new HEAP manager to reduce fragmentation

Change-Id: Ibe725a43e6366d9113ec99df1cc6aafa7bbb770e
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/431
Tested-by: Jenkins Server
Reviewed-by: A. Patrick Williams III <iawillia@us.ibm.com>
Reviewed-by: Douglas R. Gilbert <dgilbert@us.ibm.com>

1 files changed, 28 insertions, 7 deletions

diff --git a/src/include/kernel/pagemgr.H b/src/include/kernel/pagemgr.H
index 6cb6fefc4..3ed2c1b34 100644
--- a/src/include/kernel/pagemgr.H
+++ b/src/include/kernel/pagemgr.H
@@ -29,6 +29,8 @@
 #include <kernel/vmmmgr.H>
 #include <builtins.h>
 #include <kernel/console.H>
+#include <util/align.H>
+#include <sys/vfs.h>
 
 /** @class PageManager
  *  @brief Manages the allocation of memory pages.
@@ -37,10 +39,10 @@
 class PageManager
 {
     public:
-	static void init();
+        static void init();
 
-	static void* allocatePage(size_t n = 1);
-	static void freePage(void*, size_t n = 1);
+        static void* allocatePage(size_t n = 1);
+        static void freePage(void*, size_t n = 1);
 
         /**
          * Query state for available memory
@@ -48,9 +50,16 @@ class PageManager
          */
         static uint64_t queryAvail();
 
-	enum 
-	{ 
-	    MEMLEN = VmmManager::HTABORG,
+        /**
+         * Coalesce adjacent free memory blocks
+         * @pre This function can only be called from kernel space and
+         * requires that all other processes are quiesced
+         */
+        static void coalesce( void );
+
+        enum 
+        { 
+            MEMLEN = VmmManager::HTABORG,
 
 	    BUCKETS = 16,
 	};
@@ -62,6 +71,7 @@ class PageManager
     private:
 	void* _allocatePage(size_t);
 	void _freePage(void*, size_t);
+        void _coalesce( void );         //!< see coalesce()
 
         /** see queryAvail() */
         ALWAYS_INLINE
@@ -70,6 +80,13 @@ class PageManager
             return (100*iv_pagesAvail)/iv_pagesTotal;
         }
 
+        ALWAYS_INLINE
+        uint64_t firstPageAddr( void )
+        {
+            return ALIGN_PAGE(VFS_LAST_ADDRESS);
+        }
+            
+
             /** Statistics on number of free pages (for debug) */
         uint64_t iv_pagesAvail;
             /** Total number of pages */
@@ -77,12 +94,16 @@ class PageManager
 
 	struct page_t
 	{
-	    page_t* next;
+	    page_t* next;       //!< Next block of pages
+            page_t* prev;       //!< Prev block of pages
+            page_t* key;        //!< Key for pqueue
 	};
 	Util::Lockfree::Stack<page_t> first_page[BUCKETS];
 
 	page_t* pop_bucket(size_t);
 	void push_bucket(page_t*, size_t);
+
+        static size_t cv_coalesce_count;        //!< running coalesced counter
 };
 
 #endif