On Mon, 23 May 2022 07:28:41 GMT, Yi Yang <yy...@openjdk.org> wrote: > It seems that calculation of > MemoryMXBean.getNonHeapMemoryUsage(jmm_GetMemoryUsage) is wrong. > > Currently, NonHeapUsage = CodeCache + Metaspace + CompressedClassSpace > > ==> CodeHeap 'non-nmethods' 1532544 (Used) > ==> CodeHeap 'profiled nmethods' 0 > ==> CodeHeap 'non-profiled nmethods' 13952 > ==> Metaspace 506696 > ==> Compressed Class Space 43312 > init = 7667712(7488K) used = 2096504(2047K) committed = 8454144(8256K) max = > -1(-1K) > > In this way, getNonHeapMemoryUsage is larger than it ought to be, it should > be NonHeapUsage = CodeCache + Metaspace.
Sorry but I can't agree with this change as presented. By definition the total non-heap memory is the sum of all pools which identify as non-heap as per the specification: "The non-heap memory consists of one or more memory pools. The used and committed size of the returned memory usage is the sum of those values of all non-heap memory pools ..." so the existing code that sums the non-heap pools is correct. If you think `CompressedClassSpace` should not be counted then you need to argue for it to not be "non-heap". Cheers, David ------------- Changes requested by dholmes (Reviewer). PR: https://git.openjdk.java.net/jdk/pull/8831
