9 files changed, 100 insertions, 2 deletions
diff --git a/src/include/kernel/basesegment.H b/src/include/kernel/basesegment.H
index da262c2a0..574be1a1f 100644
--- a/src/include/kernel/basesegment.H
+++ b/src/include/kernel/basesegment.H
@@ -106,6 +106,11 @@ class BaseSegment : public Segment
         static int mmSetPermission(void* i_va,
                                       uint64_t i_size,
                                       PAGE_PERMISSIONS i_access_type);
+         /**
+          * @breif Cast out older physical memory pages
+          * @param[in] castout Constraint
+          */
+         virtual void castOutPages(uint64_t i_type);
 
     private:
         /**
diff --git a/src/include/kernel/block.H b/src/include/kernel/block.H
index 2421f97f9..88c6664c2 100644
--- a/src/include/kernel/block.H
+++ b/src/include/kernel/block.H
@@ -156,6 +156,20 @@ class Block
         void updateRefCount( uint64_t i_vaddr,
 			     PageTableManager::UsageStats_t i_stats );
 
+        /**
+         * @brief Cast out older phyiscal memory pages
+         * @param[in] i_type - Castout contraint @see VmmManager::castOutPages()
+         * @return number of pages cast out
+         */
+        size_t castOutPages(uint64_t i_type);
+
+        /**
+         * @brief Evict a memory page
+         * @param[in] i_pte shadow page table entry
+         * @return true of page was evicted
+         */
+        bool evictPage(ShadowPTE* i_pte);
+
         friend class Segment;
         friend class BaseSegment;
         friend class StackSegment;
diff --git a/src/include/kernel/cpu.H b/src/include/kernel/cpu.H
index ee24bdd64..ac09da288 100644
--- a/src/include/kernel/cpu.H
+++ b/src/include/kernel/cpu.H
@@ -77,6 +77,9 @@ struct cpu_t
 
     /** XSCOM mutex to serialize access per CPU */
     mutex_t xscom_mutex;
+
+    /** counter for executePeriodics */
+    size_t periodic_count;
 };
 
 /** @fn getCpuId
diff --git a/src/include/kernel/cpumgr.H b/src/include/kernel/cpumgr.H
index 31759564b..b60c72bc6 100644
--- a/src/include/kernel/cpumgr.H
+++ b/src/include/kernel/cpumgr.H
@@ -29,7 +29,12 @@
 class CpuManager
 {
     public:
-	enum { MAXCPUS = KERNEL_MAX_SUPPORTED_CPUS };
+	enum 
+        { 
+            MAXCPUS = KERNEL_MAX_SUPPORTED_CPUS,
+            CPU_PERIODIC_CHECK_MEMORY = 64,
+            CPU_PERIODIC_FLUSH_PAGETABLE = 1024,
+        };
 
 	/** @fn getCurrentCPU
 	 *  Returns a pointer to the current CPU structure by using the
@@ -60,6 +65,13 @@ class CpuManager
      */
     static uint32_t getShutdownStatus() { return cv_shutdown_status; }
 
+    /** @fn executePeriodics
+     * Perform periodic actions
+     * @param[in] cpu_t the CPU
+     */
+    static void executePeriodics(cpu_t * i_cpu);
+
+
     protected:
 	CpuManager();
 	~CpuManager() {}
diff --git a/src/include/kernel/pagemgr.H b/src/include/kernel/pagemgr.H
index eeed535e0..6cb6fefc4 100644
--- a/src/include/kernel/pagemgr.H
+++ b/src/include/kernel/pagemgr.H
@@ -27,6 +27,8 @@
 #include <limits.h>
 #include <util/lockfree/stack.H>
 #include <kernel/vmmmgr.H>
+#include <builtins.h>
+#include <kernel/console.H>
 
 /** @class PageManager
  *  @brief Manages the allocation of memory pages.
@@ -40,6 +42,12 @@ class PageManager
 	static void* allocatePage(size_t n = 1);
 	static void freePage(void*, size_t n = 1);
 
+        /**
+         * Query state for available memory
+         * @returns percent of pages available
+         */
+        static uint64_t queryAvail();
+
 	enum 
 	{ 
 	    MEMLEN = VmmManager::HTABORG,
@@ -55,8 +63,17 @@ class PageManager
 	void* _allocatePage(size_t);
 	void _freePage(void*, size_t);
 
+        /** see queryAvail() */
+        ALWAYS_INLINE
+        uint64_t _queryAvail() const 
+        {
+            return (100*iv_pagesAvail)/iv_pagesTotal;
+        }
+
             /** Statistics on number of free pages (for debug) */
         uint64_t iv_pagesAvail;
+            /** Total number of pages */
+        uint64_t iv_pagesTotal;
 
 	struct page_t
 	{
diff --git a/src/include/kernel/ptmgr.H b/src/include/kernel/ptmgr.H
index 8eca3f213..9ae092857 100644
--- a/src/include/kernel/ptmgr.H
+++ b/src/include/kernel/ptmgr.H
@@ -160,6 +160,11 @@ class PageTableManager
      */
     static void printPT( void );
 
+    /**
+     * @brief Flush reference status & unload unused pages
+     */
+    static void flush( void );
+
 
   protected:
     /**
@@ -452,6 +457,11 @@ class PageTableManager
      */
     void pushUsageStats( PageTableEntry* i_pte );
 
+    /**
+     * @brief see flush
+     */
+    void _flush( void );
+
     // Allow testcase to see inside
     friend class ptmgrtest;
 };
diff --git a/src/include/kernel/segment.H b/src/include/kernel/segment.H
index d7a4a7547..798539309 100644
--- a/src/include/kernel/segment.H
+++ b/src/include/kernel/segment.H
@@ -89,6 +89,12 @@ class Segment
 	    return;
 	};
 
+        /**
+         * @brief Cast out older physical memory pages
+         * @param[in] i_type Constraint @see VmmManager::castOutPages
+         */
+        virtual void castOutPages(uint64_t i_type) {} // default to NOOP
+
     protected:
             /** The base address of the segment. */
         const uint64_t iv_baseAddress;
diff --git a/src/include/kernel/segmentmgr.H b/src/include/kernel/segmentmgr.H
index a8f4e002d..7232c7d4f 100644
--- a/src/include/kernel/segmentmgr.H
+++ b/src/include/kernel/segmentmgr.H
@@ -118,6 +118,12 @@ class SegmentManager
         static void updateRefCount( uint64_t i_vaddr,
 				    PageTableManager::UsageStats_t i_stats );
 
+        /**
+         * @brief Cast out oldest physical memory pages
+         * @param[in] castout type
+         */
+        static void castOutPages(uint64_t i_type);
+
 
     private:
         /** See handlePageFault. */
@@ -129,11 +135,13 @@ class SegmentManager
             /** See updateRefCount. */
 	void _updateRefCount( uint64_t i_vaddr,
 			      PageTableManager::UsageStats_t i_stats );
+        /** See castOutPages */
+        void _castOutPages(uint64_t i_type);
 
         /** See findPhysicalAddress */
         uint64_t _findPhysicalAddress(uint64_t i_vaddr) const;
 
-        ALWAYS_INLINE inline
+        ALWAYS_INLINE
         size_t getSegmentIdFromAddress(uint64_t i_addr) const
         {
             return i_addr >> SLBE_s;  
diff --git a/src/include/kernel/vmmmgr.H b/src/include/kernel/vmmmgr.H
index ef8e6c362..5c7a75d5d 100644
--- a/src/include/kernel/vmmmgr.H
+++ b/src/include/kernel/vmmmgr.H
@@ -55,6 +55,12 @@ class VmmManager
             RO_EXE_ACCESS,
         };
 
+        enum castout_t
+        {
+            NORMAL,
+            CRITICAL,
+        };
+
         static void init();
         static void init_slb();
 
@@ -104,6 +110,17 @@ class VmmManager
          * @return the physical address or -EFAULT @see errno.h
          */
         static uint64_t findPhysicalAddress(uint64_t i_vaddr);
+
+        /**
+         * @brief Cast out older physical memory pages
+         * @param[in] castout constraint
+         */
+        static void castOutPages(castout_t i_ct);
+
+        /**
+         * @brief Flush pagetable, Update shadow page info
+         */
+        static void flushPageTable( void);
         
         /**
          * @brief Remove pages by a specified operation of the given size
@@ -157,6 +174,12 @@ class VmmManager
         /* See mmSetPermission */
         int _mmSetPermission(void* i_va,uint64_t i_size, PAGE_PERMISSIONS i_access_type);
 
+        /** See castOutPages */
+        void _castOutPages(castout_t i_ct);
+
+        /** See flushPageTable */
+        void _flushPageTable( void );
+
     public:
         friend class Block;