From 17648493df478fa9316cc9ed66fe6bc1c2c820a4 Mon Sep 17 00:00:00 2001 From: willcl-ark Date: Tue, 29 Mar 2022 13:06:53 +0100 Subject: doc: Speed up functional test runs using ramdisk Using a ramdisk for the functional tests can give worthwhile speed-ups for developers and reviewers. Add notes to test/README.md on how to setup, use and erase a ramdisk on Linux. --- test/README.md | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'test/README.md') diff --git a/test/README.md b/test/README.md index 8fffde888d..87a3acb768 100644 --- a/test/README.md +++ b/test/README.md @@ -107,6 +107,34 @@ how many jobs to run, append `--jobs=n` The individual tests and the test_runner harness have many command-line options. Run `test/functional/test_runner.py -h` to see them all. +#### Speed up test runs with a ramdisk + +If you have available RAM on your system you can create a ramdisk to use as the `cache` and `tmp` directories for the functional tests in order to speed them up. +Speed-up amount varies on each system (and according to your ram speed and other variables), but a 2-3x speed-up is not uncommon. + +To create a 4GB ramdisk on Linux at `/mnt/tmp/`: + +```bash +sudo mkdir -p /mnt/tmp +sudo mount -t tmpfs -o size=4g tmpfs /mnt/tmp/ +``` + +Configure the size of the ramdisk using the `size=` option. +The size of the ramdisk needed is relative to the number of concurrent jobs the test suite runs. +For example running the test suite with `--jobs=100` might need a 4GB ramdisk, but running with `--jobs=32` will only need a 2.5GB ramdisk. + +To use, run the test suite specifying the ramdisk as the `cachedir` and `tmpdir`: + +```bash +test/functional/test_runner.py --cachedir=/mnt/tmp/cache --tmpdir=/mnt/tmp +``` + +Once finished with the tests and the disk, and to free the ram, simply unmount the disk: + +```bash +sudo umount /mnt/tmp +``` + #### Troubleshooting and debugging test failures ##### Resource contention -- cgit v1.2.3