diff --git a/crate/process/src/interrupt.rs b/crate/process/src/interrupt.rs
new file mode 100644
index 0000000..f75102e
--- /dev/null
+++ b/crate/process/src/interrupt.rs
@@ -0,0 +1,29 @@
+#[inline(always)]
+#[cfg(target_arch = "x86_64")]
+pub unsafe fn disable_and_store() -> usize {
+    let rflags: usize;
+    asm!("pushfq; popq $0; cli" : "=r"(rflags));
+    rflags & (1 << 9)
+}
+
+#[inline(always)]
+#[cfg(target_arch = "riscv32")]
+pub unsafe fn disable_and_store() -> usize {
+    let sstatus: usize;
+    asm!("csrrci $0, 0x100, 1" : "=r"(sstatus));
+    sstatus & 1
+}
+
+#[inline(always)]
+#[cfg(target_arch = "x86_64")]
+pub unsafe fn restore(flags: usize) {
+    if flags != 0 {
+        asm!("sti");
+    }
+}
+
+#[inline(always)]
+#[cfg(target_arch = "riscv32")]
+pub unsafe fn restore(flags: usize) {
+    asm!("csrs 0x100, $0" :: "r"(flags));
+}
\ No newline at end of file
diff --git a/crate/process/src/lib.rs b/crate/process/src/lib.rs
index d6e4c7d..d798459 100644
--- a/crate/process/src/lib.rs
+++ b/crate/process/src/lib.rs
@@ -4,6 +4,7 @@
 #![feature(linkage)]
 #![feature(nll)]
 #![feature(vec_resize_default)]
+#![feature(asm)]
 #![feature(exact_size_is_empty)]
 
 extern crate alloc;
@@ -16,11 +17,12 @@ extern crate spin;
 #[macro_use]
 extern crate std;
 
-mod process_manager;
+pub mod process_manager;
 mod processor;
 pub mod scheduler;
 pub mod thread;
 mod event_hub;
+mod interrupt;
 
 pub use process_manager::*;
 pub use processor::Processor;
diff --git a/crate/process/src/process_manager.rs b/crate/process/src/process_manager.rs
index 9df6a69..a013c13 100644
--- a/crate/process/src/process_manager.rs
+++ b/crate/process/src/process_manager.rs
@@ -39,6 +39,7 @@ pub struct ProcessManager {
     procs: Vec<Mutex<Option<Process>>>,
     scheduler: Mutex<Box<Scheduler>>,
     wait_queue: Vec<Mutex<Vec<Pid>>>,
+    children: Vec<Mutex<Vec<Pid>>>,
     event_hub: Mutex<EventHub<Event>>,
     exit_handler: fn(Pid),
 }
@@ -49,6 +50,7 @@ impl ProcessManager {
             procs: new_vec_default(max_proc_num),
             scheduler: Mutex::new(scheduler),
             wait_queue: new_vec_default(max_proc_num),
+            children: new_vec_default(max_proc_num),
             event_hub: Mutex::new(EventHub::new()),
             exit_handler,
         }
@@ -183,7 +185,7 @@ impl ProcessManager {
         let mut proc_lock = self.procs[target].lock();
         let proc = proc_lock.as_ref().expect("process not exist");
         match proc.status {
-            Status::Exited(_) => self.wait_queue[target].lock().retain(|&i| i != pid),
+            Status::Exited(_) => self.del_child(pid, target),
             _ => panic!("can not remove non-exited process"),
         }
     }
@@ -210,13 +212,20 @@ impl ProcessManager {
 
     pub fn set_parent(&self, pid: Pid, target: Pid) {
         self.wait_queue[target].lock().push(pid);
+        self.children[pid].lock().push(target);
     }
-    pub fn del_parent(&self, pid: Pid, target: Pid) {
+    pub fn del_child(&self, pid: Pid, target: Pid) {
         self.wait_queue[target].lock().retain(|&i| i != pid);
+        self.children[pid].lock().retain(|&i| i != target);
+    }
+    pub fn get_children(&self, pid: Pid) -> Vec<Pid>{
+        self.children[pid].lock().clone()
     }
 
     pub fn exit(&self, pid: Pid, code: ExitCode) {
-        (self.exit_handler)(pid);
+        for child in self.children[pid].lock().drain(..) {
+            self.wait_queue[child].lock().retain(|&i| i != pid);
+        }
         self.set_status(pid, Status::Exited(code));
     }
      /// Called when a process exit
@@ -226,6 +235,7 @@ impl ProcessManager {
         }
 
         proc.context = None;
+        (self.exit_handler)(pid);
     }
 }
  fn new_vec_default<T: Default>(size: usize) -> Vec<T> {
diff --git a/crate/process/src/processor.rs b/crate/process/src/processor.rs
index 9b56c48..518dcbd 100644
--- a/crate/process/src/processor.rs
+++ b/crate/process/src/processor.rs
@@ -3,6 +3,7 @@ use alloc::sync::Arc;
 use spin::Mutex;
 use core::cell::UnsafeCell;
 use process_manager::*;
+use interrupt;
 
 /// Process executor
 ///
@@ -52,14 +53,15 @@ impl Processor {
     ///   via switch back to the scheduler.
     pub fn run(&self) -> ! {
         let inner = self.inner();
+        unsafe { interrupt::disable_and_store(); }
         loop {
             let proc = inner.manager.run(inner.id);
             trace!("CPU{} begin running process {}", inner.id, proc.0);
             inner.proc = Some(proc);
             unsafe {
-                inner.loop_context.switch_to(&mut *inner.proc.as_mut().unwrap().1);
+                inner.loop_context.switch_to(&mut *inner.proc.as_mut().expect("context should not be None").1);
             }
-            let (pid, context) = inner.proc.take().unwrap();
+            let (pid, context) = inner.proc.take().expect("proc should not be None");
             trace!("CPU{} stop running process {}", inner.id, pid);
             inner.manager.stop(pid, context);
         }
@@ -71,12 +73,17 @@ impl Processor {
         trace!("yield start");
         let inner = self.inner();
         unsafe {
+            let flags = interrupt::disable_and_store();
             inner.proc.as_mut().unwrap().1.switch_to(&mut *inner.loop_context);
+            interrupt::restore(flags);
         }
     }
 
     pub fn pid(&self) -> Pid {
-        self.inner().proc.as_ref().expect("pid should not be none").0
+        if self.inner().proc.is_none() {
+            return 0;
+        }
+        self.inner().proc.as_ref().expect("pid should not be None").0
     }
 
     pub fn context(&self) -> &Context {
@@ -94,3 +101,4 @@ impl Processor {
         }
     }
 }
+
diff --git a/crate/process/src/thread.rs b/crate/process/src/thread.rs
index a0e9048..4dc7e45 100644
--- a/crate/process/src/thread.rs
+++ b/crate/process/src/thread.rs
@@ -97,6 +97,7 @@ pub fn spawn<F, T>(f: F) -> JoinHandle<T>
     // 在Processor中创建新的线程
     let context = new_kernel_context(kernel_thread_entry::<F, T>, f as usize);
     let pid = processor().manager().add(context);
+    processor().manager().set_parent(current().id(), pid);
 
     // 接下来看看`JoinHandle::join()`的实现
     // 了解是如何获取f返回值的
diff --git a/kernel/src/fs.rs b/kernel/src/fs.rs
index 025cdad..456e422 100644
--- a/kernel/src/fs.rs
+++ b/kernel/src/fs.rs
@@ -20,6 +20,12 @@ _binary_user_riscv_img_end:
 
 pub fn shell() {
     // load riscv32/x86_64 user program
+    use sync;
+    /// below are test for sync, uncomment them if need
+    //sync::test::philosopher_using_mutex();
+    //sync::test::philosopher_using_monitor();
+
+
     info!("come into shell!");
     #[cfg(target_arch = "riscv32")]
     let device = {
@@ -43,9 +49,6 @@ pub fn shell() {
     let layout = Layout::from_size_align(BUF_SIZE, 0x1000).unwrap();
     let buf = unsafe{ slice::from_raw_parts_mut(alloc(layout), BUF_SIZE) };
     // start interaction
-    use sync;
-    //sync::test::philosopher_using_mutex();
-    //sync::test::philosopher_using_monitor();
     loop {
         print!(">> ");
 
diff --git a/kernel/src/process/mod.rs b/kernel/src/process/mod.rs
index fdc197a..60497cb 100644
--- a/kernel/src/process/mod.rs
+++ b/kernel/src/process/mod.rs
@@ -31,7 +31,6 @@ pub fn init() {
 
 static PROCESSORS: [Processor; MAX_CPU_NUM] = [Processor::new(), Processor::new(), Processor::new(), Processor::new(), Processor::new(), Processor::new(), Processor::new(), Processor::new()];
 
-/// Ugly solution for sys_wait(0) (wait for any child)
 #[derive(Default)]
 pub struct Process {
     parent: AtomicUsize,
@@ -39,34 +38,9 @@ pub struct Process {
 }
 
 impl Process {
-    pub fn new_fork(pid: usize, parent: usize) {
-        PROCESS[pid].parent.store(parent, Ordering::Relaxed);
-        PROCESS[parent].children.lock().push(pid);
-    }
     pub fn proc_exit(pid: usize) {
         info!("proc_exit");
-        for child in PROCESS[pid].children.lock().clone() {
-            info!("del child {}", child);
-            processor().manager().del_parent(pid, child);
-        }
-    }
-    pub fn get_children() -> Vec<usize> {
-        Self::current().children.lock().clone()
-    }
-    pub fn do_wait(pid: usize) {
-        Self::current().children.lock().retain(|&p| p != pid);
     }
-    fn current() -> &'static Self {
-        &PROCESS[thread::current().id()]
-    }
-}
-
-lazy_static! {
-    pub static ref PROCESS: Vec<Process> = {
-        let mut vec = Vec::new();
-        vec.resize_default(MAX_PROCESS_NUM);
-        vec
-    };
 }
 
 /// Get current thread struct
diff --git a/kernel/src/sync/test.rs b/kernel/src/sync/test.rs
index 43a4615..7c8fdeb 100644
--- a/kernel/src/sync/test.rs
+++ b/kernel/src/sync/test.rs
@@ -105,7 +105,7 @@ fn philosopher(table: Arc<Table>) {
     trace!("philosopher starting finish");
 
     for h in handles {
-        h.join().expect("join expects some value");
+        h.join().expect("handle should not be none");
     }
     println!("philosophers dining end");
 }
diff --git a/kernel/src/syscall.rs b/kernel/src/syscall.rs
index 0b755d0..0823beb 100644
--- a/kernel/src/syscall.rs
+++ b/kernel/src/syscall.rs
@@ -66,7 +66,6 @@ fn sys_fork(tf: &TrapFrame) -> i32 {
     //memory_set_map_swappable(context.get_memory_set_mut());
     let pid = processor().manager().add(context);
     processor().manager().set_parent(thread::current().id(), pid);
-    Process::new_fork(pid, thread::current().id());
     //memory_set_map_swappable(processor.get_context_mut(pid).get_memory_set_mut());
     info!("fork: {} -> {}", thread::current().id(), pid);
     pid as i32
@@ -77,7 +76,7 @@ fn sys_fork(tf: &TrapFrame) -> i32 {
 fn sys_wait(pid: usize, code: *mut i32) -> i32 {
     loop {
         let wait_procs = match pid {
-            0 => Process::get_children(),
+            0 => processor().manager().get_children(thread::current().id()),
             _ => vec![pid],
         };
         if wait_procs.is_empty() {
@@ -90,7 +89,6 @@ fn sys_wait(pid: usize, code: *mut i32) -> i32 {
                         unsafe { code.write(exit_code as i32); }
                     }
                     processor().manager().wait_done(thread::current().id(), pid);
-                    Process::do_wait(pid);
                     info!("wait: {} -> {}", thread::current().id(), pid);
                     return 0;
                 }