Add a mmap benchmark

editor/src/pool.rs

@@ -308,3 +308,29 @@ where
         }
     }
 }
+
+#[test]
+fn mmap_benchmark() {
+    use std::time::SystemTime;
+
+    let start_time = SystemTime::now();
+    let pool = Pool::with_capacity(1234567890);
+    let end_time = SystemTime::now();
+    let elapsed = end_time.duration_since(start_time).unwrap();
+
+    println!("Time to init pool: {:?}", elapsed);
+
+    // touch a bunch of pages to see how long they take to fault in
+    for i in 1..100 {
+        let start_time = SystemTime::now();
+        unsafe {
+            *pool.nodes.offset(i * 10) = [1; NODE_BYTES];
+        };
+        let end_time = SystemTime::now();
+        let elapsed = end_time.duration_since(start_time).unwrap();
+
+        println!("Time to touch page {}: {:?}", i, elapsed);
+    }
+
+    assert_eq!(pool.capacity, 128);
+}