Improve user-space page allocator.

    * Allow page allocation system call to force coalesce if a
      contiguous block is unavailable.  [long-term enhancement]

    * Workaround lack of large contiguous memory for PageTable
      test-cases, which require 256K, by allocating a VMM block.
      This should be removed when story 43401 is implemented.
      [short-term workaround]

Change-Id: Idddb30eaa3aeac52d56b82a70355095f31d4a0cd
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/1369
Tested-by: Jenkins Server
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
Reviewed-by: Douglas R. Gilbert <dgilbert@us.ibm.com>
Reviewed-by: A. Patrick Williams III <iawillia@us.ibm.com>

3 files changed, 62 insertions, 29 deletions

diff --git a/src/kernel/cpumgr.C b/src/kernel/cpumgr.C
index 2a5c2edcc..4fdc8fde9 100644
--- a/src/kernel/cpumgr.C
+++ b/src/kernel/cpumgr.C
@@ -43,6 +43,7 @@ uint64_t CpuManager::cv_shutdown_status = 0;
 Barrier CpuManager::cv_barrier;
 bool CpuManager::cv_defrag = false;
 size_t CpuManager::cv_cpuCount = 0;
+bool CpuManager::cv_forcedMemPeriodic = false;
 InteractiveDebug CpuManager::cv_interactive_debug;
 
 CpuManager::CpuManager()
@@ -188,11 +189,16 @@ void CpuManager::executePeriodics(cpu_t * i_cpu)
             cv_interactive_debug.startDebugTask();
         }
 
+        bool forceMemoryPeriodic = __sync_fetch_and_and(&cv_forcedMemPeriodic,
+                                                        false);
+
         ++(i_cpu->periodic_count);
-        if(0 == (i_cpu->periodic_count % CPU_PERIODIC_CHECK_MEMORY))
+        if((0 == (i_cpu->periodic_count % CPU_PERIODIC_CHECK_MEMORY)) ||
+           (forceMemoryPeriodic))
         {
             uint64_t pcntAvail = PageManager::queryAvail();
-            if(pcntAvail < PageManager::LOWMEM_NORM_LIMIT)
+            if((pcntAvail < PageManager::LOWMEM_NORM_LIMIT) ||
+               (forceMemoryPeriodic))
             {
                 VmmManager::flushPageTable();
                 ++(i_cpu->periodic_count);   // prevent another flush below
@@ -210,7 +216,8 @@ void CpuManager::executePeriodics(cpu_t * i_cpu)
         {
             VmmManager::flushPageTable();
         }
-        if(0 == (i_cpu->periodic_count % CPU_PERIODIC_DEFRAG))
+        if((0 == (i_cpu->periodic_count % CPU_PERIODIC_DEFRAG)) ||
+           (forceMemoryPeriodic))
         {
             // set up barrier based on # cpus cv_barrier;
             // TODO whatif other cpus become active?
@@ -240,3 +247,7 @@ void CpuManager::executePeriodics(cpu_t * i_cpu)
     }
 }
 
+void CpuManager::forceMemoryPeriodic()
+{
+    cv_forcedMemPeriodic = true;
+}
diff --git a/src/kernel/ptmgr.C b/src/kernel/ptmgr.C
index 3d7f28578..bf8937b78 100644
--- a/src/kernel/ptmgr.C
+++ b/src/kernel/ptmgr.C
@@ -1,25 +1,26 @@
-//  IBM_PROLOG_BEGIN_TAG
-//  This is an automatically generated prolog.
-//
-//  $Source: src/kernel/ptmgr.C $
-//
-//  IBM CONFIDENTIAL
-//
-//  COPYRIGHT International Business Machines Corp. 2011
-//
-//  p1
-//
-//  Object Code Only (OCO) source materials
-//  Licensed Internal Code Source Materials
-//  IBM HostBoot Licensed Internal Code
-//
-//  The source code for this program is not published or other-
-//  wise divested of its trade secrets, irrespective of what has
-//  been deposited with the U.S. Copyright Office.
-//
-//  Origin: 30
-//
-//  IBM_PROLOG_END
+/*  IBM_PROLOG_BEGIN_TAG
+ *  This is an automatically generated prolog.
+ *
+ *  $Source: src/kernel/ptmgr.C $
+ *
+ *  IBM CONFIDENTIAL
+ *
+ *  COPYRIGHT International Business Machines Corp. 2011-2012
+ *
+ *  p1
+ *
+ *  Object Code Only (OCO) source materials
+ *  Licensed Internal Code Source Materials
+ *  IBM HostBoot Licensed Internal Code
+ *
+ *  The source code for this program is not published or other-
+ *  wise divested of its trade secrets, irrespective of what has
+ *  been deposited with the U.S. Copyright Office.
+ *
+ *  Origin: 30
+ *
+ *  IBM_PROLOG_END_TAG
+ */
 #include <kernel/ptmgr.H>
 #include <kernel/vmmmgr.H>
 #include <util/singleton.H>
@@ -295,7 +296,8 @@ void PageTableManager::flush( void )
 /********************
  Private/Protected Methods
  ********************/
-
+#include <sys/mm.h> //@TODO: Remove with 43401
+#include <usr/vmmconst.h> //@TODO: Remove with 43401.
 /**
  * @brief  Constructor
  */
@@ -304,7 +306,16 @@ PageTableManager::PageTableManager( bool i_userSpace )
 {
     if( i_userSpace )
     {
-        ivTABLE = new char[getSize()];
+        //@TODO: Remove with 43401.
+        // Don't have enough contiguous memory to do this allocation, so
+        // allocate a VMM block instead.
+        ivTABLE = reinterpret_cast<char*>(VMM_VADDR_RMVPAGE_TEST - getSize());
+        mm_alloc_block(NULL, ivTABLE, getSize());
+        mm_set_permission(ivTABLE, getSize(), WRITABLE | ALLOCATE_FROM_ZERO);
+
+        //@TODO: Add back after 43401.
+        //ivTABLE = new char[getSize()];
+
         //printk( "** PageTableManager running in USER_SPACE : ivTABLE = %p**\n", ivTABLE );
     }
     else
@@ -335,7 +346,11 @@ void PageTableManager::invalidatePT( void )
 PageTableManager::~PageTableManager()
 {
     if( ivTABLE ) {
-        delete[] ivTABLE;
+        //@TODO: Remove after 43401.
+        mm_remove_pages(RELEASE, ivTABLE, getSize());
+
+        //@TODO: Add back after 43401.
+        //delete[] ivTABLE;
     }
 }
 
diff --git a/src/kernel/syscall.C b/src/kernel/syscall.C
index b6fa46f8a..b061a4877 100644
--- a/src/kernel/syscall.C
+++ b/src/kernel/syscall.C
@@ -677,8 +677,10 @@ namespace Systemcalls
      */
     void MmAllocPages(task_t* t)
     {
+        ssize_t pages = TASK_GETARG0(t);
+
         // Attempt to allocate the page(s).
-        void* page = PageManager::allocatePage(TASK_GETARG0(t), true);
+        void* page = PageManager::allocatePage(pages, true);
         TASK_SETRTN(t, reinterpret_cast<uint64_t>(page));
 
         // If we are low on memory, call into the VMM to free some up.
@@ -696,6 +698,11 @@ namespace Systemcalls
                 __sync_lock_release(&one_at_a_time);
             }
         }
+        else if ((page == NULL) && (pages > 1))
+        {
+            CpuManager::forceMemoryPeriodic();
+        }
+
     }
 };