Finish swap for multi-user process

crate/memory/Cargo.toml

@@ -4,3 +4,4 @@ version = "0.1.0"
 authors = ["WangRunji <wangrunji0408@163.com>"]
 
 [dependencies]
+log = "0.4"

crate/memory/src/addr.rs

@@ -1,4 +1,6 @@
 use core::ops::{Add, AddAssign};
+use super::paging::*;
+use super::memory_set::*;
 
 pub type VirtAddr = usize;
 pub type PhysAddr = usize;
@@ -73,4 +75,45 @@ impl Iterator for PageRange {
             None
         }
     }
+}
+
+/// frame for the swapmanager
+#[derive(Debug, Copy, Clone, PartialOrd, Ord)]
+#[repr(C)]
+pub struct Frame  {
+    page_table: usize, // the raw pointer for the frame's memory set's inactive page table
+    virtaddr: VirtAddr, // the virtual addr for the frame
+    token: usize, // the token for frame
+}
+
+impl Frame{
+    pub fn get_page_table(&self) -> usize {
+        self.page_table
+    }
+
+    pub fn get_virtaddr(&self) -> VirtAddr {
+        self.virtaddr
+    }
+
+    pub fn get_token(&self) -> usize{
+        self.token
+    }
+
+    pub fn new(pt: usize, addr: VirtAddr, pttoken: usize) -> Self{
+        Frame {
+            page_table: pt,
+            virtaddr: addr,
+            token: pttoken,
+        }
+    }
+} 
+
+impl PartialEq for Frame{
+    fn eq(&self, other: &Frame) -> bool {
+        self.token == other.token && self.virtaddr == other.virtaddr
+    }
+}
+
+impl Eq for Frame{
+    
 }

crate/memory/src/lib.rs

@@ -2,6 +2,8 @@
 #![feature(alloc)]
 
 extern crate alloc;
+#[macro_use]
+extern crate log;
 
 // To use `println!` in test
 #[cfg(test)]

crate/memory/src/memory_set.rs

@@ -66,6 +66,8 @@ pub trait InactivePageTable {
     **  @retval Stack                the stack allocated
     */
     fn alloc_stack() -> Stack;
+
+    unsafe fn with_retval<T>(&self, f: impl FnOnce() -> T) -> T;
 }
 
 /// a continuous memory space when the same attribute
@@ -367,6 +369,14 @@ impl<T: InactivePageTable> MemorySet<T> {
         });
         areas.clear();
     }
+
+    /*
+    **  @brief  get the mutable reference for the inactive page table
+    **  @retval: &mut T                 the mutable reference of the inactive page table 
+    */
+    pub fn get_page_table_mut(&mut self) -> &mut T{
+        &mut self.page_table
+    }
 }
 
 impl<T: InactivePageTable> Clone for MemorySet<T> {
@@ -387,6 +397,7 @@ impl<T: InactivePageTable> Clone for MemorySet<T> {
 
 impl<T: InactivePageTable> Drop for MemorySet<T> {
     fn drop(&mut self) {
+        info!("come into drop func for memoryset");
         self.clear();
     }
 }

crate/memory/src/paging/mod.rs

@@ -3,6 +3,7 @@
 //! Implemented for every architecture, used by OS.
 
 use super::*;
+use super::memory_set::InactivePageTable;
 #[cfg(test)]
 pub use self::mock_page_table::MockPageTable;
 

crate/memory/src/swap/fifo.rs

@@ -3,32 +3,36 @@
 use alloc::collections::VecDeque;
 use super::*;
 
+
 #[derive(Default)]
-pub struct FifoSwapManager {
-    deque: VecDeque<VirtAddr>,
+pub struct FifoSwapManager  {
+    deque: VecDeque<Frame>,
 }
 
 impl SwapManager for FifoSwapManager {
     fn tick(&mut self) {}
 
-    fn push(&mut self, addr: usize) {
-        self.deque.push_back(addr);
+    fn push(&mut self, frame: Frame) {
+        debug!("SwapManager push token: {:x?} vaddr: {:x?}", frame.get_token(), frame.get_virtaddr());
+        self.deque.push_back(frame);
     }
 
-    fn remove(&mut self, addr: usize) {
+    fn remove(&mut self, token: usize, addr: VirtAddr) {
+        debug!("SwapManager remove token: {:x?} vaddr: {:x?}", token, addr);
         let id = self.deque.iter()
-            .position(|&x| x == addr)
+            .position(|ref x| x.get_virtaddr() == addr && x.get_token() == token)
             .expect("address not found");
         self.deque.remove(id);
     }
 
-    fn pop<T, S>(&mut self, _: &mut T, _: &mut S) -> Option<VirtAddr>
+    fn pop<T, S>(&mut self, _: &mut T, _: &mut S) -> Option<Frame>
         where T: PageTable, S: Swapper
     {
         self.deque.pop_front()
     }
 }
 
+/*
 #[cfg(test)]
 mod test {
     use super::*;
@@ -49,4 +53,5 @@ mod test {
             10, 11, 11];
         test_manager(FifoSwapManager::default(), &ops, &pgfault_count);
     }
-}
+}
+*/

crate/memory/src/swap/mock_swapper.rs

@@ -4,7 +4,6 @@
 //! Used to test page table operation
 
 use super::Swapper;
-//use alloc::btree_map::BTreeMap;
 use alloc::collections::BTreeMap;
 use core::mem::uninitialized;
 

crate/memory/src/swap/mod.rs

@@ -8,19 +8,23 @@
 
 use super::*;
 use super::paging::*;
+use super::memory_set::InactivePageTable;
+use super::addr::Frame;
+use alloc::rc::Rc;
 use core::ops::{Deref, DerefMut};
 
 //pub use self::fifo::FifoSwapManager;
-pub use self::enhanced_clock::EnhancedClockSwapManager;
+//pub use self::enhanced_clock::EnhancedClockSwapManager;
 
 pub mod fifo;
-mod enhanced_clock;
+//mod enhanced_clock;
 pub mod mock_swapper;
 //#[cfg(test)]
 //mod mock_swapper;
 
 /// Manage all swappable pages, decide which to swap out
 pub trait SwapManager {
+    //type Inactive: InactivePageTable;
     /*
     **  @brief  update intarnal state pre tick
     **          Called when tick interrupt occured
@@ -30,25 +34,26 @@ pub trait SwapManager {
     /*
     **  @brief  update intarnal state when page is pushed into memory
     **          Called when map a swappable page into the memory
-    **  @param  addr: VirtAddr       the virual address of the page pushed into memory
+    **  @param  frame: Frame       the Frame recording the swappable frame info
     **  @retval none
     */
-    fn push(&mut self, addr: VirtAddr);
+    fn push(&mut self, frame: Frame);
     /*
     **  @brief  update intarnal state when page is removed from memory
     **          Called to delete the addr entry from the swap manager
+    **  @param  token: usize         the inactive page table token for the virtual address
     **  @param  addr: VirtAddr       the virual address of the page removed from memory
     **  @retval none
     */
-    fn remove(&mut self, addr: VirtAddr);
+    fn remove(&mut self, token: usize, addr: VirtAddr);
     /*
     **  @brief  select swap out victim when there is need to swap out a page
     **          (The params is only used by `EnhancedClockSwapManager` currently)
     **  @param  page_table: &mut T   the current page table
     **  @param  swapper: &mut S      the swapper used
-    **  @retval Option<VirtAddr>     the virual address of the victim page, if present
+    **  @retval Option<Frame>     the Frame of the victim page, if present
     */
-    fn pop<T, S>(&mut self, page_table: &mut T, swapper: &mut S) -> Option<VirtAddr>
+    fn pop<T, S>(&mut self, page_table: &mut T, swapper: &mut S) -> Option<Frame>
         where T: PageTable, S: Swapper;
 }
 
@@ -100,11 +105,52 @@ impl<T: PageTable, M: SwapManager, S: Swapper> SwapExt<T, M, S> {
     }
 
     /*
-    **  @brief set a virtual address (a page) swappable
+    **  @brief set a page swappable
+    **  @param pt: *mut T2           the raw pointer for the target page's inactive page table
     **  @param addr: VirtAddr        the target page's virtual address
     */
-    pub fn set_swappable(&mut self, addr: VirtAddr){
-        self.swap_manager.push(addr);
+    pub fn set_swappable<T2: InactivePageTable>(&mut self, pt: *mut T2, addr: VirtAddr){
+        let token = unsafe{
+            (*pt).token()
+        };
+        let frame = Frame::new(pt as usize, addr, token);
+        self.swap_manager.push(frame);
+    }
+
+    /*
+    **  @brief remove a page (given virtual address) from swappable pages, if the page is swapped, swap in at first
+    **  @param pt: *mut T2           the raw pointer for the target page's inactive page table
+    **  @param addr: VirtAddr        the target page's virtual address
+    **  @param alloc_frame:          the function to alloc a free physical frame for once
+    */
+    pub unsafe fn remove_from_swappable<T2: InactivePageTable>(&mut self, pt: *mut T2, addr: VirtAddr, alloc_frame: impl FnOnce() -> PhysAddr){
+        trace!("come into remove_from swappable");
+        let Self {ref mut page_table, ref mut swap_manager, ref mut swapper} = self;
+        let targetpt = &mut *(pt);
+        let pttoken = {
+            debug!("the target page table token is {:x?}", targetpt.token());
+            targetpt.token()
+        };
+        debug!("try to change pagetable");
+        let targetaddr = targetpt.with(||{
+            let token = {
+                let entry = page_table.get_entry(addr);
+                if !entry.swapped() {
+                    swap_manager.remove(pttoken, addr);
+                    return;
+                }
+                let token = entry.target() / PAGE_SIZE;
+                let frame = alloc_frame();
+                entry.set_target(frame);
+                entry.set_swapped(false);
+                entry.set_present(true);
+                entry.update();
+                token
+            };
+            let data = page_table.get_page_slice_mut(addr);
+            swapper.swap_in(token, data).unwrap();
+        });
+        trace!("come outof femove_from swappable");
     }
 
     /*
@@ -113,55 +159,72 @@ impl<T: PageTable, M: SwapManager, S: Swapper> SwapExt<T, M, S> {
     **  @param  target: VirtAddr     the target physics address
     **  @retval none
     */
+    /*
     pub fn map_to_swappable(&mut self, addr: VirtAddr, target: PhysAddr) -> &mut T::Entry {
         self.swap_manager.push(addr);
         self.map(addr, target)
-    }
+    }*/
+
     /*
     **  @brief  Swap out any one of the swapped pages
     **  @retval Result<PhysAddr, SwapError>
     **                               the physics address of released frame if success,
     **                               the error if failed
     */
-    pub fn swap_out_any(&mut self) -> Result<PhysAddr, SwapError> {
-        let victim = {
+    pub fn swap_out_any<T2: InactivePageTable>(&mut self) -> Result<PhysAddr, SwapError> {
+        let victim: Option<Frame> = {
             let Self {ref mut page_table, ref mut swap_manager, ref mut swapper} = self;
             swap_manager.pop(page_table, swapper)
         };
+        info!("swap out page {}", victim.unwrap().get_virtaddr());
         match victim {
             None => Err(SwapError::NoSwapped),
-            Some(addr) => self.swap_out(addr),
+            Some(frame) => self.swap_out::<T2>(&frame),
         }
     }
+
     /*
     **  @brief  Swap out page
-    **  @param  addr: VirtAddr       the virual address of beginning of page
+    **  @param  frame: Frame       the Frame of page recording the page info
     **  @retval Result<PhysAddr, SwapError>
     **                               the physics address of the original map target frame if success,
     **                               the error if failed
     */
-    fn swap_out(&mut self, addr: VirtAddr) -> Result<PhysAddr, SwapError> {
-        let data = self.page_table.get_page_slice_mut(addr);
-        let entry = self.page_table.get_entry(addr);
-        if entry.swapped() {
-            return Err(SwapError::AlreadySwapped);
-        }
-        let token = self.swapper.swap_out(data).map_err(|_| SwapError::IOError)?;
-        let target = entry.target();
-        entry.set_target(token * PAGE_SIZE);
-        entry.set_swapped(true);
-        entry.set_present(false);
-        entry.update();
-        Ok(target)
+    fn swap_out<T2: InactivePageTable>(&mut self, frame: &Frame) -> Result<PhysAddr, SwapError> {
+        let Self {ref mut page_table, ref mut swap_manager, ref mut swapper} = self;
+        let ret = unsafe{
+            let pt = &mut *(frame.get_page_table() as *mut T2);
+            pt.with_retval(||{
+                //use core::slice;
+                //let data = unsafe { slice::from_raw_parts_mut((frame.virtaddr & !(PAGE_SIZE - 1)) as *mut u8, PAGE_SIZE) };
+                let data = page_table.get_page_slice_mut(frame.get_virtaddr());
+                let entry = page_table.get_entry(frame.get_virtaddr());
+                if entry.swapped() {
+                    return Err(SwapError::AlreadySwapped);
+                }
+                //assert!(!entry.swapped(), "Page already swapped!");
+                let token = swapper.swap_out(data).map_err(|_| SwapError::IOError)?;
+                //let token = swapper.swap_out(data).unwrap();
+                let target = entry.target();
+                entry.set_target(token * PAGE_SIZE);
+                entry.set_swapped(true);
+                entry.set_present(false);
+                entry.update();
+                Ok(target)
+            })
+        };
+        ret
     }
     /*
-    **  @brief  map the virtual address to a target physics address and then swap in page data
+    **  @brief  map the virtual address to a target physics address and then swap in page data, noted that the page should be in the current page table
+    **  @param pt: *mut T2           the raw pointer for the swapping page's inactive page table
     **  @param  addr: VirtAddr       the virual address of beginning of page
-    **  @param  addr: PhysAddr       the target physics address
+    **  @param  target: PhysAddr       the target physics address
     **  @retval Result<()), SwapError>
     **                               the execute result, and the error if failed
     */
-    fn swap_in(&mut self, addr: VirtAddr, target: PhysAddr) -> Result<(), SwapError> {
+    fn swap_in<T2: InactivePageTable>(&mut self, pt: *mut T2, addr: VirtAddr, target: PhysAddr) -> Result<(), SwapError> {
+        info!("come in to swap in");
         let token = {
             let entry = self.page_table.get_entry(addr);
             if !entry.swapped() {
@@ -176,12 +239,18 @@ impl<T: PageTable, M: SwapManager, S: Swapper> SwapExt<T, M, S> {
         };
         let data = self.page_table.get_page_slice_mut(addr);
         self.swapper.swap_in(token, data).map_err(|_| SwapError::IOError)?;
-        self.swap_manager.push(addr);
+        let pttoken = unsafe{
+            (*pt).token()
+        };
+        let frame = Frame::new(pt as usize, addr, pttoken);
+;
+        self.swap_manager.push(frame);
         Ok(())
     }
     /*
     **  @brief  execute the swap process for page fault
     **          This function must be called whenever PageFault happens.
+    **  @param pt: *mut T2           the raw pointer for the target page's inactive page table (exactly the current page table)
     **  @param  addr: VirtAddr       the virual address of the page fault
     **  @param  alloc_frame: impl FnOnce() -> PhysAddr
     **                               the page allocation function
@@ -189,14 +258,13 @@ impl<T: PageTable, M: SwapManager, S: Swapper> SwapExt<T, M, S> {
     **                               of beginning of the page
     **  @retval bool                 whether swap in happens.
     */
-    pub fn page_fault_handler(&mut self, addr: VirtAddr, alloc_frame: impl FnOnce() -> PhysAddr) -> bool {
+    pub fn page_fault_handler<T2: InactivePageTable>(&mut self, pt: *mut T2, addr: VirtAddr, alloc_frame: impl FnOnce() -> PhysAddr) -> bool {
         if !self.page_table.get_entry(addr).swapped() {
             return false;
         }
         // Allocate a frame, if failed, swap out a page
-        //let frame = alloc_frame().unwrap_or_else(|| self.swap_out_any().ok().unwrap());
         let frame = alloc_frame();
-        self.swap_in(addr, frame).ok().unwrap();
+        self.swap_in(pt, addr, frame).ok().unwrap();
         true
     }
 }
@@ -226,6 +294,7 @@ impl<T: PageTable, M: SwapManager, S: Swapper> DerefMut for SwapExt<T, M, S> {
     }
 }
 
+/*
 #[cfg(test)]
 mod test {
     use super::*;
@@ -288,4 +357,5 @@ mod test {
             assert_eq!(*(*page_fault_count).borrow(), count);
         }
     }
-}
+}
+*/

crate/process/src/processor.rs

@@ -257,6 +257,11 @@ impl<T: Context, S: Scheduler> Processor_<T, S> {
         &self.get(self.current_pid).context
     }
 
+    pub fn current_context_mut(&mut self) -> &mut T {
+        let id = self.current_pid;
+        &mut self.get_mut(id).context
+    }
+
     /*
     **  @brief  get pid of current process
     **  @param  none

kernel/Cargo.lock

@@ -235,6 +235,9 @@ dependencies = [
 [[package]]
 name = "ucore-memory"
 version = "0.1.0"
+dependencies = [
+ "log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
 
 [[package]]
 name = "ucore-process"

kernel/src/arch/riscv32/paging.rs

@@ -238,9 +238,9 @@ impl InactivePageTable for InactivePageTable0 {
 
     /*
     * @param: 
-    *   f: a function to do something for a muatable activepagetable
+    *   f: a function to do something with the temporary modified activate page table
     * @brief: 
-    *   temporarily map the pagetable as an active page and apply f on the it 
+    *   temporarily map the inactive pagetable as an active p2page and apply f on the temporary modified active page table 
     */
     fn edit(&mut self, f: impl FnOnce(&mut Self::Active)) {
         active_table().with_temporary_map(&satp::read().frame(), |active_table, p2_table: &mut RvPageTable| {
@@ -259,6 +259,10 @@ impl InactivePageTable for InactivePageTable0 {
         });
     }
 
+    /*
+    * @brief:
+    *   active self as the current active page table
+    */
     unsafe fn activate(&self) {
         let old_frame = satp::read().frame();
         let new_frame = self.p2_frame.clone();
@@ -269,6 +273,12 @@ impl InactivePageTable for InactivePageTable0 {
         }
     }
 
+    /*
+    * @param:
+    *   f: the function to run when temporarily activate self as current page table
+    * @brief:
+    *   Temporarily activate self and run the process
+    */
     unsafe fn with(&self, f: impl FnOnce()) {
         let old_frame = satp::read().frame();
         let new_frame = self.p2_frame.clone();
@@ -285,6 +295,37 @@ impl InactivePageTable for InactivePageTable0 {
         }
     }
 
+    /*
+    * @param:
+    *   f: the function to run when temporarily activate self as current page table
+    * @brief:
+    *   Temporarily activate self and run the process, and return the return value of f
+    * @retval:
+    *   the return value of f
+    */
+    unsafe fn with_retval<T>(&self, f: impl FnOnce() -> T) -> T{
+        let old_frame = satp::read().frame();
+        let new_frame = self.p2_frame.clone();
+        debug!("switch table {:x?} -> {:x?}", old_frame, new_frame);
+        if old_frame != new_frame {
+            satp::set(satp::Mode::Sv32, 0, new_frame);
+            sfence_vma_all();
+        }
+        let target = f();
+        debug!("switch table {:x?} -> {:x?}", new_frame, old_frame);
+        if old_frame != new_frame {
+            satp::set(satp::Mode::Sv32, 0, old_frame);
+            sfence_vma_all();
+        }
+        target
+    }
+
+    /*
+    * @brief:
+    *   get the token of self, the token is self's pagetable frame's starting physical address
+    * @retval:
+    *   self token
+    */
     fn token(&self) -> usize {
         self.p2_frame.number() | (1 << 31) // as satp
     }

kernel/src/lib.rs

@@ -69,8 +69,8 @@ pub fn kmain() -> ! {
     // the test is not supported in riscv32(maybe)
     //thread::test::local_key();
     //thread::test::unpack();
-    sync::test::philosopher_using_mutex();
-    sync::test::philosopher_using_monitor();
+    //sync::test::philosopher_using_mutex();
+    //sync::test::philosopher_using_monitor();
     //sync::mpsc::test::test_all();
 
     // come into shell

kernel/src/memory.rs

@@ -7,6 +7,8 @@ use ucore_memory::{*, paging::PageTable};
 use ucore_memory::cow::CowExt;
 pub use ucore_memory::memory_set::{MemoryArea, MemoryAttr, MemorySet as MemorySet_, Stack};
 use ucore_memory::swap::*;
+use alloc::collections::VecDeque;
+use process::processor;
 
 pub type MemorySet = MemorySet_<InactivePageTable0>;
 
@@ -22,6 +24,7 @@ lazy_static! {
     pub static ref FRAME_ALLOCATOR: Mutex<FrameAlloc> = Mutex::new(FrameAlloc::default());
 }
 
+
 lazy_static! {
     static ref ACTIVE_TABLE: Mutex<CowExt<ActivePageTable>> = Mutex::new(unsafe {
         CowExt::new(ActivePageTable::new())
@@ -33,7 +36,7 @@ pub fn active_table() -> MutexGuard<'static, CowExt<ActivePageTable>> {
     ACTIVE_TABLE.lock()
 }
 
-// Page table for swpa in and out
+// Page table for swap in and out
 lazy_static!{
     static ref ACTIVE_TABLE_SWAP: Mutex<SwapExt<ActivePageTable, fifo::FifoSwapManager, mock_swapper::MockSwapper>> = 
         Mutex::new(unsafe{SwapExt::new(ActivePageTable::new(), fifo::FifoSwapManager::default(), mock_swapper::MockSwapper::default())});
@@ -54,7 +57,7 @@ pub fn alloc_frame() -> Option<usize> {
     let ret = FRAME_ALLOCATOR.lock().alloc().map(|id| id * PAGE_SIZE + MEMORY_OFFSET);
     trace!("Allocate frame: {:x?}", ret);
     //do we need : unsafe { ACTIVE_TABLE_SWAP.force_unlock(); } ???
-    Some(ret.unwrap_or_else(|| active_table_swap().swap_out_any().ok().unwrap()))
+    Some(ret.unwrap_or_else(|| active_table_swap().swap_out_any::<InactivePageTable0>().ok().unwrap()))
 }
 
 pub fn dealloc_frame(target: usize) {
@@ -88,8 +91,11 @@ pub fn page_fault_handler(addr: usize) -> bool {
         return true;
     }
     // handle the swap in/out
+    info!("start handling swap in/out page fault");
     unsafe { ACTIVE_TABLE_SWAP.force_unlock(); }
-    if active_table_swap().page_fault_handler(addr, || alloc_frame().unwrap()){
+    let mut temp_proc = processor();
+    let pt = temp_proc.current_context_mut().get_memory_set_mut().get_page_table_mut();
+    if active_table_swap().page_fault_handler(pt as *mut InactivePageTable0, addr, || alloc_frame().unwrap()){
         return true;
     }
     false

kernel/src/process/context.rs

@@ -1,8 +1,9 @@
 use arch::interrupt::{TrapFrame, Context as ArchContext};
-use memory::{MemoryArea, MemoryAttr, MemorySet, active_table_swap};
+use memory::{MemoryArea, MemoryAttr, MemorySet, active_table_swap, alloc_frame};
 use xmas_elf::{ElfFile, header, program::{Flags, ProgramHeader, Type}};
 use core::fmt::{Debug, Error, Formatter};
 use ucore_memory::{Page};
+use ::memory::{InactivePageTable0};
 
 pub struct Context {
     arch: ArchContext,
@@ -106,14 +107,9 @@ impl Context {
             });
         }
 
+        
         //set the user Memory pages in the memory set swappable
-        for area in memory_set.iter(){
-            for page in Page::range_of(area.get_start_addr(), area.get_end_addr()) {
-                    let addr = page.start_address();
-                    active_table_swap().set_swappable(addr);
-                }
-        }
-        info!("finish setting memory swappable.");
+        memory_set_map_swappable(&mut memory_set);
 
         Context {
             arch: unsafe {
@@ -127,7 +123,7 @@ impl Context {
     /// Fork
     pub fn fork(&self, tf: &TrapFrame) -> Self {
         // Clone memory set, make a new page table
-        let memory_set = self.memory_set.clone();
+        let mut memory_set = self.memory_set.clone();
 
         // Copy data to temp space
         use alloc::vec::Vec;
@@ -143,12 +139,39 @@ impl Context {
                 }
             });
         }
+        // map the memory set swappable
+        memory_set_map_swappable(&mut memory_set);
 
         Context {
             arch: unsafe { ArchContext::new_fork(tf, memory_set.kstack_top(), memory_set.token()) },
             memory_set,
         }
     }
+
+    pub fn get_memory_set_mut(&mut self) -> &mut MemorySet {
+        &mut self.memory_set
+    }
+
+}
+
+impl Drop for Context{
+    fn drop(&mut self){
+        //set the user Memory pages in the memory set unswappable
+        let Self {ref mut arch, ref mut memory_set} = self;
+        let pt = {
+            memory_set.get_page_table_mut() as *mut InactivePageTable0
+        };
+        for area in memory_set.iter(){
+            for page in Page::range_of(area.get_start_addr(), area.get_end_addr()) {
+                let addr = page.start_address();
+                unsafe {
+                    active_table_swap().remove_from_swappable(pt, addr, || alloc_frame().unwrap());
+                }
+            }
+        }
+        info!("Finishing setting pages unswappable");
+        
+    }
 }
 
 impl Debug for Context {
@@ -186,4 +209,23 @@ fn memory_attr_from(elf_flags: Flags) -> MemoryAttr {
     // TODO: handle readonly
     if elf_flags.is_execute() { flags = flags.execute(); }
     flags
+}
+
+/*
+* @param: 
+*   memory_set: the target MemorySet to set swappable
+* @brief:
+*   map the memory area in the memory_set swappalbe, specially for the user process
+*/
+fn memory_set_map_swappable(memory_set: &mut MemorySet){
+    let pt = unsafe {
+        memory_set.get_page_table_mut() as *mut InactivePageTable0
+    };
+    for area in memory_set.iter(){
+        for page in Page::range_of(area.get_start_addr(), area.get_end_addr()) {
+            let addr = page.start_address();
+            active_table_swap().set_swappable(pt, addr);
+        }
+    }
+    info!("Finishing setting pages swappable");
 }