diff --git a/Chapter09/Cargo.toml b/Chapter09/Cargo.toml
index 7b7c7af..a0acf01 100644
--- a/Chapter09/Cargo.toml
+++ b/Chapter09/Cargo.toml
@@ -3,7 +3,6 @@ name = "Chapter9"
 version = "1.0.0"
 
 [dependencies]
-cpuprofiler = "0.0.2"
 flame = "0.2"
 rand = "0.4.2"
 
@@ -30,3 +29,7 @@ path = "performance_profiling2.rs"
 [[bin]]
 name = "performance_profiling3"
 path = "performance_profiling3.rs"
+
+[[bin]]
+name = "performance_profiling4"
+path = "performance_profiling4.rs"
diff --git a/Chapter09/README.md b/Chapter09/README.md
index aac2a37..a01c3cd 100644
--- a/Chapter09/README.md
+++ b/Chapter09/README.md
@@ -1,4 +1,4 @@
-This chapter makes use of Google's [cpuprofiler](http://goog-perftools.sourceforge.net/doc/cpu_profiler.html),
-which needs to be installed separately. It will not be installed through the normal cargo build process.
+This chapter makes use of Cargo Profiler and valgrind.
+They will not be installed through the normal cargo build process and need separate installation.
 
-[GPerftools](https://github.com/gperftools/gperftools) is also available on Github.
+[Cargo Profiler](https://github.com/kernelmachine/cargo-profiler) installation instructions are available on Github.
diff --git a/Chapter09/performance_profiling4.rs b/Chapter09/performance_profiling4.rs
new file mode 100644
index 0000000..a800833
--- /dev/null
+++ b/Chapter09/performance_profiling4.rs
@@ -0,0 +1,23 @@
+fn a(n: u64) -> u64 {
+   if n>0 {
+      b(n);
+      b(n);
+   }
+   n * n
+}
+
+fn b(n: u64) -> u64 {
+   c(n);
+   c(n);
+   n + 2 / 3
+}
+
+fn c(n: u64) -> u64 {
+   a(n-1);
+   a(n-1);
+   vec![1, 2, 3].into_iter().map(|x| x+2).sum()
+}
+
+fn main() {
+   a(6);
+}