A crude benchmark to compare spin loop hint to yield

examples/latency/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "latency"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+num_cpus = "1.13.1"
+rand = "0.8.4"
+spin_sleep = { path = "../.." }

examples/latency/src/main.rs

@@ -0,0 +1,30 @@
+use std::time::{Duration, Instant};
+
+use rand::Rng;
+
+fn main() {
+    let interval = Duration::from_millis(15);
+
+    let cpus = num_cpus::get();
+    let spinners: Vec<_> = (0..cpus).map(|_| {
+        std::thread::spawn(|| {
+            let mut rng = rand::thread_rng();
+            // Run a lottery instead of boring infinite loop so that it doesn't get misoptimized
+            while rng.gen::<u64>() > 0 {}
+        })
+    }).collect();
+
+    let mut i = 0;
+    let mut sum = Duration::default();
+    loop {
+        let now = Instant::now();
+        let deadline = now + interval;
+        spin_sleep::sleep(interval);
+        sum += Instant::now() - deadline;
+        i += 1;
+        if i % 100 == 0 {
+            dbg!(sum / 100);
+            sum = Duration::default();
+        }
+    }
+}

src/lib.rs

@@ -148,6 +148,7 @@ impl SpinSleeper {
         // spin the rest of the duration
         while start.elapsed() < duration {
             thread::yield_now();
+            // std::hint::spin_loop();
         }
     }