Merge pull request #3139 from mpirvu/newactivpolicy

Change heuristics for activating compilation threads
eclipse-openj9 · Oct 5, 2018 · 1b800b0 · 1b800b0
2 parents 856d92e + c7c2da3
commit 1b800b0
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Showing 2 changed files with 19 additions and 17 deletions.
diff --git a/runtime/compiler/control/CompilationThread.cpp b/runtime/compiler/control/CompilationThread.cpp
@@ -388,22 +388,23 @@ TR_YesNoMaybe TR::CompilationInfo::shouldActivateNewCompThread()
    // determined based on the number of CPUs, then the upper bound of comp threads is _numTargetCPUs-1
    // However, if the compilation threads are starved (on Linux) we may want
    // to activate additional comp threads irrespective of the CPU entitlement
-   if (TR::Options::_useCPUsToDetermineMaxNumberOfCompThreadsToActivate ||
-       !_starvationDetected)
+   if (TR::Options::_useCPUsToDetermineMaxNumberOfCompThreadsToActivate)
       {
-      if (getNumCompThreadsActive() >= getNumTargetCPUs() - 1)
+      if (getNumCompThreadsActive() < getNumTargetCPUs() - 1)
          {
-         return TR_no;
+         if (_queueWeight > compThreadActivationThresholds[getNumCompThreadsActive()])
+            return TR_yes;
          }
-      else
+      else if (_starvationDetected)
          {
-         if (_queueWeight > compThreadActivationThresholds[getNumCompThreadsActive()])
+         // comp thread starvation; may activate threads beyond numCpu-1
+         if (_queueWeight > compThreadActivationThresholdsonStarvation[getNumCompThreadsActive()])
             return TR_yes;
          }
       }
-   else // comp thread starvation; may activate threads beyond numCpu-1
+   else // number of compilation threads indicated by the user
       {
-      if (_queueWeight > compThreadActivationThresholdsonStarvation[getNumCompThreadsActive()])
+      if (_queueWeight > compThreadActivationThresholds[getNumCompThreadsActive()])
          return TR_yes;
       }
 

diff --git a/runtime/compiler/control/J9Options.cpp b/runtime/compiler/control/J9Options.cpp
@@ -1990,22 +1990,23 @@ J9::Options::fePostProcessJIT(void * base)
    //
    if (_numUsableCompilationThreads <= 0)
       {
-#ifdef LINUX
-      // For linux we may want to create more threads to overcome thread
-      // starvation due to lack of priorities
-      //
-      if (!TR::Options::getCmdLineOptions()->getOption(TR_DisableRampupImprovements) &&
-          !TR::Options::getAOTCmdLineOptions()->getOption(TR_DisableRampupImprovements))
-         _numUsableCompilationThreads = MAX_USABLE_COMP_THREADS;
-#endif // LINUX
+      _useCPUsToDetermineMaxNumberOfCompThreadsToActivate = true;
+      if (TR::Compiler->target.isLinux())
+         {
+         // For linux we may want to create more threads to overcome thread
+         // starvation due to lack of priorities
+         //
+         if (!TR::Options::getCmdLineOptions()->getOption(TR_DisableRampupImprovements) &&
+            !TR::Options::getAOTCmdLineOptions()->getOption(TR_DisableRampupImprovements))
+            _numUsableCompilationThreads = MAX_USABLE_COMP_THREADS;
+         }
       if (_numUsableCompilationThreads <= 0)
          {
          // Determine the number of compilation threads based on number of online processors
          // Do not create more than numProc-1 compilation threads, but at least one
          //
          uint32_t numOnlineCPUs = j9sysinfo_get_number_CPUs_by_type(J9PORT_CPU_ONLINE);
          _numUsableCompilationThreads = numOnlineCPUs > 1 ? std::min((numOnlineCPUs - 1), static_cast<uint32_t>(MAX_USABLE_COMP_THREADS)) : 1;
-         _useCPUsToDetermineMaxNumberOfCompThreadsToActivate = true;
          }
       }