Merge pull request #3515 from amicic/lower_init_age

Initial Tenure Age
eclipse-omr · Feb 6, 2019 · d68d38c · d68d38c
2 parents 4612762 + 917c983
commit d68d38c
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Showing 3 changed files with 19 additions and 6 deletions.
diff --git a/gc/base/GCExtensionsBase.hpp b/gc/base/GCExtensionsBase.hpp
@@ -1410,10 +1410,10 @@ class MM_GCExtensionsBase : public MM_BaseVirtual {
 		, scavengerScanOrdering(OMR_GC_SCAVENGER_SCANORDERING_HIERARCHICAL)
 #endif /* OMR_GC_MODRON_SCAVENGER || OMR_GC_VLHGC */
 #if defined(OMR_GC_MODRON_SCAVENGER)
-		, scvTenureRatioHigh(J9_SCV_TENURE_RATIO_HIGH)
-		, scvTenureRatioLow(J9_SCV_TENURE_RATIO_LOW)
+		, scvTenureRatioHigh(OMR_SCV_TENURE_RATIO_HIGH)
+		, scvTenureRatioLow(OMR_SCV_TENURE_RATIO_LOW)
 		, scvTenureFixedTenureAge(OBJECT_HEADER_AGE_MAX)
-		, scvTenureAdaptiveTenureAge(J9_OBJECT_HEADER_AGE_DEFAULT)
+		, scvTenureAdaptiveTenureAge(0)
 		, scvTenureStrategySurvivalThreshold(0.99)
 		, scvTenureStrategyFixed(false)
 		, scvTenureStrategyAdaptive(true)

diff --git a/gc/base/standard/Scavenger.cpp b/gc/base/standard/Scavenger.cpp
@@ -423,6 +423,19 @@ MM_Scavenger::masterSetupForGC(MM_EnvironmentStandard *env)
 	scavengerStats->_tenureSpaceAllocBytesAcumulation += heapStatsTenureSpace._allocBytes;
 	scavengerStats->_semiSpaceAllocBytesAcumulation += heapStatsSemiSpace._allocBytes;
 
+	/* Check if scvTenureAdaptiveTenureAge has not been initialized or forced (by cmdline option) */
+	if (0 == _extensions->scvTenureAdaptiveTenureAge) {
+		/* With larger initial Nursery sizes, we'll reduce initial tenure age, to help promote peristant object sooner. */
+		_extensions->scvTenureAdaptiveTenureAge = OMR_OBJECT_HEADER_AGE_DEFAULT;
+
+		uintptr_t tenureAgeAdjustement = MM_Math::floorLog2(_extensions->heap->getActiveMemorySize(MEMORY_TYPE_NEW) / MINIMUM_NEW_SPACE_SIZE);
+		if (tenureAgeAdjustement < _extensions->scvTenureAdaptiveTenureAge) {
+			_extensions->scvTenureAdaptiveTenureAge -= tenureAgeAdjustement;
+		} else {
+			_extensions->scvTenureAdaptiveTenureAge = 1;
+		}
+	}
+
 	/* Record the tenure mask */
 	_tenureMask = calculateTenureMask();
 

diff --git a/include_core/omrgcconsts.h b/include_core/omrgcconsts.h
@@ -466,10 +466,10 @@ typedef enum {
 #define J9VMGC_SIZECLASSES_LOG_SMALLEST 0x4
 
 /* Default object age for generational collectors */
-#define J9_OBJECT_HEADER_AGE_DEFAULT 0xA
+#define OMR_OBJECT_HEADER_AGE_DEFAULT 0x9
 
-#define J9_SCV_TENURE_RATIO_LOW 10
-#define J9_SCV_TENURE_RATIO_HIGH 30
+#define OMR_SCV_TENURE_RATIO_LOW 10
+#define OMR_SCV_TENURE_RATIO_HIGH 30
 #define OMR_SCV_REMSET_FRAGMENT_SIZE 32
 #define OMR_SCV_REMSET_SIZE 16384