On Oct 22, 2024, at 22:26, Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: > > On Tue, Oct 22, 2024 at 12:13:12AM -0700, Christoph Hellwig wrote: >> On Tue, Oct 22, 2024 at 09:10:18AM +0200, Peter Zijlstra wrote: >>> Ah, well, the thing that got us here is that we (Andrii and me) wanted >>> to use -1 as an 'invalid' value to indicate SRCU is not currently in >>> use. >>> >>> So it all being int is really rather convenient :-) >> >> Then please document that use. Maybe even with a symolic name for >> -1 that clearly describes these uses. > > Would this work? > > #define SRCU_INVALID_INDEX -1 Is there any similar guarantee of the return value of get_state_synchronize_rcu or start_poll_synchronize_rcu, like invalid value? > > Whatever the name, maybe Peter and Andrii define this under #ifndef > right now, and we get it into include/linux/srcu.h over time. > > Or is there a better way? Or name, for that matter. > > Thanx, Paul >
