Following is heap usage information is from jmap -heap, I am using Java 1.8, I noticed that the survivor space's capacity is only 40MB, I would ask how this 40MB is calculated.
Garbage-First (G1) GC with 8 thread(s)
Heap Configuration:
MinHeapFreeRatio = 40
MaxHeapFreeRatio = 70
MaxHeapSize = 17179869184 (16384.0MB)
NewSize = 1073741824 (1024.0MB)
MaxNewSize = 10301210624 (9824.0MB)
OldSize = 5452592 (5.1999969482421875MB)
NewRatio = 2
SurvivorRatio = 6
MetaspaceSize = 21807104 (20.796875MB)
CompressedClassSpaceSize = 1073741824 (1024.0MB)
MaxMetaspaceSize = 2147483648 (2048.0MB)
G1HeapRegionSize = 8388608 (8.0MB)
Heap Usage:
G1 Heap:
regions = 2048
capacity = 17179869184 (16384.0MB)
used = 2224567944 (2121.513313293457MB)
free = 14955301240 (14262.486686706543MB)
12.948689656332135% used
G1 Young Generation:
Eden Space:
regions = 74
capacity = 5368709120 (5120.0MB)
used = 620756992 (592.0MB)
free = 4747952128 (4528.0MB)
11.5625% used
Survivor Space:
regions = 5
capacity = 41943040 (40.0MB)
used = 41943040 (40.0MB)
free = 0 (0.0MB)
100.0% used
G1 Old Generation:
regions = 187
capacity = 3179282432 (3032.0MB)
used = 1561867912 (1489.513313293457MB)
free = 1617414520 (1542.486686706543MB)
49.126428538702406% used