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(libc.info)Statistics of Malloc

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Statistics for Memory Allocation with `malloc'
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   You can get information about dynamic memory allocation by calling
the `mallinfo' function.  This function and its associated data type
are declared in `malloc.h'; they are an extension of the standard
SVID/XPG version.

 - Data Type: struct mallinfo
     This structure type is used to return information about the dynamic
     memory allocator.  It contains the following members:

    `int arena'
          This is the total size of memory allocated with `sbrk' by
          `malloc', in bytes.

    `int ordblks'
          This is the number of chunks not in use.  (The memory
          allocator internally gets chunks of memory from the operating
          system, and then carves them up to satisfy individual
          `malloc' requests; see Note: Efficiency and Malloc.)

    `int smblks'
          This field is unused.

    `int hblks'
          This is the total number of chunks allocated with `mmap'.

    `int hblkhd'
          This is the total size of memory allocated with `mmap', in
          bytes.

    `int usmblks'
          This field is unused.

    `int fsmblks'
          This field is unused.

    `int uordblks'
          This is the total size of memory occupied by chunks handed
          out by `malloc'.

    `int fordblks'
          This is the total size of memory occupied by free (not in
          use) chunks.

    `int keepcost'
          This is the size of the top-most releasable chunk that
          normally borders the end of the heap (i.e. the high end of
          the virtual address space's data segment).


 - Function: struct mallinfo mallinfo (void)
     This function returns information about the current dynamic memory
     usage in a structure of type `struct mallinfo'.