General :: Does The Backtrace Call Lost Memory

Here is a test code for memory alloc and free. It is to detect whether the allocs and frees match. From the result, after backtrace call, there is some memory alloc, but it does not free these memories after calling or the process exit. Why? Nomorlly, the memory alloced need to be freed after use, or the memory will leak. But I run this program for about some times, and find that though the system memory does not real leak,the free memory decreases, and the cache increases(Use free command).

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