Index: benchmark/readyQ/churn.rs
===================================================================
--- benchmark/readyQ/churn.rs	(revision b029e310a1f8c23ce729205f17e9c08e8b462305)
+++ benchmark/readyQ/churn.rs	(revision b029e310a1f8c23ce729205f17e9c08e8b462305)
@@ -0,0 +1,117 @@
+use std::sync::Arc;
+use std::sync::atomic::Ordering;
+use std::time::Instant;
+
+use tokio::runtime::Builder;
+use tokio::sync;
+use tokio::time::{sleep,Duration};
+
+use rand::Rng;
+
+use clap::{Arg, App};
+use num_format::{Locale, ToFormattedString};
+
+#[path = "../bench.rs"]
+mod bench;
+
+// ==================================================
+struct Churner {
+	start: sync::Notify,
+}
+
+async fn churn_main( this: Arc<Churner>, spots: Arc<Vec<sync::Semaphore>>, exp: Arc<bench::BenchData>, skip_in: bool ) -> u64 {
+	let mut skip = skip_in;
+	this.start.notified().await;
+
+	let mut count:u64 = 0;
+	loop {
+		let r : usize = rand::thread_rng().gen();
+
+		let spot : &sync::Semaphore = &spots[r % spots.len()];
+		if !skip { spot.add_permits(1); }
+		spot.acquire().await.forget();
+		skip = false;
+
+		count += 1;
+		if  exp.clock_mode && exp.stop.load(Ordering::Relaxed) { break; }
+		if !exp.clock_mode && count >= exp.stop_count { break; }
+	}
+
+	exp.threads_left.fetch_sub(1, Ordering::SeqCst);
+	count
+}
+
+// ==================================================
+fn main() {
+	let options = App::new("Churn Tokio")
+		.args(&bench::args())
+		.arg(Arg::with_name("nspots")  .short("s").long("spots")  .takes_value(true).default_value("1").help("Number of spots in the system"))
+		.get_matches();
+
+	let nthreads  = options.value_of("nthreads").unwrap().parse::<usize>().unwrap();
+	let nprocs    = options.value_of("nprocs").unwrap().parse::<usize>().unwrap();
+	let nspots    = options.value_of("nspots").unwrap().parse::<usize>().unwrap();
+
+	let exp = Arc::new(bench::BenchData::new(options, nthreads, None));
+
+	let s = (1000000 as u64).to_formatted_string(&Locale::en);
+	assert_eq!(&s, "1,000,000");
+
+	let spots : Arc<Vec<sync::Semaphore>> = Arc::new((0..nspots).map(|_| {
+		sync::Semaphore::new(0)
+	}).collect());
+
+	let thddata : Vec<Arc<Churner>> = (0..nthreads).map(|_| {
+		Arc::new(Churner{
+			start: sync::Notify::new(),
+		})
+	}).collect();
+
+	let mut global_counter :u64 = 0;
+	let mut duration : std::time::Duration = std::time::Duration::from_secs(0);
+	let runtime = Builder::new_multi_thread()
+		.worker_threads(nprocs)
+		.enable_all()
+		.build()
+		.unwrap();
+
+	runtime.block_on(async {
+		let threads: Vec<_> = (0..nthreads).map(|i| {
+			tokio::spawn(churn_main(thddata[i].clone(), spots.clone(), exp.clone(), i < nspots))
+		}).collect();
+		println!("Starting");
+
+		sleep(Duration::from_millis(100)).await;
+
+		let start = Instant::now();
+
+		for i in 0..nthreads {
+			thddata[i].start.notify_one();
+		}
+
+		duration = exp.wait(&start).await;
+
+		println!("\nDone");
+
+		for i in 0..nspots {
+			spots[i].add_permits(10000);
+		}
+
+		for t in threads {
+			let c = t.await.unwrap();
+			global_counter += c;
+		}
+	});
+
+	println!("Duration (ms)        : {}", (duration.as_millis()).to_formatted_string(&Locale::en));
+	println!("Number of processors : {}", (nprocs).to_formatted_string(&Locale::en));
+	println!("Number of threads    : {}", (nthreads).to_formatted_string(&Locale::en));
+	println!("Number of spots      : {}", "6");
+	println!("Total Operations(ops): {:>15}", (global_counter).to_formatted_string(&Locale::en));
+	println!("Ops per second       : {:>15}", (((global_counter as f64) / duration.as_secs() as f64) as u64).to_formatted_string(&Locale::en));
+	println!("ns per ops           : {:>15}", ((duration.as_nanos() as f64 / global_counter as f64) as u64).to_formatted_string(&Locale::en));
+	println!("Ops per threads      : {:>15}", (global_counter / nthreads as u64).to_formatted_string(&Locale::en));
+	println!("Ops per procs        : {:>15}", (global_counter / nprocs as u64).to_formatted_string(&Locale::en));
+	println!("Ops/sec/procs        : {:>15}", ((((global_counter as f64) / nprocs as f64) / duration.as_secs() as f64) as u64).to_formatted_string(&Locale::en));
+	println!("ns per ops/procs     : {:>15}", ((duration.as_nanos() as f64 / (global_counter as f64 / nprocs as f64)) as u64).to_formatted_string(&Locale::en));
+}