Remove the DefaultMaxDirectMemory configuration and let the JVM set its default, while still allowing it to be overridden by -XX:MaxDirectMemorySize

Author: postalservice14

calculator/calculator.go

@@ -42,9 +42,7 @@ func (c Calculator) Calculate() ([]fmt.Stringer, error) {
 	headRoom := c.headRoom()
 
 	directMemory := j.MaxDirectMemory
-	if directMemory == nil {
-		d := memory.DefaultMaxDirectMemory
-		directMemory = &d
+	if directMemory != nil {
 		options = append(options, *directMemory)
 	}
 
@@ -69,12 +67,12 @@ func (c Calculator) Calculate() ([]fmt.Stringer, error) {
 		options = append(options, *stack)
 	}
 
-	overhead := c.overhead(headRoom, directMemory, metaspace, reservedCodeCache, stack)
+	overhead := c.overhead(headRoom, metaspace, reservedCodeCache, stack)
 	available := memory.Size(*c.TotalMemory)
 
 	if overhead > available {
-		return nil, fmt.Errorf("required memory %s is greater than %s available for allocation: %s, %s, %s, %s x %d threads",
-			overhead, available, directMemory, metaspace, reservedCodeCache, stack, *c.ThreadCount)
+		return nil, fmt.Errorf("required memory %s is greater than %s available for allocation: %s, %s, %s x %d threads",
+			overhead, available, metaspace, reservedCodeCache, stack, *c.ThreadCount)
 	}
 
 	heap := j.MaxHeap
@@ -85,8 +83,8 @@ func (c Calculator) Calculate() ([]fmt.Stringer, error) {
 	}
 
 	if overhead+memory.Size(*heap) > available {
-		return nil, fmt.Errorf("required memory %s is greater than %s available for allocation: %s, %s, %s, %s, %s x %d threads",
-			overhead+memory.Size(*heap), available, directMemory, heap, metaspace, reservedCodeCache, stack, *c.ThreadCount)
+		return nil, fmt.Errorf("required memory %s is greater than %s available for allocation: %s, %s, %s, %s x %d threads",
+			overhead+memory.Size(*heap), available, heap, metaspace, reservedCodeCache, stack, *c.ThreadCount)
 	}
 
 	return options, nil
@@ -104,9 +102,8 @@ func (c Calculator) metaspace() memory.MaxMetaspace {
 	return memory.MaxMetaspace((*c.LoadedClassCount * 5800) + 14000000)
 }
 
-func (c Calculator) overhead(headRoom memory.Size, directMemory *memory.MaxDirectMemory, metaspace *memory.MaxMetaspace, reservedCodeCache *memory.ReservedCodeCache, stack *memory.Stack) memory.Size {
+func (c Calculator) overhead(headRoom memory.Size, metaspace *memory.MaxMetaspace, reservedCodeCache *memory.ReservedCodeCache, stack *memory.Stack) memory.Size {
 	return headRoom +
-		memory.Size(*directMemory) +
 		memory.Size(*metaspace) +
 		memory.Size(*reservedCodeCache) +
 		memory.Size(int64(*stack)*int64(*c.ThreadCount))

calculator/calculator_test.go

@@ -45,11 +45,10 @@ func TestCalculator(t *testing.T) {
 
 		it("uses default and calculated values", func() {
 			g.Expect(c.Calculate()).To(ConsistOf(
-				memory.DefaultMaxDirectMemory,
 				memory.MaxMetaspace(19800000),
 				memory.DefaultReservedCodeCache,
 				memory.DefaultStack,
-				memory.MaxHeap(231858240),
+				memory.MaxHeap(242344000),
 			))
 		})
 
@@ -58,10 +57,11 @@ func TestCalculator(t *testing.T) {
 			c.JvmOptions.MaxDirectMemory = &d
 
 			g.Expect(c.Calculate()).To(ConsistOf(
+				memory.MaxDirectMemory(1048576),
 				memory.MaxMetaspace(19800000),
 				memory.DefaultReservedCodeCache,
 				memory.DefaultStack,
-				memory.MaxHeap(241295424),
+				memory.MaxHeap(242344000),
 			))
 		})
 
@@ -70,10 +70,9 @@ func TestCalculator(t *testing.T) {
 			c.JvmOptions.MaxMetaspace = &m
 
 			g.Expect(c.Calculate()).To(ConsistOf(
-				memory.DefaultMaxDirectMemory,
 				memory.DefaultReservedCodeCache,
 				memory.DefaultStack,
-				memory.MaxHeap(250609664),
+				memory.MaxHeap(261095424),
 			))
 		})
 
@@ -82,10 +81,9 @@ func TestCalculator(t *testing.T) {
 			c.JvmOptions.ReservedCodeCache = &r
 
 			g.Expect(c.Calculate()).To(ConsistOf(
-				memory.DefaultMaxDirectMemory,
 				memory.MaxMetaspace(19800000),
 				memory.DefaultStack,
-				memory.MaxHeap(482467904),
+				memory.MaxHeap(492953664),
 			))
 		})
 
@@ -94,10 +92,9 @@ func TestCalculator(t *testing.T) {
 			c.JvmOptions.Stack = &s
 
 			g.Expect(c.Calculate()).To(ConsistOf(
-				memory.DefaultMaxDirectMemory,
 				memory.MaxMetaspace(19800000),
 				memory.DefaultReservedCodeCache,
-				memory.MaxHeap(231858240),
+				memory.MaxHeap(242344000),
 			))
 		})
 
@@ -106,7 +103,6 @@ func TestCalculator(t *testing.T) {
 			c.JvmOptions.MaxHeap = &h
 
 			g.Expect(c.Calculate()).To(ConsistOf(
-				memory.DefaultMaxDirectMemory,
 				memory.MaxMetaspace(19800000),
 				memory.DefaultReservedCodeCache,
 				memory.DefaultStack,

memory/max_direct_memory.go

@@ -22,8 +22,6 @@ import (
 	"strings"
 )
 
-const DefaultMaxDirectMemory = MaxDirectMemory(10 * Mibi)
-
 var maxDirectMemoryRE = regexp.MustCompile(fmt.Sprintf("^-XX:MaxDirectMemorySize=(%s)$", sizePattern))
 
 type MaxDirectMemory Size