13 docs tagged with "locking"

atomict, the operation families, the ordering each does and does not carry, and why refcountt exists separately.

The decision table, six worked selections, and the cost hierarchy from an uncontended atomic to cross-NUMA ping-pong.

lockdep and what it proves, KCSAN for data races, and a real splat read line by line.

Where the kernel genuinely goes lock-free, and an honest account of why most kernel code should not.

Why a plain access is not safe, what each barrier actually orders, and why this is the page arm64 changes the most.

Sleeping locks that spin first, owner tracking, and why semaphores are now rare.

Eliminating sharing rather than protecting it, and what that costs in preemption discipline.

The API, the ordering it encodes, and the rules that make RCU misuse silently fatal rather than loudly wrong.

Readers that take no locks and pay nothing, writers that publish a new version and defer reclamation until every reader has left.

Why a reader-writer lock is often slower than a plain one, and where rw_semaphore is genuinely the right answer.

Lockless readers with a retry loop, the constraints that puts on a reader, and the canonical use in timekeeping.

Busy-waiting and when it is right, the queued implementation, and the absolute rule against sleeping while holding one.

Four independent sources of concurrency and the context matrix that determines every locking choice in the folder.