On Wed, Aug 16, 2017 at 1:40 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > I was wondering why the shm_toc code was using BUFFERALIGN and not > MAXALIGN, and I now suspect that the answer is "it's an entirely > undocumented kluge to make the atomics code not crash on 32-bit > machines, so long as nobody puts a pg_atomic_uint64 anywhere except > in a shm_toc".
Well, shm_toc considerably predates 64-bit atomics, so I think the causality cannot run in that direction. shm_toc.c first appeared in the tree in January of 2014. src/include/port/atomics didn't show up until September of that year, and 64-bit atomics weren't actually usable in practice until e8fdbd58fe564a29977f4331cd26f9697d76fc40 in April of 2017. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
