Different applications and systems have different memory requirements, so there are many heap implementations:

dlmalloc  – General purpose allocator
ptmalloc2 – glibc
jemalloc  – FreeBSD and Firefox
tcmalloc  – Google
libumem   – Solaris

Standard Linux distributions use glibc for memory management.

System Calls

There are 2 underlying system calls for allocating and freeing memory:

• brk
  • Heap memory operations
• mmap
  • Memory mapping operations

You can use cat /proc/<pid>/maps to view a process’s allocated heap memory and mapped memory.