gregory/docs/behind-the-scenes/default-max-threads.md

Default max-threads

The default max-threads uses a simple algorithm to get how many threads.

if total_threads >= 32 {
    return total_threads - 4;
} else if total_threads >= 12 {
    return total_threads - 2;
} else if total_threads >= 3 {
    return total_threads - 1;
} else {
    return total_threads;
}

i.e. with total_threads as the number of threads the CPU(s) has:

• If the CPU has 32 or more threads, it will use all but 4 threads
• If the CPU has 12 or more threads, it will use all but 2 threads
• If the CPU has 3 or more threads, it will use all but 1 thread
• Otherwise, i.e. if the CPU has 1 to 2 threads, it will use all threads

---

Alternative algorithm I tried:

if total_threads >= 32 {
    return total_threads - total_threads.div_ceil(10);
} else if total_threads >= 12 {
    return total_threads - 2;
} else if total_threads >= 3 {
    return total_threads - 1;
} else {
    return total_threads;
}