How epoll Works: Readiness, Level vs Edge Trigger, and Why select Doesn't Scale
A process that accepts ten thousand TCP connections cannot afford to ask the kernel about each socket in turn. select(2) and poll(2) copy ...
A process that accepts ten thousand TCP connections cannot afford to ask the kernel about each socket in turn. select(2) and poll(2) copy ...
A process that accepts ten thousand TCP connections cannot afford to ask the kernel about each socket in turn. select(2) and poll(2) copy ...
A shared linked list in the kernel can be walked by thousands of cores at once. A writer still has to insert or delete a node. If every walk...
A CPU core runs one thread at a time. Everything else that looks concurrent is a lie the operating system maintains by switching. The policy...
A kernel module can do almost anything. That is why loading one is a privileged act and why a bug in one can take the machine with it. eBPF ...
TCP can carry bytes in order. It cannot tell you who is on the other end, and it cannot stop a path observer from reading those bytes. HTTPS...
A tight loop of read and write pays for a privilege crossing on every operation. After Spectre-era mitigations that crossing got more expe...
A load that misses DRAM can cost hundreds of cycles. A load that hits L1 often costs a handful. That gap is why two programs with the same b...
How mmap Works: File-Backed Pages, MAP_PRIVATE, and Why Zero-Copy Matters A process that wants the contents of a 4 GB file does not have to...