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>

1 files changed, 14 insertions, 3 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;
+}