diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 10a9a0eb..d0c370b6 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -33,13 +33,13 @@ jobs:
         uses: actions-rs/cargo@v1.0.3
         with:
           command: clippy
-          args: --features flamegraph,prost-codec -- -D warnings
+          args: --all-targets --features flamegraph,prost-codec -- -D warnings
 
       - name: Run cargo clippy protobuf
         uses: actions-rs/cargo@v1.0.3
         with:
           command: clippy
-          args: --features flamegraph,protobuf-codec -- -D warnings
+          args: --all-targets --features flamegraph,protobuf-codec -- -D warnings
 
   build:
     name: Build
diff --git a/examples/backtrace_while_sampling.rs b/examples/backtrace_while_sampling.rs
index 90b6d613..224da1d6 100644
--- a/examples/backtrace_while_sampling.rs
+++ b/examples/backtrace_while_sampling.rs
@@ -1,6 +1,5 @@
 // Copyright 2021 TiKV Project Authors. Licensed under Apache-2.0.
 
-use pprof;
 use std::fs::File;
 
 fn deep_recursive(depth: i32) {
@@ -22,13 +21,10 @@ fn main() {
         deep_recursive(20);
     }
 
-    match guard.report().build() {
-        Ok(report) => {
-            let file = File::create("flamegraph.svg").unwrap();
-            report.flamegraph(file).unwrap();
+    if let Ok(report) = guard.report().build() {
+        let file = File::create("flamegraph.svg").unwrap();
+        report.flamegraph(file).unwrap();
 
-            println!("report: {:?}", &report);
-        }
-        Err(_) => {}
+        println!("report: {:?}", &report);
     };
 }
diff --git a/examples/flamegraph.rs b/examples/flamegraph.rs
index aee6e3bd..18ccdfd6 100644
--- a/examples/flamegraph.rs
+++ b/examples/flamegraph.rs
@@ -1,6 +1,5 @@
 // Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.
 
-use pprof;
 use std::fs::File;
 
 #[inline(never)]
@@ -67,8 +66,8 @@ fn prepare_prime_numbers() -> Vec<usize> {
         }
     }
     let mut prime_numbers = vec![];
-    for i in 2..10000 {
-        if prime_number_table[i] {
+    for (i, exist) in prime_number_table.iter().enumerate().skip(2) {
+        if *exist {
             prime_numbers.push(i);
         }
     }
@@ -91,22 +90,17 @@ fn main() {
             if is_prime_number2(i, &prime_numbers) {
                 v += 1;
             }
-        } else {
-            if is_prime_number3(i, &prime_numbers) {
-                v += 1;
-            }
+        } else if is_prime_number3(i, &prime_numbers) {
+            v += 1;
         }
     }
 
     println!("Prime numbers: {}", v);
 
-    match guard.report().build() {
-        Ok(report) => {
-            let file = File::create("flamegraph.svg").unwrap();
-            report.flamegraph(file).unwrap();
+    if let Ok(report) = guard.report().build() {
+        let file = File::create("flamegraph.svg").unwrap();
+        report.flamegraph(file).unwrap();
 
-            println!("report: {:?}", &report);
-        }
-        Err(_) => {}
+        println!("report: {:?}", &report);
     };
 }
diff --git a/examples/malloc_hook.rs b/examples/malloc_hook.rs
index fb19ad2b..bc322af4 100644
--- a/examples/malloc_hook.rs
+++ b/examples/malloc_hook.rs
@@ -2,7 +2,6 @@
 
 extern crate libc;
 
-use pprof;
 use std::ffi::c_void;
 
 #[cfg(not(all(target_os = "linux", target_env = "gnu")))]
@@ -78,8 +77,8 @@ fn prepare_prime_numbers() -> Vec<usize> {
         }
     }
     let mut prime_numbers = vec![];
-    for i in 2..10000 {
-        if prime_number_table[i] {
+    for (i, exist) in prime_number_table.iter().enumerate().skip(2) {
+        if *exist {
             prime_numbers.push(i);
         }
     }
diff --git a/examples/multithread.rs b/examples/multithread.rs
index d31bdc37..d16863ac 100644
--- a/examples/multithread.rs
+++ b/examples/multithread.rs
@@ -1,6 +1,5 @@
 // Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.
 
-use pprof;
 use std::sync::Arc;
 
 #[inline(never)]
@@ -35,8 +34,8 @@ fn prepare_prime_numbers() -> Vec<usize> {
         }
     }
     let mut prime_numbers = vec![];
-    for i in 2..10000 {
-        if prime_number_table[i] {
+    for (i, exist) in prime_number_table.iter().enumerate().skip(2) {
+        if *exist {
             prime_numbers.push(i);
         }
     }
@@ -76,7 +75,7 @@ fn main() {
         })
         .unwrap();
 
-    let p3 = prime_numbers.clone();
+    let p3 = prime_numbers;
     std::thread::spawn(move || loop {
         let mut _v = 0;
 
@@ -88,11 +87,8 @@ fn main() {
     });
 
     loop {
-        match guard.report().build() {
-            Ok(report) => {
-                println!("{:?}", report);
-            }
-            Err(_) => {}
+        if let Ok(report) = guard.report().build() {
+            println!("{:?}", report);
         };
         std::thread::sleep(std::time::Duration::from_secs(1))
     }
diff --git a/examples/multithread_flamegraph.rs b/examples/multithread_flamegraph.rs
index dfb7faeb..af8f8148 100644
--- a/examples/multithread_flamegraph.rs
+++ b/examples/multithread_flamegraph.rs
@@ -1,6 +1,5 @@
 // Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.
 
-use pprof;
 use std::fs::File;
 use std::sync::Arc;
 
@@ -36,8 +35,8 @@ fn prepare_prime_numbers() -> Vec<usize> {
         }
     }
     let mut prime_numbers = vec![];
-    for i in 2..10000 {
-        if prime_number_table[i] {
+    for (i, exist) in prime_number_table.iter().enumerate().skip(2) {
+        if *exist {
             prime_numbers.push(i);
         }
     }
@@ -78,7 +77,7 @@ fn main() {
         })
         .unwrap();
 
-    let p3 = prime_numbers.clone();
+    let p3 = prime_numbers;
     std::thread::spawn(move || loop {
         let mut _v = 0;
 
@@ -90,14 +89,11 @@ fn main() {
     });
 
     std::thread::sleep(std::time::Duration::from_secs(5));
-    match guard.report().build() {
-        Ok(report) => {
-            let file = File::create("flamegraph.svg").unwrap();
-            report.flamegraph(file).unwrap();
+    if let Ok(report) = guard.report().build() {
+        let file = File::create("flamegraph.svg").unwrap();
+        report.flamegraph(file).unwrap();
 
-            println!("{:?}", report);
-        }
-        Err(_) => {}
+        println!("{:?}", report);
     };
 
     //    pprof::PROFILER.lock().unwrap().stop();
diff --git a/examples/post_processor.rs b/examples/post_processor.rs
index 6d079027..91886885 100644
--- a/examples/post_processor.rs
+++ b/examples/post_processor.rs
@@ -1,6 +1,5 @@
 // Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.
 
-use pprof;
 use std::sync::Arc;
 
 #[inline(never)]
@@ -35,8 +34,8 @@ fn prepare_prime_numbers() -> Vec<usize> {
         }
     }
     let mut prime_numbers = vec![];
-    for i in 2..10000 {
-        if prime_number_table[i] {
+    for (i, exist) in prime_number_table.iter().enumerate().skip(2) {
+        if *exist {
             prime_numbers.push(i);
         }
     }
@@ -77,7 +76,7 @@ fn main() {
         })
         .unwrap();
 
-    let p3 = prime_numbers.clone();
+    let p3 = prime_numbers;
     std::thread::spawn(move || loop {
         let mut _v = 0;
 
@@ -89,17 +88,14 @@ fn main() {
     });
 
     loop {
-        match guard
+        if let Ok(report) = guard
             .report()
             .frames_post_processor(|frames| {
                 frames.thread_name = "PROCESSED".to_string();
             })
             .build()
         {
-            Ok(report) => {
-                println!("{:?}", report);
-            }
-            Err(_) => {}
+            println!("{:?}", report);
         };
         std::thread::sleep(std::time::Duration::from_secs(1))
     }
diff --git a/examples/prime_number.rs b/examples/prime_number.rs
index 060cc44b..831de1fe 100644
--- a/examples/prime_number.rs
+++ b/examples/prime_number.rs
@@ -1,7 +1,5 @@
 // Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.
 
-use pprof;
-
 #[inline(never)]
 fn is_prime_number(v: usize, prime_numbers: &[usize]) -> bool {
     if v < 10000 {
@@ -34,8 +32,8 @@ fn prepare_prime_numbers() -> Vec<usize> {
         }
     }
     let mut prime_numbers = vec![];
-    for i in 2..10000 {
-        if prime_number_table[i] {
+    for (i, exist) in prime_number_table.iter().enumerate().skip(2) {
+        if *exist {
             prime_numbers.push(i);
         }
     }
@@ -58,11 +56,8 @@ fn main() {
 
         println!("Prime numbers: {}", v);
 
-        match guard.report().build() {
-            Ok(report) => {
-                println!("{:?}", report);
-            }
-            Err(_) => {}
+        if let Ok(report) = guard.report().build() {
+            println!("{:?}", report);
         };
     }
 }
diff --git a/examples/profile_proto.rs b/examples/profile_proto.rs
index 7ffb7884..5546ec5c 100644
--- a/examples/profile_proto.rs
+++ b/examples/profile_proto.rs
@@ -1,6 +1,5 @@
 // Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.
 
-use pprof;
 use pprof::protos::Message;
 use std::fs::File;
 use std::io::Write;
@@ -69,8 +68,8 @@ fn prepare_prime_numbers() -> Vec<usize> {
         }
     }
     let mut prime_numbers = vec![];
-    for i in 2..10000 {
-        if prime_number_table[i] {
+    for (i, exist) in prime_number_table.iter().enumerate().skip(2) {
+        if *exist {
             prime_numbers.push(i);
         }
     }
@@ -93,29 +92,24 @@ fn main() {
             if is_prime_number2(i, &prime_numbers) {
                 v += 1;
             }
-        } else {
-            if is_prime_number3(i, &prime_numbers) {
-                v += 1;
-            }
+        } else if is_prime_number3(i, &prime_numbers) {
+            v += 1;
         }
     }
 
     println!("Prime numbers: {}", v);
 
-    match guard.report().build() {
-        Ok(report) => {
-            let mut file = File::create("profile.pb").unwrap();
-            let profile = report.pprof().unwrap();
+    if let Ok(report) = guard.report().build() {
+        let mut file = File::create("profile.pb").unwrap();
+        let profile = report.pprof().unwrap();
 
-            let mut content = Vec::new();
-            #[cfg(not(feature = "protobuf-codec"))]
-            profile.encode(&mut content).unwrap();
-            #[cfg(feature = "protobuf-codec")]
-            profile.write_to_vec(&mut content).unwrap();
-            file.write_all(&content).unwrap();
+        let mut content = Vec::new();
+        #[cfg(not(feature = "protobuf-codec"))]
+        profile.encode(&mut content).unwrap();
+        #[cfg(feature = "protobuf-codec")]
+        profile.write_to_vec(&mut content).unwrap();
+        file.write_all(&content).unwrap();
 
-            println!("report: {:?}", report);
-        }
-        Err(_) => {}
+        println!("report: {:?}", report);
     };
 }
diff --git a/rustfmt.toml b/rustfmt.toml
new file mode 100644
index 00000000..a15352fc
--- /dev/null
+++ b/rustfmt.toml
@@ -0,0 +1,2 @@
+edition = "2021"
+reorder_imports = true
diff --git a/src/addr_validate.rs b/src/addr_validate.rs
index 10dc27c4..9e9a34c6 100644
--- a/src/addr_validate.rs
+++ b/src/addr_validate.rs
@@ -102,7 +102,7 @@ mod test {
     fn validate_stack() {
         let i = 0;
 
-        assert_eq!(validate(&i as *const _ as *const libc::c_void), true);
+        assert!(validate(&i as *const _ as *const libc::c_void));
     }
 
     #[test]
@@ -110,13 +110,13 @@ mod test {
         let vec = vec![0; 1000];
 
         for i in vec.iter() {
-            assert_eq!(validate(i as *const _ as *const libc::c_void), true);
+            assert!(validate(i as *const _ as *const libc::c_void));
         }
     }
 
     #[test]
     fn failed_validate() {
-        assert_eq!(validate(0 as *const libc::c_void), false);
-        assert_eq!(validate((-1 as i32) as usize as *const libc::c_void), false)
+        assert!(!validate(std::ptr::null::<libc::c_void>()));
+        assert!(!validate(-1_i32 as usize as *const libc::c_void))
     }
 }