JPH03147156A - Swap processing system for required physical page - Google Patents

Abstract

PURPOSE:To accelerate a swap processing by limiting the object of swap-out to a physical page, which is required for swapping-in a process, only out of all the physical pages used by the process. CONSTITUTION:A process swap-out means SF3 swaps out only the physical page, which is required for swapping-in the process selected by a swap-in process selecting means SF1, out of the physical pages belonging to the process, which is selected by a swap-out processing selecting means SF2, according to a page swap-out means SOF. The passing time of a process control table is updated to '0' corresponding to the swapped-out process and process state information is updated to 'OUT' to show a swapped-out state, respectively. Then, the number of the swapped-out pages is added to a swap-out page number. Thus, the swap processing is accelerated.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention writes an image on the main memory of a computer to an auxiliary memory, or writes an image written on the auxiliary memory to the main memory. Concerning the swap-out and swap-in processing methods.

[Prior Art] Conventionally, a process to be swapped out has all its physical pages to be swapped out.

Therefore, unused physical pages were also being swapped out.

[Problems to be Solved by the Invention] The conventional method described above swaps out all physical pages of the process to be swapped out.

Swap space was needed to swap out entire processes. Furthermore, when the process is swapped in next time, all new physical pages are allocated even if the previous physical pages remain. Unnecessary data transfers have to take place.

The drawback was that it was time consuming.

SUMMARY OF THE INVENTION An object of the present invention is to provide a swap processing method that solves the above-mentioned problems by swapping out only physical pages that are required during swap-in.

[Means for Solving the Problems] The swap processing method for necessary physical pages according to the present invention is a swap processing method for inputting and outputting process images between the main storage device and the auxiliary storage device of a computer. A process management table that stores the number of pages and swapout pages for each process.

A page swapout means for swapping out physical pages.

A page swap-in means for swapping in physical pages.

In response to the swap request, a process whose elapsed time is the longest among the processes whose process state information in the process management table indicates swap-out is selected as the process to be swapped in.

Swap-in process selection means for obtaining the number of swap-out pages of the selected process.

In order to secure the physical pages required by the swap-in process, the process state information in the process management table indicates swap-out,
and the number of all physical pages of that process is not equal to the number of swap-out pages, and the process is not selected by the swap-in process selection means, and if such a process does not exist, the process management table is Swap-out process selection means for selecting a process whose elapsed time is the longest among the processes whose process state information indicates swap-in as a process to be swapped out.

Of the physical pages belonging to the process selected by the swap-out process selection means, only the physical pages required to swap in the process selected by the swap-in process selection means are swapped out by the page swap-out means. Then, the elapsed time in the process management table corresponding to the swapped out process is updated to "0", the process state information is updated to information indicating that it has been swapped out, and the number of swapped out pages is updated. A process swapout means that adds up the number of out pages.

When a physical page has been swapped out.

The page of the process selected by the swap-in process selection means is swapped into a physical page using the page swap-in means, and the elapsed time of the process management table corresponding to the swapped-in process is set to "0". , a process swap-in means for updating the number of swap-out pages to "0" in the process state information indicating that the process status information has been swapped in.

[Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a system to which a swap processing method according to an embodiment of the present invention is applied.

The system of this embodiment has one page swap-in means SIF.
and page swap-out means SOF.

It is composed of a process management table PTn that manages processes to be swapped, and a process swap means SF that controls swap processing. Further, the process swapping means SF includes a swap-in process selection means SF1 which selects a process to be swapped in using a process management table PTn, and a swap-out process selection means SF2 which selects a process to be swapped out using a process management table PTn. , a process swap-out means SF3 for swapping out processes, and a process swap-in means S for swapping in processes.
F4.

Referring to FIG. 2, the process management table PTn is
It has elapsed time Tn, process state information Sn, total number of pages PTn, and swap-out page number SPn.

Next, the operation of the ninth embodiment will be explained.

First, the flow of processing will be explained with reference to FIG.

When a swap request is issued, the process swap means SF
requests the swap-in process selection means SF1 to select a process to be swapped in. The swap-in process selection means SFI selects the process whose elapsed time Tn is the longest among the processes whose process status information Sn in the process management table PTn indicates swap-out as the process to be swap-in, and obtains the number of swap-out pages SPn. .

Next, the 1-process swap means SF is a process whose process state information Sn in the process management table PTn is set to swap out, in order to secure the physical page required by the process to be swapped in by the swap-out process selection means SF2. A search is made for a process in which the number of all physical pages of that process is not equal to the number of swap-out pages, and which has not been selected by the above-mentioned swap-in process selection means SFI. If such a process does not exist, the swap-out process selection means SF2 selects the process that should be swapped out by selecting the process whose elapsed time Tn is the longest among the processes whose process state information Sn in the process management table PTn indicates swap-in. Select as.

Next, the process swapout means SF3.

Of the physical pages belonging to the process selected by the swap-out process selection means SF2, only the physical pages required to swap in the process selected by the swap-in process selection means SFI are swapped by the page swap-out means SOF. The elapsed time in the process management table corresponding to the swapped out process is updated to "0", and the process status information is updated to "OUT" indicating that the process has been swapped out.

Add the number of swapped out pages to the number of swapped out pages.

When the swap-out of the physical page is completed, the secondary process swap-in means SF4 swaps in the page of the process selected by the swap-in process selection means SF1 to the physical page using the page swap-in means SIF, and swaps in the page of the process selected by the swap-in process selection means SF1. The elapsed time of the process management table corresponding to the process that has been updated is set to "0", and the process status information is set to "IN", which indicates that the process has been updated.
Update the number of swap out pages to "0".

Next, the operation of this embodiment will be explained using a specific example. In the description of a specific example, two target process management tables are assumed to be PTl and PT2, respectively.

FIG. 3 shows the initial state of this embodiment. Process status information S1 of the process indicated in the process management table PTI
is “IN” indicating that the swap has been swapped in (ζ), and the elapsed time T1 of Rikiku and others after being swapped in is “5°”.
, the total number of pages TPI is "20", and the swapped out page number SP1 is 0". Also, the process state information S2 of the process shown in the process management table PT2 indicates that it has been swapped out. “OU”
T'', and the elapsed time T2 since being swapped out
is "9", the total page number TP2 is "5", and the swap-out page number SP2 is "5@".

When a swap request is issued, the process swap means SF
selects a process to be swapped out using the swap-in process selection means SF1. The swap-in process selection means SFI refers to the process management table and selects the process indicated in the process management table PT2 as the next process to be swapped in from the "OUT" process whose process state information Sn indicates that it has been swapped out. Select the process that will be used.

Next, in order to secure the physical memory necessary for swapping in the processes indicated in the process management table PT2, the swap-out process selection means SF2 is used to select a process to be swapped out. The swap-out process selection means SF2 refers to the process management table and selects a process to be swapped out. In this example, the process indicated in the process management table PTI, which is the only swap-in process, is selected.

Next, in order to secure the physical pages of the swap-knob-out page number SP2 necessary for swapping in the process shown in the process management table PT2, the process swap-out means SF3 is used to process the process shown in the process management table PTI. Swap out physical pages with swap out page number SP2 from among the physical pages used by
UT” The number of swap out pages SPI is updated to the number of swap out pages SP2.

Next, the process swap-in means SF4 is used to swap in the swapped-out page of the process indicated in the process management table PT2 to the physical page swapped out by the process swap-out means SF3. The elapsed time T2 of “
0'', the process state information S2 is updated to ``IN'', and the swap out page number SP2 is updated to ``0''. This state is shown in FIG.

Next, when a swap request is issued after a certain period of time has elapsed, the process swap means SF requests the swap-in process selection means SFI to select a process to be swapped in. The swap-in process selection means SFI refers to the process management table PTn and selects the process state information S.
“OUT” indicating that n is switched out
The process indicated in the process management table PTI is selected as the next process to be swapped in from among the processes in .

Next, in order to secure the physical memory necessary for swapping in the process indicated in the process management table PTI, the swap-out process selection means SF2 is used to select the process to be swapped out. The swap-out process selection means SF2 refers to the process management table and selects a process to be swapped out.

In this example, the process that is currently being swapped out and for which all physical pages have not been swapped out is selected by the swap-in process selection means SFI as the process to be swapped in, so the process management table is the only process that is being swapped in. Select the process indicated by PT2.

Next, in order to secure the physical pages of the swap-out page number SPI necessary for swapping in the process indicated by the process management table PTI, the process swap-out means SF3 is used to secure the physical pages of the process management table PTI.
From among the physical pages used by the process indicated by T2, swap out the physical pages with the swap-out page number SP1, set the elapsed time T2 of the process management table PT2 to "0", and set the process state information S2 to "OUT".
The number of swap-out pages SP2 is updated to the number of swap-out pages SPI.

Next, using the process swap-in means SF4, the swapped-out page of the process indicated in the process management table PTI is swapped in to the physical page swapped out by the process swap-out means SF3, and the progress of the process management table PTI is swapped in. Time T1 is '0''
, the process state information S1 is updated to "IN", and the number of swap-out pages SPI is updated to "0". This state is shown in FIG.

As described above, according to this embodiment, it was possible to perform swap processing by targeting only the physical pages required for swap-in of a process.

[Effects of the Invention] As is clear from the above description, the present invention can swap out only the physical pages necessary for swapping in a process from all the physical pages used by the process, thereby reducing unnecessary The swap area can be used effectively without using the swap area. Also,
Swap processing can be sped up because unnecessary data transfer is not performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a system to which a swap processing method according to an embodiment of the present invention is applied, FIG. 2 is a diagram showing the configuration of the process management table in FIG. 1, and FIGS. The figure is a diagram showing the situation at a point in time in this embodiment. PTn...Process management table, Tn...Elapsed time, Sn...Process status information, TPn...Total number of pages, SPn...Number of swap-out pages, SOF.
...Page swap out means, SIF...Page swap in means, SF...Process swap means, S
Fl... Swap-in process selection means, SF2...
Swap-out process selection means, SF3: process swap-out means, SF4: process swap-in means. Figure 1 Figure 2

Claims (1)

[Claims] 1. In a swap processing method that inputs and outputs process images between the main memory and auxiliary memory of a computer, elapsed time, process status information, total number of pages, and number of swapped out pages are recorded for each process. a process management table to store; a page swap-out means for swapping out physical pages; a page swap-in means for swapping in physical pages; and in response to a swap request, the process state information in the process management table is A swap-in process selection means for selecting a process that has the longest elapsed time among swap-out processes as a process to be swapped in, and obtaining the number of swap-out pages of the selected process; and a process to be swapped in. In order to secure a physical page for
and the number of all physical pages of that process is not equal to the number of swap-out pages, and the process is not selected by the swap-in process selection means, and if such a process does not exist, the process management table is swap-out process selection means for selecting a process whose elapsed time is the longest among the processes whose process state information indicates swap-in as a process to be swapped out; and a physical page belonging to the process selected by the swap-out process selection means. Of these, only the physical pages required to swap in the process selected by the swap-in process selection means are swapped out by the page swap-out means, and the process management table corresponding to the swapped-out process is swapped out. Process swap-out means for updating the elapsed time to "0", updating the process state information to information indicating that the process has been swapped out, and adding the number of swapped out pages to the number of swapped out pages. When the swap-out of the physical page is completed, the page of the process selected by the swap-in process selection means is swapped in to the physical page using the page swap-in means, and the process management corresponding to the swapped-in process is performed. and process swap-in means for updating the elapsed time in the table to "0", the process state information to information indicating that the process has been swapped in, and the number of swap-out pages to "0". and the required physical page swapping method.