Tasks not using whole cpu

[ria8651]

I have 8 cores on my computer but thread_num returns 2. When running tasks bevy only uses half my CPU. how can I use my whole CPU for async tasks?

Thanks

[bjorn3]

You need to insert a DefaultTaskPoolOptions resource into the World that specifies how much threads are dedicated to what kind of task (io, async compute, compute) By default half of all threads are assigned to compute:

bevy/crates/bevy_core/src/task_pool_options.rs

Lines 56 to 81 in cf221f9

	DefaultTaskPoolOptions {
	// By default, use however many cores are available on the system
	min_total_threads: 1,
	max_total_threads: std::usize::MAX,
	// Use 25% of cores for IO, at least 1, no more than 4
	io: TaskPoolThreadAssignmentPolicy {
	min_threads: 1,
	max_threads: 4,
	percent: 0.25,
	},
	// Use 25% of cores for async compute, at least 1, no more than 4
	async_compute: TaskPoolThreadAssignmentPolicy {
	min_threads: 1,
	max_threads: 4,
	percent: 0.25,
	},
	// Use all remaining cores for compute (at least 1)
	compute: TaskPoolThreadAssignmentPolicy {
	min_threads: 1,
	max_threads: std::usize::MAX,
	percent: 1.0, // This 1.0 here means "whatever is left over"
	},
	}

[ria8651]

I can see the struct TaskPoolThreadAssignmentPolicy here but it doesn't seem to be public? It also doesn't show up on docs.rs. How do I create an instance of this struct?

[bjorn3]

Looks like only DefaultTaskPoolOptions is exported. (

bevy/crates/bevy_core/src/lib.rs

Line 12 in 4c3c4b5

pub use task_pool_options::DefaultTaskPoolOptions;

) Seems like an oversight. I think DefaultTaskPoolOptions::default() and then accessing the fields will work though.