This article explains the low‑level mechanisms of brk and mmap in Linux, compares their characteristics, shows why malloc selects one over the other based on allocation size, and provides practical code examples, performance tips, and common pitfalls for developers.
This article explains how the C functions malloc and free allocate and release memory, covering stack vs heap, the brk and mmap system calls, fragmentation, header metadata, and why both allocation strategies are needed for efficient memory management.
This article explains how the Linux kernel implements heap memory management, covering the heap data structure, the mm_struct fields start_brk and brk, the brk/sbrk and malloc/free allocation methods, the brk and mmap system calls, and the internal glibc structures heap_info and malloc_state that track heap state.
This article explains why calling malloc in C only reserves virtual address space, how the kernel maps it to physical memory on demand, and the roles of the brk pointer, memory layout, and page‑fault handling, illustrated with a 1 GB allocation example and detailed diagrams.
This article explains Linux's virtual address space layout, the six user‑space memory segments, how malloc decides between brk and mmap based on allocation size, the behavior of free, and why both allocation methods are needed for performance and memory management.
The article explains Linux kernel virtual memory management on 64‑bit ARM64 Android systems, detailing user‑ and kernel‑space address layout, physical vs. linear addresses, allocation mechanisms such as brk and mmap, common allocators, key structures like mm_struct and vm_area_struct, and the functions that control mmap layout and unmapped‑area selection.
