Use jmap to get a running JVM configuration
For example:
<path2java>/bin/jmap -heap <pid>
JVM version is 17.0-b16 using parallel threads in the new generation. using thread-local object allocation. Concurrent Mark-Sweep GC Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 6442450944 (6144.0MB) NewSize = 1879048192 (1792.0MB) MaxNewSize = 1879048192 (1792.0MB) OldSize = 5439488 (5.1875MB) NewRatio = 2 SurvivorRatio = 9 PermSize = 268435456 (256.0MB) MaxPermSize = 268435456 (256.0MB) Heap Usage: New Generation (Eden + 1 Survivor Space): capacity = 1708261376 (1629.125MB) used = 1067020744 (1017.5902786254883MB) free = 641240632 (611.5347213745117MB) 62.462381869131484% used Eden Space: capacity = 1537474560 (1466.25MB) used = 907030712 (865.0118942260742MB) free = 630443848 (601.2381057739258MB) 58.994843595981195% used From Space: capacity = 170786816 (162.875MB) used = 159990032 (152.57838439941406MB) free = 10796784 (10.296615600585938MB) 93.67820991521968% used To Space: capacity = 170786816 (162.875MB) used = 0 (0.0MB) free = 170786816 (162.875MB) 0.0% used concurrent mark-sweep generation: capacity = 4563402752 (4352.0MB) used = 621343728 (592.5595550537109MB) free = 3942059024 (3759.440444946289MB) 13.615798599579755% used Perm Generation: capacity = 268435456 (256.0MB) used = 149968392 (143.02100372314453MB) free = 118467064 (112.97899627685547MB) 55.86757957935333% used