jmap -heap

UseConcMarkSweepGC.txt

[root@NYSJHL102-239 ~]# /opt/j2sdk/bin/jmap -heap 24694
Attaching to process ID 24694, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 11.0-b15

using parallel threads in the new generation.
using thread-local object allocation.
Concurrent Mark-Sweep GC

Heap Configuration:
   MinHeapFreeRatio = 40
   MaxHeapFreeRatio = 70
   MaxHeapSize      = 4194304000 (4000.0MB)
   NewSize          = 1598029824 (1524.0MB)
   MaxNewSize       = 1598029824 (1524.0MB)
   OldSize          = 2596274176 (2476.0MB)
   NewRatio         = 7
   SurvivorRatio    = 8
   PermSize         = 67108864 (64.0MB)
   MaxPermSize      = 536870912 (512.0MB)

Heap Usage:
New Generation (Eden + 1 Survivor Space):
   capacity = 1438253056 (1371.625MB)
   used     = 928309832 (885.3052444458008MB)
   free     = 509943224 (486.3197555541992MB)
   64.54426278653428% used
Eden Space:
   capacity = 1278476288 (1219.25MB)
   used     = 818712984 (780.7855453491211MB)
   free     = 459763304 (438.4644546508789MB)
   64.03818292795744% used
From Space:
   capacity = 159776768 (152.375MB)
   used     = 109596848 (104.51969909667969MB)
   free     = 50179920 (47.85530090332031MB)
   68.59373197485131% used
To Space:
   capacity = 159776768 (152.375MB)
   used     = 0 (0.0MB)
   free     = 159776768 (152.375MB)
   0.0% used
concurrent mark-sweep generation:
   capacity = 2596274176 (2476.0MB)
   used     = 609357240 (581.1283493041992MB)
   free     = 1986916936 (1894.8716506958008MB)
   23.470450294999967% used
Perm Generation:
   capacity = 67108864 (64.0MB)
   used     = 33631936 (32.07391357421875MB)
   free     = 33476928 (31.92608642578125MB)
   50.1154899597168% used

UserParallelGC.txt

[root@NYSJHL102-238 ~]# /opt/j2sdk/bin/jmap -heap 10762
Attaching to process ID 10762, please wait...
Debugger attached successfully.
Server compiler detected.
JVM version is 11.0-b15

using thread-local object allocation.
Parallel GC with 8 thread(s)

Heap Configuration:
   MinHeapFreeRatio = 40
   MaxHeapFreeRatio = 70
   MaxHeapSize      = 4194304000 (4000.0MB)
   NewSize          = 2686976 (2.5625MB)
   MaxNewSize       = -65536 (-0.0625MB)
   OldSize          = 5439488 (5.1875MB)
   NewRatio         = 2
   SurvivorRatio    = 8
   PermSize         = 67108864 (64.0MB)
   MaxPermSize      = 536870912 (512.0MB)

Heap Usage:
PS Young Generation
Eden Space:
   capacity = 1048641536 (1000.0625MB)
   used     = 260250520 (248.1942367553711MB)
   free     = 788391016 (751.8682632446289MB)
   24.817872558502202% used
From Space:
   capacity = 174718976 (166.625MB)
   used     = 69894752 (66.65682983398438MB)
   free     = 104824224 (99.96817016601562MB)
   40.00409892512191% used
To Space:
   capacity = 174718976 (166.625MB)
   used     = 0 (0.0MB)
   free     = 174718976 (166.625MB)
   0.0% used
PS Old Generation
   capacity = 2796224512 (2666.6875MB)
   used     = 3542896 (3.3787689208984375MB)
   free     = 2792681616 (2663.3087310791016MB)
   0.12670284466771745% used
PS Perm Generation
   capacity = 67108864 (64.0MB)
   used     = 32583008 (31.073577880859375MB)
   free     = 34525856 (32.926422119140625MB)
   48.55246543884277% used