virtual_memory_sim

A virtual memory simulation created for educational purposes using the Rust programming language and a few packages from crates.io. The program was created to simulate standard operating system behavior where a logical address space is provided in lieu of the physical resources available to a system. Like the real version, demand paging is used to keep only necessary data in memory and infrequently referenced elements risk being paged out.

While this project was created to aid in my learning of some operating system concepts, it can also be used to test virtual memory page victimization algorithms with minor modifications.

Requirements

• Cargo version $\approx$ 1.73.0

Getting Started

Getting started with the project is trivial thanks to the suite of tools provided by Rust's cargo. After cloning the repository, the simulation can be compiled and run by issuing the command

cargo run

within the project directory.

Example

virtual memory simulation
simulation configuration values:
Config {
    file_storage: "BACKING_STORE.bin",
    file_validation: "correct.txt",
    file_address: "addresses.txt",
    size_table: 64,
    size_tlb: 16,
    size_frame: 256,
    delay_us: 250,
}

running simulation: ⠒
Stats Tracked
---------------------------------
page_hits:                00000183
tlb_hits:                 00000063
tlb_flushes:              00000170
attempted_memory_acceses: 00001000
correct_memory_accesses:  00001000


tlb hit ratio:            0.063000
page hit ratio:           0.183000

Note: The cache hit ratios listed above are poor due to the sequence of memory accesses employed (addresses.txt) was generated randomly. Better results can be found in practice by using data with better temporal locality (e.g. a program).

CLI Options

To see all available options which modify runtime behavior, issue the command

cargo run -- --help

to have them written to stdout. Note that any of the options displayed can also be specified as environment variables (consult config.rs for details).

Example

virtual memory simulation
Usage: virtual_memory_sim [OPTIONS]

Options:
      --file-storage <FILE_STORAGE>        [default: BACKING_STORE.bin]
      --file-validation <FILE_VALIDATION>  [default: correct.txt]
      --file-address <FILE_ADDRESS>        [default: addresses.txt]
      --size-table <SIZE_TABLE>            [default: 64]
      --size-tlb <SIZE_TLB>                [default: 16]
      --size-frame <SIZE_FRAME>            [default: 256]
      --delay-us <DELAY_US>                [default: 250]
  -h, --help                               Print help
  -V, --version                            Print version