On Sun, Jan 19, 2026 at 03:11:18PM +0100, Peter Zijlstra wrote: > By holding an extra rcu_sync reference, the percpu rwsem is kept into > the the slow path, avoiding the rcu-sync on down_write(), which was very > prevalent per this: > > https://lkml.kernel.org/r/[email protected]
Makes sense, though I wonder if we should have a separate percpu-rwsem API for this rather than directly accessing the lock-internal rcu_sync state? Other future percpu_rw_semaphore users may benefit as well. - Joel
