off-heap memory used by oakMap can not be released

[fujian-zfj]

I use oakMap instead of concurrentSkipListMap in my project, while I find something strange. When I no longer use an oakMap, java heap memory used by this oakMap is released, but off-heap memory does not seems to be released.

I use NMT to track the use of off-heap memory, and I find something strange.

ggggggggg

The heap memory occupied by current process is very small, but through the linux system command "top" found that it occupies huge memory. And I analyze the memory distribution in heap and find that heap memory used by the current process is very small. By the way, therer is no OakMap object in heap memory.