On Tue, 27 Jun 2023 at 18:40, Andres Freund <and...@anarazel.de> wrote: > On 2023-06-27 14:49:48 +0300, Ants Aasma wrote: > > If you want to experiment, here is a rebased version of something I > > hacked up a couple of years back on the way to Fosdem Pgday. I didn't > > pursue it further because I didn't have a use case where it showed a > > significant difference. > > Thanks for posting! > > Based on past experiments, anything that requires an atomic op during spinlock > release on x86 will be painful :/. I'm not sure there's a realistic way to > avoid that with futexes though :(.
Do you happen to know if a plain xchg instruction counts as an atomic for this? I haven't done atomics stuff in a while, so I might be missing something, but at first glance I think using a plain xchg would be enough for the releasing side. -- Ants
