We have found that splitting tasks too aggressively we can create a lot of extra work in setup and teardown of the tests, which causes us to split tasks even more, which leads to more setup and teardown. By limiting the number of sub-tasks we create, we can contain the growth of the setup/teardown overhead.

In some exploration, it appears that a max split of 3 gives us similar makespans as we currently have, which minimizing the overhead of additional tasks.

As a server engineer,
I want tasks in my patch builds split optimally,
So that I can minimize the amount of time I spend waiting for a patch build.

AC:

• All required builders set the max_sub_suites value to 3.
• Non-required builders set the max_sub_suites value to 1.