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(ClassTypeSpace+NonClassTypeSpace)+CompressedClassSpace(ClassTypeSpace)`
>
> ==> 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`.
src/hotspot/share/services/management.cpp line 753:
> 751: for (int i = 0; i < MemoryService::num_memory_pools(); i++) {
> 752: MemoryPool* pool = MemoryService::get_memory_pool(i);
> 753: if (pool->is_codeheap() || pool->is_metaspace()) {
Our only special case is that all the memory reported by
`CompressedKlassSpacePool` are already reported by `MetaspacePool`, so
shouldn't we do this:
if (pool->is_non_heap() && !pool->is_compressed_klass_space()) {
// skip CompressedKlassSpacePool since its memory is already reported by
// MetaspacePool
-------------
PR: https://git.openjdk.java.net/jdk/pull/8831
