On Sun, Nov 20, 2022 at 3:43 PM Andres Freund <and...@anarazel.de> wrote: > The lwlock wait queue scalability issue [1] was quite hard to find because of > the exponential backoff and because we adjust spins_per_delay over time within > a backend. > > I think the least we could do to make this easier would be to signal spin > delays as wait events. We surely don't want to do so for non-contended spins > because of the overhead, but once we get to the point of calling pg_usleep() > that's not an issue. > > I don't think it's worth trying to hand down more detailed information about > the specific spinlock we're waiting on, at least for now. We'd have to invent > a whole lot of new wait events because most spinlocks don't have ones yet. > > I couldn't quite decide what wait_event_type to best group this under? In the > attached patch I put it under timeouts, which doesn't seem awful.
I think it would be best to make it its own category, like we do with buffer pins. -- Robert Haas EDB: http://www.enterprisedb.com
