diff --git a/kernel/src/fs.rs b/kernel/src/fs.rs
index 7c6d4cc..d4a5eeb 100644
--- a/kernel/src/fs.rs
+++ b/kernel/src/fs.rs
@@ -42,7 +42,7 @@ impl Device for MemBuf {
         buf[..len].copy_from_slice(&slice[offset..offset + len]);
         Some(len)
     }
-    fn write_at(&mut self, offset: usize, buf: &[u8]) -> Option<usize> {
+    fn write_at(&mut self, _offset: usize, _buf: &[u8]) -> Option<usize> {
         None
     }
 }
@@ -105,31 +105,31 @@ macro_rules! impl_inode {
     () => {
         fn info(&self) -> Result<FileInfo> { unimplemented!() }
         fn sync(&self) -> Result<()> { unimplemented!() }
-        fn resize(&self, len: usize) -> Result<()> { unimplemented!() }
-        fn create(&self, name: &str, type_: FileType) -> Result<Arc<INode>> { unimplemented!() }
-        fn unlink(&self, name: &str) -> Result<()> { unimplemented!() }
-        fn link(&self, name: &str, other: &Arc<INode>) -> Result<()> { unimplemented!() }
-        fn rename(&self, old_name: &str, new_name: &str) -> Result<()> { unimplemented!() }
-        fn move_(&self, old_name: &str, target: &Arc<INode>, new_name: &str) -> Result<()> { unimplemented!() }
-        fn find(&self, name: &str) -> Result<Arc<INode>> { unimplemented!() }
-        fn get_entry(&self, id: usize) -> Result<String> { unimplemented!() }
+        fn resize(&self, _len: usize) -> Result<()> { unimplemented!() }
+        fn create(&self, _name: &str, _type_: FileType) -> Result<Arc<INode>> { unimplemented!() }
+        fn unlink(&self, _name: &str) -> Result<()> { unimplemented!() }
+        fn link(&self, _name: &str, _other: &Arc<INode>) -> Result<()> { unimplemented!() }
+        fn rename(&self, _old_name: &str, _new_name: &str) -> Result<()> { unimplemented!() }
+        fn move_(&self, _old_name: &str, _target: &Arc<INode>, _new_name: &str) -> Result<()> { unimplemented!() }
+        fn find(&self, _name: &str) -> Result<Arc<INode>> { unimplemented!() }
+        fn get_entry(&self, _id: usize) -> Result<String> { unimplemented!() }
         fn fs(&self) -> Arc<FileSystem> { unimplemented!() }
         fn as_any_ref(&self) -> &Any { self }
     };
 }
 
 impl INode for Stdin {
-    fn read_at(&self, offset: usize, buf: &mut [u8]) -> Result<usize> {
+    fn read_at(&self, _offset: usize, buf: &mut [u8]) -> Result<usize> {
         buf[0] = self.pop() as u8;
         Ok(1)
     }
-    fn write_at(&self, offset: usize, buf: &[u8]) -> Result<usize> { unimplemented!() }
+    fn write_at(&self, _offset: usize, _buf: &[u8]) -> Result<usize> { unimplemented!() }
     impl_inode!();
 }
 
 impl INode for Stdout {
-    fn read_at(&self, offset: usize, buf: &mut [u8]) -> Result<usize> { unimplemented!() }
-    fn write_at(&self, offset: usize, buf: &[u8]) -> Result<usize> {
+    fn read_at(&self, _offset: usize, _buf: &mut [u8]) -> Result<usize> { unimplemented!() }
+    fn write_at(&self, _offset: usize, buf: &[u8]) -> Result<usize> {
         use core::str;
         let s = str::from_utf8(buf).map_err(|_| ())?;
         print!("{}", s);
diff --git a/kernel/src/logging.rs b/kernel/src/logging.rs
index 86bd1c2..8769c1a 100644
--- a/kernel/src/logging.rs
+++ b/kernel/src/logging.rs
@@ -44,22 +44,21 @@ macro_rules! with_color {
 
 fn print_in_color(args: fmt::Arguments, color: Color) {
     use crate::arch::io;
-    let mutex = log_mutex.lock();
+    let _guard = log_mutex.lock();
     io::putfmt(with_color!(args, color));
 }
 
 pub fn print(args: fmt::Arguments) {
     use crate::arch::io;
-    let mutex = log_mutex.lock();
+    let _guard = log_mutex.lock();
     io::putfmt(args);
 }
 
 struct SimpleLogger;
 
 impl Log for SimpleLogger {
-    fn enabled(&self, metadata: &Metadata) -> bool {
-        true
-//        metadata.level() <= Level::Info
+    fn enabled(&self, _metadata: &Metadata) -> bool {
+       true
     }
     fn log(&self, record: &Record) {
         static DISABLED_TARGET: &[&str] = &[
diff --git a/kernel/src/sync/mod.rs b/kernel/src/sync/mod.rs
index cfa5071..17de3ed 100644
--- a/kernel/src/sync/mod.rs
+++ b/kernel/src/sync/mod.rs
@@ -48,6 +48,7 @@
 //!	    Dining_Philosophers --> Monitor
 //!	end
 //! ```
+#![allow(dead_code)]
 
 pub use self::condvar::*;
 pub use self::mutex::*;