mimalloc-nim

This package provides an easy way to use mimalloc for Nim with ARC/ORC. It includes the necessary configuration and setup to integrate mimalloc into your Nim projects.

Installation

You can install this package using Nimble:

nimble install mimalloc

Usage

To use mimalloc, simply add the following to your project's .nims file:

import mimalloc/config

Then, compile your project with the -d:useMimalloc flag:

nim c -d:useMimalloc your_file.nim

There's also a -d:mimallocDynamic flag that makes the program link against mimalloc dynamically.

Performance

Mimalloc is advertised as having great performance, and that is true. It's especially useful with ARC/ORC with threads because currently ARC/ORC can be slower for single-threaded allocation-heavy applications when compiled with --threads:on (see bug #18146).

Some results for the code in this benchmark (it's a traditional binarytrees benchmark). Checked with hyperfine './src/main 18' on a Ryzen 7 3700X machine:

Command	Time (min)
-d:danger --mm:refc	1.453 s
-d:danger --mm:refc --threads:on	1.513 s
-d:danger --mm:orc (without Mimalloc)	683.0 ms
-d:danger --mm:orc --threads:on (without Mimalloc)	1.368 s
-d:danger --mm:orc (with Mimalloc)	562.0 ms
-d:danger --mm:orc --threads:on (with Mimalloc)	597.6 ms

One advantage of linking Mimalloc statically is that with LTO the compiler can inline memory-allocation code from the allocator itself, resulting in even better performance:

Command	Time (min)
-d:danger --mm:refc --threads:on -d:lto	1.424 s
-d:danger --mm:orc -d:lto (without Mimalloc)	609.9 ms
-d:danger --mm:orc --threads:on -d:lto (without Mimalloc)	1.302 s
-d:danger --mm:orc -d:lto (with Mimalloc)	509.3 ms
-d:danger --mm:orc --threads:on -d:lto (with Mimalloc)	514.2 ms

Mimalloc Version

This package includes mimalloc v2.1.7 with all the extra files removed (e.g. the bin folder). If you want to use another mimalloc version, you can replace the mimalloc folder in the package with your desired version from https://github.com/microsoft/mimalloc.

Licensing

This package is licensed under the MIT license (see LICENSE).

The benchmark code in benchmark/main.nim comes from Programming Language Benchmarks.

Mimalloc itself is also MIT licensed. If you link with it statically, you must retain its LICENSE file (available in src/mimalloc/LICENSE) with your program's distribution in some way.