JPS62131350A - Page control system for garbage collector - Google Patents

Abstract

PURPOSE:To reduce the number of times of paging by providing a means which performs page-out and invalidates pages in consideration of the access tendency of a copy type garbage collector. CONSTITUTION:When a GC flag 2 is referred to detect the execution of garbage collection and a memory space register 3 is referred to copy data, to which memory access is effective, to an unused memory space, a page cross check part 6 checks whether data exceeds a page boundary or not, and a check signal is sent to a page table control part 8 if it exceeds the page boundary. The page table control part 8 updates contents of a page table and an LRU 11 on a basis of the check signal so that page-out of the page in the copy destination is performed, and the control part 8 instructs an MSC 7 page-out and updates contents of the page table 10 and the LRU 11 on a basis of indication information from a page invalidating part 9 so that the memory space filled up with ineffective data by garbage collection is invalidated.

Description

[Detailed Description of the Invention] [Overview] The present invention provides an information processing system that performs garbage collection wx7, and pages that are not accessed during and after the garbage collection is executed, and invalidates unnecessary pages. This is a garbage collector that reduces the number of paging operations and performs high-speed processing without performing paging control.

[Conventional technology]

Conventionally, in busy information processing systems, the functions of paging control and garbage collector have not been organically coupled and have operated independently.

[Problem that the invention seeks to solve]

Normal copy type garbage collector attack/2 minutes (memory)
The program is executed by dividing the space into two equal parts, transferring valid data from one space to the other space as appropriate. After the garbage collection W, the copy source space is no longer valid and is not read again (READ), but it is paged out and stored in an external storage such as a disk. Garbage collection again! During I/, valid data is copied from one space to the other space 1417, but the copied data is not accessed in the copy destination space until garbage collection is completed. In this way, during garbage collection training, the page in the copy destination space does not need to exist in real memory once the copying is completed. Since this copy destination page is on real memory, other pages will be deleted, resulting in a large amount of paging overhead. Similarly, in the garbage collection w/Mt, since the page of the copy source space exists on the real memory, extra paging must be performed to load the page storing the necessary data.

In addition, the garbage collection system has the disadvantage that the overhead is considerable because the entire space is accessed at random.

The present invention addresses the above drawbacks! The purpose was to reduce the number of paging operations and enable high-speed processing.

[Means for resolving the concession]

The purpose is to perform garbage collection by the garbage collector 15 in the CPU 1 in an H slag processing system having a copy type garbage collector. The page cross-check unit 6 checks whether the destination page is full due to the copy, and the page cross-check unit 6 checks whether the page is full. The present invention is characterized by providing a page table creation means for setting the page as a page out target when receiving a signal indicating that the page has become a page out, and invalidating the page 9 that was the copy source when the garbage collection ends. This is achieved through the garbage collector's page control scheme.

[Effect]

The present invention is a system that takes into account the access tendency of a copy type garbage collector and provides means for appropriately performing page out and page invalidation to reduce the number of paging times.

A copy type garbage collector collects invalid data and compresses the Vi area by dividing the memory space into two and copying valid data from the used space to the unused space. , unused sky 1!
The IK valid natator is copied, and after copying, the copied data is not accessed until garbage collection W/ is completed and it is used again. Therefore, if valid data is copied to the page in the unused space that is the copy destination,
By paging out the page (outputting it to external storage), the real storage can be used effectively. Furthermore, after the garbage collection W is completed, all valid data is copied from the used space.This method aims to improve the efficiency of paging control by reducing the number of pageouts.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a system configuration diagram showing one implementation of the present invention.

In the figure, l is CPU (central processing unit), 2 is GC
7 lag, 3 is memory space register, 4 is address register, 5 is data register, 6 is page loader, 7 is MSC (Main Storage Container)
trollerλ, 8 is a page table restraining leg, 9 is a page invalidation part, IO is a page table, 11 is LRU, 1
2 is an MS (Main Storage+), l3 is a channel, 14 is a disk, and 15 is a garbage collector. FIG. 2 is a diagram showing details of a page table showing an embodiment of the present invention.

In the figure, 21 is a page number, 22 is a physical address,
23 indicates a page-out condition. When the garbage collector 15 is activated, the central processing unit 1 sets the GC flag 2 (garbage collector/when the garbage collector is in progress, the flag is on, and the page cross-out condition is detected. When garbage collection 1 is completed, the MGC flag 2 is turned on.
Turn off. The central processing unit #t also includes the start address of each memory space divided into two equal parts in the memory space register 3;
Send end address data. Further, the central processing unit 1 transmits a logical address for IJ access to the address register 4I/c, and performs data transmission/reception with the data register 5fc. The memory register 3 receives data from the central processing unit t71, stores the start address and end address of the memory space divided into two parts, and also processes the page cross check unit 6 and page invalidation unit. 9. The page cross check section 6 outputs to GC.
Referring to flag 2, garbage collection is in progress (the GC flag is on), and memory access is performed by referring to memory space register 3. When attempting to retrieve valid data into an unused memory space, a page boundary is crossed. I'm checking what's going on. If the number is exceeded, the page table control unit 8 sends a check signal to the effect that the number has been exceeded.

In addition, MSC (Main Storage Cont
The logical address from the address register 4 is used by the page table system 1111 unit 8 to refer to the physical address 22 of the page table 10 (see FIG. 2), and the logical address is input to the desired physical address. Based on physical address? By accessing jMS 12 and sending and receiving data, and by instructing channel 13 to load pages on disk 14 (containing user files and page files (6)) to MS 12, pages of lltMs + 2 is stored on the disk 141'I: on channel 13 exit 1.

Page table! The IJJ section 8 accesses the page table 10 based on the instruction from the MSC 7 and outputs the contents of the page table IO to the MSC 7&C.
Update l l 1.

In addition, based on the check call signal from the page cross check P6, the page table control unit sends the page table LRU 11 so as to page out the copy destination page.
(It is Least Recently Used and corresponds to the page table.) Change the contents,
Instructs MSC7 to page out. Furthermore, the page table control unit 8 controls the page table IO so that the memory space filled with invalid data is invalidated by garbage collection based on the instruction information from the page invalidation unit 9.
，! - Modify the contents of LRU11. The page invalidation unit refers to the GC flag 2 and the memory space register 3, and uses the address of the copy source memory space to determine the page to be invalidated by the page table system when garbage collection 1 is completed. 8.

〔Effect of the invention〕

As described above, with end-of-life access, processing can be sped up because invalidation of unnecessary pages, secondary copying of pages that are not accessed, and unnecessary page-ins and page-outs can be omitted.

[Brief explanation of drawings]

Figure ta1 is a system configuration diagram showing one implementation of the present invention. FIG. 2 is a diagram showing details of a page table showing an embodiment of the present invention. Explanation of symbols, 1 is CPU (Central Processing Unit), 2 is GC
7 lags, 3 is memory space registers, 4 is address registers, 5 is delta registers, 6 is page crosscheck 1 part, 7 is MSC (Maln 5tor-age C
ontroller), 8 is a page table subsection, 9
is the page invalid part, lO is the page table, and 11 is the LRU
%12 is MS (Main Storage+, 13 is channel, 14 is disk, 15 is garbage collector

Claims (1)

[Claims] In an information processing system equipped with a copy type garbage collector, there is provided a page cross check means for checking whether a copy destination page is full with copied data, and a page cross check means for checking whether the page is full. A page control method for a garbage collector, characterized in that a page table control means is provided for setting a page as a page-out target when a check signal is received and invalidating a copy source space at the end of garbage collection.