On 2015-06-30 22:19:02 +0300, Heikki Linnakangas wrote: > >Hm. Right. A recheck of the value after the queuing should be sufficient > >to fix? That's how we deal with the exact same scenarios for the normal > >lock state, so that shouldn't be very hard to add. > > Yeah. It's probably more efficient to not release the spinlock between > checking the value and LWLockQueueSelf() though.
Right now LWLockQueueSelf() takes spinlocks etc itself, and is used that way in a bunch of callsites... So that'd be harder. Additionally I'm planning to get rid of the spinlocks around queuing (they show up as bottlenecks in contended workloads), so it seems more future proof not to assume that either way. On top of that I think we should, when available (or using the same type of fallback as for 32bit?), use 64 bit atomics for the var anyway. > I'll take a stab at fixing this tomorrow. Thanks! Do you mean both or "just" the second issue? Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
