If an instruction in the program is once executed, the instruction may be executed again soon; if a certain data has been accessed, the data may be accessed again soon. Typical reasons for time constraints are due to the presence of a large number of loop operations in the program.

Once a program accesses a certain storage unit, its nearby storage units will also be accessed soon. That is, the addresses accessed by the program within a period of time may be concentrated within a certain range. A typical situation is the program's Executed sequentially.

Refers to the discrete allocation method used in memory allocation, which is the basis for the implementation of virtual memory

It means that a job is divided into multiple times and loaded into the memory for running. That is, it is not necessary to load all the jobs when they are running. It is only necessary to load the part of the program and data currently to be run into the memory. Multiplicity is the most important feature of virtual memory

Refers to allowing swapping in and out between the swap area of ​​memory and external storage during the running of the job.

It refers to the ability to logically expand the memory capacity so that the memory capacity seen by the user is much larger than the actual memory capacity.

hardware

Request memory allocation in paging

Physical block allocation algorithm

page loading strategy

hardware

That is, the page that has just been swapped out will be accessed again soon, and it needs to be loaded back in. At this time, it is necessary to select another page to load out.

Select the page that has been in memory the longest and eliminate it

Register support

Special stack structure

Improved type - increase the thinking judgment of the modified position M

free page linked list

Modify page list