JPS60221847A - Adaptive garbage collection system - Google Patents

Abstract

PURPOSE:To improve a memory utilization factor, and to reduce the frequency of garbage collection by distributing and assigning a main storage in accordance with a memory consumption quantity with regard to each data type. CONSTITUTION:An arithmetic processing, interchange of a data to a main storage 2, and interchange of a data to an I/O control device under the control of a channel are executed at a main arithmetic part 1 of a data control device. Also, in order to control a garbage collector system, a useful data and a useless data are distributed and compressed by using a memory compressing circuit 8, and the useful data is shunted to a safe area. Also, an area is reassigned by controlling a memory size register 3 for designating a size of each area which has distributed each area of the storage 2 to each data type. Subsequently, the assignment of the area is determined by controlling a memory scanning circuit 4 for executing an access to a memory consumption quantity counter 5, memory consumption quantity forecasting circuit 6, the previous forecasting quantity holding circuit 7 and the storage 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to garbage collection in data processing devices, and in particular to a garbage collector that divides the target memory into various data areas (which cannot be used interchangeably). The present invention relates to area distribution control for each memory area in a data processing device having.

<Prior art and background> In conventional garbage collection in such data processing devices, memory consumption is calculated for each type of program used for data processing, or more specifically for each type of data for each task handled. Some people may have noticed that the amounts are different, but
Normally, the memory size allocation is fixed, and garbage collection is activated when the memory area allocated to any one data type becomes empty, so if the allocation is inappropriate, some data type will cause a bottleneck. There is a problem in that each time the corresponding area becomes full, garbage collection is performed while other areas are still quite empty, which increases the frequency of garbage collection and reduces the efficiency of data processing. Note that in order to avoid such a drop in efficiency, it would be good if the allocation could be done well and allocated according to the amount of memory consumed, but with general-purpose data processing equipment, it is not possible to limit the work or the programs used, and it is necessary to allocate the allocation in advance. It has been difficult to predict and optimally determine the memory size for each data type, that is, to allocate it, because the conditions are uncertain.

Purpose and Features> In view of the above, an object of the present invention is to provide a method of adaptively allocating memory size to improve memory usage efficiency and reduce the number of garbage collection activations, thereby improving data processing efficiency. In order to achieve the above object, an object of the present invention is to provide a means for setting an allocated area size for each data type to be managed in information processing that has a garbage collector and performs garbage collector control. A means for monitoring memory consumption by data type, a means for storing memory consumption by each data type at least at the time of the previous garbage collection, and a means for controlling these, and the garbage collection is performed at a certain point in time. In this case, the distribution setting for the next area size is performed by extrapolating and predicting the current and/or past memory consumption data.

In other words, the present invention uses an extrapolation method, but for data types that consume a large amount of memory compared to the allocated memory size, the memory size for the next time is expanded, and for data types that are smaller than the allocated memory size, it is reduced. This is done every time garbage collection is performed.

<Embodiment> The figure is an explanatory diagram of an embodiment of the present invention. The figure shows the configuration around the garbage collector and the main storage (MS) 2-t that is the object of collection. In addition to exchanging data with the I10 device by controlling the channel, it also controls the garbage collector system, that is, uses the memory compression circuit 8 to separate and compress useful data and unnecessary data, and to store useful data in a safe area. At the same time, it controls the memory size register 3 which specifies the size (area address) of each area in which the area of MS2 is distributed according to each data type, thereby re-allocating the area. To determine this allocation, a memory consumption counter 5. Memory consumption prediction circuit 6. MS2 controls the previous predicted value holding circuit 7 and performs arithmetic processing.
Memory scan circuit for accessing 4. It controls a memory compression circuit 8 that edits cleared reusable areas and storage areas for useful data that are still to be used in the MS 2 after performing garbage collection and dividing the area into area division and extrapolated predicted values. In the above configuration, if you first set the memory size register 3 to determine the memory size for each data type and proceed with data processing with MS2 divided, as the processing progresses, MS2 will be accessed and become free. The actual amount of memory consumed by each data type is counted by the memory consumption counter 5 via the memory scan circuit 4, and the actual amount of memory used is calculated using this value and the value of the memory size register 3. are compared, and when either of them is full, garbage collection is performed, unnecessary data is cleared by the memory compression circuit 8, useful data is re-edited, and subsequent processing is continued. Every time garbage collection is performed, the memory consumption prediction circuit 6
The memory consumption is predicted for each data type based on the consumption record accumulated in the memory consumption counter 5 and the previous allocation value stored in the predicted value holding circuit 7 that held the previous predicted value. Create a value and store the created value in the predicted value holding circuit 7
The memory size register 3 is held at the same time as the created value and set in the memory size register 3 to reallocate the area. Actually, initially, the value of the memory size register 3 and the value of the predicted value holding circuit 7 are set to appropriately determined values in the same way as the memory size register.

With this kind of control, the distribution will be adaptively updated according to the actual performance each time the garbage collector operates, so even if it is not full at the same time, the distribution will be equalized according to the consumption amount. This increases memory usage efficiency (reduces the number of operations) and improves data processing efficiency.

To give a more specific example of the contents of the predictive extrapolation operation of the memory consumption prediction circuit, the overall size of MS2 (
The actual value of memory consumption for each data type (the value counted by memory consumption counter 5) is U(J)i, and the corresponding predicted value of memory consumption is Let U(jli be the corresponding amount of active (stored useful data) memory cells and define it as a(jl i, where the suffix j is the distribution version number and the suffix i indicates the respective data type. In addition, α (0≦
α≦1) When the safety factor is defined as β (β≧0), the memory erase RIM prediction circuit 6 calculates the previous predicted value U(jl)i held in the predicted value holding circuit 7 and the current actual value LJ(j )i
Using U(j)i=α・U(j)i+(1−α)・U
In order to perform an operation to increase (j-1)i and distribute inactive areas to be reused in accordance with these ratios,
Extrapolation parameter t(jl to tO)-(M-(1+β)・
The amount of allocated memory cells for each data type, including active cells and reusable cells, is determined by calculation in the form 蓓(J)i)/蓓UU)i based on these values. , 5(
j) i-(1+β)・a fj) i + t (J)
・This value is stored in the predicted value holding circuit 7 and set in the memory size register 3, and useful data is returned to each newly allocated area for garbage disposal. The collection work and area redistribution are completed.As for the above parameters, α gradually settles down to a certain value while the same program does the same or similar work, so the initial cent is 0. As long as the value of .5 is about 0.1 and the safety factor β is 0.5 or more, it is practically acceptable.

Please note that these values are just examples, but even if these parameters are not appropriate, the memory usage efficiency will decrease accordingly, and the execution of the program or work may be affected by stopping or malfunctioning. does not occur.

<Effects> As explained above, according to the present invention, the main storage can be allocated according to the amount of memory consumed for each data type, thereby improving memory usage efficiency and reducing the degree of garbage collection operation. Data processing ability can be improved by reducing the amount of data.

BRIEF DESCRIPTION OF THE DRAWINGS The figure is an explanatory diagram of an embodiment of the present invention. In the figure, 1 is the main processing unit, 2 is the main female storage, 3 is the memory size register, 4 is the memory scan circuit, 5 is the memory consumption counter, 6 is the memory consumption prediction circuit, 7 is the predicted value holding circuit, and 8 is the A memory compression circuit is shown.

Claims (1)

[Claims] In an information processing device that has a garbage collector and performs garbage collection control, there is provided a means for setting an allocated area size for each data type to be managed, a means for monitoring memory consumption for each data type, and at least a previous garbage collection. It has a means for storing memory consumption for each data type at the time of collection and a means for controlling these, and when garbage collection is executed at a certain point, the next area size allocation setting is set based on the current and/or past memory consumption. An adaptive garbage collection method characterized by extrapolating and predicting consumption data and setting the distribution.