On Tue, Apr 7, 2026 at 6:55 PM Xuneng Zhou <[email protected]> wrote: > > On Tue, Apr 7, 2026 at 9:46 PM Alexander Korotkov <[email protected]> > wrote: > > > > On Tue, Apr 7, 2026, 16:18 Andres Freund <[email protected]> wrote: > >> > >> Hi, > >> > >> On 2026-04-07 21:05:40 +0800, Xuneng Zhou wrote: > >> > I’ve posted two patches. The first fixes the duplication issue > >> > reported by Andres and is fairly straightforward. The second turned > >> > out to be more complex than expected, and I’m still working through > >> > possible solutions. Feedback or alternative approaches would be very > >> > helpful. > >> > I also spent some time drafting a patch to address the memory ordering > >> > issue and will post it later. > >> > >> I propose quickly applying a minimal patch like the attached, to get the > >> test > >> performance back to normal. > >> > >> Will do so unless somebody protests within in one CI cycle and one coffee. > > > > > > I would be able to review them only after several hours. But +1 for > > applying now to get rid of buildfarm slowdown. > > Here is a patch addressing the memory order issue reported earlier.
I agree to change in WaitLSNWakeup(), memory barrier looks necessary there. Regarding GetCurrentLSNForWaitType(), I don't think barrier is needed here, nor think it makes things clearer. I think it would be enough to comment that LWLock operations in addLSNWaiter()/deleteLSNWaiter() provide necessary barriers. ------ Regards, Alexander Korotkov Supabase
