I Built malloc() from Scratch in C — Here’s What Went Wrong

Most of us use malloc() without thinking about what happens underneath. I decided to implement my own memory allocator in C to understand it better. This wasn’t for production use, just to learn how allocation, fragmentation, and concurrency actually behave in practice. I also benchmarked it against glibc’s malloc to see where it stands. Implementation Overview My allocator currently includes: Thread-local cache Free lists (bins) for different size ranges Direct mmap for larger allocations A cus