On Thu, 4 Jun 2026 07:15:07 +0000 Dmitry Ilvokhin <[email protected]> wrote:
> Add the contended_release trace event. This tracepoint fires on the > holder side when a contended lock is released, complementing the > existing contention_begin/contention_end tracepoints which fire on the > waiter side. > > This enables correlating lock hold time under contention with waiter > events by lock address. > > Add trace_contended_release()/trace_call__contended_release() calls to > the slowpath unlock paths of sleepable locks: mutex, rtmutex, semaphore, > rwsem, percpu-rwsem, and RT-specific rwbase locks. > > Where possible, trace_contended_release() fires before the lock is > released and before the waiter is woken. For some lock types, the > tracepoint fires after the release but before the wake. Making the > placement consistent across all lock types is not worth the added > complexity. > > For reader/writer locks, the tracepoint fires for every reader releasing > while a writer is waiting, not only for the last reader. > > Signed-off-by: Dmitry Ilvokhin <[email protected]> > Acked-by: Paul E. McKenney <[email protected]> Acked-by: Usama Arif <[email protected]>
