Physical memory allocation system, program execution scheduling system, and information processor

• US 5,568,635 A
• Filed: 02/23/1994
• Issued: 10/22/1996
• Est. Priority Date: 02/24/1993
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yamaguchi, Ryuichi
• Primary Examiner(s): Kim, Matthew M.
• Application Number:
  US08/200,489
• Time in Patent Office: 972 Days
• Field of Search: 364/200 MS, 364/900 MS, 395/425, 395/497.01, 395/497.02, 395/497.03, 395/497.04, 395/600
• US Class Current: 711/171
• CPC Class Codes: G06F 12/0223 User address space allocation, e.g. contiguous or non contiguous base addressing
• CPC Class Codes: G06F 12/08 in hierarchically structured memory systems, e.g. virtual memory systems

Abstract

A physical memory allocation system comprising an area estimation section, a program modification section, a program size read-in section, a memory size read-in section, a user control table, a size compare section, and an area allocation section. The area estimation section, after a program has been run for a predetermined period of time, measures a memory area size referred to by the program (i.e. the program size). The program modification section writes the program size to the program. The program size read-in section inputs the program size and the memory size read-in section inputs a user allocation size held at the user control table at program execution time. The size compare section makes a comparison in size between the user allocation size and the program size thereby outputting one of these two sizes that is found to be smaller than the other as an at-execution-time size. In the area allocation section, an amount of physical memory that a program can use is taken as an at-execution-time size. Taking such a physical memory size as a low limit, physical memory allocation is carried out effectively. This reduces the frequency of swapping and the loss of time.

Claims

1. A physical memory allocation system having a physical memory and a virtual memory wherein said physical memory is organized in such a way that data stored in said virtual memory are copied to said physical memory, and plural programs receiving execution requests are handled according to commands issued by command means, said physical memory allocation system comprising:

(a) a memory size read-in section which inputs a physical memory occupation size allocated to a respective user who runs a program, said physical memory occupation size being a user allocation size,

(b) an area estimation section which runs said program for a fixed period of time so as to measure a storage area size referred to by said program, said storage area size being a program size,

(c) a program modification section which writes said program size estimated by said area estimation section to said program,

(d) a program size read-in section which inputs said program size from said program at the time when said program is executed, and

(e) a size compare section which receives outputs of said memory size read-in section and said program size read-in section for comparison in size between said user allocation size and said program size thereby outputting one of these two sizes that is found to be smaller than the other as an at-execution-time allocation size,

wherein said command means receives an output of said size compare section to issue a command so that a specified amount of physical memory according to said at-execution-time allocation size is given at the time when said program is executed.

2. The physical memory allocation system as in claim 1 wherein, when said program size is found to be greater than said user allocation size, said size compare section issues a warning message conveying such a condition to a user who runs a program.

3. The physical memory allocation system as in claim 2 wherein said warning message is displayed on a terminal display screen.

4. The physical memory allocation system as in claim 1 wherein said area estimation section measures a storage area size referred to by said program within a unit time a plurality of times to use an average of the measured storage area sizes as a program size at the time when said program is executed.

5. An information processor having a physical memory and a virtual memory wherein said physical memory is organized in such a way that data stored in said virtual memory are copied to said physical memory, and plural programs receiving execution requests are handled according to commands issued by command means, said information processor comprising:

(a) a user priority read-in section which fetches a priority allocated to a respective user who runs a program, said priority being a user priority,

(b) an area estimation section which runs said each program for a fixed period of time so as to measure a storage area size referred to by said each program, said storage area size being a program size,

(c) a priority-in section which, taking a priority referred to by each user to the execution of said each program as a program priority, makes a comparison in size between said program size of one program and said program size of the other program thereby lowering said program priority of a program found to have a smaller size,

(d) a priority modification section which, upon receipt of an output of said priority-in section, writes said program priority to said each program,

(e) a program priority read-in section which inputs said program priority from said each program at program execution time, and

(f) a priority compare section which receives outputs of said user priority read-in section and said program priority read-in section for comparison in priority ranking between said user priority and said program priority thereby outputting one of these two priorities that is found to have a lower rank than the other as an at-execution-time priority,

wherein said command means issues, upon receipt of an output of said priority compare section, a command so as to select between said plural programs according to said at-execution-time priority.