High-performance Rust: Understanding and eliminating memory fragmentation

- Memory fragmentation is a performance problem in systems programming where free memory is split into many small, non-contiguous chunks, causing allocations to slow down or fail even when enough total memory exists. - Rust is a modern systems language focused on safety and performance, used for high-throughput servers, databases, game engines, and browser components (e.g., Firefox's Servo engine). Its performance characteristics heavily depend on how it manages memory. - In low-level languages like Rust and C++, developers often bypass the default system allocator (e.g., glibc's malloc) and use custom allocators (jemalloc, mimalloc, snmalloc) to reduce fragmentation and improve cache behavior for specific workloads. - Key strategies to avoid fragmentation include: pre-allocating a fixed pool of objects (arena allocation), using slab allocators for same-sized objects, and designing data structures that minimize frequent allocations and deallocations of varying sizes.