The reported freed memory is incorrect

[Kadri314]

There are some cases, the GC pauses increase the memory heap size, example below:

[2022-08-23T14:36:33.337+0200][0.157s] GC(2) Pause Young (Normal) (G1 Evacuation Pause) 147M->148M(1028M) 7.903ms --> increased by 1mb

the GCVIWER in this case will do the following:
before= 147
after=148
totalFreedMemory+=before - after ;
--> in this case we subtract the totalFreedMemory by (1)

The solution should avoid adding into the totalFreedMemory when before-after is <0 :
before= 147
after=148
diff= before - after
totalFreedMemory+= diff >= 0 ? diff : 0

Please apply a fix to this issue, as the reported totalFreedMemory is incorrect.

Regards,
Alkadri