An MMTk binding for the Julia programming language.

Checking out and Building Julia with MMTk

Besides checking out the binding, it is also necessary to checkout a fork containing a modified version of the Julia repository (https://github.com/mmtk/julia). For example, we check out the fork as a sibling of mmtk-julia. For step-by-step instructions, read the section "Quick Building Guide".

The directory structure should look like the diagram below:

Your working directory/
├─ mmtk-julia/
│  ├─ julia/
│  └─ mmtk/
├─ julia/ (should be cloned manually)
└─ mmtk-core/ (optional)

Build Julia binding in Rust

Before building Julia, build the binding in mmtk-julia/mmtk. Note that we currently support either immix or stickyimmix implementations in mmtk-core (build it with cargo build --features immix or cargo build --features stickyimmix). Add --release at the end if you would like to have a release build, otherwise it is a debug build.

Build Julia with MMTk

To build Julia with MMTk, create a Make.user file in the top-level directory of the Julia repository and add an entry WITH_MMTK=1. Finally, set the following environment variables:

export MMTK_BUILD=release # or debug depending on how you build the Julia binding in Rust
export MMTK_JULIA_DIR=<path-to-mmtk-julia>

Then run make with the environment variables mentioned above. Please also make sure to install any dependency considering any particular requirement from both Julia and MMTk.

Heap Size

Currently MMTk supports a fixed heap limit or variable heap within an interval. The default is a variable heap with the minimum heap size set to Julia's default_collection_interval and the maximum size set to 70% of the free memory available. To change these values set the environment variables MMTK_MIN_HSIZE and MMTK_MAX_HSIZE to set the mininum and maximum size in megabytes, or MMTK_MIN_HSIZE_G and MMTK_MAX_HSIZE_G to set the size in gigabytes. If both environment variables are set, MMTk will use the size in megabytes. To set a fixed heap size, simply set only the variables MMTK_MAX_HSIZE or MMTK_MAX_HSIZE_G, or set MMTK_MIN_HSIZE or MMTK_MIN_HSIZE_G to 0. Note that these values can be decimal numbers, e.g. MMTK_MAX_HSIZE_G=1.5.

These environment variables are set during julia initialization time, so they can be set per-julia process.

Quick Building Guide

(1) Clone this repo: https://github.com/mmtk/mmtk-julia (run git clone https://github.com/mmtk/mmtk-julia)

(2) Clone this repo: https://github.com/mmtk/julia (run git clone https://github.com/mmtk/julia.git)

(3) In mmtk-julia/mmtk, run cargo build --features immix --release

(4) In julia, create a file Make.user, and add WITH_MMTK=1.

(5) In julia, run MMTK_PLAN=Immix MMTK_BUILD=release MMTK_JULIA_DIR=/absolute/path/mmtk-julia make (or with MMTK_PLAN=StickyImmix).

If you would like to have a debug build, remove --release from Step (3) and use MMTK_BUILD=debug in Step (5)

Further information

More about MMTk: https://github.com/mmtk/mmtk-core

More about Julia: https://github.com/JuliaLang/julia