From 53c0dcf17acd23af4783b24ecd0639b85e319850 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Tue, 1 Oct 2019 18:10:18 -0700
Subject: [PATCH] Don't offset the number of rayon workers by 1

If we pass rayon 0 workers it still spawns 1, so both 1 and 2 threads
were actually spawning one thread each. Let's remove the off-by-one so
1 and 2 cores should show a significant difference.
---
 examples/raytrace-parallel/src/lib.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/raytrace-parallel/src/lib.rs b/examples/raytrace-parallel/src/lib.rs
index fbb9ad68..696c565e 100644
--- a/examples/raytrace-parallel/src/lib.rs
+++ b/examples/raytrace-parallel/src/lib.rs
@@ -60,7 +60,7 @@ impl Scene {
         // Configure a rayon thread pool which will pull web workers from
         // `pool`.
         let thread_pool = rayon::ThreadPoolBuilder::new()
-            .num_threads(concurrency - 1)
+            .num_threads(concurrency)
             .spawn_handler(|thread| Ok(pool.run(|| thread.run()).unwrap()))
             .build()
             .unwrap();