Merge pull request #3495 from amicic/bound_tenure_noCM

Bound Tenure Expand
eclipse-openj9 · Feb 5, 2019 · dfbca14 · dfbca14
2 parents 49fe250 + 8648c0d
commit dfbca14
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Showing 6 changed files with 44 additions and 2 deletions.
diff --git a/gc/base/GCExtensionsBase.hpp b/gc/base/GCExtensionsBase.hpp
@@ -251,6 +251,8 @@ class MM_GCExtensionsBase : public MM_BaseVirtual {
 
 #if defined(OMR_GC_MODRON_SCAVENGER)
 	MM_SublistPool rememberedSet;
+	uintptr_t oldHeapSizeOnLastGlobalGC;
+	uintptr_t freeOldHeapSizeOnLastGlobalGC;
 #endif /* OMR_GC_MODRON_SCAVENGER */
 #if defined(OMR_GC_STACCATO)
 	MM_RememberedSetSATB* sATBBarrierRememberedSet; /**< The snapshot at the beginning barrier remembered set used for the write barrier */
@@ -1276,6 +1278,11 @@ class MM_GCExtensionsBase : public MM_BaseVirtual {
 		, requestedPageFlags(OMRPORT_VMEM_PAGE_FLAG_NOT_USED)
 		, gcmetadataPageSize(0)
 		, gcmetadataPageFlags(OMRPORT_VMEM_PAGE_FLAG_NOT_USED)
+#if defined(OMR_GC_MODRON_SCAVENGER)
+		, rememberedSet()
+		, oldHeapSizeOnLastGlobalGC(UDATA_MAX)
+		, freeOldHeapSizeOnLastGlobalGC(UDATA_MAX)
+#endif /* OMR_GC_MODRON_SCAVENGER */		
 #if defined(OMR_GC_STACCATO)
 		, sATBBarrierRememberedSet(NULL)
 #endif /* OMR_GC_STACCATO */

diff --git a/gc/base/gcutils.cpp b/gc/base/gcutils.cpp
@@ -155,6 +155,10 @@ getPercolateReasonAsString(PercolateReason mode)
 		return "previous scavenge aborted";
 	case CONCURRENT_MARK_EXHAUSTED:
 		return "concurrent mark exhausted";
+	case PREVENT_TENURE_EXPAND:
+		return "prevent tenure expand";
+	case MET_PROJECTED_TENURE_MAX_FREE:
+		return "met projected tenure max free";
 	case NONE_SET:
 	default:
 		return "unknown";

diff --git a/gc/base/j9mm.tdf b/gc/base/j9mm.tdf
@@ -912,3 +912,5 @@ TraceEvent=Trc_MM_LOAResize_expandWithRange2 Overhead=1 Level=1 Group=loaresize
 TraceEvent=Trc_MM_LOAResize_contractWithRange Overhead=1 Level=1 Group=loaresize Template="LOA resized on heap contraction: heapSize %zu,  LOA ratio is %.3f --> LOA base is now %p LOA size %zu"
 
 TraceEvent=Trc_MM_Scavenger_percolate_concurrentMarkExhausted Overhead=1 Level=1 Group=percolate Template="Percolating due to exhausted Concurrent Mark"
+TraceEvent=Trc_MM_Scavenger_percolate_preventTenureExpand Overhead=1 Level=1 Group=percolate Template="Percolating to prevent Tenure expand"
+TraceEvent=Trc_MM_Scavenger_percolate_tenureMaxFree Overhead=1 Level=1 Group=percolate Template="Percolating due to meeting Tenure max free"
diff --git a/gc/base/standard/ParallelGlobalGC.cpp b/gc/base/standard/ParallelGlobalGC.cpp
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 1991, 2018 IBM Corp. and others
+ * Copyright (c) 1991, 2019 IBM Corp. and others
  *
  * This program and the accompanying materials are made available under
  * the terms of the Eclipse Public License 2.0 which accompanies this
@@ -540,6 +540,9 @@ MM_ParallelGlobalGC::masterThreadGarbageCollect(MM_EnvironmentBase *env, MM_Allo
 #if defined(OMR_GC_MODRON_SCAVENGER)
 	/* Merge sublists in the remembered set (if necessary) */
 	_extensions->rememberedSet.compact(env);
+
+	_extensions->oldHeapSizeOnLastGlobalGC = _extensions->heap->getActiveMemorySize(MEMORY_TYPE_OLD);
+	_extensions->freeOldHeapSizeOnLastGlobalGC = _extensions->heap->getApproximateActiveFreeMemorySize(MEMORY_TYPE_OLD);
 #endif /* OMR_GC_MODRON_SCAVENGER */
 
 	/* Restart the allocation caches associated to all threads */

diff --git a/gc/base/standard/Scavenger.cpp b/gc/base/standard/Scavenger.cpp
@@ -4284,6 +4284,30 @@ MM_Scavenger::internalGarbageCollect(MM_EnvironmentBase *envBase, MM_MemorySubSp
 		}
 	}
 
+	if (!_extensions->concurrentMark) {
+			uintptr_t previousUsedOldHeap = _extensions->oldHeapSizeOnLastGlobalGC - _extensions->freeOldHeapSizeOnLastGlobalGC;
+			float maxTenureFreeRatio = _extensions->heapFreeMaximumRatioMultiplier / 100.0f;
+			float midTenureFreeRatio = (_extensions->heapFreeMinimumRatioMultiplier + _extensions->heapFreeMaximumRatioMultiplier) / 200.0f;
+			uintptr_t soaFreeMemorySize = _extensions->heap->getApproximateActiveFreeMemorySize(MEMORY_TYPE_OLD) - _extensions->heap->getApproximateActiveFreeLOAMemorySize(MEMORY_TYPE_OLD);
+
+			/* We suspect that next scavegne will cause Tenure expansion, while Tenure free ratio is (was) already high enough */
+			if ((scavengerGCStats->_avgTenureBytes > soaFreeMemorySize) && (_extensions->freeOldHeapSizeOnLastGlobalGC > (_extensions->oldHeapSizeOnLastGlobalGC * midTenureFreeRatio))) {
+				Trc_MM_Scavenger_percolate_preventTenureExpand(env->getLanguageVMThread());
+
+				bool result = percolateGarbageCollect(env, subSpace, NULL, PREVENT_TENURE_EXPAND, J9MMCONSTANT_IMPLICIT_GC_PERCOLATE);
+				Assert_MM_true(result);
+				return true;
+			}
+			/* There was Tenure heap growth since last Global GC, and we suspect (assuming live set size did not grow) we might be going beyond max free bound. */
+			if ((_extensions->heap->getActiveMemorySize(MEMORY_TYPE_OLD) > _extensions->oldHeapSizeOnLastGlobalGC) && (_extensions->heap->getActiveMemorySize(MEMORY_TYPE_OLD) * maxTenureFreeRatio < (_extensions->heap->getActiveMemorySize(MEMORY_TYPE_OLD) - previousUsedOldHeap))) {
+				Trc_MM_Scavenger_percolate_tenureMaxFree(env->getLanguageVMThread());
+
+				bool result = percolateGarbageCollect(env, subSpace, NULL, MET_PROJECTED_TENURE_MAX_FREE, J9MMCONSTANT_IMPLICIT_GC_PERCOLATE);
+				Assert_MM_true(result);
+				return true;
+			}
+	}
+
 	/**
 	 * Language percolation trigger	
 	 * Allow the CollectorLanguageInterface to advise if percolation should occur.

diff --git a/include_core/omrgcconsts.h b/include_core/omrgcconsts.h
@@ -372,7 +372,9 @@ typedef enum {
 	EXPAND_FAILED,
 	ABORTED_SCAVENGE,
 	CRITICAL_REGIONS,
-	CONCURRENT_MARK_EXHAUSTED
+	CONCURRENT_MARK_EXHAUSTED,
+	PREVENT_TENURE_EXPAND,
+	MET_PROJECTED_TENURE_MAX_FREE
 } PercolateReason;
 /**
  * @}