Schedule executor benchmark

benches/benches/bevy_ecs/scheduling/executor.rs

@@ -0,0 +1,65 @@
+use bevy_app::{App, Update};
+use bevy_ecs::prelude::*;
+use bevy_tasks::{ComputeTaskPool, TaskPool};
+use criterion::Criterion;
+use rand::random;
+use std::time::{Duration, Instant};
+
+fn s_system<const N: usize>() {
+    let now = Instant::now();
+    while Instant::now() - now < Duration::from_nanos(1) {
+        // spin, simulating work being done
+    }
+}
+
+macro_rules! chain_systems {
+  ($schedule:ident;$($indent:tt),*) => {
+      $schedule.add_systems(($(s_system::<$indent>,)*).chain());
+  };
+}
+
+pub fn executor(c: &mut Criterion) {
+    let mut group = c.benchmark_group("executor");
+    group.warm_up_time(std::time::Duration::from_millis(500));
+    group.measurement_time(std::time::Duration::from_secs(4));
+    group.bench_function("single-thread", |b| {
+        let mut world = World::new();
+        let mut schedule = Schedule::default();
+        schedule.set_executor_kind(bevy_ecs::schedule::ExecutorKind::SingleThreaded);
+
+        // spawn 16 systems in chain
+        chain_systems!(schedule;0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15);
+
+        schedule.initialize(&mut world);
+        b.iter(move || {
+            schedule.run(&mut world);
+        });
+    });
+
+    ComputeTaskPool::get_or_init(TaskPool::default);
+    let thread_num = ComputeTaskPool::get().thread_num();
+
+    for system_count_per_batch in [1, 10, 50, 100] {
+        group.bench_function(
+            format!(
+                "multi-thread({})-{}-per-batch",
+                thread_num, system_count_per_batch
+            ),
+            |b| {
+                let mut world = World::new();
+                let mut schedule = Schedule::default();
+                schedule.set_executor_kind(bevy_ecs::schedule::ExecutorKind::MultiThreaded);
+
+                // spawn 16 batches, each with `system_count_per_batch` systems per batch.
+                for i in 0..system_count_per_batch {
+                    chain_systems!(schedule;0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15);
+                }
+
+                schedule.initialize(&mut world);
+                b.iter(move || {
+                    schedule.run(&mut world);
+                });
+            },
+        );
+    }
+}

benches/benches/bevy_ecs/scheduling/mod.rs

@@ -3,10 +3,12 @@ use criterion::criterion_group;
 mod run_condition;
 mod running_systems;
 mod schedule;
+mod executor;
 
 use run_condition::*;
 use running_systems::*;
 use schedule::*;
+use executor::*;
 
 criterion_group!(
     scheduling_benches,
@@ -20,4 +22,5 @@ criterion_group!(
     schedule,
     build_schedule,
     empty_schedule_run,
+    executor,
 );