> Really? Why?
Because it was found to be lighter weight. See §5 (bottom of ppg 8).
https://kib.kiev.ua/kib/pgsql_perf.pdf
> According to the notes in our code, named POSIX semaphores
> are the least attractive of the three Unixoid semaphore APIs we support,
> because they require eating a file descriptor per backend per
> max_connection slot. That's a lot of FDs in any large configuration.
> FreeBSD's support for SysV semaphores would have to be pretty darn awful
> to make me think this was a good change, and I've not heard complaints
> in that direction before.
>
> If you meant to propose using *unnamed* POSIX semaphores, that might be
> a reasonable change, but it would still need some supporting evidence.
https://lists.freebsd.org/pipermail/svn-src-stable-10/2014-October/003515.html
-sc
--
Sean Chittenden
sean@chittenden.org
