Use SpinLock on FileTable for efficiency

kernel/src/process/clone.rs

@@ -394,16 +394,16 @@ fn clone_fs(
 }
 
 fn clone_files(
-    parent_file_table: &Arc<Mutex<FileTable>>,
+    parent_file_table: &Arc<SpinLock<FileTable>>,
     clone_flags: CloneFlags,
-) -> Arc<Mutex<FileTable>> {
+) -> Arc<SpinLock<FileTable>> {
     // if CLONE_FILES is set, the child and parent shares the same file table
     // Otherwise, the child will deep copy a new file table.
     // FIXME: the clone may not be deep copy.
     if clone_flags.contains(CloneFlags::CLONE_FILES) {
         parent_file_table.clone()
     } else {
-        Arc::new(Mutex::new(parent_file_table.lock().clone()))
+        Arc::new(SpinLock::new(parent_file_table.lock().clone()))
     }
 }
 

kernel/src/process/process/builder.rs

@@ -28,7 +28,7 @@ pub struct ProcessBuilder<'a> {
     argv: Option<Vec<CString>>,
     envp: Option<Vec<CString>>,
     process_vm: Option<ProcessVm>,
-    file_table: Option<Arc<Mutex<FileTable>>>,
+    file_table: Option<Arc<SpinLock<FileTable>>>,
     fs: Option<Arc<RwMutex<FsResolver>>>,
     umask: Option<Arc<RwLock<FileCreationMask>>>,
     resource_limits: Option<ResourceLimits>,
@@ -67,7 +67,7 @@ impl<'a> ProcessBuilder<'a> {
         self
     }
 
-    pub fn file_table(&mut self, file_table: Arc<Mutex<FileTable>>) -> &mut Self {
+    pub fn file_table(&mut self, file_table: Arc<SpinLock<FileTable>>) -> &mut Self {
         self.file_table = Some(file_table);
         self
     }
@@ -152,7 +152,7 @@ impl<'a> ProcessBuilder<'a> {
         let process_vm = process_vm.or_else(|| Some(ProcessVm::alloc())).unwrap();
 
         let file_table = file_table
-            .or_else(|| Some(Arc::new(Mutex::new(FileTable::new_with_stdio()))))
+            .or_else(|| Some(Arc::new(SpinLock::new(FileTable::new_with_stdio()))))
             .unwrap();
 
         let fs = fs

kernel/src/process/process/mod.rs

@@ -79,7 +79,7 @@ pub struct Process {
     /// Process group
     pub(super) process_group: Mutex<Weak<ProcessGroup>>,
     /// File table
-    file_table: Arc<Mutex<FileTable>>,
+    file_table: Arc<SpinLock<FileTable>>,
     /// FsResolver
     fs: Arc<RwMutex<FsResolver>>,
     /// umask
@@ -180,7 +180,7 @@ impl Process {
         process_vm: ProcessVm,
 
         fs: Arc<RwMutex<FsResolver>>,
-        file_table: Arc<Mutex<FileTable>>,
+        file_table: Arc<SpinLock<FileTable>>,
 
         umask: Arc<RwLock<FileCreationMask>>,
         resource_limits: ResourceLimits,
@@ -611,7 +611,7 @@ impl Process {
 
     // ************** File system ****************
 
-    pub fn file_table(&self) -> &Arc<Mutex<FileTable>> {
+    pub fn file_table(&self) -> &Arc<SpinLock<FileTable>> {
         &self.file_table
     }
 
@@ -724,7 +724,7 @@ mod test {
             String::new(),
             ProcessVm::alloc(),
             Arc::new(RwMutex::new(FsResolver::new())),
-            Arc::new(Mutex::new(FileTable::new())),
+            Arc::new(SpinLock::new(FileTable::new())),
             Arc::new(RwLock::new(FileCreationMask::default())),
             ResourceLimits::default(),
             Nice::default(),