All, FYI, the system which sparked this original discussion turned out, on extensive analysis, to have ZFS-level filesystem corruption. The polling issues were related to that rather than to Postgres.
-- -- Josh Berkus PostgreSQL Experts Inc. http://www.pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers