https://github.com/FRex/rampin

Try to make Windows preload files into RAM by memory mapping and touching them.
https://github.com/FRex/rampin

Last synced: 28 days ago
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Try to make Windows preload files into RAM by memory mapping and touching them.

• Host: GitHub
• URL: https://github.com/FRex/rampin
• Owner: FRex
• License: unlicense
• Created: 2019-05-31T04:43:33.000Z (over 5 years ago)
• Default Branch: master
• Last Pushed: 2021-02-20T15:23:14.000Z (almost 4 years ago)
• Last Synced: 2024-08-04T02:09:22.264Z (4 months ago)
• Language: C
• Homepage:
• Size: 15.6 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• AwesomeCppGameDev - rampin

README

        
# rampin

A small C program to try keep a file or few in Windows RAM cache. For a Unix

(not only Linux) alternative see [vmtouch](https://linux.die.net/man/8/vmtouch).

Takes one or more filenames as arguments, opens them as read only and memory

maps them whole, then accesses each 4 KiB page of it to bring them into memory

and then sleeps for 30 seconds and accesses them again to keep them in memory.

**By default it never quits so you'll have to somehow kill it once you are done.**

A sole `-h` will print full help to stdout. Options `-0`, `-1`, etc. up to `-9` will

make it quit after that many sleep + touch loops, not counting the initial one

so `-0` will map the file, touch all pages once, and quit right after, `-1`

will map, touch once, and sleep once and touch again and then quit, etc.

This program only makes sense if you have RAM to spare and/or are on 64-bit. I

wrote it to speed up level loading in an old game that has a total of 5 GiB of

assets and a 32-bit exe, so the game, OS and all the assets fit into my PC's RAM.

**This program might easily backfire if used too greedily and your OS might start paging to disk!**

To make it easier to rampin entire dir tree I use this help script named `rampintree`,

but mapping and touching many files one after another has been added recently to the

`rampin` program itself so just `rampin *` or `rampin` + list of files works too.

You can write a similar script in Powershell, Batch, pure sh and Busybox, etc.

In the future `rampin` will likely offer an option to recurse directories on its

own (if you need that option now you can open an issue here to let me know).

```

#!/bin/bash

if [ "$#" -eq 1 ]

then

    find "$1" -type f | xargs -P 99000 -I @ rampin @

fi

```

The above might work poorly and cause lower reading speeds on an HDD. For an

HDD a script that reads files one by one (and uses only one process) could be:

```

#!/bin/bash

if [ "$#" -eq 1 ]

then

    rampin `find "$1" -type f`

fi

```

Go to releases to download a Windows exe compiled with Pelles C with no `-O2`

to avoid running into any `-O2` optimizer bug similar to this one that affected

`stb_image`: [Pelles C forum bug report](https://forum.pellesc.de/index.php?topic=7837.0)