Prevent excess SimpleLruTruncate() deletion.
Every core SLRU wraps around. With the exception of pg_notify, the wrap
point can fall in the middle of a page. Account for this in the
PagePrecedes callback specification and in SimpleLruTruncate()'s use of
said callback. Update each callback implementation to fit the new
specification. This changes SerialPagePrecedesLogically() from the
style of asyncQueuePagePrecedes() to the style of CLOGPagePrecedes().
(Whereas pg_clog and pg_serial share a key space, pg_serial is nothing
like pg_notify.) The bug fixed here has the same symptoms and user
followup steps as 592a589a04bd456410b853d86bd05faa9432cbbb. Back-patch
to 9.5 (all supported versions).
Reviewed by Andrey Borodin and (in earlier versions) by Tom Lane.
Discussion: https://postgr.es/m/20190202083822.GC32531@gust.leadboat.com
Branch
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REL_10_STABLE
Details
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https://git.postgresql.org/pg/commitdiff/9afba9b0e28259e71e70db7f919c39f050ddd05d
Modified Files
--------------
src/backend/access/transam/clog.c | 27 +++++--
src/backend/access/transam/commit_ts.c | 34 +++++---
src/backend/access/transam/multixact.c | 38 +++++----
src/backend/access/transam/slru.c | 143 +++++++++++++++++++++++++++++----
src/backend/access/transam/subtrans.c | 17 ++--
src/backend/commands/async.c | 7 +-
src/backend/storage/lmgr/predicate.c | 109 +++++++++++++++++++++----
src/include/access/slru.h | 16 +++-
8 files changed, 312 insertions(+), 79 deletions(-)
