--- rust-crossbeam-channel-0.5.4.orig/benches/crossbeam.rs
+++ rust-crossbeam-channel-0.5.4/benches/crossbeam.rs
@@ -37,7 +37,7 @@ mod unbounded {
 
     #[bench]
     fn par_inout(b: &mut Bencher) {
-        let threads = num_cpus::get();
+        let threads = num_cpus::get().clamp(2,8);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = unbounded::<i32>();
 
@@ -100,7 +100,7 @@ mod unbounded {
 
     #[bench]
     fn spmc(b: &mut Bencher) {
-        let threads = num_cpus::get() - 1;
+        let threads = (num_cpus::get() - 1).clamp(2,8);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = unbounded::<i32>();
 
@@ -136,7 +136,7 @@ mod unbounded {
 
     #[bench]
     fn mpsc(b: &mut Bencher) {
-        let threads = num_cpus::get() - 1;
+        let threads = (num_cpus::get() - 1).clamp(2,8);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = unbounded::<i32>();
 
@@ -172,7 +172,7 @@ mod unbounded {
 
     #[bench]
     fn mpmc(b: &mut Bencher) {
-        let threads = num_cpus::get();
+        let threads = num_cpus::get().clamp(4,16);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = unbounded::<i32>();
 
@@ -248,7 +248,7 @@ mod bounded_n {
 
     #[bench]
     fn spmc(b: &mut Bencher) {
-        let threads = num_cpus::get() - 1;
+        let threads = (num_cpus::get() - 1).clamp(2,8);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = bounded::<i32>(steps * threads);
 
@@ -284,7 +284,7 @@ mod bounded_n {
 
     #[bench]
     fn mpsc(b: &mut Bencher) {
-        let threads = num_cpus::get() - 1;
+        let threads = (num_cpus::get() - 1).clamp(2,8);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = bounded::<i32>(steps * threads);
 
@@ -320,7 +320,7 @@ mod bounded_n {
 
     #[bench]
     fn par_inout(b: &mut Bencher) {
-        let threads = num_cpus::get();
+        let threads = num_cpus::get().clamp(2,8);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = bounded::<i32>(threads);
 
@@ -354,7 +354,7 @@ mod bounded_n {
 
     #[bench]
     fn mpmc(b: &mut Bencher) {
-        let threads = num_cpus::get();
+        let threads = num_cpus::get().clamp(4,16);
         assert_eq!(threads % 2, 0);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = bounded::<i32>(steps * threads);
@@ -445,7 +445,7 @@ mod bounded_1 {
 
     #[bench]
     fn spmc(b: &mut Bencher) {
-        let threads = num_cpus::get() - 1;
+        let threads = (num_cpus::get() - 1).clamp(2,8);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = bounded::<i32>(1);
 
@@ -481,7 +481,7 @@ mod bounded_1 {
 
     #[bench]
     fn mpsc(b: &mut Bencher) {
-        let threads = num_cpus::get() - 1;
+        let threads = (num_cpus::get() - 1).clamp(2,8);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = bounded::<i32>(1);
 
@@ -517,7 +517,7 @@ mod bounded_1 {
 
     #[bench]
     fn mpmc(b: &mut Bencher) {
-        let threads = num_cpus::get();
+        let threads = num_cpus::get().clamp(4,16);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = bounded::<i32>(1);
 
@@ -598,7 +598,7 @@ mod bounded_0 {
 
     #[bench]
     fn spmc(b: &mut Bencher) {
-        let threads = num_cpus::get() - 1;
+        let threads = (num_cpus::get() - 1).clamp(2,8);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = bounded::<i32>(0);
 
@@ -634,7 +634,7 @@ mod bounded_0 {
 
     #[bench]
     fn mpsc(b: &mut Bencher) {
-        let threads = num_cpus::get() - 1;
+        let threads = (num_cpus::get() - 1).clamp(2,8);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = bounded::<i32>(0);
 
@@ -670,7 +670,7 @@ mod bounded_0 {
 
     #[bench]
     fn mpmc(b: &mut Bencher) {
-        let threads = num_cpus::get();
+        let threads = num_cpus::get().clamp(4,16);
         let steps = TOTAL_STEPS / threads;
         let (s, r) = bounded::<i32>(0);