wl1497 - ndb - dynamic mem in ndbd

  Impl. NdbdSuperPool (subclass of SuperPool) that uses Ndbd_mem_manager
  Impl. micro benchmark


storage/ndb/src/kernel/vm/Makefile.am:
  Add NdbdSuperPool , which impl. SuperPool
storage/ndb/src/kernel/vm/SuperPool.cpp:
  remove virtuallity
storage/ndb/src/kernel/vm/SuperPool.hpp:
  Remove unneccesary virtuality
storage/ndb/src/kernel/vm/ndbd_malloc_impl.cpp:
  Add util methods used by NdbdSuperPool
storage/ndb/src/kernel/vm/ndbd_malloc_impl.hpp:
  Add util methods used by NdbdSuperPool
storage/ndb/src/kernel/vm/NdbdSuperPool.cpp:
  New BitKeeper file ``storage/ndb/src/kernel/vm/NdbdSuperPool.cpp''
storage/ndb/src/kernel/vm/NdbdSuperPool.hpp:
  New BitKeeper file ``storage/ndb/src/kernel/vm/NdbdSuperPool.hpp''
storage/ndb/src/kernel/vm/bench_pool.cpp:
  New BitKeeper file ``storage/ndb/src/kernel/vm/bench_pool.cpp''

8 files changed, 574 insertions, 8 deletions

diff --git a/storage/ndb/src/kernel/vm/Makefile.am b/storage/ndb/src/kernel/vm/Makefile.am
index f2bef8ba1f7..3e89508e851 100644
--- a/storage/ndb/src/kernel/vm/Makefile.am
+++ b/storage/ndb/src/kernel/vm/Makefile.am
@@ -20,7 +20,8 @@ libkernel_a_SOURCES = \
         Mutex.cpp SafeCounter.cpp \
         Rope.cpp \
 	SuperPool.cpp \
-	ndbd_malloc.cpp ndbd_malloc_impl.cpp
+	ndbd_malloc.cpp ndbd_malloc_impl.cpp \
+        NdbdSuperPool.cpp
 
 INCLUDES_LOC = -I$(top_srcdir)/storage/ndb/src/mgmapi
 
@@ -44,7 +45,7 @@ libkernel.dsp: Makefile \
 	@$(top_srcdir)/storage/ndb/config/win-sources $@ $(libkernel_a_SOURCES)
 	@$(top_srcdir)/storage/ndb/config/win-libraries $@ LIB $(LDADD)
 
-EXTRA_PROGRAMS = ndbd_malloc_impl_test
+EXTRA_PROGRAMS = ndbd_malloc_impl_test bench_pool
 ndbd_malloc_impl_test_CXXFLAGS = -DUNIT_TEST
 ndbd_malloc_impl_test_SOURCES = ndbd_malloc_impl.cpp
 ndbd_malloc_impl_test_LDFLAGS = @ndb_bin_am_ldflags@ \
@@ -52,3 +53,11 @@ ndbd_malloc_impl_test_LDFLAGS = @ndb_bin_am_ldflags@ \
   $(top_builddir)/mysys/libmysys.a \
   $(top_builddir)/dbug/libdbug.a \
   $(top_builddir)/strings/libmystrings.a
+
+bench_pool_SOURCES = bench_pool.cpp ndbd_malloc.cpp \
+                     SuperPool.cpp NdbdSuperPool.cpp ndbd_malloc_impl.cpp
+bench_pool_LDFLAGS = @ndb_bin_am_ldflags@ \
+  $(top_builddir)/storage/ndb/src/libndbclient.la \
+  $(top_builddir)/mysys/libmysys.a \
+  $(top_builddir)/dbug/libdbug.a \
+  $(top_builddir)/strings/libmystrings.a
diff --git a/storage/ndb/src/kernel/vm/NdbdSuperPool.cpp b/storage/ndb/src/kernel/vm/NdbdSuperPool.cpp
new file mode 100644
index 00000000000..29174ab2e43
--- /dev/null
+++ b/storage/ndb/src/kernel/vm/NdbdSuperPool.cpp
@@ -0,0 +1,228 @@
+/* Copyright (C) 2003 MySQL AB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include <ndb_global.h>
+#include "SuperPool.hpp"
+#include "ndbd_malloc_impl.hpp"
+#include "NdbdSuperPool.hpp"
+
+#define PSI (1 << (BMW_2LOG + 2))
+
+struct AllocArea
+{
+  AllocArea(AllocArea* next);
+
+  Uint16 m_currPage;                        // 2
+  Uint16 m_numPages;  // number of pages    // 2
+  SuperPool::PtrI m_firstPageI;             // 4
+  void* m_memory;     // page-aligned pages // 4/8
+  struct AllocArea* m_nextArea;             // 4/8
+  // tot 16/24
+};
+
+AllocArea::AllocArea(AllocArea* next)
+{
+  m_nextArea = next;
+  m_firstPageI = RNIL;
+  m_currPage = m_numPages = 0;
+  m_memory = 0;
+}
+
+NdbdSuperPool::NdbdSuperPool(class Ndbd_mem_manager & mm,
+			     Uint32 pageSize, Uint32 pageBits) :
+  SuperPool(pageSize, pageBits),
+  m_mm(mm),
+  m_currArea(0), m_firstArea(0)
+{
+  m_memRoot = m_mm.get_memroot();
+  
+  m_shift = Ndbd_mem_manager::log2((1 << (BMW_2LOG + 2)) / pageSize) - 1;
+  m_add = (1 << m_shift) - 1;
+}
+
+NdbdSuperPool::~NdbdSuperPool()
+{
+  Uint32 cnt = PSI / sizeof(AllocArea);
+  AllocArea* ap = m_firstArea;
+  while(ap != 0)
+  {
+    AllocArea * first = ap;
+    for(Uint32 i = 0; i<cnt; i++)
+    {
+      if (ap->m_numPages)
+      {
+	m_mm.release(ap->m_memory, ap->m_numPages >> m_shift);
+      }
+      ap = ap->m_nextArea;
+    }
+    m_mm.release((void*)first, 1);
+  }
+}
+
+bool
+NdbdSuperPool::init_1()
+{
+  Uint32 pageCount = (1 << m_pageBits);
+  if (m_pageEnt == 0) {
+    // allocate page entry array
+    Uint32 bytes = pageCount * sizeof(PageEnt);
+    m_pageEnt = static_cast<PageEnt*>(malloc(bytes));
+    if (m_pageEnt == 0)
+      return false;
+    for (Uint32 i = 0; i < pageCount; i++)
+      new (&m_pageEnt[i]) PageEnt();
+  }
+  if (m_pageType == 0) {
+    // allocate type check array
+    Uint32 bytes = pageCount;
+    m_pageType = static_cast<Uint8*>(malloc(bytes));
+    if (m_pageType == 0)
+      return false;
+    memset(m_pageType, 0, bytes);
+  }
+  
+  return true;
+}
+
+static
+void
+initAllocAreaPage(AllocArea * p1)
+{
+  AllocArea * ap = p1;
+  Uint32 cnt = PSI / sizeof(AllocArea);
+  for(Uint32 i = 0; i<cnt; i++, ap++)
+  {
+    new (ap) AllocArea(ap + 1);
+  }
+
+  (p1 + cnt - 1)->m_nextArea = 0;
+}
+
+bool
+NdbdSuperPool::init_2()
+{
+  m_memRoot = m_mm.get_memroot();
+
+  Uint32 cnt = 1;
+  AllocArea* p1 = (AllocArea*)m_mm.alloc(&cnt, 1);
+  if (p1 == 0)
+    return false;
+
+  initAllocAreaPage(p1);
+  m_currArea = p1;
+  m_firstArea = p1;
+  return true;
+}
+
+SuperPool::PtrI
+NdbdSuperPool::getNewPage()
+{
+  AllocArea* ap = m_currArea;
+  Uint32 curr = ap->m_currPage;
+  Uint32 cnt = ap->m_numPages;
+  if (curr == cnt)
+  {
+    // area is used up
+    if (! (ap = allocMem()))
+    {
+      abort();
+      return RNIL;
+    }
+    curr = ap->m_currPage;
+    cnt = ap->m_numPages;
+  }
+
+  assert(curr < cnt);
+  PtrI pageI = ap->m_firstPageI;
+  Uint32 recBits = m_recBits;
+  Int32 ip = ((Int32)pageI >> recBits) + curr;
+  pageI = ip << recBits;
+  ap->m_currPage = curr + 1;
+  return pageI;
+}
+
+Uint32
+NdbdSuperPool::allocAreaMemory(AllocArea* ap, Uint32 tryPages)
+{
+  Uint32 cnt = (tryPages + m_add) >> m_shift;
+  void* p1 = m_mm.alloc(&cnt, 1);
+  if (p1 == 0)
+  {
+    abort();
+    return 0;
+  }
+  Uint32 pageI = getPageI(p1);
+  ap->m_firstPageI = pageI;
+  ap->m_currPage = 0;
+  ap->m_memory = p1;
+  ap->m_numPages = cnt << m_shift;
+  return cnt;
+}
+
+AllocArea*
+NdbdSuperPool::allocArea()
+{
+  AllocArea * curr = m_currArea;
+  AllocArea * next = curr->m_nextArea;
+  if (next == 0)
+  {
+    Uint32 cnt = 1;
+    AllocArea* p1 = (AllocArea*)m_mm.alloc(&cnt, 1);
+    if (p1 == 0)
+      return 0;
+    
+    initAllocAreaPage(p1);
+
+    m_currArea->m_nextArea = p1;
+    return m_currArea = p1;
+  }
+  else
+  {
+    m_currArea = m_currArea->m_nextArea;
+    return m_currArea;
+  }
+}
+
+AllocArea*
+NdbdSuperPool::allocMem()
+{
+  // compute number of additional pages needed
+  if (m_totPages >= m_maxPages)
+  {
+    abort();
+    return 0;
+  }
+  Uint32 needPages = (m_totPages == 0 ? m_initPages : m_incrPages);
+  
+  // add new area
+  AllocArea* ap = allocArea();
+  if (ap == 0)
+  {
+    abort();
+    return 0;
+  }
+  
+  Uint32 numPages;
+  if (!(numPages = allocAreaMemory(ap, needPages)))
+  {
+    abort();
+    return 0;
+  }
+  
+  // update counts
+  m_totPages += numPages;
+  return ap;
+}
diff --git a/storage/ndb/src/kernel/vm/NdbdSuperPool.hpp b/storage/ndb/src/kernel/vm/NdbdSuperPool.hpp
new file mode 100644
index 00000000000..fc552357a4f
--- /dev/null
+++ b/storage/ndb/src/kernel/vm/NdbdSuperPool.hpp
@@ -0,0 +1,55 @@
+/* Copyright (C) 2003 MySQL AB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#ifndef NDBD_SUPER_POOL_HPP
+#define NDBD_SUPER_POOL_HPP
+
+#include "SuperPool.hpp"
+
+struct AllocArea;
+
+class NdbdSuperPool : public SuperPool
+{
+public:
+  NdbdSuperPool(class Ndbd_mem_manager&, Uint32 pageSize, Uint32 pageBits);
+  
+  // Destructor.
+  virtual ~NdbdSuperPool();
+  
+  // Get new page from current area.
+  virtual PtrI getNewPage();
+
+  // Call first...on all superpools (uses malloc)
+  bool init_1(); 
+  
+  // Call second...uses mm
+  bool init_2();
+  
+  virtual bool allocMemory() { return allocMem() != 0; }
+private:
+  Uint32 allocAreaMemory(AllocArea*, Uint32 pages);
+  AllocArea* allocArea();
+  AllocArea* allocMem();
+  
+  // List of malloc areas.
+  Uint32 m_shift, m_add;
+  class Ndbd_mem_manager & m_mm;
+
+  AllocArea* m_currArea;
+  AllocArea* m_firstArea;
+};
+
+#endif
diff --git a/storage/ndb/src/kernel/vm/SuperPool.cpp b/storage/ndb/src/kernel/vm/SuperPool.cpp
index c61bfcc3541..00b6fbc780e 100644
--- a/storage/ndb/src/kernel/vm/SuperPool.cpp
+++ b/storage/ndb/src/kernel/vm/SuperPool.cpp
@@ -644,7 +644,7 @@ HeapPool::getNewPage()
   if (ap->m_currPage == ap->m_numPages) {
     // area is used up
     if (ap->m_nextArea == 0) {
-      if (! allocMemory())
+      if (! allocMemoryImpl())
         return RNIL;
     }
     ap = m_currArea = ap->m_nextArea;
@@ -711,7 +711,7 @@ HeapPool::allocArea(Area* ap, Uint32 tryPages)
 }
 
 bool
-HeapPool::allocMemory()
+HeapPool::allocMemoryImpl()
 {
   if (! allocInit())
     return false;
diff --git a/storage/ndb/src/kernel/vm/SuperPool.hpp b/storage/ndb/src/kernel/vm/SuperPool.hpp
index 187383f5f71..8f649a2b32a 100644
--- a/storage/ndb/src/kernel/vm/SuperPool.hpp
+++ b/storage/ndb/src/kernel/vm/SuperPool.hpp
@@ -580,7 +580,8 @@ public:
   bool allocArea(Area* ap, Uint32 tryPages);
 
   // Allocate memory.
-  virtual bool allocMemory();
+  virtual bool allocMemory() { return allocMemoryImpl();}
+  bool allocMemoryImpl();
 
   // List of malloc areas.
   Area m_areaHead;
diff --git a/storage/ndb/src/kernel/vm/bench_pool.cpp b/storage/ndb/src/kernel/vm/bench_pool.cpp
new file mode 100644
index 00000000000..1042059b0c5
--- /dev/null
+++ b/storage/ndb/src/kernel/vm/bench_pool.cpp
@@ -0,0 +1,249 @@
+/* Copyright (C) 2003 MySQL AB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+
+#include "NdbdSuperPool.hpp"
+#include "ArrayPool.hpp"
+#include <NdbTick.h>
+#include "ndbd_malloc_impl.hpp"
+
+template <typename T>
+inline
+void
+init(ArrayPool<T> & pool, Uint32 cnt)
+{
+  pool.setSize(cnt + 1);
+}
+
+template <typename T>
+inline
+void
+init(RecordPool<T> & pool, Uint32 cnt)
+{
+}
+
+
+template<typename T, typename R>
+inline
+void 
+test_pool(R& pool, Uint32 cnt, Uint32 loops)
+{
+  init(pool, cnt);
+  Ptr<T> ptr;
+  Uint32 *arr = (Uint32*)alloca(cnt * sizeof(Uint32));
+  {
+    printf(" ; seize "); fflush(stdout);
+    Uint64 sum = 0;
+    for(Uint32 i = 0; i<loops; i++)
+    {
+      Uint64 start = NdbTick_CurrentMillisecond();
+      for(Uint32 j = 0; j<cnt; j++)
+      {
+	bool b = pool.seize(ptr);
+	arr[j] = ptr.i;
+	assert(b);
+      }
+      Uint64 stop = NdbTick_CurrentMillisecond();      
+
+      for(Uint32 j = 0; j<cnt; j++)
+      {
+	ptr.i = arr[j];
+	pool.getPtr(ptr);
+	pool.release(ptr);
+	arr[j] = RNIL;
+      }
+      
+      sum += (stop - start);
+      if (i == 0)
+	printf("; first ; %lld", (stop - start));
+    }
+    printf(" ; avg ; %lld ; tot ; %lld", sum/loops, sum);fflush(stdout);
+  }
+
+  {
+    printf(" ; release "); fflush(stdout);
+    Uint64 sum = 0;
+    for(Uint32 i = 0; i<loops; i++)
+    {
+      for(Uint32 j = 0; j<cnt; j++)
+      {
+	bool b = pool.seize(ptr);
+	arr[j] = ptr.i;
+	assert(b);
+      }
+
+      Uint64 start = NdbTick_CurrentMillisecond();
+      for(Uint32 j = 0; j<cnt; j++)
+      {
+	ptr.i = arr[j];
+	pool.release(ptr);
+	arr[j] = RNIL;
+      }
+      Uint64 stop = NdbTick_CurrentMillisecond();      
+      
+      sum += (stop - start);
+    }
+    printf("; avg ; %lld ; tot ; %lld", sum/loops, sum); fflush(stdout);
+  }
+
+  {
+    printf(" ; mix"); fflush(stdout);
+    
+    Uint64 sum = 0;
+    Uint64 start = NdbTick_CurrentMillisecond();
+    for(Uint32 i = 0; i<loops * cnt; i++)
+    {
+      int pos = rand() % cnt;
+      ptr.i = arr[pos];
+      if (ptr.i == RNIL)
+      {
+	pool.seize(ptr);
+	arr[pos] = ptr.i;
+	assert(ptr.i != RNIL);
+      }
+      else
+      {
+	pool.release(ptr);
+	arr[pos] = RNIL;
+      }
+    }
+    Uint64 stop = NdbTick_CurrentMillisecond();    
+    
+    for(Uint32 j = 0; j<cnt; j++)
+    {
+      ptr.i = arr[j];
+      if (ptr.i != RNIL)
+      {
+	pool.getPtr(ptr);
+	pool.release(ptr);
+      }
+      arr[j] = RNIL;
+    }
+    
+    sum += (stop - start);
+    printf(" ; %lld", sum); fflush(stdout);
+  }
+  
+  {
+    printf(" ; getPtr"); fflush(stdout);
+
+    for(Uint32 j = 0; j<cnt; j++)
+    {
+      bool b = pool.seize(ptr);
+      arr[j] = ptr.i;
+      assert(b);
+    }
+
+    Uint64 sum = 0;
+    Uint64 start = NdbTick_CurrentMillisecond();
+    for(Uint32 i = 0; i<loops * cnt; i++)
+    {
+      int pos = rand() % cnt;
+      ptr.i = arr[pos];
+      pool.getPtr(ptr);
+    }
+    Uint64 stop = NdbTick_CurrentMillisecond();    
+
+    for(Uint32 j = 0; j<cnt; j++)
+    {
+      ptr.i = arr[j];
+      pool.getPtr(ptr);
+      pool.release(ptr);
+      arr[j] = RNIL;
+    }
+    
+    sum += (stop - start);
+    printf(" ; %lld", sum); fflush(stdout);
+  }
+  ndbout_c("");
+}
+
+template <Uint32 sz> struct Rec { char data[sz-4]; Uint32 nextPool; };
+typedef Rec<32> Rec32;
+typedef Rec<36> Rec36;
+typedef Rec<256> Rec256;
+typedef Rec<260> Rec260;
+
+Ndbd_mem_manager mem;
+
+template <typename T>
+inline
+void test_rp(Uint32 cnt, Uint32 loop, Uint32 pgsz)
+{
+  printf("RP ; %d ; ws ; %d ; page ; %d", 
+	 sizeof(T), (sizeof(T)*cnt) >> 10, pgsz >> 10);
+  NdbdSuperPool sp(mem, pgsz, 19);
+  GroupPool gp(sp);
+  sp.init_1();
+  sp.init_2();
+  
+  sp.setInitPages(4);
+  sp.setIncrPages(4);
+  sp.setMaxPages(~0);
+  sp.allocMemory();
+  
+  RecordPool<T> pool(gp);
+  test_pool<T, RecordPool<T> >(pool, cnt, loop);
+}
+
+template <typename T>
+inline
+void test_ap(Uint32 cnt, Uint32 loop)
+{
+  printf("AP ; %d ; ws ; %d ; page ; n/a", sizeof(T), (cnt * sizeof(T))>>10);
+  ArrayPool<T> pool;
+  test_pool<T, ArrayPool<T> >(pool, cnt, loop);
+}
+
+int
+main(int argc, char **argv)
+{
+  mem.init(10000);
+
+  Uint32 cnt = 100;
+  Uint32 loop = 300000;
+
+  while(cnt <= 1000000)
+  {
+    test_rp<Rec32>(cnt, loop, 8192);
+    test_rp<Rec32>(cnt, loop, 32768);
+    test_ap<Rec32>(cnt, loop);
+    
+    test_rp<Rec36>(cnt, loop, 8192);
+    test_rp<Rec36>(cnt, loop, 32768);
+    test_ap<Rec36>(cnt, loop);
+
+    test_rp<Rec256>(cnt, loop, 8192);
+    test_rp<Rec256>(cnt, loop, 32768);
+    test_ap<Rec256>(cnt, loop);
+
+    test_rp<Rec260>(cnt, loop, 8192);
+    test_rp<Rec260>(cnt, loop, 32768);
+    test_ap<Rec260>(cnt, loop);
+
+    cnt *= 100;
+    loop /= 100;
+  }
+}
+
+void
+ErrorReporter::handleAssert(const char * msg, const char * file, 
+			    int line, int)
+{
+  ndbout << "ErrorReporter::handleAssert activated - " 
+	 << " line= " << line << endl;
+  abort();
+}
diff --git a/storage/ndb/src/kernel/vm/ndbd_malloc_impl.cpp b/storage/ndb/src/kernel/vm/ndbd_malloc_impl.cpp
index 5443fdf1300..e78a1cc1194 100644
--- a/storage/ndb/src/kernel/vm/ndbd_malloc_impl.cpp
+++ b/storage/ndb/src/kernel/vm/ndbd_malloc_impl.cpp
@@ -84,7 +84,7 @@ Ndbd_mem_manager::init(Uint32 pages)
     release(start+1, end - 1 - start);    
   }
 
-  return 0;
+  return true;
 }
 
 void
@@ -200,6 +200,25 @@ Ndbd_mem_manager::alloc(Uint32* ret, Uint32 *pages, Uint32 min)
   * pages = 0;
 }
 
+void*
+Ndbd_mem_manager::alloc(Uint32 *pages, Uint32 min)
+{
+  Uint32 ret;
+  alloc(&ret, pages, min);
+  if (pages)
+  {
+    return m_base_page + ret;
+  }
+  return 0;
+}
+
+void
+Ndbd_mem_manager::release(void* ptr, Uint32 cnt)
+{
+  Uint32 page = ((Alloc_page*)ptr) - m_base_page;
+  release(page, cnt);
+}
+
 void
 Ndbd_mem_manager::insert_free_list(Uint32 start, Uint32 size)
 {
diff --git a/storage/ndb/src/kernel/vm/ndbd_malloc_impl.hpp b/storage/ndb/src/kernel/vm/ndbd_malloc_impl.hpp
index e497f62b92a..15b5c9c390e 100644
--- a/storage/ndb/src/kernel/vm/ndbd_malloc_impl.hpp
+++ b/storage/ndb/src/kernel/vm/ndbd_malloc_impl.hpp
@@ -64,8 +64,12 @@ public:
   bool grow(Uint32 pages = 0);
 
   void dump() const ;
-private:
-  
+
+  void* get_memroot() const { return (void*)m_base_page;}
+
+  void* alloc(Uint32 * pages, Uint32 min_requested);
+  void release(void* ptr, Uint32 cnt);
+
   /**
    * Compute 2log of size 
    * @note size = 0     -> 0
@@ -73,6 +77,7 @@ private:
    */
   static Uint32 log2(Uint32 size);
 
+private:
   /**
    * Return pointer to free page data on page
    */