Hi, On 2025-03-03 21:31:42 +0100, Tomas Vondra wrote: > On 3/3/25 19:10, Andres Freund wrote: > > On 2024-09-21 20:33:49 +0200, Tomas Vondra wrote: > >> I've finally pushed this, after many rounds of careful testing to ensure > >> no regressions, and polishing. > > > > One minor nit: I don't like that FP_LOCK_SLOTS_PER_BACKEND is now > > non-constant > > while looking like a constant: > > > > #define FP_LOCK_SLOTS_PER_BACKEND > > (FP_LOCK_SLOTS_PER_GROUP * FastPathLockGroupsPerBackend) > > > > I don't think it's a good idea to have non-function-like #defines that > > reference variables that can change from run to run. > > > > Fair point, although it can't change "run to run" - not without a > restart.
That's what I meant with "run to run". > It's not a proper constant, of course, but it seemed close > enough. Yes, it might confuse people into thinking it's a constant, or > is there some additional impact? That seems plenty. I just looked at the shem sizing function and was confused because I didn't see where the max_locks_per_transaction affects the allocation size. > The one fix I can think of is making it look more like a function, > possibly just like this: > > #define FastPathLockSlotsPerBackend() \ > (FP_LOCK_SLOTS_PER_GROUP * FastPathLockGroupsPerBackend) > > Or do you have another suggestion? That'd work for me. Greetings, Andres Freund
