Fix typo and outdated information in README.barrier

David Rowley <drowley@postgresql.org>

Commit: e71219ca11fabf5a1a184e76a0b1959e06de8e0d
Author: David Rowley <drowley@postgresql.org>
Date: 2021-05-17T21:57:43Z
Releases: 10.18
Fix typo and outdated information in README.barrier

README.barrier didn't seem to get the memo when atomics were added. Fix
that.

Author: Tatsuo Ishii, David Rowley
Discussion: https://postgr.es/m/20210516.211133.2159010194908437625.t-ishii%40sraoss.co.jp
Backpatch-through: 9.6, oldest supported release

Files

PathChange+/−
src/backend/storage/lmgr/README.barrier modified +5 −7

Discussion