target candidate resource is equal to or greater than the target value of the current avoidance target resource, the process proceeds to step S9 described above. In this case, the execution CPU determination unit 7 outputs a determination result to the avoidance target specifying unit 13, and the avoidance target specifying unit 13 in the resource exclusion information storage unit 11 avoids the avoidance target information corresponding to the current avoidance target resource. The target value information is deleted, and predetermined information is recorded in the avoidance target information and target value information corresponding to the avoidance target candidate resource.

  As described above, the multiprocessor system 100 according to the present embodiment can reduce processing associated with resource release waiting, and can allocate the CPU resources accordingly to processing of another process, improving the processing efficiency of the system. The effect that it can be made is produced.

  In addition, the multiprocessor system 100 according to the present embodiment enables the avoidance operation in which resource contention is predicted at the stage before the process next acquires the execution right of the CPU, that is, at the time when the process wakes up and enters the wait state in the execution queue 3 (Execution queue movement, etc.) can be performed in advance, and it is possible to avoid permanent conflicts. In addition, there is no need to perform forced task switching by interrupts during process operation, minimizing processing capacity degradation due to overhead. There is an effect that it can be performed.

  Further, since the multiprocessor system 100 according to the present embodiment can identify a resource related to CPU waste and avoid resource conflict targeting a process that uses the resource, the resource that is the target of competition There is an effect that the influence on the process unrelated to the process can be suppressed.

  In the multiprocessor system 100 according to the present embodiment, the resource exclusion target in the resource exclusion information storage unit 11 is set to one resource, but the present invention is not limited to this.

  For example, depending on the number of resources used in the multiprocessor system 100, a predetermined number of resources or less may be targeted for avoidance, the avoidance target information may be recorded, and the total waiting time may be recorded as target value information.

  In this case, when the resource to be avoided (candidate resource to be avoided) newly recorded is recorded in the resource exclusion information storage unit 11 and the avoidance target exceeds a predetermined number, the resource exclusion information The minimum target value among the target values corresponding to the avoidance target resource (current avoidance target resource) recorded in the storage unit 11 is compared with the total waiting time corresponding to the avoidance target candidate resource.

  When the total waiting time corresponding to the avoidance target candidate resource exceeds the minimum target value among the target values corresponding to the current avoidance target resource, the minimum target value information and the corresponding avoidance target information are The predetermined information is recorded in the avoidance target information and target value information corresponding to the avoidance target candidate resource.

  In the multiprocessor system 100 according to the present embodiment, the execution CPU determination unit 7 determines whether each process is a process that uses a resource to be avoided when the process is woken up. Based on this, one CPU among a plurality of CPUs is assigned to each process to be woken up. However, the avoidance target specifying unit 13 may have the function instead of the execution CPU determining unit 7. .

(Second embodiment of the present invention)
FIG. 9 is a schematic diagram showing the main configuration of the multiprocessor system according to the second embodiment, FIG. 10A is an explanatory diagram showing an example of information recorded in the process execution storage unit, and FIG. FIG. 10C is an explanatory diagram illustrating an example of information recorded in the CPU process information storage unit. 9 and 10, the same reference numerals as those in FIGS. 1 to 8 denote the same or corresponding parts, and the description thereof is omitted.

  The average waiting time calculating unit 10a calculates a total waiting time for each resource of the resource ID based on the resource ID and the waiting time information from the exclusive information collecting unit 9, and adds the number of each resource in the resource ID to each resource. Calculate the number of uses of. In addition, the average waiting time calculating unit 10a calculates an average waiting time (hereinafter referred to as an average waiting time) obtained by dividing the number of times of use with respect to the total waiting time, and calculates the average waiting time for each resource of the resource ID. The number of uses is updated (newly recorded) in the resource exclusion information storage unit 11a.

  For example, as shown in FIG. 10B, the resource exclusion information storage unit 11a has information on average waiting time (hereinafter referred to as average waiting time information), information on the number of uses, and the average waiting time being a predetermined reference value. Information that identifies a resource that has been exceeded as a avoidance target resource (hereinafter referred to as avoidance target information), and target value information that has an average waiting time corresponding to the avoidance target resource as a target value (hereinafter, Are stored in association with each resource of the resource ID. The predetermined reference value is tuned according to the system environment. For example, in the multiprocessor system 100 that requires real-time performance, a setting in units of msec to μsec is assumed.

  For example, when the reference value is set to 100 msec, in the information shown in FIG. 10A (FIG. 2A), the resource α is used three times from time T1 to time T4, and the total waiting time Is 360 msec, the average waiting time is 120 msec, which exceeds the reference value, so that the resource α is a target for avoiding resource contention.

  The conflict detection unit 12a detects that the average waiting time exceeds a predetermined reference value based on the average waiting time information recorded in the resource exclusion information storage unit 11a, and outputs the detection result to the avoidance target specifying unit 13a. To do.

  The avoidance target specifying unit 13a records avoidance target information for the resource whose average waiting time exceeds a predetermined reference value in the resource ID of the resource exclusion information storage unit 11a, and records the average waiting time as target value information. To do.

  In this embodiment, there is one resource to be avoided, and information is recorded in the initial stage for the avoidance target and target value columns of the resource exclusion information storage unit 11a, and the average waiting time is predetermined. When there are a plurality of resources exceeding the reference value, the avoidance target information and the target value information are recorded for the one resource having the longest average waiting time.

  In addition, the information recorded in the avoidance target and target value fields of the resource exclusion information storage unit 11a indicates that the process using the avoidance target resource then uses another resource, and the other resource's This is held until the average waiting time exceeds the target value of the resource to be avoided.

  The multiprocessor system 100 according to the second embodiment differs from the first embodiment only in that an average waiting time calculation unit 10a is provided instead of the total waiting time calculation unit 10. Except for the operational effects of the average waiting time calculation unit 10a, the same operational effects as those of the first embodiment are obtained.

  In the first embodiment described above, the waiting time for resource release is usually short for a certain resource, but a long waiting time occurs suddenly only in a specific monitoring period, and the total waiting time becomes the reference value. If it exceeds, this resource becomes a target for avoiding resource contention, but the improvement in processing efficiency is slight.

  On the other hand, in the present embodiment, the resource exclusion information storage unit 11a holds the average waiting time information, and the resource that is the resource conflict avoidance target is specified based on the average waiting time information. As a result, the multiprocessor system 100 according to the present embodiment grasps an accurate contention state in real time, gives priority to a resource that takes a relatively long time for the waiting time for resource release, and makes it a target for avoiding resource contention. As compared with the first embodiment, there is an effect that the processing efficiency can be further improved.

(Third embodiment of the present invention)
FIG. 11 is a sequence diagram showing a procedure for updating the process execution storage unit of the multiprocessor system according to the third embodiment. FIG. 12 shows a procedure for avoiding contention when the process wakes up in the multiprocessor system according to the third embodiment. It is a flowchart. 11 and 12, the same reference numerals as those in FIGS. 1 to 10 denote the same or corresponding parts, and the description thereof is omitted.

  In the present embodiment, as a precondition, a user of the multiprocessor system 100 uses a system call (sched-setaffinity, etc.) or the like to allocate and operate CPUs that operate some processes in a fixed manner. Suppose. For example, when the allocation setting is performed so that the process B is fixedly operated by the CPU # 1, a flag indicating that the process B is allocated to the CPU # 1 is recorded in the process information existing in the memory. ing.

  11 is obtained by adding a new step S204a between step S204 and step S205 in FIG. 5. FIG. 12 shows a new step between step S11 and step S9 in FIG. S11a is added.

  In steps S204a and S11a, the execution CPU determination unit 7 refers to the process information in the memory, and CPUs other than the CPU corresponding to the shortest waiting time among CPUs corresponding to the resources to be avoided are specified processes. It is determined whether or not the CPU is fixed and assigned. If the execution CPU determining unit 7 determines that the fixed allocation is performed, the fixed CPU is allocated to the process to be woken up instead of the CPU corresponding to the shortest waiting time. . If the execution CPU determination unit 7 determines that the fixed CPU is not allocated, the CPU corresponding to the shortest waiting time is allocated to the process to be woken up.

  Note that the multiprocessor system 100 according to the third embodiment differs from the first embodiment only in that CPUs for operating some processes are fixedly allocated and operated. Except for the effects, the same effects as those of the first embodiment are obtained.

In the first embodiment described above, the other processes (process B and process C) are aggregated in the CPU # 2 in which the process A with the shortest waiting time among the processes A to C using the resource α is operating. As described above, in addition to the process A, the process B and the process C are connected to the execution queue 3 of the CPU # 2.
On the other hand, in the present embodiment, the operation is performed so that the other processes (process B and process C) are concentrated on the CPU # 1 to which the process B is fixedly assigned.

  That is, when the process to be woken up is process B, process B is connected to the execution queue 3 of the same CPU # 1 as the previous time, and the process to be woken up is process A or process C. Process A or Process C is connected to the execution queue 3 of the same CPU # 1. As for the wake-up of other processes not directly related to the avoidance target resource α, the existing scheduling operation is followed as in the first embodiment described above.

  As a result, in the multiprocessor system 100 according to the present embodiment, even when there is a process in which the operating CPU is fixed, the waiting state for resource release is maintained without affecting the fixed operation of the CPU as much as possible. This avoids the waiting time and achieves the effect of reducing the waiting time and improving the processing efficiency of the system. In addition, the multiprocessor system 100 according to the present embodiment has an effect that it is possible to realize operation of a process that can be reflected in a more detailed operation design in consideration of immediacy.

It is the schematic which shows the main structures of the multiprocessor system which concerns on 1st Embodiment. (A) is explanatory drawing which shows an example of the information recorded on a process execution storage part, (b) is explanatory drawing which shows an example of the information recorded on a resource exclusive information storage part, (c) is CPU It is explanatory drawing which shows an example of the information recorded on a process information storage part. It is explanatory drawing which shows the process operation example before the conflict avoidance in a multiprocessor system. It is a sequence diagram which shows the update procedure of a resource exclusive information storage part and a CPU process information storage part. It is a sequence diagram which shows the update procedure of a process execution storage part. It is explanatory drawing which shows the process operation example after the conflict avoidance in a multiprocessor system. (A) is explanatory drawing which shows the other example of the information recorded on a process execution storage part, (b) is explanatory drawing which shows the other example of the information recorded on a resource exclusive information storage part, ( (c) is explanatory drawing which shows the other example of the information recorded on CPU process information storage part. It is a flowchart which shows the procedure of the conflict avoidance at the time of process wakeup in a multiprocessor system. It is the schematic which shows the main structures of the multiprocessor system which concerns on 2nd Embodiment. (A) is explanatory drawing which shows an example of the information recorded on a process execution storage part, (b) is explanatory drawing which shows an example of the information recorded on a resource exclusive information storage part, (c) is CPU It is explanatory drawing which shows an example of the information recorded on a process information storage part. It is a sequence diagram which shows the update procedure of the process execution storage part of the multiprocessor system which concerns on 3rd Embodiment. 10 is a flowchart illustrating a procedure for avoiding contention when waking up a process in a multiprocessor system according to a third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Process wake-up part 2 Wait queue 3 Execution queue 4 Execution queue connection part 5 Processor 6 Pause process 7 Execution CPU determination part 8 Process execution storage part 9 Exclusive information collection part 10 Total waiting time calculation part 10a Average waiting time calculation part 11, 11a Resource exclusion information storage unit 12, 12a Conflict detection unit 13, 13a Avoidance target identification unit 14 CPU process information storage unit 100 Multiprocessor system

Claims (5)

In a multiprocessor system including a multiprocessor in which a process that occupies the execution right of one of a plurality of processors uses an arbitrary resource and performs parallel processing by the plurality of processors,
When one process operating on one of the plurality of processors uses a resource, another process operating on another processor requests a lock on the resource being used and / or A contention detection unit that detects resource contention based on the waiting time after a lock request;
An avoidance target identifying unit that identifies a resource that is a conflict target in the detected resource conflict as an avoidance target to avoid resource conflict;
When each process is woken up, it is determined whether each process is a process that uses the avoidance target resource, and one of the plurality of processors is selected for each process to be woken up based on the determination result. An execution processor determination unit to which
Based on the waiting time, a total waiting time calculating unit that accumulates the waiting time for each resource;
An information storage unit having a table for each resource and storing processor information and waiting time information corresponding to the resource of each table;
With
The avoidance target specifying unit specifies a resource whose total waiting time exceeds a predetermined reference value as a resource to be avoided based on the accumulation result for each resource by the total waiting time calculating unit,
The execution processor determination unit determines whether the process is a process using the avoidance target resource with respect to the resource used by the process to be woken up based on the identified avoidance target resource. When the process to be avoided uses the avoidance target resource, the process corresponding to the predetermined waiting time stored in the information storage unit among the waiting time corresponding to the avoidance target resource A multiprocessor system characterized by assigning to In a multiprocessor system including a multiprocessor in which a process that occupies the execution right of one of a plurality of processors uses an arbitrary resource and performs parallel processing by the plurality of processors,
When one process operating on one of the plurality of processors uses a resource, another process operating on another processor requests a lock on the resource being used and / or A contention detection unit that detects resource contention based on the waiting time after a lock request;
An avoidance target identifying unit that identifies a resource that is a conflict target in the detected resource conflict as an avoidance target to avoid resource conflict;
When each process is woken up, it is determined whether each process is a process that uses the avoidance target resource, and one of the plurality of processors is selected for each process to be woken up based on the determination result. An execution processor determination unit to which
Based on the waiting time, an average waiting time calculating unit that calculates an average time of the waiting time for each resource ;
An information storage unit having a table for each resource and storing processor information and waiting time information corresponding to the resource of each table;
With
Based on the calculation result for each resource by the average waiting time calculating unit, the avoidance target specifying unit specifies a resource whose average waiting time exceeds a predetermined reference value as a resource to be avoided,
The execution processor determining unit, based on the prior SL avoidance of resource identified, it is determined whether the process that the process uses the avoidance of resources to the resource used by a process to be the wake-up, the When the process to be woken up uses the avoidance target resource, the processor corresponding to the predetermined waiting time stored in the information storage unit among the waiting time corresponding to the avoidance target resource is woken up. A multiprocessor system characterized by assigning to a process. In the multiprocessor system according to claim 1 or 2 ,
Among the processors that operate the process that uses the resource to be avoided, a processor other than the processor that corresponds to the predetermined waiting time is fixedly assigned as a processor that operates the specific process, and When the process to be used uses a resource to be avoided, the execution processor determination unit replaces the processor corresponding to the predetermined waiting time with the fixedly allocated processor for the process to be woken up. Multiprocessor system characterized by assigning A process that occupies the execution right of one processor among a plurality of processors uses an arbitrary resource, has a multiprocessor that executes parallel processing by the plurality of processors, a table for each resource, and An information storage unit that stores processor information and waiting time information corresponding to resources of each table, and a conflict avoidance method for a multiprocessor system,
When one process operating on one of the plurality of processors uses a resource, another process operating on another processor requests a lock on the resource being used and / or Based on the waiting time after requesting the lock, a total waiting time calculating step for accumulating the waiting time for each resource,
Based on the integration result for each resource by the total waiting time calculation step , a conflict detection step of detecting resource conflict,
An avoidance target identifying step for identifying a resource that is a conflict target in the detected resource conflict as an avoidance target to avoid resource conflict;
When each process is woken up, it is determined whether each process is a process that uses the avoidance target resource, and one of the plurality of processors is selected for each process to be woken up based on the determination result. and the execution processor determining step of assigning a processor,
It includes,
The avoidance target specifying step specifies a resource whose total waiting time exceeds a predetermined reference value as a resource to be avoided based on the accumulation result for each resource by the total waiting time calculating step,
The execution processor determination step determines whether the process is a process using the avoidance target resource with respect to the resource used by the process to be woken up based on the identified avoidance target resource, and When the process to be avoided uses the avoidance target resource, the process corresponding to the predetermined waiting time stored in the information storage unit among the waiting time corresponding to the avoidance target resource Conflict avoidance method characterized by assigning to A process that occupies the execution right of one processor among a plurality of processors uses an arbitrary resource, has a multiprocessor that executes parallel processing by the plurality of processors, a table for each resource, and An information storage unit that stores processor information and waiting time information corresponding to resources of each table, and a conflict avoidance method for a multiprocessor system,
When one process operating on one of the plurality of processors uses a resource, another process operating on another processor requests a lock on the resource being used and / or An average waiting time calculating step for calculating an average time of the waiting time for each resource based on the waiting time after the request for the lock ;
Based on the calculation result for each resource by the average waiting time calculation step , a conflict detection step of detecting resource conflict;
An avoidance target identifying step for identifying a resource that is a conflict target in the detected resource conflict as an avoidance target to avoid resource conflict;
When each process is woken up, it is determined whether each process is a process that uses the avoidance target resource, and one of the plurality of processors is selected for each process to be woken up based on the determination result. and the execution processor determining step of assigning a processor,
It includes,
The avoidance target specifying step specifies a resource whose average waiting time exceeds a predetermined reference value as a avoidance target resource based on a calculation result for each resource by the average waiting time calculating step,
The execution processor determination step determines whether the process is a process using the avoidance target resource with respect to the resource used by the process to be woken up based on the identified avoidance target resource, and When a process to be avoided uses a resource to be avoided, a process corresponding to a predetermined waiting time stored in the information storage unit among the waiting times corresponding to the resource to be avoided is set as the process to be woken up. Conflict avoidance method characterized by assigning to

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